\ ACADEMY OF SCIENCES OF THE USSR A.N. SEVERTZOV INSTITUTE OF EVOLUTIONARY AND ECOLOGY OF ANIMALS USSR ORNITHOLOGICAL SOCIETY MOSCOW STATE UNIVERSITY XVIII CONGRESSUS INTERNATIONALE ORNITHOLOGICI Moscow, August 16—24, 1982 VOLUME II Editors: V.D. ILYICHEV and V.M. GAVRILOV MOSCOW "NAUKA" 1985 UDC 598.2 XVIII CONGRESSUS INTERNATION ALIS ORNITHOLOGICUS Moscow, August 16—25, 1982 ACTA Volume II This volume contains full text of forenoon symposia: Adaptations of birds to man-made environments Ecology of raptors Dynamics of birds ranges Density regulation in bird populations Ontogeny and phylogeny of cognitive processes Physiology of the avian egg Adaptive significance of colonies and flocks physiology of reproduction, moult and migration Avian respiration Volume contains also abstracts of afternoon symposia, abstracts of poster presentations, some full poster presentations, reports of round¬ table discussions, the list of Congress Members Editorial board V.D. Ilyichev, V.M. Gavrilov (Editors-in-Chief ) , S.M. Smirensky (Scientific Sécrétai?), A.N.Temchin, E.N. Kurochkin, O.L.Silajewa .j. 2005000000- 594 042(02 )-S5 Ee3 OÖ'bHBJieHHH © A.N. Severtzov Institute of Evolutionary Morphology and Ecology of Animals of the USSR Academy of Sciences, 1985 Symposium ADAPTATIONS OF BIRDS TO MAN-MADE ENVIRONMENTS Convener: L. TOMIALOJC, POLAND Co-convener: A.K. RUSTAMOV, USSR RAVKIN Yu.S. ANTHROPOGENIC TRANSFORMATIONS OF AVIAN COMMUNITIES IN THE USSR FOREST ZONE RUSTAMOV A.K. BIRDS AND MAN-INDUCED ENVIRONMENTAL CHANGES IN THE ARID ZONE OF THE USSR MORGAN R. CHANGES IN THE BREEDING AVIFAUNA OF AGRICULTURAL LAND IN LOW¬ LAND BRITAIN BLONDEL J. MEDITERRANEAN BIRD FAUNAS IN THE LIGHT OF ANTHROPIC PRESS! TR F SINCE THE NEOLITHIC TOMIALOJC L, URBANIZATION AS A TEST OF ADAPTIVE POTETINALS IN BIRDS DYRCZ A. BREEDING ECOLOGY OF THE TWO POPULATIONS OF TURDUS GRAYI AT LOCALITIES OF DIFFERENT HUMAN INFLUENCE IN PANAMA LOWLAND ANTHROPOGENIC TRANSFORMATIONS OF AVIAN COMMUNITIES IN THE USSR FOREST ZONE Yu. S.Ravkin Biological Institute, Siberian Branch of the USSR Academy of Sciences, Novosibirsk, USSR The results of bird censuses in 328 habitats of East-European and Siberian forest zone, including some habitats of forested terraces of forest-steppe and secondary forest-steppe were analysed. All the censuses were carried out on the basis of method ( Ravkin, 1967 ) and coyer more than 16.000 km from May 15th (or June 1st) to August 31st (1960-1981). In northern locations (sub- zones) the replacement of coniferous forests by mixed stand (which follows se¬ lective cutting) or by secondary overgrown extensive clearings and bums brings only insignificant change in values of diversity, bird community bio¬ mass, and transformed energy indices. In southern locations such as southern parts of boreal region, secondary forest-steppe and forested terraces of forest-steppe, however, the values of these indices clearly increase when calculated for early stages of succession on clearings and bums, for mixed forests formed on older clearings and sometimes even partly ploughed areas. In such cases considerable changes in the species composition of predominat¬ ing birds are also found. The decrease of these indices were observed on the stages of small-leaved forests for pasture digression and extensive fields. The construction of buildings leads to particularly pronounced increase in the summative community indices, except that of diversity, which essentially decreases. For all that those changes are less in northern locations (subzo¬ nes) that in southern ones. Thus, anthropogenic transformation of forest bird communities is essen¬ tial only in those cases when it is not within the framework of natural suc¬ cession (forest maturation, pyrogenic succession or following the outbreak of pests), namely urbanization, pasture digression, extensive monocultural agroceonosis and, naturally, construction of hydro-electric power stations. The factor analysis study had shown that in the bird communities of each locations (subzones) of West Siberia has three principal trends of changes. Former coincides with natural differences in woodiness from the forests of interstream areas, through the tessellated habitats to the bottomlands of large rivers. The second trend coincides with differenses in productivity and damping. It’s first row goes from the waterless valley's forests, through the damp and paludose forests to the wooded back fens and further to the rised bogs. The second row coincides with environmental changes from the mosaic natural habi¬ tats of waterless valleys through fields with copses to the woodless transi¬ tional and rised bogs. The third row of this trend goes from the meadows, through the flood-land's back fens to the nonfloodland' s back fens and furt¬ her to the same opened transitional and rised bogs. The third trend is connected with building. It goes from the flood-plains of large rivers, through the settlements in their ranges to the nonflood- land’s villages and further to the outskirts of towns and urban parks, and further to the central part with multistory buildings. 580 The main changes in avian communities in the forest-steppe's pine forests are connected with discreasing of woodness also in three directions. The first as in the forest zone follows from the forests to the mosaic habitats and further to the bottomland meadows. The second is connected with impove¬ rishment because of ploughing and pasture degression. The rows connected with damping are represented only by initial stage of conversion from bottom land meadows of large rivers to the opened back fens. The third trend, as in the forest zone is directed from the bottom land habitats in connection with buildings firstly of country (rural) type, further to the outskirts of towns and to the centre with multistory buildiDgs. When the forests are occupied by gardens with temporary building ôr the forests are disposed in the middle of housing estates in the towns of diffuse type the latter begins from this habitats. The quantative estimation of anthropogenic influence on bird communities is desirable. It may be calculated with the help of linear qualitative appro¬ ximation with due regard for nonlinear changes of communities. To observe the degree of environmental factor's influence on the communities in the whole but not on the separate species or the particular parameters of the communi¬ ties, it is necessary at first to pass on the integral estimation of their heterogeneity. Such measure is the Jaccard 'a coefficient (Jaccard 1902) calculated with due regard for the abundance of birds (Ravkin,i973). This coefficient reflects not only species specificity of communities, but the abundance of species, the degree of overlapping of their number in the com¬ paring habitats, correlated with differences in the same indices. The compa¬ rison of the degree of coincidence of communities 's resemblance and the same influence of the main environmental factors make it possible to judge about the correlation between the heterogeneity of communities and environment. In¬ cluding the anthropogenio influence (Ravkin, 1967, 1973), To our regret we have no comparable data of bird's censuses in the towns of forest zone. The bird's communities of the urban habitats are investiga¬ ted only in the villages. Multiple approximation of variability of avian communities in the kind of resemblance index' es matrix by the environmental factors fluctuates from 75 to 897» of dispersion. The most indices of the ac¬ counted dispersion are in the mounting-forest belts (89% in the first half of summer and 87 - in the second). The lesser part of variability is possible to explane inside of separate subzones of forest zone in the plain (in the southern taiga of West Siberia correspondingly 87 and 83% and of the West and Middle Siberia - 80 and 77%). In the whole zone in the ranges of river Ob region the indices are lesser (80 and 75%). The. approximation is effective enough when the separate numbers of display of environmental factors are used (for instance the high, middle and low woodness) as the separate subsi¬ diary indications. Besides the such simple factors, their indivisible combi¬ nations (nature regimes) take part in approximation. They are formed by 17 comparatively simple factors. They are: woodness "macrowoodness », mosaic re- gionality , faunal provinciality, absolute altitude under sea levél, altitu¬ dinal zonality, subzonal alteration of climate, damping, composition of forest-making freeds, productivity and providing of phy tocoenosises by mine¬ ral mitrition, "steppeness» , dimension of swamp tracts, presence of reser¬ voirs of high trophic, presence of yeroiks and the anthropogenic influence - 581 building, forest felling, pasture of cattle, hay-making, ploughing, regulat¬ ion of river flow. The whole complex of anthropogenic factors in the forest - mountain belts of North-Eastern Altai (including secondary forest-steppe and the golets'es and pregolets'a habitats) determinates 21-2255 of dispersion of summer bird communities. In the forest zone of river Ob region this indices from 1256 and just as many as in the southern taiga of West Siberia (10-12%) and in the same subzone in the West and Middle Siberia - 6 and 13% (in the I and IX half o.f summer not accounting the town’s ornitocomplexes ). The differences of indices are connected with the considerably greater ploughing in piedmonts of Altai and West Siberia in comparing with Middle Siberia. In average by the whole data the influence of anthropogenic trans¬ formation explains 14-15% of dispersion of summer bird's communities. The most important in this data is the influence of differences in woodness (43- 46%) and some other factors .closely correlated with it ("macrowoodness", the forest type of landscape, the composition of forest-making breeds) and also productivity, and in the mountains-altitudinal zonality. By the way, the most part of environmental signs are correlated with others, including anthropogenic influence and woodness because the first in the considerable degree determinate the second. In the Ob valley within the limits of forest-steppe the pine forests and derivative communities are prevail over by their area. We may consider this territory as the part of the forest zone in the limits of forest-steppe. Here of the urban territories not only the settlements are investigated but also the Novosibirsk city. It permits to conduct the more complete estimation of the anthropogenic influence on avian communities. At the expense of sharp differences of bird’s populations of town from the more or less natural com¬ munities anthropogenic influence explains here already 52-53% of territorial variability of communities. If we exclude the birds of the town from the cal¬ culations, the estimation decreases more than twice (20-22%). The relation with woodness of the territory form 21-2855, and after excluding of urban com¬ munities - 33-44%. Novosibirsk is situated on the boundary of forest-steppe and podtaiga zo¬ nes. Therefore it is possible to include the data of it's bird's population in the calculations of the forest's zone with some assumptions. The including of data of this ornitocomplexes in the forest zones and belts for the first half of the year by 2 years of our investigations increase the power of rela¬ tion with anthropogenic influence to 35% (i.e. on 20%) and decreases the estimation of influence of woodness on 33% (I.e. on 10%). Proceeding from this estimations we may suggest with confidence that in the limits of West Siberia the* anthropogenic influence determinate the con¬ siderate part of territorial variability of bird's populations of forest zone, in any case, just the same with separate, the most significant natural factors of the environment. In the European part of the forest zone where the area of habitats, transformed by man, is just more, the influence of people's activity, apparently predominate among environmental factors. In conclusion I express my sincere gratitude to L. G. Vartapetov, S.M.Tsybu- lin, B.N. Fomin, E.S.Preobrajenskaja, I.V.Pokrovskaja, N.A.Koslov, E.S.Ravkin, 582 V.A.Udkin, V. N. Blinov and V.S.DJukov for their amiable permission to use during this work their data, recorded on the magnetic tapes of the data's bank of the laboratory of the zoological monitoring of the Biological Insti tute (Siberian Branch of the Academy of Sciences of the USSR). SUMMARY The results of bird censuses in 328 habitats of East-European and Siberian forest zone, including some habitats of secondary forest-steppe, were analy¬ sed. In northern locations (subzones) the replacement of coniferous forests by mixed stands (which follows selective cutting) or by secondarily overgrown extensive clearings and bums brings only insignificant change in the values of diversity, density, bird community biomass, and transformed energy in¬ dices. In southern locations such as southern parts of boreal region se condary forest-steppe woods or forests, however, the values of these’indices clearly increase when calculated for early stages of succession on clearings an bums, for mixed forests formed on older clearings and sometimes even partly ploughed areas. In such cases considerable changes in the species composition of predominating birds are also found. The construction of build¬ ings leads to particularly pronounced increase in the summative conmmity in- ices, except that of diversity, which essentially decreases. On the other hand lower values of these indices were observed for the stages of small- eaved forests, for pasture degression and extensive fields. Generally in northern regions the differences between primeval and secondai? habitats cause smaller variations in index values than in southern ones. Thus, anthropogenic transformations of forest bird communities is essen Wal only in those cases when it is not within the frame - work of natural" succession (forest maturation, pyrogenic succession or following the out break of pests), namely urbanization, pasture degression, extensive monocul- tural fanning and construction of hydro-electric power stations. When analyzing regional differences in bird fauna, only 15% 0f heteroge¬ neity in bird community composition (expressed as coefficients of resemb lance in quantitative traits) can be easily connected with anthropogenic changes. On the whole, under the multiple approximation, about 85% of dispersion of coefficients in resemblance matrices is possible to explain Refer nee Jaccard P. - Bull. Soc. Vaund. Sei. Nat., 1902, ^8, p. 69-130. Naumov R.L. Ptitsi v ochagakh klestchevogo enzefalita Krasnoÿarskogo krava Avtoreferat dissertatsii kandidata biologicheskikh nauk.Moskva, 1 964. 19 n avkin Yu.S. - Ini Priroda ochagov klestchevogo enzefalita na Altaye. Novo-* sibirski Nauka, 1967, p. 66-75. Ravkin Yu.S. Ptitsi lesnoy zony Priobya. Novosibirsk: Nauka, 1973. 375 p. 583 BIRDS AND MAN-MADE ENVIRONMENTAL CHANGES IN THE ARID ZONE OP THE USSR A. K. Rustamov The Turkmen Agricultural Institute, Ashkhabad, USSR The problem "Birds in the man-made landscape" has been one of. the central problems of ornithology within the last ten years. To-day it is more than ever closely linked with the problem "Man and biosphere". Man-made changes in landscapes are natural. They are determined by society needs as well as by the type of landscape and ecosystem (Gladkov, Rustamov, 1965). In this connection we can note, that typical and trophic chains of arid ecosystems, in comparison with other terrestrial ecosystems of the USSR, are simpler, and that is why they are fragile and come rather easily under the influence of anthropogenic factors. Under these circumstances greater thoughtfulness and carefulness are needed in utilizing arid areas and trans¬ forming their ecosystems. The USSR zone of deserts stretches from the shores of the Caspian Sea to the west up to the Djungar Ala Tau, Tien Shan and the Pamirs-Alai to the east and south-east. The southern, boundary passes along the Kopetdag and Paropamis foothills. To the east of the Caspian Sea there are desert areas in the Eastern Caucasus. The main desert landscapes are si¬ tuated in Central Asia and Kazakhstan, their total area making up about 230 million ha. Deserts are diverce: clayey, detritus and sandy. They differ in their ecosystems and fauna. The avifauna of the USSR arid zone includes 300 species and subspecies. 60 to 65 of them are nesting and settled birds, the rest stay in the deserts temporarily (migrating, wintering and casually flying by birds). They are intrazonal. Typical desert species form no more than half of the nest fauna. They are: Pterocles orientalis, Pt. alchata, Chlamydotis undulata, Cursorius cursor, Burhinus oedichemus, CharadriUB leschenaultii, Ch. aslaticus, Capri- mulgU8 aegyptius, Dendrocopos màjor, Oenanthe deserti, O.isabellina, Scoto- cerca inquiéta, Sylvia curruca, S.nana, Hlppolais -rama, Hippolais languida, Galerida cristata. Passer simplex, P.ammodendri , Podoces panderi and others. Ecological and genealogical links of these species with the desert are deep and Btable. They possess a number of morphophysiological and adaptive featu¬ res and adaptive behavior methods allowing them to exist under extreme con¬ ditions. In the process of evolution these formB have succeeded in gaining and consolidating exceptionally important adaptive features, i.e. economical water intake and the ability to retain it in the organizm ( Rustamov, 1954). Man-made environmental changes almost always tell negatively on typical desert birds, but the same changes tell positively on ecologically plastic (intrazonal) species. It is well-known, for example, that irrigation, the opening up of virgin lands and ploughing, destruction of bushes has led to the narrowing of the range, the reduction of the size, the splitting up of the population and the vanishing from these areas of many typical desert species, in particular - Pterocles orientalis, Chlamydotis undulata, Curso¬ rius cursor, Charadrius aslaticus, Ch. leschenaultii, Sylvia nana, Passer simplex, Podoces panderi. The appearance and nesting on irrigated and deve¬ loped areas of the desert of Columba livia, Streptopelia senegalensis,Upupa ep°p s, Acridotheres trlstls, Passer domesticus, P.montanus and others testi¬ fies to the "florishing" of the ecologically plastic species. The composition, distribution and size of the bird population change according to the period of time (duration) and intensity (degree) of the in¬ fluence exercised by man and his activities on the landscape and its fauna (Drozdov, 1967). Time is of course an important factor, but much depends on the intensity of the anthropogenic pressure. Thus, for example, the avifauna of the oasis in the centre of the Repetek biosphere reserve has, in compari¬ son with other areas of the Eastern Karakums, a more "cultivated" character (Accipiter badius, Athene noctua, Upupa epops, Columba livia. Acridotheres ~latls» --sser domesticus. P.montanus. Rhodospiza obsoleta and others), acquired within the period of the past 80-110 years. In all 45 species and subspecies of birds, including 9 nesting ones, were registered in the Repetek reserve anthropogenic areas. In summer the size of the bird population in the anthropogenic biotopes of the reserve makes up 3896.3 individuals peril, to’ 300 3 i - Î! habltats’ wMch were not transformed, there are from 26.9 0 JU0'3 Individuals per 1 sq km. The comparison with the avifauna, which developed during the past 20-25 ITZZ.Zl area8 °f the KarakUm Cana1’ Sh°WS that the Re*etek oa.i8 fauna 200 sulci T01,6"' ?he Mrd faUnB °f the KarakUm CSnal iDcludes -»» than 0 species and suspectes of birds, including about 80 nesting ones. 4nd there is another example: in spring in the Karakum desert in the regions of fin L°°l deVal°Pment 22 individuals fall on 1 sq km, 70 and 31 individuals sq m in noticeably transformed ecosystems and 100 and 90 - in verv transformed ones (oases). That is the result of irrigation. Water is a powerful factor in the transformation of desert ecosystem. T e penetration of man into the desert began with the discover? of wlter eop e learned to dig wells and kyarizes and to construct sardobas. A kyari 1 is remarkable irrigation construction, with its aid fresh underground wa !” are brought from the foothill to the desert valley. A sardoba, on the other hand, serves as a reservoir for collecting winter and spring precipi tation. These irrigation constructions are far removed from each other. Wear them nan settles with his cattle and there appear- spots of crop areas. This initial impact of man on the desert which is connected with the appearance o water slightly improves birds living conditions and among some of birds there arise contacts with water and other elements of man-made landscape (Rustamov, 1956). p The omithogeographical significance of these contacts lies in the fact jmt it is quite often from these contacts the species begin to habite near man. Subsequently, the transformation of the temporar? contacts into constant ones is not obligator?. It is quite another thing, when canals and reservoir! are constructed, broad irrigation networks, supplying fields with water ap pear, settlements, orchads, field-protecting shelterbelts are layed out An that has a great anthropogenic influence on the desert. It is caused bj lar ge-scale irrigation of arid areas. As a result of that ranges become wLer or narrower, new relations within the ecosystems arise, birds mode of life and behaviour change to a great extent. All that takes place under the in- 585 fluence of irrigation and water conveyance, indirect anthropogenic influence upon bird s through the change of their places of habitation (Rustamov, 1930). Natural arid ecosystems are rather improductive. The coming of an abundan¬ ce of water to the desert raises the feeding capacity of transformed lands, increases productivity of the ecosystems and satisfies water requirements of birds. Favourable ecological conditions spread to vast areas and serve as a kind of a gutter, through which birds (from already formed anthropogenic eco¬ systems) settle on developed lands. Thus birds habitating on the Amudarya, Murgab, Tedjen rivers and on the intrazonal complexes of adjacent deserts practically besiege settlements and cultivated areas along the Karakum canal. Cultivated lands expand, and following that a marked intra-range settling of different bird species takes place (Rustamov, 1976). Omithogeographically this settling occurs mainly thanks to species brought from river valleys and only partly taken from undeveloped desert areas. Such a picture may be ob¬ served not only with birds, but with other groups of animals, including in¬ sects, fishes, amphibia, reptiles and mammals. Consequently, agricultural desert reclamation, relying on broad irrigat¬ ion development, possesses an important ecological characteristic of continui¬ ty, which at the same time is important for omithogeography , as it is con¬ ductive to intra-ranged bird settling. Intra-ranged settling is the settling of birds within the range of the ever widening area of the biotopes, which answer the requirements of the spe¬ cies. The appearance of Columba livia, Passer montanus, P « domeBtlcus and others on the irrigated areas is an example of intra-range settling of certain species. When in connection with favourable ecological conditions the corres¬ ponding groups of bird species (Ardea cinerea, Botaurus stellares, Wycticorax nycticorax, Himantopus himantopus, Vanellachettusla leucura, Charadrlus du- bius. Pica pica, Stumue vulgaris, Motacilla flava, Bmberlza brunlceps, Hl- rundo rustics, Riparia riparia and others) move from river valleys of East Turkmenia onto the Karakum canal, then we speak about large-scale intra- ran¬ ge bird settling. Birds of this group on the Karakum canal make up from 40 to 60% of nesting species (Belskaya, 1967). As is generally known, when birds settle for good, the range of the species widens. For example, Acrldotheres tristis nests in a number of places of the Karakum canal. The irrigation of arid lands considerably influenced bird settling- during their migration and wintering. In favourable years 500-600 thousand ducks, coots, geese and other waterfowl winter on all artificial reservoirs, that makes up 10% of all birds, concentrating on large winterings of the USER. Such mass winterings developed during the past 20-25 years. Lakes with drain water are less favourable and the number. of wintering birds is insignificant. Reservoirs that appeared on arid lands attract many birds during their spring and autumn flights. "Broad front" migration, which is quite usual for bird movement in the desert, abates and is replaced by relatively narrow flight ways along artificial lakes (Rustamov, 1976). Water in some places of the desert radically changes the appearance of the ecosystem and its fauna. Before the formation of the large reservoir in the Sarykamysh hollow, 20 bird species in all habitated there. These were mainly desert species (Rustamov, 1948). 'When in the beginning of the 60-ies 586 drainage waters were thrown from irrigated fields into the hollow, a saltish- water reservoir appeared, stretching from the north to the south for a length of 130 km and from the west to the east - 60 km. In 1975^1976 84 bird spe¬ cies, including 24 nesting ones, were observed at the Sarykamysh reservoir. Bird species habitating on water and near water dominate in the fauna of the reservoir. Thus the total number of Pelecanus crispus on the investigated area of the reservoir reached 1 thousand species, Fulica atra - 600 species, Phalacrocorax carbo - 1.5 thousand species and about 250 nests of Hydroprogne caspia were found there (Velikanov, Khokhlov, 1979). Up to no v/ we have spoken about the indirect impact through irrigation and water conveyance on birds, as one of the components of arid ecosystems. This impact is the result of other economic activities of man, such as exploring of minerals, constructing of oil- and gas-pipes, a railway and motor-roads, etc. It has been established, for example, that the building of the railway in the sandy lands of the North-East Karakums near the Caspian Sea, led to a sharp change in the composition of bird fauna. The number of nesting species has increased one and a half times, mainly by burrow,- rock and synanthropic species not to be found in undisturbed by man sandy lands. The composition of the fauna has become' more diverse and less specific for the sandy desert. At the same time the general density of the bird population has been reduced more than two times . The formation of favourable to man ornithologie complexes in the desert has unfortunately been going on and is still going on spontaneously. This process can't even be called controlled. To avoid this, ornithologists should at least participate in the planning of the large-scale alterations of the arid ecosystems (Rustamov, 1980). References Belskaya G.S. - In: Ptisi kultumogo landshafta. Ashkhabad, 1967, p. 9-16. Velikanov V.P., Khokhlov A.N. - In: Prirodnaya sreda i ptisi poberezhiy Kaspiiskogo morya i prilezhastchikh nizmennostey . Baku, 1979, p. 236-240. Gladkov N.A., Rustamov A.K. - In: Sovremennye problemy omitologii. Frunze, 1965, p. 111-156. Drozdov N.N. - In: Ornitologia. Moscow, 1967, vyp. 8, p. 3-46. Rustamov A.K. — Doklady AN SSSR, 1949, vol. LX, N 8, p. 1449—1451. Rustamov A.K. - Tr. Turkm. selkhosinstituta (Ashkhabad), 1956, vol. VIII, p. 279-291. Rustamov A.K. - Problemy osvoenia pustyn, 1969, N 2, p. 9-14. Rustamov A.K. - In: Teoreticheskie i prikladnye aspekty okhrany prirody i okhotovedenia. Vol. 84. Moskva, 1976, p. 40-44. Rustamov A.K. - In: Ekologia, geografia i okhrana ptits. Leningrad, 1980, p. 138-143. Rustamov A.K. -In: Acta Congr. Int. Om.,1954. Basel, 1955, p. 510-515. 587 CHANGES IN THE BREEDING AVIFAUNA OF AGRICULTURAL LAND IN LOWLAND BRITAIN Robert Morgan British Trust for Ornithology, Beech Grove, Tring, Hertfordshire, England INTRODUCTION The agricultural landscape of lowland Britain is among the most drastical¬ ly altered by man. 2,000 years ago the lowlands were clothed in broad-leaved forest interspersed with marshes. Gradually the change from forest to an agricultural landscape took place until today 80% of the land use in Britain is agricultural and only 8 % remains forested. It is difficult to establish the gains and losses of the avifauna during this long transition. Certainly the drainage of the once extensive tracts of marsh helped towards the ex¬ tinction of such speices as Crane Grus grus. Spoonbill Platal ea_l eue or o_dia , Bittern Botaurus stellaris and Black Tern Chlidonias niger. It i s also clear that the opening up of the forests allowed the colonisation of scrub and open country species of birds into this much diversified habitat, but the majority of British farmland species are those with a woodland origin - the dominant species being Blackbird Turdus merula, Durmock Prun e 11 a_modularis , Skylark Alauda arvenslB, Robin Erithacus rubecula and chaffinch Fringilla coelebs (Williamson, 1967). After the development of the open field system of the Anglo-, axons the agricultural landscape of lowland Britain remained relatively unchanged for a long period. The modern day landscape of a mosaic of fields, often bounded by hedgrows , with a patchwork of small pieces of woodland, ponds and farmst¬ eads is largely due to the Enclosure period 1750-1850. In this review of changes in the breeding avifauna of agricultural land in lowland Britain I shall consider the causes of change due to man's farming activities as well as changes due to natural phenomena such as climate, po pulation pressure and range expansion and contraction. Much oi the informât ion comes from the British Trust for Ornithology's population monitoring sur¬ veys, the Common Birds Census, Waterways Bird Survey and Nest Records Scheme, although information has been included from other sources where appropriate. CHANGES IN THE AVIFAUNA IN RELATION TO AGRICULTURAL CHANGE Following the Industrial Revolution of the 18th century an expansion of farming to a commercial industry took place resulting from the steep rise in human population. New technology led to an increase in mechanisation and one of the first species to suffer was the Corncrake Crex c.rex. A decline was first noticed in the second half of the 19th century- in the areas of greatest cultivation in south east England. The mechanical cutting of hay allowed mowing to take place progressively earlier, so destroying adult birds, nests and small young. The decline still continues with the species all but extinct as a breeding species in England and Wales with a reduction in occupied 10 km squares between 1968-1972 and 1978-1979 of 95% in England and Wales and 56% in Scotland. The major strongholds are now in the west of Scotland, especial¬ ly the islands, where the small meadows with the adjoining marshes are still farmed by traditional methods and are not cut .until late July (Cadbury , ■ 980 ) . 588 -0 Since 1945 agriculture has greatly Intensified due to modem technology and also encroached more and more on other habitats. HABITAT LOSS Among the habitats most affected by agricultural expansion since the 1940s are lowland heath and chalk grassland, valuable for their specialised bird communities (Puller, 1982). The losses have been considerable. For example, between 1811 and I960, 40% of Dorset heathland was lost while during I960 to 1978 a further 40% was eroded (Stubbs, 1980), mostly ploughed up for arable farmland. The conversion of so much heath and grassland, together with a re¬ duction in grazing on the remainder, due to myxomatosis affecting .the rabbit Oryotolawis cunlculus population from 1954, has had a locally deleterious effect on populations of grassland species in southern England such as the ffheatear Oenanthe oenanthe and Stone Curlew Burhinus oedicnemus. For examp¬ le, both are now almost extinct as breeding species in Sussex, southern Eng¬ land, whereas in 1938 they were relatively abundant (Shrubb, 1979). This is also true for many other areas in lowland Britain. In fact the majority of pairs of Stone Curlews- in Britain are now to be found breeding on arable farmland where they are subject to much greater disturbance and suffer higher losses of eggs and young due to farming activities (Glue, Morgan, 1974). Another major form of habitat loss on farmland is caused by increased drainage. The rate of drainage improvement of arable famland and also of flood- meadows and grazing marshes has risen steeply since 1945 - from 12,000 hecta¬ res per year to over 100,000 hectares per year at present (Williams, 1982). There has been an estimated 30% reduction in the area of old pasture in Bri¬ tain since 1940 (Moore, 1962). This has led to the decline of many populati¬ ons of breeding waders, particularly Redshank Tringa totanus. Snipe Gallinago gall in ago and Lapwing Vanellue vanellus. In many midland and southern coun¬ tries of England there has been a widespread decrease in Snipe due to improved drainage (Parslow, 1973) and the population index from the Common Birds Cen¬ sus and Waterways Bird Survey shows an 18% decrease between 1974 and 1978 (Marchant, Hyde, 1978). In Sussex, southern England the Snipe population had decreased from 500 pairs in 1938 to less than 100 pairs in 1967 and for Red¬ shank from 400 pairs to 250 pairs in the same period (Shrubb, 1979). The Common Birds Census population index also shows a decline for Lapwing in the south and east of Britain but not in the north and west (Marchant^ pers. comm. ). To facilitate improveddrainage many rivers and streams in lowland Britain have undergone drastic changes in the form of widening and straightening the channels and regrading the stream bed, usually involving the felling of bank- side tress and scrub (Smith, 1975). This represents a large loss of habitat for many specialised riparian species. At present the British Trust for Or¬ nithology and the Royal Society for the Protection of Birds are gathering in¬ formation on the bird populations of managed and unmanaged stretches of ri¬ vers, in some instances on the same sections before and after management by the Water Authorities, to assess the initial impact and subsequent changes in bird communities. For example, censuses carried out on a farm in Dorset south¬ ern England, showed populations of between 21 and 29 pairs of 7 breeding ri¬ verside species in each of three years before dredging and bank clearance operations took place but only 12 pairs were present three years afterwards 589 (Williamson, 1971). The species most affected we re the Reed Warbler Acroce- phalUB scirpaceus and Sedge Warbler Acrocephalus sehoenobaenus , the latter showing a movement away from the river to breed along hedgerow ditches. Moor¬ hens Gallinula chloropus can also be greatly affected by dredging as shown by an example from the Waterways Bird Survey where the numbers were reduced from five to one following management work (Marchant, Hyde, 1980). HEDGEROWS One of the most obvious changes in the farmland landscape of Britain is the loss of hedgerows - 23% (225,260 km) since 1945 (Stubbs, 1980). There has been much controversy over the value of hedges to wildlife - on the one hand the farmer wishing to make the running of the farm as efficient as possible and the conservationist on the other hand seeing all habitat loss as detri¬ mental for, wildlife. Hedgerows provide nest sites, food and shelter for birds and are more im¬ portant for some species than others. The size, shape and management of hedges greatly affects their value to nesting birds (Moore et al., 1967) and there¬ fore some hedgerow Iobs, particularly of poorer quality hedges, will not ne¬ cessarily lead to a significant reduction in the numbers of birds on the farm farm (liurtoQ, Westwood, 197^; Bull et al. ,1976). However, a comparison of the open field system of farming with virtually no hedgerow with nearby enclosed land showed a three-fold increase in the number of birds when the hedge nesting species were included (Moore et al., 1967). A Common Birds Census carried out on a Cambridgeshire farm in eastern England from 1964-71 showed that a loss of 95% of hedgerows led to a 49% loss of species nesting in hedgerow, tree and thicket (Evans, 1971). Some species were not affected by this hedgerow loss and even increased, for example Skylark and Reed Bunting Emberiza schoenlclua. Hedgerows are known to be important components of the farmland habitat for ïellowhammepe Emberiza citrinella. Studies on the effect of severe cut-back of hedgerows on farmland in Hertfordshire, southern England, showed that the Yellowhammer responded to this loss of habitat quality by greatly expanding its territory size (Morgan, O'Connor, 1980), perhaps in order to obtain suf¬ ficient food. On the same farm the Dunnock Prunella modularls responded by shifting territories from the cut-back internal hedgerows to the previously less preferred boundary hedges remaining. Although the relationship between birds and hedgerows is as yet poorly known, it is already clear that for some species they are of major importance: among the farmland species monitored by the Common Birds Census 37% of the species are positively correlated with hedgerows with trees and 30% with hedgerow density, a much greater proportion than with variables such as area of woodland, scrub and lines of trees (O' Con¬ nor, in prep.). A factor contributing to hedgerow loss is the infection of elm trees Ill mus spp. with Dutch elm disease. Between 1969 and 1978 out of a total of 17.1 mil¬ lion elms, 10.6 million were dead or dying and 5 million had been felled. Prom a study using Nest Record Scheme data the loss of elms was considered to have caused a large reduction in the available nest sites for Kestrel Falco tin- nunculuo , Tawny Owl Otrix aluco. Stock Dove Columba oenas and, in particular, Bam Owl T^t p alba (Osborne, 1982). Some species, notably Woodpeckers (Pi- SMae) and Hu thatch- Sitta europaea may have benefitted from the temporary abundance of beetle larvae on dead elms, but Chiff chaffs Phylloscopus col- lybita have also declined on those Common Birds Census plots affected by Dutch elm disease compared with unaffected plots (Osborne ,in prep.). PESTICIDES The possible effects of pesticides on farmland bird populations first came to light during the 1950s when granivorous birds were being killed in large numbers during seed-dressing incidents and the bodieB were found to contain very high levels of organo-chlorine insecticides (Prestt, Ratcliffe, 1972). However, there is no evidence of permanent effects on populations of these species but spectacular declines have been seen in various predatory species throughout Britain such as Peregrine Falco peregrinus and Sparrowhawk Acci- piter nisus. The introduction of DDT as a seed-dressing since 1947 and the more toxic oyclodiene compounds of aldrin, dieldrin and heptachlor since 1956 were coin¬ cident with egg-shell thinning, egg-breakage and poor breeding success in Sparrowhawks, such that a marked population decline occurred over much of south, east and central England, particularly in intensive arable areas (New¬ ton, 1973). Sparrowhawk populations breeding away from arable land did not show this poor breeding success, and in these areas organochlorine pesticides were never widely used (Newton, 1974). The situation is healthier now follow¬ ing restrictions on the use of these chemicals and the Sparrowhawk is once more frequently seen hunting over farmland areas. Since the inception of the Common Birds Census in 1962 the percentage of farmland and woodland plots re¬ cording Sparrowhawks has steadily increased (Marchant, 1980). Another species that showed a large scale population decline in the 1950s, particularly on arable farmland, was the Stock Dove (Parslow, 1973). A recent study using nest record card data has shown that breeding success was much lower in the period 1950-69 than in the preceding or succeeding decades, thus coinciding with the main period of organochlorine pesticide usage (O'Connor, Mead, 1981). Another group of chemicals that have affected birdlife in lowland farmland areas in Britain are herbicides. Herbicide use on cereals dates back to the beginning of the century but was not extensive until the 1960s. Between 1969 and 1977 the annual acreage sprayed with herbicides has increased by 25$ (Stubbs, 1980). The effect of spraying is to reduce the dicotyledenous weed flora which in turn reduces the arthropod biomass in the fields. A single application of certain herbicides to a cereal field in April will, by June, have reduced the arthropod biomass by two-thirds compared with an unsprayed control field (Southwood, Cross, 19&9). Grey Partridges Perdix perdix have been declining in Britain since the 1950s due to a change in chick survival. This has been caused largely by the reduction in arthropod food through the increased application of herbicides making the chicks more dependent on aphids as food. This renders the chicks very susceptible to spring temperature as the aphids move into cereal fields much later in cold springs (Potts, 1970). The Common Birds Census index for the Linnent Ac an this cannabina also shows a decline from 1962-81 and this species is very dependent on the weeds of cultivation (Newton, 1972). Perhaps herbicides are again responsible. 591 OTHER FACTORS AFFECTING CHANGE IN THE BREEDING AVIFAUNA Changes In the breeding avifauna can be caused by other, natural factors such as climate, population pressure and range expansion or contraction in¬ dependent of changes in agricultural practices. CHANGES IN WINTER SURVIVAL Small, resident species such as the Wren Troglodytes troglodytes. Long¬ tailed Tit Aegithalos cauda tus and Treecreeper Certhia familiarls were parti¬ cularly reduced in numbers in the two severe winters monitored by the Common Birds Census in 1962-63 and 1978-79. Larger species were not affected so badly. Also, the survival of species wintering in parts of West Africa, sub¬ ject to severe drought conditions between 1968 and 1969, were much reduced; by up to 75% in the case of iVhitethroat Sylvia communis (Winstanley et al., 1974). Other farmland species showing declines correlated with the Sahelian drought include Sedge Warbler, Garden Warbler Sylvia borln. Spotted Flycat- cber M?clcapa striata and Swallow Hirundo rustics (Marchant, 1982). FARMLAND AS A SUBOPTIMAL HABITAT The habitat preferences of a particular species may be influenced by these large scale changes in population levels. For instance following the 1962-63 cold winter the majority of Wren territories were concentrated in to woodland and streamside habitats and as these habitats became saturated with the in- in population level, gardens and finally farmland hedgerows were oc¬ cupied (Williamson, 1969). Farmland is therefore a suboptimal habitat for the Wren and this has also been shown for the Great Tit Parus major (Krebs, 1 and the tfoodpigeon Columba palumbus (Murton, Westwood, 1974). RANGE EXPANSION AND CONTRACTION 'ma y, let us consider changes due to range contraction or expansion. ,f. ?ln+10,°n the 6dge °f the range for a number of species and is therefore tv, * v S m°re affected by Population changes than the centre of the range. „ Red-backed Shrike Lan^s_collurio is an example of a scrub and hedgerow opecies n severe decline in Britain since the 1950s. The population had 197B1Me At vT" 253 PalrS ln 1960 t0 81 PairS ln 1971 ; a drop of 6855 (BlbbW. • e same time one of the most dramatic examples of range expansion to re \ Collared Dove Streptopelia decaocto from Asia across Europe , ° rl 8 n in 19j5‘ Tbis species now breeds over most of the country ( Sharrock^l 976 ^ fr°m SpeCially pr(?tected to belnS a farmland pest ACKNOWLEDGEMENTS . This paper is based, to a large extent, on the work of the British Trust or Ornithology -s Common Birds Census and Nest Records Schemes. It is a P easure to thank the many contributors to these schemes and also the Nature R r;TCy C0uncl1 f0r providlnS the necessary funding. My thanks to • . u er and R.J. O'Connor for useful comments during the preparation of the manuscript. 592 References Bibby C. - Bird Study, 1973, 20, p. 103-110. Bull A.L., Mead O.J., Williamson K. - Bird Study, 1976, 23, p. 163-182. Cadbury C.J. - Bird Study, I960, 27, p. 203-218. Evans P.J. - Cambridge Bird Club Report, 1971, 1972, 45, p. 36-39. Puller R.J . Bird habitats in Britain. Calton, Poyser, 1982. Clue D.E., Morgan H.A. - Bird Study, 1974, p. 21-28. Krebs J.R. - Ecology, 1971, 52, p. 2-22. Marchant J.H. - Bird Study, 1980, 27, p. 152-154. Marchant J.H. - Bird Study, 1982, 29, p. 143-148. Moore N.W. - Brit. Birds, 1962, 55, p. 428-436. Moore N.W., Hooper M.D., Davis B.N.K. - J. Appl. Ecol., 1967,4, p. 201-220. Morgan R.A., O'Connor R.J. - Bird Study, 1980, 27, p. 155-162. Murton R.K., Westwood N.J. - Brit. Birds, 1974, 67, p. 41-69. Newton I. Pinches. L.: Collins, 1972. Newton I. - Brit. Birds, 1973, 66,, p. 271-278. Newton I. - J. Appl. Ecol., 1974, 21, P« 95-102. O'Connor R.J., Mead C.J. Population level and nesting biology of the Stock Dove Columba ocnas in Great Britain, 1930-1980. Report to the United Kingdom Nature Conservancy Council. 1981, p. 1-47. Osborne P. - Bird Study, 1982, 29, p. 2-16. Potts G.R, - Bird Study, 1970, 21» p. 145-166. Prestt I., Ratcliffe D.A. Effects of organochlorine insecticides on European birdlife. Proc. Int. Om. Congr. 15, 1972, p. 486-513. Sharrock J.T.R. The Atlas of Breeding Birds in Britain and Ireland. Calton. Poyser, 1976. Shrubb M. The birds of Sussex, their present status. Chichester. Phillimore 1979. Smith A.E. - Bird Study, 1975, 22, p. 249-254. Southwood T.R.E. , Cross D.J. - J. Anim. Ecol., 1969, 38» p. 497-509. Stubbs A.E. Nature Conservancy Council Chief Scientist's Team. Notes N 21. Williams G. - BTO News, 1982, 119. Williamson K. - Bird Study, 1967, 2i» P* 210-226. Williamson K. - Bird Study, 1969, 16, p. 53-59. Williamson K. - Bird Study, 1971, 2§, P* 80-96. Winstanley D., Spencer R., Williamson K. - Bird Study, 1974, 2T_, p. I-14. 2. 3aK. 981 593 MEDITERRANEAN BIRD FAUNAS IN THE LIGHT OP ANTHROPIC PRESSURE SINCE THE NEOLITHIC Jacques Blondel Centre d’Etudes phytosociologiques et Ecologiques/CNRS: Route de Mende, B. P. 5051 - 34033 - Montpellier Cédex, Prance THE BIRD FAUNAS OP THE MEDITERRANEAN AREA BEFORE THE IMPACT OF MAN Any attempt to describe the influence of human activities on bird faunas needs first to know what was the pattern of the distribution of species and communities before the impact of man began to be apparent on the landscape. Needless to say that such a task is hazardous and speculative but several cues help us to know something about the nature of the avifaunas during the Atlantic period (7500 - 4500 BP), that is just before the intervention of neolithic man on a large scale starts to be apparent in pollinie diagrams (Pons, 1981; Pons, Quézel, 1981). An examination of the biogeographic affini¬ ties of the 209 land birds out of the 335 species breeding in the Mediterra¬ nean basin shows that they belong to three main faunal categories (Blondel, 1982): 1) boreal sylvatic species widespread in both deciduous and mixed fo¬ rests of the Palearctic = 74 species, 2) birds of Palearctic grasslands and of southern and south-eastern steppes = 92 species, 3) birds of mediterranean type shrublands = 43 species. A first conclusion which merges from these fi¬ gures is the importance of birds of boreal sylvatic origin. Palaeobotanical studies show that at the maximum of development of forest vegetation during the Atlantic period, forests were widespread in many forms everywhere in the mediterranean area (Beug, 1967; Triat-Laval, 1978; Pons, Quézel, 1981). Many indications, both palaeobotanical and paleontological (Moure r-Chauvi ré , 1975; Blondel in press) suggest that the bird faunas of these climactic forests of the mediterranean basin were not markedly different from those of temperate deciduous and conifer forests further north. So, the largest part of bird communities of the Mediterranean were dominated either by boreal forest spe¬ cies in the deciduous lowland and conifer montane forests or by freshwater irds (70 species = 21% of the total) in marshes, rivers and lakes. Such a situation is an inheritance of glacial times when the forest avifaunas of urope could survive only in the mediterranean basin (Moreau, 1954). These ^UnaS expanded n°rth during post-glacial times as they probably +^ring 6aCh lnterSlacial period since the beginning of the Pleistocene, composition remained roughly the same within the mediterranean ba¬ sin in the interglacial time as the one at the present time, until the be¬ ginning of human pressure. Nevertheless it .mist be emphasized that the great opographical and geobotanical diversity of the Mediterranean always allowed besides the medioeuropean avifaunas the existence of truly mediterranean spe- c es and species of steppes in -£he mosaic of habitats which exists in the re¬ gion since the beginning of the Pleistocene. On average, the steppic and m ar d species which evolved in the xeric habitats encircling the Mediterr¬ anean from the shores of the Atlantic ocean to the steppes of Central Asia r example Larks, Chats, Sandgrouses) had by these times a more southern distribution than now as will be shown later. the mediterranean species are concerned, it was shown elsewhere 594 ■in this Congress (Blondel in press) that some spéciation took place during the Pleistocene within the present mediterranean area, especially for bush species such as Sylvia spp., Hippolai b spp., Alectoris spp. and some others. For these species as well as for other bush species of more northern origin, it must be recognized that some shrubland-like habitats must always have been present since the beginning of glacial times, which is confirmed by pa- leo botanists (Sue, 1973; Vemet, 1972). This is not surprising given the great physiographic diversity of the region. Botanists have shown that since the setting up of a truly mediterranean bioclimate by the end of the Pliocene some kind of matorrals (maouis, garrigues, phrygana) dominated by a truly me¬ diterranean vegetation have always been present, even during the most severe phases of the last glaciation, but at a much lower geographical scale than now and under the form of local patches. Hence the small number of bush spe- oies auch as Sylvia which evolved locally in contrast with the dominance of temperate forest species which made up the great bulk of land birds. THE CONSEQUENCES OP HUMAN ACTIVITIES ON MEDITERRANEAN BIRD COMMUNITIES: INDIRECT EVIDENCE The bird communities of climactic mediterranean forests The mediterranean habitats have been under human pressure for 4000 to 6000 years according to the places. This strong pressure results everywhere in the reduction of forests and the extension of matorrals. Our minds are so much impregnated by the modem landscapes that it is difficult to Imagine that most matorrals are secondary formations which took the place of former fo¬ rests. Since my experience is mostly from southern Prance, T shall mainly deal with the bird communities of this region. One of the most puzzling facts that the ornithologist can notice is that the bird communities which live in the few rellctual patches of old forests which are near a climactic state have no mediterranean character. How to ex¬ plain such an apparent paradox? The comparison of the bird communities of four old forests, two of them in central Prance (Burgundy and Fontainebleau near Paris) and the two remaining in mediterranean Prance (Provence and Cor¬ sica) shows that on average the composition of these four communities is cuite similar (Table 1). There is less species in Provence and especially In Corsica because of island effect (Blondel, 1979, 1981). Only five species were found in the mediterranean forests. Actually, three of them (Luscinia megarh.vnchoe. PhyllOBCOnus bonelli and Parus crlstatus) breed in the surroun¬ dings of the temperate forests which were censussed, Certhia familiaris in Corsica is replaced on the mainland by Certhia brachydactyla and Eertnus cit- rlnella is a species of the southern Alps which has important populations everywhere in Corsica. On the other hand, 17 species (Columba oenas. Picus canus , Dryocopus martius, Picoides médius, Jynx torquilla. Anthus trivialis. Prunella modularis, Phoenicurus phoenicurus, Turdus philomelos. Phylloscopus trochilus. Phyl Iosco nus sibllatrix, Iduscicapa bypoleuca. Parus palustris. Parus montanus .Pyrrhula pyrrhula, Coccothraustes coccothraustes . Bturnus vul¬ garis) which breed in the temperate forests are absent from the two mediter¬ ranean ones but the mediterranean area is out of the range of most of them and only Oolumba oenas, Phoenicurus phoenicurus, Coccothraustes coccothrmisten 595 Table 1. Composition (numbers of breeding pairs per 10 ha) of bird com¬ munities in four old forests, two in central Prance (Burgundy, Perry, Frochot, 1970; Fontainebleau, le Louam, Spitz, 1978) and two in mediterranean France (Provence, Corsica, Blondel, 1979). + = density less than .1 breeding pair Region Dominant tree Columba oenas Columba palumbue Cuoulu8 canorus Pious viridis Pious cams Dryocopus martius Picoides major Picoides minor Picoides médius Jyrw. torquilla Anthus trivialie Troglodytes troglod. Prunella nodularis Phoeniauru8 phoenic. Erithacus rubeoula Luacinia megarhynch. Turdus merula Turdus philomeloe Turdus viscivorus Sylvia atricapilla Phylloecopus trochilus Phyllo8copus colly bita Phylloscopu8 bonelli Phylloecopus 8ibilatrix Regulus igniaapillus Ficedula hypoleuca Musciaapa striata Aegithalos caudatus Parus palustris Parus montanue Parus cri8tatus Parus ater Parus caeruleus Parus major Sitta europaea Certhia familiaris Certhia brachydactyla Fringilla coelebs Pyrrhula pyrrhula Coco, coccothraustea Stumus vulgaris Oriolus oriolu8 Garrulus glandarius Serinu8 citrinella Number of species Burgundy Fontainebleau Provence Corsica Quercus Fagus Quercu8 Quercus pedunculata si Ivatica ilex ilex + + + + . 1 . 1 + .3 . 1 . 1 . 1 .3 . 1 + + .7 . 1 1.8 1 . 1 .3 + .3 1.0 + + 1 .5 2.3 14.5 5.0 5.0 2.2 .8 2.3 2.9 9.2 6.1 5.7 1 .4 1 .0 1 1 .1 3.8 1 . 1 .3 • 1 .2 .5 4.2 5.5 6.7 + .4 7.4 .8 3.6 6.1 1 . 1 1 .8 1.5 9.0 2.8 .2 1 .8 .4 .5 1 .0 2.4 3.7 .2 3.2 .5 .2 4.1 12.6 14.1 11.6 14. 1 4.7 14.5 3.2 4.7 3.8 4.1 2.2 1.6 5.6 2.5 6.9 5.6 4.4 7.7 6.4 2.0 .6 1 .5 3.9 .8 .1 . 1 .6 1.0 .4 22. 33 23 17 596 and Stumus vulgaris can be found in some mediterranean habitats. 'He have cal¬ culated an index of similarity (beta-diversity using Shannon's formula) bet¬ ween the four communities taken two by two (Table 2). As expected, the pairs of communities which are geographically the nearest are more similar between them than with the others but one must notice that the Quercus ilex forest of Provence is very similar with the Quercus pedunculata forest of Burgundy. The differences with the corslcan forest are more a result of species impoverish¬ ment due to insular isolation than of some biogeographical trend because only two species, Certhla famlllarls and Bcrinue citrlnella are particular to the island forest. He can conclude from these comparisons that the differences between the bird communities of the mediterranean climactic forests and those of the temperate forests are only differences in richness. This impoverishment is perceptible in Provence but is much more pronounced in the corsical forest; it must be related to the position of the region at the southern margin of Eurasia (Blondel, 1979, 1981). Table 2. Indices of' similarity of the bird communities of the four forests taken two by two. Figures are ji -diversities using Shannon's formula (H^ = H'^ - .5(H' ^ + H'.)) B = Burgundy, F = Fontainebleau, P = Provence, C = Corsica B F P F .79 - P .75 .71 - C .63 .64 CO r- • The dynamics of bird communities along ecological su c c es si Ç)nj3 The impact of man on the mediterranean vegetation and the degradation of habitats can be illustrated by a gradient of decreasing complexity of vegetat¬ ion from an old forest (right of Fig. 1 ) to a steppe (left of fig. 1). This can be considered as an oversimplified generalisation of the consequences of human activities on mediterranean vegetation. Such a succession was studied in Provence and 7 stages of development were defined using criteria of struc¬ ture of the vegetation. The bird communities of each of these stages were cen- sussed by the I.Ï.A. method (Blondel et al., 1981). Table 3 gives the list of species found in each habitat and figure 1 the proportion of the three main biogeographical categories along the gradient: birds of steppes and grass¬ lands, mediterranean species, boreal sylvatic birds (categories compiled from Voous’, 1960; Moreau, 1966; Blondel, 1981). The main result of this analysis is that nearly all the species of stage 1 belong to faunal types originating either from the steppes of the southern Palearctic (Turkestanian-Mediterranean and Palaeoxeric faunal types of Voous I960, i.e. Otis tetrax, Burbinus oedi- cnemus) or from Palaearctic grasslands (Alauda arvensis) whereas all the spe¬ cie of stage 7 (forest) are non mediterranean palaearctic forest species. In the mediterranean-like shmblands, especially in stages 3, 4 and 5, we find three sets of species: T) some species of steppes and grasslands which manage to colonize the patches of very low scrab or nearly bare ground between the bushes rtntvnra campestris, Oenanthe hispaniça^ Bullula arbores, Aleçtoris 597 20-r Height of vegetation (m ) 10- 5- 1- 1 Stag es : I j II III 1 IV 1 V ' VI 1 1 VII Steppes ond qrasslonds 98.6 1 1 31.1 1 1 1 1 31.7 l 1.8 1 1 1 1 1 1 1 3.3 3.1 1 1 t 1 0 Mediterranean 1 1.4 1 68.4 | l 56.4 | 57.4 1 1 1 | 1 1 24.4 1 15.9 | 1 1 0 Boreal forests 1 o ! -L i 0.5 | - - 1 1 11.9 | 1 41.1 1 1 1 1 l 1 72.3 | i 81.0 1 1 | | 1 100 ' g- 1. Biogeographical composition of the bird communities in seven stages of a succession of Holm oak Quercus ilex in Provence. The trend is c aracterized oy a regular decrease of mediterranean species and species n habitats (steppes and grasslands) and an increase of medioeuropean species in the old climactic forest. See text for further explanations (cal¬ culated from Blondel, 1981, Appendix 2: 382) a), 2) some ecologically tolerant non mediterranean forest species which '-•radntur ri ^ the 8ylvatic habitats into the highest matorrals (Aegithalos PhjmoscopuB collybl ta, Oarrulus glandarlus. Turdus memqla. Sylvia t , a’ -'Cj-Plte.r nlou^, Parus major. Brlthacus rubecula) and 3) a few nean br !rranea" SPeCleS WhlCh eV°1Ved Withln the ««it- of the Mediterra- t 1 ” an “Vergreen ah rublike vegetation. The best example of this ca- <, nnd-it-," - P fnUB ^LlVlS' Wlth flVS symPatric species, Sylvia conspicillata, S.melanoçephala, S^cantillans and S.hortensis. - - a(15! arlnof°tClrl0n i8 thSt °Ut °f the 48 8peCles of the only considered al sp^cîf"^ 0rlgin “d the °nly SpecieS wMch rtan be mediterranean matorraTs are the^i T haVe eV°lved lo the evergreen „„„ 8 are the five warblers just mentioned . wMch are mostiy secondai7 anthr°pi° formati°n8 surprising that +v, 6 a°hlevement of spéciation processes, it is not 4 meters high d J* C0VmxnitUa are very Poor: in a low garrigue only only 12^sneci T by ^rcus 11 ex an(i perçus coccifera. there are S.melanoeenVinio 22*6 breedlne Pal™/10 ha with Sylvia undata, whereas in the^’ ~ :antlllane and tosclnia megarfiynchos as dominant species are 28 specie» ype of habitat in Burgundy (Quercus pedunculata) there 190-191). The" °+a Zin£ 44"4 breeding pairs/10 ha (Perry, Pruchot, 1970: the former habité Strlklng dirference between Provence and Burgundy is that specîrwm! I" ° mUCh h0t 80,1 dry f°r the P-etration of forest ” he latter* sylvatic surroundings make them comfortable 598 Table 3. List of species censussed in each habitat of , the ecological succession (see legend of fig. 1) SG = birds of steppes and grasslands, M = mediterranean species, BP = birds belonging to european, Palaearctic and holarctic non mediterranean faunal types. The sequence of species is that of their rank of apparition in the gradient from the first habitat to the last (see Blondel 1981 for further details) Species Faunal categorie Found in habitats Circus pygargus Otis tetrax Pteroale8 alchata Burhinue oedianemue CalandreVLa cinerea Alauda arvensis Sylvia aonspicillata Anthus campestris Oenanthe kispanica Emberiza hortulana bullula arbor ea Lanius excubitor Sylvia undata Alectoris rufa Carduelia cannabina Pica pica Clamator glandarius (Afro-tropical) Sylvia melanocephala Sylvia cantillans Aegithalos caudatus Phylloscopus collybita Luscinia megarhynchoa Streptopelia turtur Garrulue glandariue Turdue merula Sylvia Hortensie Sylvia atricapilla Circaetua gallicus ( Indo-african) Accipiter niaua Hippolaia polyglotta Cuculus aanorus Parus major Phylloscopus bonelli Erithacus rubecula Regulus ignicapillus Picus viridis F ringilla coelebs Sitta europaea Certhia braahydactyla Columba palumbus Picoides major Picoides minor Oriolua oriolua Parus caeruleue Parus ater Parus cristatua Troglodytes troglodytes Turdue visdvorus SG 1 SG 1 SG 1 SG 1 SG 1 SG 1 M 2 SG 1-2-5 M 1-2-3 SG 2-3 SG 2-3 SG 2-3-4 M S-3-4-6 M 1-2-3-4-5-6 SG 2— 3-4-6 BF 2— 3-4-6 4 M M BF BF BF SG BF BF M BF 6 BF 5-6-7 M 6 BF 5-6-7 BF 5-6-7 BF 5-6-7 BF 5-6-7 BF 6-7 BF 6-7 BF 6-7 BF 6-7 BF 6-7 BF 7 BF 7 BF 7 BF 7 BF 7 BF 7 BF 7 BF 7 BF 7 3-4-S-e 3-4— 5-6 s s 3- 4-S-6-7 4- 5-6 3-4-S-6-7 3-4-5-6-7 5- 6 5-6-7 599 in the first stages of the succession. Thus the difference in the structure of communities between the first stages of ecological successions and the climactic stage are much stronger in Provence than in Burgundy. As an example the mean value of beta-diversity H'^ between stages 3,4,5 and stage 7 is .81 in Provence instead of .48 in Burgundy (calculated from Blondel, 1979; Perry, Prochot, 1970). The deforestation and the dramatic degradation of most lowland and semimontane habitats in the Mediterranean under the pressure of man gave rise to a spatial extension of both steppic and mediterranean species which were foimerly much less numerous and had a more patchy distribution. On the other hand, there was an important withdrawal of boreal and temperate forest birds and probably a loss of some large species because of the crumbling of favourable habitats into small isolated woodlots. THE CHANGES OP MEDITERRANEAN BIRD COMMUNITIES SINCE THE BEGINNING OP THE CENTURY In the previous sections, only Indirect evidence from biogeography and ve¬ getation dynamics could tell us something about the modification of bird com¬ munities under the pressure of man. But historical data, some of them very recent, enlighten and confirm the preceding views, at least in southern Pran¬ ce where I live. Rural Prance is characterized by a general country desertion which started at the end of the XIXth century and was accelerated after the first world war, then the second. Actually, because of an increase in human demography and a very severe exploitation of the vegetation during the second world war, human pressure on natural habitats was very severe between the years 1940 and 1950 and this probably recalled that which prevailed during several millena¬ ries, since the Neolithic or Bronze age (Pons in litt.). But this pression which lasted only one decade or so stopped almost at once just after the war because of the generalization of fossil fuel instead of firewood for machines and domestic use. As a result there is a generalized resumption of vegetation with more and more old coppices which become taller and taller. This results in an important increase of the woody biomass. Simultaneously, botanists no¬ tice that this "biological coming back" (= "remontée biologique") is accompa¬ nied by a strong subduing of the mediterranean character of the vegetation: "deB surfaces occupées par des taillis plus ou moins bas de Chêne vert ont fait place à un taillis haut de Chênes pubescents, des buxaies claires se sont peuplées de Chenes, voire de Hêtres, des lavandaies se sont parsemées de Chenes caducifoliés ayant repris de souches anciennes" (Pons in litt.). An example oi this extension of three tree species, Holm oak Que reus ilex. Pu¬ bescent oak Quercus pubescens and Alep pine Plnus halepensis is given on Table 4. Incidentally, this evolution of the vegetation raises some ques¬ tions about the climax in Mediterranean lowlands. It is probable that deci¬ duous oaks, namely Quercus pubescens. should be more widespread than what was formerly believed. This fits well with the fact that the biogeographic origin of the birds of mediterranean forests is the same as that of the birds of central Europe. When they analyzed the avifaunal changes of the Camargue and its surrôun- dings during one century,' Blondel, Isemann (1981) found that out of 30 chan- 600 Table 4. Evolution of areas (thousands of ha) covered by Quercus pubescens , Quercus ilex and Pinus halepensis in the french mediterranean region since the beginning of the century (after Acherar 1981) Species surfaces in 1904-1908 surfaces in percent 1 971-1978 change Quercus pubescens Quercus ilex Pinus halepensis 235 310 1 14 TOTAL 659 306 + 30.2 227 26.8 187 + 64.0 720 + 9.3 ges, 6 were extinctions and 24 were new acquisitions (Table 5). Now, if we except water birds with which we are not directly concerned here, many of the new species are medioeuropean forest birds which progressively come back in their former habitats, especially in the Rhone forest, since man stopped cutting wood. Furthermore in many cases, the dramatic destruction of forests by wood cutting, fire and overgrazing, produced such catastrophic erosion of soils that importent reafforestation programs started in southern France as soon as the end of the last century and are still in progress. As a result, many mediterranean mountains which were almost bare of woody vegetation a century ago are now covered with true forests. The extension of surfaces planted with Alep pine (Table 4) is partly due to human intervention. Although artificial, many of these forests are now inhabited by sylvatic medioeuropean species which drove back species of open landscapes which have invaded such degrada- ted habitats. Thus these forest species were indirectly reintroduced by man (Blondel, 1976). Table 5. Avifaunal changes of the Camargue since 1840 (Blondel, Isenmann, 1981) _ Extinctions : 6 Numenius arquata Uelanooorypha oalandra Acquisitions : 24 between 1840 and 1938 : 9 Anas strepera Netta rufina Thalasaeus sandvioensis since 1938 : 15 Ardea cinerea Ardeola ibis Acaipiter nisus Milvus migrans Phasianus co lehicus Lanius collurio Sylvia bovin Saxicola vubetva Turdus visoivovus Clamator glandavius Picoidee major Picoides minor Aegithaloe aaudatus Garrulua glandavius Sylvia atrioapilla Larus melanocephalus Columba palumbus Streptopelia deoaooto Phoenicurus phoeniouvus Phoenicurus ochvuros Erithacus vubeoula Stumus vulgaris Corvus monedula Troglodytes troglodytes Phylloscopus eollybita — _ 601 BIBLIOTHÈQUE As a matter of fact, the speed of the vegetation improvement is high enough to be noticed by the biologist: this is true not only for botanists but also for ornithologists: during the last 20 years, at least six species (Buteo_buteo, Ferais apivorus. Dryocopus martius. Turdus phllomelos. Sltta europaea, Parus palustris) which were unknown as breeding birds in Provence have enlarged their distributional area towards the south. Although somewhat circumstantial, difficult to quantify and rather loca¬ lized in some parts of the mediterranean region, such examples are good in¬ dices of a slow but significant return of mediterranean biotas towards the natural spontaneous equilibrium. There is very little chance that such an equilibrium be fully realized specially since the energy crisis will make more and more demand upon the living biomass so that we are probably at the present time "at the top of the wave". Anyhow, this trend confirms the in¬ formations given by palaeobotany , paleontology, biogeography and ecology, na. mely that plants as well as birds and other animals tend to reoccupy their former habitats thanks to a subduing of human pressure on mediterranean landscapes. URBANIZATION Urban settlements have existed for at least 3500 years, specially in the eastern Mediterranean where there were flourishing pregreek civilisations in e Middle East, Turkey, Crete, etc. The building materials of these ancient c es as well as their spatial organization and the way of life of their inhabitants were probably very favourable for a progressive adaptation of many species to live in the immediate vicinity of man, more or less as com¬ mensals. This must be true for such species as Ibises, Storks, Kites, Vultu- re„. Falcons (F. tinnunculus , F.naumanni). Doves, some Owls (Tyto alba. Athena SC0P.B)> Swifts, Swallows, Phoenicurus ochruros. Emberiza strio- — ’ Sparrows, several Pinches, Sturaus unicolor. Crows etc. To be a suc¬ cessful commensal of human cities it is required to be inquisitive, familiar, gregarious, sociable, cunning, omnivorous but never harmful to human inte- Fome large species are very useful as municipal scavengers and were protected for this reason. umba livia was the only species to be domesticated and largely spread y man especially the Romans) but some others were introduced outside their na ura range as game birds (Partridges, Pheasants). For most of the species, fd-irp + + nsa'Lism was a start*ng point for demographic and spatial expansion thrm >, sp°rtation man, intentional or not, and spontaneous expansion ough cities). Unfortunately very little is known about the role of an- cationr^'^6“ Urbanlzation °n life histories and the range modifi¬ ai . 6 8pecies- But close commensal relationship with man, such as W ° Wae described by Meininger et al. (I960) for Corvus splendens populations is known to live away from man must have had important percussions on the distribution and adaptive characters of the species. have dJ! n °f Cltie8’ 8peclally the biggest ones and human crowds bein* oJlh aWay mSny °f theSe Species* specially big raptors, some of them j ,6 Verg® °f extincti°n in some parts of the Mediterranean. This to a standardization of bird communities in such a way that there are 602 very few differences between them whatever their geographical location in Europe. Marchetti, Gsfllner (1976) have analyzed the dynamics of bird communi¬ ties along a gradient of increasing urbanization from the periphery to the center of the city of Marseille. Their data allowed me to compare the distri¬ butional range of the birds of the city with their biogeographic characters. In a previous paper, Blondel, Hue (1978) defined an index of geographical distribution for each of the 264 species of birds breeding in Prance. This was done from the Atlas des oiseaux nicheurs de Prance (Yeatman, 1976). If we calculate the average value of hiB index for all the species in each stage of our gradient of urbanization we see that the higher the degree of urbani¬ zation, the more widespread in Prance are the bird species (Pig. 2). Actual¬ ly, most of the birds which have a southern distribution in Europe (underli¬ ned on table 6) are in the upper part of table 6, that is to say in habitats where there iB still some mediterranean vegetation. Tn the two last stages of most severe urbanization (stages 6 and 7), all the species except Sylvia melanocephala can be found in any other european city. Prom this it can be concluded that unfortunately modem mediterranean large cities cannot tell us anything about the history of synanthropisation and its role on the patterns of distribution and adaptive characters of the species involved. Actually we could discuss at length the patterns of distri¬ bution and community organization of the birds within the city but this would be out of the scope of this paper and our conclusions would be about the same as those of many other papers on this subject elsewhere in Europe (see for instance Nuoverta, 1971 ; Davis, Click, 1978). It has been suggested (Erz, 1966) that mnny of the species commonly found in the european large cities belong to a pool of more or less man-adapted populations which exchange propagules between themselves in the archipelago of cities and which are more or less isolated from populations of the peripheric natural habitats. Such an hypo¬ thesis could hold true for some species but not for others; in any case, it remains highly speculative and has to be tested by demographic and genetic studies. CONCLUSION The overall conclusion which merges from the set of data which have been collected can be summarized as follows: Because of the privileged geographical situation of the Mediterranean basin at the limit between the great continen¬ tal Eusasian and African land masses and in close proximity to the semi-arid habitats to the south and to the temperate biome to the north, the richness of the bird fauna is exceptionally high (335 breeding species on an area of ca 2 970 000 km2). This richness was enhanced by the great physiographical and geobotanical diversity of the region. Hence the juxtaposition of faunas of very different origin since we can find species of boreal fir beech fo¬ rests and birds of xeric steppes only a few kilometers apart but at different elevations. Contrary to what was fomerly believed, this situation exists since the beginning of the Pleistocene but the extent of the different types of habitats has changed greatly according to the prevailing climates. But even at the climax of the last glaciation which was the most severe, the ther¬ mophilous species. could survive locally thanks to the diversity of topographi- 6O5 Fig. 2. Indices of geographic repartition in France of the bird communi¬ ties of seven stages of increasing urbanization in the city of Marseille. While most of the species of first stage (open scrub habitat at the peri¬ phery of the city) are mediterranean species localized in southern Prance (low index of repartition, small symbol circle inside the sketch of Prance), all the species of stage 7 are widely distributed in Prance (calculated and drawn from Marchetti, Gallner, 1976; Blondel, Hue, 1978). cal situations as it is strongly suggested by the persistance of a truly medi¬ terranean vegetation. During the Atlantic optimum (7500 - 4500 BP), most of the lowlands and mountains up to the tree limit were mainly forested with both deciduous trees and conifers. On the other hand, mediterranean habitats such as matorrals were localized and patchily distributed according to local situations, natural catastrophes such as fires, etc. Pollenanalyses have shown that as early as the Neolithic, some 5000 years ago, the first traces of human action on the environment became apparent with discontinuities in the pollinie diagrams and apparition of domesticated cereals. Prom this epoch on¬ wards, human pressure never stopped and among the main consequences of this action, there was an increase of formations dominated by the Holm oak Que reus ilex at the expense of the broad leaf oaks and a tremendous spatial generali¬ zation of matorrals and garrigues. Moreover, modifications effected by man in the sense of habitat simplification (grazing, felling, fires) in land manage¬ ment (creation of new habitats) and in subdivision of the landscape enhanced the mosaic character of the environment. As a consequence, the history of bird faunas is characterized by a strong decrease of forest species which are the same as those of Central Europe to the advantage of more thermophilous species: mediterranean and steppic. The anthropic character of most matorrals probably explains why there are so few species in this kind of habt tat. There were probably too small in extension and too patchy for spéciation processes to take place. For this reason and contrary to plants and insects, there are very few truly mediterranean species and the bird fauna of the Mediterranean is a mixture of species of very different biogeographic origin. The softening of human pressure for one century finds expression in the return of sylvatic medio-european communities. In other words, the history of bird faunas in the Mediterranean is characterized by a periodic shifting of biotas according to the vicissitudes of the climate and to the action of man. Many points remain obscure and deserve further studies, for instance the Table 6. Ordination of the 50 species of birds breeding in the city of Marseille according to the position of the center of gravity (barycentre = black dots) of their distribution along a gradient of T stages of increasing urbanization. The horizontal lines represent the number of stages in which each species occurs. Species of mediterranean biogeographic origin are underlined. See text for explanations (calculated after JVIarchetti. Gallner, 1976) Gradient of urbanization N* 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 30 39 40 41 42 43 44 45 46 47 48 49 50 of species Lullula arborea Ri paria rupe atria Umiua excubi tor Monti co la eaxatilig Garrulue glandariuo Emberiza hortu lana CE nan the himxznica Connie corax Montioola aolitgriue ulvia oanti liana j i 'i j J Ant-hue campeBtriß A pun melba Saxioola torquata Sylvia conevicillata Âlauda arveneia Sylvia corrminie fEgithaloe oaudatue Emberiza calcmdra Pica pica Fringilla coelebs Upupa epope Laniua senator Phoenicurue phoenicurue Sylvia melanocephala CardueliB cannao-ina Luecinia megarhynchoB Sylvia horteneie fticulue canorue A tuecicapa striata Serinuo canaria Carduelie carduelia Certhia braahydactyla Parue major Hirundo ruetica Cietioola juncidio C'ttia crtn Troglodyte o trog tody tea CardueliB ehlorie Hippo laie polyglotte Sylvia atricapilla Deliohon urbioa StumuB vulgccrie Streptopelia decaoato Corvue monedula Apue apuo Phoenicurue oahruroe Paaeer domeeticue Purdue merula Columba livia 605 consequences of human impact on the patterns of distribution of species within and outside the mediterranean basin and the effect or urbanization on adaptive characters of the species. t SUMMARY Palaeobotany , paleontology as well as biogeographical and ecological cues support the hypothesis that at the end of postglacial times, during the cli¬ matic optimum (Atlantic period, 7500 - 4500 BP), the bird faunas of the me¬ diterranean area were dominated by medioeuropean forest species in the de¬ ciduous lowland and conifer montane forests which were widespread everywhere in the mediterranean basin. The truly mediterranean component of the bird communities was never important but always present even at the maximum of glacial times because of the permanent existence of patches of mediterranean matorrals in which some species evolved (i.e. genus Sylvia). The consequences of human pressure which is very strong since at least 4000 years are a drama¬ tic reduction of forests and an extension of matorrals which are only secon¬ dary formations. This found expression by a shrinking back to the north of forest species and a progression of the few mediterranean species and of the thermophilous southern species originating from steppic and semi-arid regions. s an example it is shown that the few relictual patches of old climatic fo¬ rests support bird communities which are very similar to those of central rope with no mediterranean species. Thanks to the industrial revolution in e XIX“ century and the two world wars, there is since one century a general country desertion by man. As a consequence there is a significant return of orest vegetation with its accompanying birds. This trend confirm the infor- ma ons given by palaeobotany, paleontology, biogeography and ecology .namely otas tend to reoccupy their former habitats thanks to a subduing of uman pressure. So, the history of bird faunas in the Mediterranean is a g grap lc balance between "northern" medioeuropean avifaunas and "southern" v aunas originating mainly from the steppic and semi-arid regions to the J.“1, 1° the 80Uth of the Mediterranean. At a long term this balance is Finnn climatic vi°i8situdes and/or by human impact on the landscapes, is discussed1"016 ^ Urbanlzatlon on the distribution patterns of some species ACKHOW LEGEMENTS ter^1! W°r* WSS partly financed by grants of the CNRS (Greco "Forêt médi- n enne'). I am indebted to Mrs M.C.Britton-Mella who improved the English. References AChMill °°l0nisati0n des friches par le Pin d’Alep (Plnus halenensis 1981. anS 60 bS88eS garrigues du Montpelliérais. Thèse, Montpellier, ~ ReV* Palaeobot* Ralynol., 1967, 2, p. 271-279. Blon/l t* ' Alm* SCi' P0rest*> ^76> 33.' P- 221-245. ndel J. Biogéographie et Ecologie. P. : Masson, 1979. °WorldJ* "nIn: Madlterranean-Type shrublands. Coll. Ecosystems of the ElesevJr.’igsi^ p^e^ss.0*8*1'1’ D•W,G00dall, R*L*SPecht* Amsterdam: 606 Blondel J. Ecologia Mediterranea, 1982. Blondel J. Proc. XVIII Int. Om. Cong.,1986. Blondel J., Perry C., Frochot B. - In: Estimating the numbers of terrestrial birds. Stud. Avian Biol. 6 / Eds. C.J. Ralph, J.M. Scott. Cooper Om. Soc., 1981, p. 414-420. Blondel J., Hue R. - Alauda, 1978, 46, p. 107-129. Blondel J., Isenmann P. - Guide des Oiseaux de Camargue. Neuchâtel. Dela- chaux and Niestlé, 1981. Davis A.M. , Glick Th. P. - Environm. Conserv., 1978, 5, p. 299-304. Erz W. - Ostrich suppl., 1966, 6, p. 357-363. Ferry C., Prochot B. - La Terre et la Vie, 1970, 24, p. 153-250. Marchetti M. , Gallner J. Cl. Recherches sur l'écologie des oiseaux nicheurs de la zone urbaine de Marseille. Marseille: Thèse, 1976. Meininger P.L., Mullié W.C., Bruun B. - Le Gerfaut, 1980, 70, p. 245-250. Moreau R.E. - Ibis, 1954, 96, p. 411-431. Moreau R.E. The Bird faunas of Africa and its islands. Acad. Press, 1966. Mourer-Chauviré C. Les oiseaux du Pleistocene moyen et supérieur de Prance. Lyon: Thèse, 1975. Nuorteva P. - Ann. Zool., Tenn., 1971, 8, p. 547-553. Bons A. - in: See Blondel / Eds. P. di Castri, .W.Goodall, R. L. Specht, 1981, p. 131-138. Pons A., Quézel P. La mise en place, l'évolution et la caractétisation de la flore et de la végétation méditerranéennes. Naturalia MonspelienBia, 1981. 231 p. Spitz P., Le Louam H. -In: Problèmes d' Ecologie: Ecosystèmes terrestres / Eds. M.Lamotte, P.Bourlière. P.: Masson, 1978, p.102-H°. Suc J.p. - Bull. Ass. Pr. Et. Quat., 1973, 34» p. 13-24. Triat-Laval H. Contribution pollenanalytique à l'histoire tardi- et post¬ glaciaire de la végétation de la basse vallée du Rhône. Marseille: Thèse, 1978. ■Vemet J.L. - Et. Quat. Mém. , 1972, J_, p. 329-339,341-343. Voous K. H. Atlas of European Birds. Amsterdam. Nelson, I960. Meatman L. Atlas des oiseaux nicheurs de France. Soc. Orn. Pr. Paris, 1979. 607 URBANIZATION AS A TEST OP ADAPTIVE POTENTIALS IN BIRDS Ludwik Tomialojc Natural Histoiy Museum of University, Sienkiewicza 21, 50-335 Wroclaw, Poland This presentation is a condensed version of a fuller review to be pub¬ lished separately. Therefore the literature quotations ara here restricted to a minimum. My aim is a present-day synthesis of the knowledge on bird co¬ lonizations of urban habitats, restricted to the European conditions. The generalizations offered in this paper have a tentative character being for¬ mulated intuitively though on the basis of large material from almost a hundred of towns and cities. Such an approach was unavoidable because of a limited statistical comparability of existing quantitative urban studies (Tomialojc , in prep.). There are also frequent pitfalls in the urban-non- urban comparisons, as not every piece of nominally "urban" land offers real urban ecological conditions, and, equally, not every non-urban area repre¬ sents a natural state. For fruitful urban-nonurban comparisons clear (typical or most advanced) conditions should be selected, e.g. the natural state of arboreal birds should be looked for in extensive forests resistent to the influences from the neighbouring farmland. Several studies have even failed to disclose the sharp differences which exist in nature, because they have concentrated on only a small section of a continuous habitat gradient. The c onclusioDcan be equally confusing when someone pulls together the data picked up randomly from the whole gradient of man-made and man- transformed habitats and, while analysing them, divides the material only into two ca¬ tegories: urban and non-urban or forest versus non-forest. The only promis¬ ing procedure is to split data into at least three categories; between ex¬ tremal categories the differences may appear to be significant. The comparison of extreme states, primaeval and urban, under which a spe¬ cies can thrive is of special scientific value (Tomialojc, 1980, 1982). Urban studies can offer the "experimental" conditions; this opportunity was too rarely exploited for the studies in population dynamics. The reasons for bird colonizations of urban areas - Three groups of factors can be recognized here: the attracting forces ve colonizations), the inhibiting factors and the pressures from outside (passive colonizations),. The importance of the former two groups of factors has already been we documented in literature. The disagreement occurs in the case of forced (passive) colonization. The question is: does the colonization of urban areas depend on the abundance of birds in the surrounding natural habitats? W.Erz (1966) offered a negative answer to it. Nowadays, however, the im¬ portance of "superabundant" individuals from optimal habitats for the sub¬ sequent colonization of suboptimal ones has become well recognized (Klu^ver, 951, Brown, 1969; Krebs, 1971; Watson, Moss, 1970, etc.). It remains to be checked how frequently this surplus occurs as a natural phenomenon or when 608 it results from earlier anthropogenic disturbances (Brown, 1969). The fol¬ lowing arguments speak in favour of forced urban colonizations: a) The pro¬ nounced parallelism in the patterns of geographic distribution of breeding densities in urban and non-urban populations of a species, which is observed on the continental and on the local scale (Bozhko, 1968; Saemann, 1969; Tomialojc, Profus, 1977). The successful colonizations usually start from the most dense, eury topic and expansive wild populations of a species, b) Be¬ fore a successful colonization several unsuccessful attempts were observed, which suggests that the frequency of intrusions is of crucial importance here (Tomialojc, 1976). c) High density of non-urban or "source" populations can he either primaeval and wide-spread over several habitats (as it is in the quantitative centre of a species breeding range), or primaeval and local (as it is on the margins of the breeding range, when e.g. arboreal birds penet¬ rate open landscape, the grassland, semidesert or tundra), or finally secon¬ dary and (usually) local. The last case results from man-induced reduction of forests and formation of the island-like woods. In all these three si¬ tuations there exists either primaeval or secondary superabundance of indivi¬ duals (at least males) expelled from the "source" populations by their social mechanisms. Thus, at an initial period of colonization the human settlements frequently represent a suboptimal habitat with the colonizers presumably car¬ ding the inferior competitive qualities, d) A west-east gradient of decreas¬ ing total bird density can be observed over the Europe, not only the south- north directed one (Novikov, I960; Tomialojc, Walankiewicz, Wesolowski in prep.). It is still not known to what degree it results from the natural cli¬ matic cline (oceanic-continental) and to what degree from differences in the intensity and duration of human transforming activity. The reduction of the once forest dominated cover of the Western Europe presumably yielded the in¬ crease in the local (within remaining patches of woods) bird density of se¬ veral forest species because of: a decreased predation pressure (Tomialojc, 1980 and in prep.), lowered pressure of man himself, the natural and man-in¬ duced amelioration of the climatic, chiefly wintering (Kalela, 1950), con¬ ditions, and the secondary sedentariness of the once migratory West-Euro- pean forest birds (Lack, 1947, 1966). All this allows to expect the develop¬ ment of "superabundance" in some western non-urban bird populations, which in turn could force the colonization of human settlements. The additional circumstance is that the success in invading the urban areas is more probable in a region where "source" populations have undergone first-step changes "cultural and/or inherited), which frequently were incor¬ rectly classified as the primaevally possessed "preadaptations" to man-made habitats. Our recent studies in the close-to-primaeval forest of Bialowieza clarify this interpretation (Tomialojc, Walankiewicz, Wesolowski, in prep.). The absence of deep preconditional transformations seems to be responsible for the conservatism of several East- or North-European bird populations, as well as those from some afforested regions of Western and Central Europe, or finally, as those native birds on other continents which fail to compete with the Europe»originated invadors. The "monophyletl c " of "polyphyletic" origin of urban populations Impressive expansion of some urban populations in Europe, chiefly of Tur- 3. 3aK. 981 ^Qg dus merula, laid basis for another controversy. It was believed that such po¬ pulations develop in a single town or region (Steinbacher, 1942; Heyder, 1955; Graczyk, 1959, 1963; Koskimies, 1956; Ljunggren, 1969, etc.). Closer examination yields an alternative, compromising, explanation: a) There is no firm reason to assume "monophyletic" origin of urban popu¬ lations to be a rule. The idea that there was no exchange of individuals between urban and non-urban Blackbirds or Woodpigeons has been rejected (Erz , 1966; Mul sow , 1976; Tomialojc, 1980). The eastward expansions may be even the result of a geographically expanding complex of factors itself. b) Some town-to-town movements certainly occur, at least on a local scale. They become actual expansions when an urban population continues to spread outside the species breeding range. c) Even a few immigrants from a distant city may stimulate local wild birds, by launching the imitation, to invade urban areas. Thus, only first stimulus would be transferred from town to town as a new "tradition", and a very limited actual genetical descendency can be introduced in this way. Presumably the success of colonizing individuals depends on the readiness of the non-urban populations to follow their example and to support genetically the development of a local urban population. There are several arguments for the "polyphyletic " origin of some urban populations: 1) Several distant centres of obviously independent species colonizations are known. For example in Columba palumbus these were: NW- Europe, Milano, Madrid, Bagdad (Tomialojc, 1976); in T. merula these were: NW-Europe and presumably Wroclaw which contained some urban Blackbirds as early as 1857, according to Pax 1925 ; b) The eastward expansion of urban T. merula was speeded up by known or suspected, intentional or accidental, introductions of these birds by humans (Pig. 1); c) Even in very remote places such a3 the Bialowieza village, which is situated amidst vast forests in Eastern Poland, the synanthropic very fame populations of Turdus philome- los, T. merula, T.iliacus, Krithacus rubecula, Carpodacus erythrlnus and Gar- rulus glandarius have developed independently of their West- or North-Buro- pean conspecifics. The degree of isolation between urban and non-urban hird populations This problem urgently needs special field studies. At present it can be only speculated that the degree of genetic isolation varies depending on the species, its migratory or resident status, and on the size and structure of urbanized areas. There could be three possibilities: a) Absence of isolation- Here both groups of birds interbreed freely and constitute a common local po¬ pulation. Such situation is most likely. in certain relatively form small birds easily penetrating human settlements, as well as in the migratory or nomadic species in which a significant shuffling of individuals occurs dur¬ ing the nonbreeding period. Examples include: Parus major and P.caeruleus in Central European towns, Hippolais icterlna or Musclcapa striata, b) Moderate isolation - Here two more or less distinct local populations co-occur and differ in their response to nan . However, even in classical cases of T. merula and C. palumbus some degree of interchange between urban and non-urban popu¬ lations occurs (Erz, 1966; Mulsow, 1976; Tomialojc, 1980). In vast cities the 610 ? i g. 1. The expansion and the present distribution of urban Blackbirds ITurdus merulfil 1 - areas occupied by the year X; 2 - main towns with urban Blackbirds- - main towns without urban Blackbirds; 4 - known or suggested (dashed ’ arrows) introductions of urban Blackbirds by man; 5 - species breeding nbreeding £ houid be stronger than in smaller human settlements, though no critical data are available. cJAluoçt total or total isolation - This is the case when a synanthropic population expands beyond the original species breed- ng range. The contact with wild population is very limited here or can be easily broken (Johnston, Klitz, 1977). In the case of a strong northward ex¬ pansion some species enter new climatic zones, which can reorganize their ge¬ netic pools (Mayr, 1926; Gladkov, 1958). Again, however, there are no de¬ tailed studies. Two future opposite tendencies are possible: the expanding urban areas will tend to increase the spatial isolation from wild populations. However, the in¬ creasing presence of green spaces in towns and the recent colonization of them by predators will lead to the convergent evolution of urban and rural populations. Changes in bird ecology in the course of urbanization. Theoretically, the most important changes in ecology are those which increase the individual fitness. In several cases this has been demonstrated for urban birds, e.g. 611 the urban Wooapigeons produce 4-6 times, sometimes 27 times, more young per season than their wild conspecif ics, and suffer 40-70 times lower adult mor¬ tality in their urban breeding places (Tomialojc, 1980 and in prep.). Better urban survival has also been documented in other bird species (Snow, 1958; Mulsow, 1976; Monaghan, 1979, etc.). This phenomenon yields several consequen¬ ces like high breeding density, and several differences in behaviour and eco¬ logy. They are mainly the opportunistic deviations from a modal value which dissappear if usual selection is restored. The primaeval mechanisms of population regulation or limitation seem to be replaced by a secondary set of factors playing the role in urban areas dense¬ ly populated by birds. Competition for food becomes more frequent while the pressure of natural enemies loses its limiting influence. This possibility has been too rarely investigated again (Vladyshevski j , 1975; Tomialojc, 1980, 1982). The nature of bird adjustments to urban life Knowledge of this aspects remains scanty. The attempts to attract our colleagues ethologists, physiologists and geneticists to detailed studies of this problem emerge as the most urgent task. The following possibilities deserve research: 1 ) Morpho-physiological and behavioural true adaptations (genetically fixed) ; 2) Environmentally acquired phaenotypical adjustments, mainly the beha¬ vioural ones ("cultural adaptations"); 3) Undirected deviations from the modal values resulting from the aba¬ tement of the nomalizing action of natural selection and from the increased intrapopulational tension (overcrowding). According to Dobzhansky et al. (1977) any inherited behaviour can be per- fectioned by experience, and probably any learned behaviour relies at least partially on a genetical basis. The inherited element was found or was sus¬ pected as contributing to the following urban changes: increasing sedenta¬ riness (Graczyk, 1963; Berthold, 1975, 1979) and increasing resistence to the winter climate, the tameness of urban individuals (by selection of gene¬ tically less nervous individuals or those with inherited better learning abi¬ lities), changing levels of territorial aggresiveness, smaller clutch-size, etc. For a long time it was assumed that the adaptive evolutionary changes were a very slow process. Lack (1965) expected that the bird populations thriving in man- transformed environments might not yet have adapted precisely to these new conditions. The latest studies of van Noordwijk, van Baien and Scharloo (1981, 1981a) have questioned this belief and indicated that consi¬ derable genetic changes can evolve even within a period of five generations, i.e. within a decade in the case of the comparatively short-lived Parus major. In view of this some hundred, or even thousand year old, urban populations were potentially able to develop significant genetic differences - the true ptations. For example, both the clutch size and the timing of breeding turned out to be partly genetically determined in some bird species. A iderable inbreeding of some urban populations can be expected as an ana- gu to that found in an insular population of Parus major (van Noordwijk, 612 nulit,- °’ V * 11 may tUr" °Ut that Prono“nced adaptability of western po- diffe °n! T the conservatism of some eastern ones results partly from a sldenf6" 1 6Kree of isolation between their urban and non-urban birds. Re- 8iaent werstero* f.-mo may develop the adaptations to new local conditions TelTel\Tr the T8tern ml5rat0^ °nes- Tt «*** be that the synanthropy in a . . °n CUltural adjustments, as it was commonly believed but ral differ n edeBree alS° ^ geneU°al adaPtations. The mainly behaviou- Physi l rr8s0f 6 fir8t Perl0d Can be 8Upported by bbe subsequent morpho- pected at le t ACCOrding to V1adyshevski j (1975) this can be ex¬ pected at least in the following features: - different stereotype of foraging movements of some urban birds- tendency to longer feeding flights; T h*M Cllh an parallel °f rr—“*" »” «"> OMObflaglae elementa la pl„„ga „iou»tlo, . rt.i I?””“1”8 "Uh oibeequeat cba.ga, i„ aiapsroai „ä .terrlt„_ y patterns and in morpho-physiology. pr.™.bîâ”nirdr “r‘“ >•”“•»«» obaaga, tl„, »n™' Z It “ “ ™’, *’ «O"« adapt. tioaa f.vo(r 1» j ases the cultural adjustments. o.l“L«I" P”rr “"f"' ,,kl”8 lnt° se“«“1 “d ecologt- man \ ^ estimate to what a^ent the adjustments of birds to that th%enri ;TthedePbend °" P-adaptive traits, so - to what degree^on Pe-ectioning (postadaptation), SUMMARY of bird d/°palatlons Pre sumably vary between species and towns. The nature a justments to urban life urgently needs studies. ACKNOWLEDGEMENTS I am deeply grateful to R.J.Ruller for improving my English. References P' ' AViM Bl0l0gy* 1975* 5, p. 77-128. rthold P. - Vogelwarte, 1977, 29 Suppl., p. 4_15 ozhko S.I. - Aquila, 1968, 75, p. 141-149. Brown J.l. - Wilson Bull., 1969, 8±, p. 293-329. Dobzhansky T. , Ayala P.J., Stebbins G.L., Valentine j w p , „ Francisco: Freeman, 1977. * * vodution. San Erz W. - in. Proc. 2nd Pan_Afrlcan 1966, p. 357-363. 4' Suppl* to Ostrich, 613 Gladkov N. A. - Omithologi ja , 1958, 2. P* 17-34. Gxaczyk R. - Ekol. pol A, 1959, 7, p. 57-82. Graczyk R. - Roczn. WSR Poznan, 1963, 17, p. 21-71. Graczyk R. - Roczn. WSR Poznan, 1974, 65, p. 49-65. Heyder R. - Beitr. Vogelkd., 1955, J8, p. 51-60. Johnston R.P., Klitz W.J, - In: Granivorous birds in ecosystems: the house sparrow / Eds. J.Pinowski, S.Ch.Kendeigh. Cambridge, 1977. Kalela 0. - Om. Penn., 1950, 27, p. 1-30. Klujver H.N. - Ardea, 1951 , 32., p. 1-135. Koskimies J. - Orn. Penn., 1956, 33, p. 77-95. Krebs J.R. - Ecology, 1971 , 52, p. 2-22. Lack D. The life of Robin. L.: Witherby, 1947. Lack D. - J. anim. Ecol., 1965, 34« P* 223-231. Lack D. Population studies of birds. Oxford: Clarendon, 1966. Ljunggren L. - Viltrevy, 1968, 5, p. 435-504. Mayr E. - j. Om., 1926, 74, p. 571-671. Monaghan P. - Ibis, 1979, 121. p. 475-481. Mu 1 sow R. - Hamb. avifaun. Beitr., 1976, U, p. 135-146. Van Noordwijk A.J., van Baien J.H., Scharloo W. - Netherl. J. 2ool., 1981, 11, p. 342-372. Van Noordwijk A.J., van Baien J.H. , Scharloo W. - Oecologia (B.), 1981a, 49, p. 158-166. ~ Van Noordwijk A.J., Scharloo W. - Evolution, 1981, 35, p. 674-688. Novikov G.A. - Zool. Zhum., i960, 39, p. 433-447. Pay P. Wirbeltierfauna von Schlesien. B. : Bomtraeger, 1925. Saemann D. - Der Palke, 1968, 16, p. 81-86. Snow D. - Ardea, 1969, 57, p. 163-171. Steinbacher C. - J. Om., 1942, 90, p. 342-360. Tomialojc L. - Acta zool. Cracov,, 1976, 21, p. 585-631. Tomialojc L. - p0l. ecol. Stud., 1980, 5, p. 141-220. Tomialojc L. - In: Animals in urban environment / Eds. M.Luniak, B.Pisarski. Wroclaw: Ossolineum, 1982, p. 131—1 39 . Tomialojc L. , Profus P. - Acta om., 1977, 2£, p. 117-177. ' Vladyshevski j D.V. Ptitey v antropogennom landshafte. Novosibirsk: Nauka,1975 Watson A., Moss R. - In: Dynamics of populations / Eds. Den Boer, S. Gradwell Waageningen, 1971 , p. 167-218. 614 BREEDING ECOLOGY OP THE TWO POPULATIONS OP TURDUS GRAYT AT .LOCALITIES OP DIFFERENT HUMAN INFLUENCE IN PANAMA LOWLAND Andrzej Dyrcz Wroalaw University, Hïroslaw, Poland The aims of the present study were: 1) to compare the breeding ecology of iq^°P^SPeCle0 WUh an°ther ln the European temperature zone (Dyrcz, J, 969), 2) to make a comparison between populations of Clay-coloured Robins, studied in two ecologically different localities. STUDY AREA AND METHODS Zone °arrJed °Ut Study from March t0 June 1979 in the former Panama Canal situated r°rr areaS ab0Ut 15 km apart‘ The flrst area (27-3 ha) -as uated in the summit Gardens, south of Gamboa. It comprised part of an ar¬ boretum and nursery with mown grass, large scattered trees, clumps of bushes nent:r:ral;:r°- sununit Gardens is surrounded ** *>»«* no seme- vicinity eB:;inlt^:h! other area °-6 ha) was in M°rgan,s ooen Balboa. This is a private plant nursery, with many high trees some 17ZZIT “d ClmPS °f bUSheS' SUIT°Unded by def°reSted ™a * Baarahed b°th 8tudy areaa ^veral times during the breeding season in der to find and check all Clay-coloured Robin nests, as soon as possible ter nest-building started. Eighty three active nests were found. The nest foofwir "Z** UBlnS 3 PeS°la 8Prlng bal£mCe’ ffld of nestling e collected using the neck collar method (e.g., Kluijver, 1933) p0ur in^afTiT SamPleS C°ntalning 1045 ltems were collected and preserved ln 70 /o alcohol for further analysis. RESULTS Breeding losses and fledgling success. Breeding losses were caused mainly the^in TablS Predati°n WaS l0Wer durlng season than during ny season which is in accordance with Morton (1971) results. Out of orty one occupied nests present during dry season, six (5%) were predated ( ut most of these close to the beginning of rainy season). Out of sixty terPTS PPCUpled dUring the rai^ aeaa°". thirty one (49« were preda- the b 3’°’ P< °*001)* Predatlon rate increased during the course of the breeding season, being highest at the end of the season. The rate of P ationwae not higher during the period of the highest active nest densi- 111 study areas. thi^^8etrer 1 8Pent 21 h°UrS Watchlng Clay-coloured Robin broods. During hiB time I saw two attempts, made by Variegated Tree Squirrel Sciurus va- -iÄoid^s, to rob the nest. I noticed also a rather mild aggr^T" t_ and tL , 'T"'8 t0 3 mle °f L°ng-talled Grackla (Cassldix mexican„*1 squirrel Cuckoos Playa cayana foraging close' to the nest. There were many indications that ground animals play important role as Clay-coloured Robin brood predators. The indications can be listed: 1) the Tobin's + h on flexible branches difficult to climb, than by the trunk (Table 2 3) the lower predation on nests situated on the palm-trees which have flexible eaves and trunks that are hard to climb (Table 3 , 4) the higher losses among nests situated lower (Table 4). 615 Table 1 . Reason of brood losses Predation Ants ffind Eggs unfertilized Other N of broods 37 1 1 1 1 Table 2. Percentage frequency of different nest-sites Species N of Nest site nesl:s Near trunk Other site Horizontal branch Other site Turdus grayi Turdus rnerula x2 Probability 124 15.4 84.6 296 36.2 63.8 17.7 P^ 0.005 56.4 33.8 43.6 66.2 17.1 P^0.005 1 a \1 e 3* bosses among broods of Clay-coloured Robin situated on palm- tree in comparison to losses on other plants n % broods suffering % successful 'X.2 predation Probability Palm tree 20 Other plant 65 30.0 60.0 70.0 40.0 4*39 P 0.05 Table 4. Brood losses and nest height n % broods suffering % successful X2 predation Probability Below 3.5 m 33 66.7 Turdus grayi 33.3 Above 4 m 15 46.7 53.3 0.99 N. S. Turdus merula Belov/ 1.5m 42 54.8 45.2 Above 2 m 51 76.5 23.5 3.96 P < 0.05 Bla^birrdiSrerrre ^ 8h°Uld be explaihed* I» contrast to the easy to bè B ° Jlay“coloured n°bin "esta are often in very exposed places the birds "/vT * ^ S1Sht‘ 1 think that 1 found the reason after watching and often'in ^ 7 ^ nestlinss the Parents forage not far from the nest when fôragingatoUnoticeen 1“dB°ape* S° they oan keep eye on the e*P°sed "eat Portant in the lig of T" ""'T0" °' * Predat°r‘ ” mlßht be ^ parents have „ 7 ° 7 f0ITOer observa«°a» which suggested that the P have a good chance to force out so-called small predators. 616 COMPARISON BETWEEN T.VO STUDIED POPULATIONS . 1B°th studied areas can be considered from the ecological point of view as islands of habitat especially suitable for Clay-coloured Robin breeding. But organ’s Gardens is an island surrounded by deforested area while Summit Car¬ dens is an island surrounded by forest. I think that it makes difference maxnly in predation rates. Obviously there should be more predators in Sum¬ mit Gardens than in Morgan's Gardens. Indeed, the losses from predation were much lower in the latter locality, and a breeding population density much K er (Table 5). The higher population density made feeding conditions wor¬ se, which caused more fruit in nestlings’ diet (which is supplemental food . °Wer "»«. th. varioue «1“ . » ‘ *M’ *" ““ « *■ P«.1M. temporal iluetua,l„a ia the en.iLJât."1“’“ “ “ °r avian migration strategies Migration in a general 00>, Individual makes in reepon T enC°mpa88es a11 move response to changes over time (B in space that an ^78 ; Gauthreaux, 622 1980), including maintenance, dispersal, and migratory movements. In this interpretive overview only the last two types of movement are considered, but maintenance movements (e.g. foraging movements, roosting movements) could be included by emphasizing smaller temporal and spatial scales of environmental change . The type of movement pattern shown by some or all the individuals in a population depends in large part of the frequency and amplitude of environ¬ mental fluctuations that cause variability in the absolute resource availa¬ bility of a habitat. The variability in the absolute resource availability of a habitat can be attributed to two distinct sources. One source is from Processes internal to the habitat that involve interactions of organisms with one another (biomass production and consumption), and the other source is from processes external to the habitat that involve environmental events or changes that are independent of the state of the habitat. Although the internal processes are important and can be evaluated when external proces¬ ses are more or less constant, the external processes are forcing mechanisms and strongly control internal system variability. Consequently the time scale of external events (environmental changes) favors resonant amplifi cat- on of internal events (changes in absolute resource availability) on the same time scale, with an appropriate lag. Mitchell (1976) has presented a variance spectium of climatic variability that spans all time scales of va¬ riability from one hour (10~4 years) to the age of the Earth (4 x 109 years). Three sharp peaks in the relative variance of climate occur at periodicities' day, 1 year, and 100,000 years. These three peaks correspond to the diurnal cycle, annual cycle, and the Quaternary ice-volume cycles. With re¬ ference to avian migration systems, the annual climatic cycle has by far the most important influence or internal events within the habitat. Because of the overwhelming influence of the annual climatic cycle, many habitats show distinct annual periodicities in absolute resource availabili- y. The amplitude of the fluctuations in ARA varies greatly depending on the geographical location of the habitat, and it is the amplitude of the annual uctuations in absolute resource availability that ultimately influences e migration patterns of birds occupying a particular habitat (Pig. 3). Breeding and Natal Dispersal The distribution of a population is inevitably more patchy than the re¬ source distribution, even if the resource distribution itself is random (Roughgarden, 1977). Thus dispersal enhances the chances that an individual with a low RHP in its natal habitat will find a suitable habitat in which to survive and reproduce. Because available habitats are randomly distributed, the orientation of dispersal movements may be random for the population an’ a whole. ^ n as The temporal pattern of dispersal movements is dependent on fluctuations in resource availability over time. Because birds should reproduce when their breeding habitat is at its maximum level of resource availability dispersal movements occur just prior to breeding (breeding dispersal of’ adults) or just after breeding (natal dispersal of young). The former move- 623 mox ARA 0 WWW B ARA 0 mox kZYVVVV ARA 0 rv^v ARA 0 7 . x"'' . . mox RRA 0 | ! — * i ■ i . i . i . i . WIWSWSWSWSWS ANNUAL CYCLES Fig. 3. Patterns of annual fluctu¬ ation in the absolute resource avair- lability (ARA) and the relative re¬ source availability (RRA) of a bree¬ ding habitat. S - breeding period, W - nDnbreeding period. See text for further explanation ments are spacing processes by which the available habitat is divided among potential claimants, and individuals that have found a place to settle may by ere avior or by their presence alone cause other individuals to look “J * 8e\tllng area elsewhere (Brown, 1975:50). The final distribution of the individuals in the occupied habitat is known as the dispersion pattem of the pecxee Brown, rians, 1970). Watal dispersal occurs just after breeding as e level of absolute resource availability begins to decrease in response o increased populations size and the annual climatic cycle (Figure 3A). In ho P7ST are USUally y0Ung females Wlth comParatively little resource sal P° enUal ln thelr natal habitats (Greenwood, 1980). Through disper- ey may fmd new habitats where they can avoid intense competitive in- ine- n + ®ecUre enough re source s to survive, increase their resource hold- thesp0 Sn ! +'hr0Ugh maturatlon and experience, and ultimately breed. Once luctance°feS^eB 0CCUrred “ ^dividual shows strong site tenacity (re- Z0Z the habltat)* Thua — an individual has achieved high habitir P°te««al, it is unlikely that it will have to leave a availability TiT* 3 haMtat* Unleae the absolute -source vlduai with h ; ;:s levele where survivai 18 in for that matt ^ U* breedlng habltat nonbreeding habitat the habitat (show sUe^dlîiÎy ^ " Z6r° “ WlU llkely retUrn t0 return mnv +. delity) once resource levels increase. For birds, P ^for ir ! are DOt °haracterlstlc «* dispersal, but they are quite ty¬ pical for migratory movements (Gauthreaux, 1982). Partial Migration is £rreafthK fluctuation in absolute resource availability of a habitat i great , but sufficient resources remain in the habitat during the nonbreed- o24 lug period to permit the survival of a portion of the population, only those individuals with relatively high resource holding potential can remain in the habitat (Figure 3B). Those individuals with lower resource holding potential must move to locations where they 'can secure enough resources to survive during the period of low AHA. This pattern of movement is called partial migration, and the individuals that must leave the habitat during the period of low ARA usually return to the habitat from which they departed when the level of ARA increases. Because age and sex are important determinants of resource holding potential, for most species the migrants are young, and in those species where males are dominant to females, the migrants are lar¬ gely female (Lack, 1954; Gauthreaux, 1978’ Greenwood, 1980). Complete Migration When the annual fluctuation in absolute resource availability of a breed- g habitat is so great that resource levels reach zero during the nonbreed- in* Period {Figure JC). uo ludlvlduul. ,h. J must move to locations where resource levels permit survival. In this case the distance of movement may be related to the resource holding poten- th vf “ lndlvidua1’ such that thoae individuals with the highest RHP move e shortest distance and those with the lowest RHP move the longest distance ^iiterentiai migration, but see Ketterson and Nolan, 1982). When all indi- v duals migrate approximately the same distance, RHP may detemine the rela¬ ve quality of the nonbreeding habitat. In both of these cases individuals w the highest RHP would tend to arrive earliest in the breeding habitat once absolute resource levels increase (Gauthreaux, 1978). Irruptive Migration and Nomadism is diÎferhntTUal flUCtUatl°n ln absolute resource availability of a habitat Jbi in ^ : year-t0“year (PigUre 3D)* the ^ movement from the a v M *ear-t0-*ear. Dispersal movements only may occur during s year with a minor decline in resources, but the following year when re- the deCllne Sharply’ 8 l8rge P°rW0n °f the P°Pulation must leave call»! Î 86 reS0Urces elsewhere. In the latter case the movement is alled irruption (Lack, 1954: 227-242; Bock, Lepthien, 1976), and the in- ividuais that move from the breeding habitat are those with low resource holding potential (Baker, 1978: 634-635). The alternation of movement pat- ™8 18 coupled with a circumboreally synchronized pattern of seed crop fluctuations in certain high-latitude tree species, and these fluctuations are possibly related to the quasi-biennial cycle of climatic variability itchell , 1976) that is harmonically related to the annual change in climate in theory when the absolute resource availability shows strong year-to- year fluctuations in a breeding area, site tenacity should not be adaptive and nomadism should be a more profitable strategy. This situation has been’ examined by Andersson (1980), and he concludes that nomadism in birds is a better strategy with cyclic than with random fluctuations in absolute re 4. 3aK. 981 625 source availability, and the advantage of nomadism increases with the in¬ terval between successive good yearB in an area. Biogeographic Migration ThUB far the annual fluctuation in the absolute resource availability of a habitat has been stressed (Figures 3 A-D), but fluctuations in absolute re. source availability can and do occur simultaneously over time periods of considerably greater length (longer wave lengths). The latter fluctuations affect not only the absolute resource availability of a habitat but also the nature of the habitat itself through long term successional changes (Figure 3E). Over successive generations the maximum resource availability in a habitat may steadily decline, so that eventually, the habitat is no longer suitable for reproduction. Through annual dispersal movements habitatB that are more suitable may be found, and eventually the range of the species will shift so that long term faunal migrations will track long term floral migrations (Gauthreaux, 1980, 1982). DIFFERENTIAL MIGRATION AND RELATIVE RESOURCE AVAILABILITY (RRA) Thus far the emphasis of this paper has been on the absolute resource availability (ARA) within a habitat and how a pattern of decline in ARA in¬ fluences the pattern of movement of a part or of the whole population from that habitat. In this section I wish to emphasize the relative resource availability (RRA) to an individual and how this may influence the migration strategy of that individual. The relative resource availability is that portion of the absolute resource availability within a habitat available to an individual because of its resource holding potential relative to that of other individuals occupying the habitat or location (Figure 3F). Even when the absolute resource availability within a habitat is high, for* an indivi¬ dual with relatively low resource holding potential, relative resource . :*'S ■'•0W* figure 3F illustrates the relative resource availability ( RA) to an adult and to a young bird of the year over successive annual c matic cycles. During the first nonbreeding period (W) the RRA declines only slightly for the adult, but for the young of the year the RRA declines sharply. During subsequent breeding and nonbreeding periods the difference between the adult and the maturing immature decreases, so that after several annual cycles, no difference exists. This pattern is fundamentally milar to that found in a number of seabird species (Dunnet et al., 1979). The patter can apply to other species as well (e.g., Cannet Pula bassana. dite otork Cl coni a ciconia, Osprey Pandlop hallaetus. Manx Sheaiwaters Puf- naS p^fflnUR) . but depending on the specie's, the number of annual cycles nee e before an individual acquires a high resource holding potential and ence a high relative resource availability will be less. The spatial extent of movements of individuals from a breeding location k an ®sta1::ionB of the differences in relative resource availability at thl n? l0Catl0n* Por bird species during the nonbreeding season ounges individuals in the population are distributed the farthest away 626 P 1 g* 4* The age dependent migration distances of Harring Gulls in relation to monthly climatic changes (modified from Moore, 1976) from the breeding location and the adults are closest to the breeding lo¬ cation. The distance from the breeding location that an individual overwint¬ ers is determined by its resource holding potential in relation to the abso¬ lute resource availability of a location such that it will have a high re- ^atlve resource availability for survival. Even though an individual may have a low resource holding potential, if it can find a suitable habitat with few or no individuals with higher resource holding potential, it will enjoy a relatively high resource availability and be able to survive. Thus individuals with high resource holding potential can move relatively short istances from breeding locations (or not at all) and secure sufficient resources for survival during periods of reduced absolute resource avaiiabi- lity* but individuals with low resource holding potential may have to move considerable distances before they can find a location where the relative resource availability is high enough for survival. The data in Figure 4 are from a month-by-month analysis of banding returns of Herring Gulls Lams ar- ^Ptatu-g from the Great Lakes °f ihe United States (Moore, 1976). In Novem- er when climatic conditions are still relatively mild, all age classes are recovered near the breeding grounds. As winter progresses, the age classes show greater segregation with maximum segregation occurring in early Februa¬ ry. Once climatic conditions improve in March all age classes move toward the reeding grounds, because the amount of absolute resource availability within the breeding areas is increasing. The axis of movement should generally fol- °w the climatic gradient and be perpendicular to the isotherms, because of the relationship between the severity of climate and absolute resource availability. CONCLUS ions The amount of resource in a habitat ultimately controls the number of in ividuals that can stay in the habitat, but the fluctuations in the amount of resource influence the number of individuals that must move from the habitat Thus, the spatial movements of birds, whether maintenance, dispersal, or migratory, are evolutionary strategies that express the expectation of tempo¬ ral changes in conditions at the present locality. It is the nature of the 627 temporal changes that dictates the type of spatial movement that an Individual will show. Temporal changes in resources can be attributed to processes within the habitat (resource production and consumption, habitat-organism feedback) and to processes outside of the habitat that involve environmental changes that are independent of the state of the habitat. Because external processes are forcing mechanisms, the time scale of external events (environmental changes) favors resonant amplification of internal events (changes in absolute resour¬ ce availability and all the covaring biological events) on the same time scale with an appropriate lag. Thus, habitats may fluctuate asynchronously in favorableness or absolute resource availability because of stochastic bio¬ logical events (different population levels in different habitats), but syn¬ chronous changes in favorableness or absolute resource availability may also be superimposed on these habitats by widespread, deterministic climatic events (daily and annual climatic cycles). When habitats fluctuate in favorableness asynchronously, a dispersal strategy will be adaptive, but when synchronous fluctuations in favorableness occur, a migration strategy will be adaptive. The type of migration pattern (partial, irruptive, short- or long-distance) shown by a species will depend on the amount of decrease in the absolute resource availability within the habitat. The individuals that Btay (if any) and the individuals that leave during periods of reduced resource availability within the habitat will de¬ pend on certain attributes of the individual and the absolute resource availa¬ bility within the habitat. The individuals with high resource holding poten¬ tial and high dominance status will perceive high relative resource availabi¬ lity and will be able to remain in a habitat with low absolute resource availa¬ bility. Those individuals in the population with low resource holding potential (and consequently experiencing no relative resource availability) will have to move as far as necessary to locate a habitat where they too can experience a relative resource availability that will permit survival. Although differences in the resource holding potential of the individuals in a population have been emphasized as being important proximal factors in the incidence of migration, the same factors may be applied to differences m migratory behavior between species. O'Connor (1981) has shown that mig¬ rant-resident differences are significantly related to body size differen¬ ces, such that the larger species show a high competitive ability to exploit resources during the breeding season and that the smaller migrant species are primarily exploiters of breeding season resources under-exploited by a resident population held down by winter mortality (see also Herrera, 1978). Thus, asymmetries in RHP such as size may be as important to species diffe¬ rences in migration as it is to individual differences in migration. SUMMARY rabmtv îf °^g!" 0Sn C0ntr01 the Spatial di^ibution and relative favo- indLcui tC1, +haWtatS “* by a0lnS 30 lnflUence directly or climitL ihf dlreotlon “d distance of the movement patterns. Likewise anges can dictate the heterogeneity of habitats in time (length 628 of favorable and unfavorable periods, and length of time a location remains suitable) and influence the phenology (timing and rate) of the movements. Thus by tracking climatic and meteorological changes through movement, birds can maximize the expectancy of finding a new suitable habitat or returning to a suitable habitat after a period of unfavorability. Depending on the rate and nature of environmental changes and the life span of the individuals, several types of "migration" patterns can be realized (e.g. , zoogeographical migrations mediated through dispersal, partial migrations, irruptive move¬ ments, and short- and long-distance seasonal migrations). The diversity of avian migration strategies can be related to the diversity of environmental changes that occur over different temporal and spatial scales. ACKNOWLEDGEMENTS I wish to thank Anna Ross, Paul Hamel, Harry LeGrand, Jr., and Jeffery Beacham for assistance during the preparation of this paper. Their patience in listening to my ideas and offering helpful suggestions have improved the paper in a number of ways. This paper was completed while my research on rd movements was being funded by the Electric Power Research Institute. erences Anders son M. -J. Anim. Ecol., 1980, 49, p. 175-184. Baker R.R. The Evolutionary Ecology of Animal Migration. N.Y.: Holmes and Meir, Inc., 1978. Bock C.E., Lepthien L.W. - Amer. Nat., 1976, 1_H)> p. 559-571 . Brown J.L. The Evo.lution of Behavior. N.Y. ; Norton, 1975. Brown J.L., Orians G.H. - Ann. Rev. Ecol. and Syst., 1970, T_, p. 239-262. Dunnet G.M., Ollason J.C., Andersson A. - Ibis, 1979, 121, p. 293-300. Gauthreaux 3. A. Jr. - In: Perspectives in Ethology. Vol. 3 / Eds. P.G. Date- son, P.H. Klopfer. N.Y. : Plenum Press, 1978, p. 17-54. Gauthreaux S.A. Jr. - In: Animal Migration, Orientation, and Navigation / Ed. by S.A.Cauthreaux, Jr. N.Y. : Academic Press, 1980, p. 103-174. Gauthreaux S.A. Jr. - Behavioral and Brain Sciences, 1981, 4 (3), p. 441. Gauthreaux S.A. Jr. - In: Avian Biology. Vol. 6 / Eds. D.S.Faraer, J.R.King, K.C. Parkes. N.Y.: Academic Press, 1982. Greenwood P.J, - Anim. Behav., 1980, 28, p. 1140-1162. Herrera C.M. - Auk, 1978, 95, p. 496-509. Ketterson E.D., Nolan V., Jr. - 1982, 99, p. 243-259. Lack D. The Natural Regulation of Animal Numbers. Oxford: Clarendon Press 1954. Maynard S.J. - Amer. Sei., 1976, 64, p.' 41-45. Maynard S.J., Parker G. A. - Anim. Behav., 1976, 24, p. 159-175. Mitchell J. Jr. - Quaternary Res., 1976, 6, p. 481-493. Moore F.R. - Bird-Banding, 1976, 47, p. 141-159. O'Connor R.J. - in: Animal Migration / Ed. by D.J.Aidley. Cambridge: Cambrid¬ ge Univ. Press, 1981, p. 167-195. Parker G.A . -J. Theor. Biol., 1974, £7, p. 223-243. Roughgarden J. - Oikos, 1977, 29, p. 52-59. 629 WHY DO BIRDS MIGRATE? INTER AND INTRA SPECIFIC COMPETITION IN THE EVOLUTION OP BIRD MIGRATION CONTRIBUTIONS PROM POPULATION ECOLOGY Stephen D. Fretwell Texas Bird Observatory Association, 1201 Moore Avenue, 1703, Portland, Texas 78374, USA There are several proposed reasons why birds migrate. The most widely ac¬ cepted, according to a recent, excellent review by Gauthreaux, is that bird migration is an adaptive response to changing environmental conditions , and/or changing biological needs (e.g. between reproductive and non-reproductive seasons). I accept this basic explanation as my starting point, and go on to consider specifically which of all the possible changes that birds face in an annual cycle are most important in causing or maintaining migration. FORMAL STATEMENT OP THE ADAPTIVE MIGRATION HYPOTHESIS First, we will consider the migratory habit as an Evolutionary Stable Strategy as defined by. Maynard-Omith. Thus, we consider how natural selection works to maintain the migratory habit. We suppose that individuals in the mi¬ gratory population vary in their propensity to migrate (for example, in dis¬ tance covered), but that extreme deviations (such as a bird that migrates only half of the way to the breeding or wintering grounds, landing outside the normal range of the species) are simply unsuccessful in survival and re¬ production, and are eliminated from the population. '.7ith them are eliminated any factors (especially genetic factors) that led them to make their deviate migration. Then bird species that migrate keep on migrating because indivi¬ duals that do not carry out a normal migration are selectively eliminated. An alternative way of viewing this hypothesis supposes that if the popu¬ lation ever did exist as a resident population in either the non-breeding or the breeding grounds, then extreme deviations from this pattern of residency which led individuals to migrate according to presently existing habits would be selected for. That is, if the population were residents, any individuals which migrated would have a higher survival or reproduction and so would in¬ crease in representation in the population. Since this argument assumes that such 'extreme deviations" would occur in both populations, and would (at least sometimes) have a genetic basis so that it could be passed on to later generations, it follows that: 1 . Natural selection against such deviates maintains existing migratory habits. 2. Natural selection for deviates resulted in the development of existing migratory habits. DEVELOPING TESTS OF THE ADAPTIVE MIGRATION HYPOTHESIS v'/HY DO BIRDS FAIL TO SURVIVE AND REPRODUCE? In order to test the adaptive migration hypothesis, we will benefit from having Gome idea about what causes migrant birds to be less successful when they migrate in an extremely different way from present patterns (or fail to 630 migrate at all). This Is a matter explored in a different area of ornithology, namely that part concerned with the regulation of population by the balance" birth and death rates. I offer the following questions and answers. 1. Question: '/my are birds nesting in some places more successful in rais¬ ing young that birds nesting in other places? Answer: The major factor affecting reproduction for most land-bird species nest predation. Pood supply is also involved, but appears to be of only minor unportance since predictions based on the hypothesis that food supply 8 llmltlne are not as generally confirmed. According to studies by Skutch and Lack, nest predation varies substantially (from 90% on small open nesting species in the tropics, to 0 % in some hole nesting species in boreal regions). redation is usually rather high (a review by Nice indicated 50% or more for ’ most species in regions with high densities of species). I and others have s own it to be density dependent. Curiously, nest predation also seems to be a good correlate with other variables that affect production, such as clutch s ze. Clutch size in birds varies as much or more than predation, and seems a trat to reflect the importance of food supply to breeding birds. However, ere are few clear demonstrations that food supply affects clutch size to a’ egree necessary to explain the great variations in the variable, while birds metimes do lay extra eggs when food supply is especially high, huge in¬ creases or variations in food supply usually lead to only minor increases in ° U Ch* 0nly 80me arctic, predacious birds show a remarkable increase in clutch with an abundance of food. However, predation correlates very well (inversely) with clutch size, utch’s data show that in the tropics, species with nests experiencing 90% Predation rates often lay only one or two eggs, while other species, with si¬ milar feeding habits, breeding in tbe same forest, at the same time, but which only experience 60%-70% predation, because they nest in protected sites ave twice the clutch size. Nice shows that this holds in temperate regions as well, where hole-nesting species have half the predation and twice the c utch of open-nesting species. One interesting comparison clearly suggests ° m® that Predation might be a causative variable affecting clutch size. In central Kansas, Loggerhead Shrikes (Lanius ludovjcianus ) and Eastern Meadow- arkö (oturaella magna) breed together in prairies dotted with scattered ora trees and cedars. The birds are the same size, feed on similar (often entical) prey (but in different manners), and nest at about the same time he meadowlarks nest on the ground, and dome over their nests so that they * are quite well protected from the elements, and might be thought to be simi¬ an to a hole-nesting species. The shrikes nest up in the shrubs, and have an open nest. However, the meadowlarks suffer high predation rates (60% or so) and only lay three to five eggs per clutch. The shrikes have a low cre¬ ation rate (20%) and lay six to eight eggs per clutch. Another interesting note about clutch sizes is that there are cases where ney don't vary. Ghorebirds (Charadrlifoiroes ) almost all lay four eggs., although the great diversity of feeding methods and the wide geographic and habitat ranges occupied would surely imply huge differences in food resources 631 “E ~ - ~ - These observations do not exclude fend 1 1 y affecting nesting success, but they do lead uT generally nept protection, * ' place moat emphasis on MeL“; r“ r? ‘r°” pi“- '••*• «• *"*•-> ■— Pl.=.. (e.g. boreal Eon.."“ "0n-b”'a"' “““« *»“ «Pd. living 1„ other HÄ.Ä’^sr.rr* in “““ *u”iv*1 •* f’”* ■— ■«- in high latitude zones. However’ I rZalTl " ^ m°rft eXtreme - - - Who Will feed and who will Bt0Pe othe 4 UP contests to decide — ; r **• — -*■ *”-• “■«I “Inner. or, »tndl,d ,, ,h , J ' ! * *” lo“ ” "‘'«I. ouch o ponies have ">» consequently mom .tint •«.. or survival mfl 7 ‘ T‘”™ “»*•«*»'■ »*>• near ««.1 « 1». z,ZTl "r : r °r »*°» .» consequently, It seems tnooL .T “ *iM*" — * -t~* comp-tt to™. (due to high predation rates □^nestsT'3]' exa“ple’ havs reproductive rates leads both +n f -* plus 3 8table environment, which result, the surXlTafidulT8tand-t°re ea8lly defended terrltortes* As a Prolue, .or. young, .Ä.^. «Cr^f “ — against the younger more difficult lGo th. 7TI .?* generation makes defense more difficult +Û ’ instability .of the environment have to "scramble" mor r ’ ^ a*lltS °ann0t be SU°h "wlnners" and — surren t JlZZZu S.™ **’ *" t0 Place , according^ the \2 lability ' ' • *CcldentB varles Place ferable, according to Cccham ^ environment, naturally is pre- that move about a lot p 7 ‘ *B ^ rather plaU8l-bl*. since birds results r„rrjn , „7 " T ca-.to.to* predation ..,1 •elf is . ttm“ “ U”f“,Utl "*«»«). »»» cold weather co.“”"."; nra^L^T""“111 *h*‘ ‘ *” .cra.ble ol dominant individuale. bi®nifi l:antly ’«creases the survival rate ■the time When a young bird , ’ i!'^ do not Increane with age past would et fg,et given that lesrnln "t reecïng .duck , 1054) which Is not what one »te climate L“ , ' «* ‘■P»'*»». ». that a seven-year-old resident Parid^r rr16 ^ ^ °nC W°Uld SUpp0Se familiar with lt„ clOT„a„”‘, *"*"•*• ”°“lb <- ~~ ror-rood Idea, 1 ' " tft auPPOrttng the more complex competition- 632 Thus, we have from avian population ecology some fairly plausible suggesti¬ ons as to why a deviant migrant might fail to be successful. A wintering bird of a tropical-temperate migrant species, which failed to migrate, but which instead stayed to breed in the wintering area, would produce far fewer young than its conspecifics, even if mating problems were solved, because its nests would be taken by predators. During the next winters, while it might be quite dominant and established on the wintering grounds, the flood of young birds produced by the migrants would create such scramble competition, that the resident deviant would likely die before it had (finally) reared a successful brood to replace itself. Tn a tropical-temperate migrant species, a bird which had bred in a tem¬ perate zone habitat, but which then failed to leave in winter, would become a temperate resident. This bird would probably fail to survive the winter, not because of cold per se, or climate, but because it would either not find enough to eat or it would be so harassed by dominants of other species that ' it would succumb. Thus, variations in nest predation in the breeding season and food limi- ation in winter might maintain existing migratory patterns, at least for land birds. HOW, THEN, DID MIGRATION EVOLVE? SOME SCENARIOS... Before considering these scenarios, we need to note an asymmetry between winter limitation by food and breeding limitation by nest predation. While both are density dependent, there is a greater potential for community ef¬ fects in nest predation than there is for food. Nest predation becomes den¬ sity dependent because a higher density of nests results in more successful predators, which, in turn, leads to greater predation pressure in the region 0t the neBt- Most nest predators- (snakes, jays, weasels), have generalized broad diets, including all sorts of prey besides birds nests, which they only specialize on when they chance upon a high density. As a result, when one species is dense, it attracts predators to most other species nesting with lt> Thle means that competition is extremely diffuse in the community and each species' success is highly dependent on the overall community density. competition for winter food, however, commonly allows more specialization, especially in stressful times. Newton, for example, showed that wintering -SEiorillidne ate entirety different kind of foods during the coldest parts of winter. mhus, most species seem to have some resources that they and they alone feed on, due to morphological, or behavioral adaptations. Such spe¬ cies, while being affected by overall community levels, also seem -to have a base level related to an independent resource that is less, or not, affected by the overall community density. How, consider a tropical resident population evolving migration. Such a resident species might have a deviant individual (and its mate), which left to breed at some higher latitude where, for some reason, there is less pré¬ dation on nests. This individual would produce more young than if it had stayed to breed with its conspecifics, but might suffer a loss in survival due to difficulties in regaining a territory among the resident birds. Howe- 633 21’ till mighVr0dUOe en0Ugh more young t0 overcome any loss in survival Then their “'v -in°Urred the aMllty to control resources by contests - - replace themselves. The residents would decline This dern e would not raise survival rates, because the migrants would take up the ’ only I sin0"1??“186 nßBtlng SUCCeSB rateB> SlnCe the being th Par ° the troplcal breeding community would not much affect t“" a"siw' **■ — »*«. r„,st:z:: co n:ric::r havo not ■<°i-a — «*« likely to have migrating deviants come home with enough extra vouL +ft 'zt::z:~ “t in th™ — -- ™ °;r * temperate rLiden, deviates to winter at lr>wPT, i , S lgratlon to the tropics would send higher the, a ,e " b ““ L” I 'h6 °V"<“11 "» »»ever, i, leTblt d«« *«*.«. tone. Invade , tronle.t • " 11 ° *” "“'h ”*8™"« individual« could a. critical L ‘ “L TC"”r“1^ ‘ “ food 1« There are few commonly mediated through contests. of the apparenUyWhCha -"T 3 C°Uld taka ^a«tage eurvival ra 3 re ^ lB communities If the higher tive cent" Th ^ mill: y.rS0Clated With bSlng the **“■» 1« a competi- However r:fTt!ln + ’ Seem8’ ^ l0ee «“* contests. if it did survive better than^t6^ ^ & t0 the troplcs- and denoy , then it could t h ^ malntaln^ their resi- success would r " in a" P«*™«*. and a normal breeding crease, until nesUng Lc ” lnCreaee f°r Senotype. It would in¬ residents would find th iCeSS ” the teraperate habitat was reduced, and the the residents would deÏ LV"' ' *° ^ thelr "**"» ap*™en uäs :: ** “ -** - — **• • — winter food would incren 3 °n’ Blnce’ as the residents declined, their resident population would'remain VÎhT ^^Tîh ThUS’ S°mft r<5mnant °f ^ ing into a migrant sneclen / 36 °f +'he troplcal resident evolv- by the migrants outweighed 'tvT *** ^ lncrease ln nestlnS success enjoyed residents, the migrants win ^ enBfUs °f contest competition enjoyed by the tlnctlon. The migrant«8 £ “T* 100r“” “d « «- competition , which lovrere the'° * î I”°re“lne' s*aai»lï Increase the aoramble tropical reject« Zlvef h °f ',V", ”"b" °f ^ ■*««... ™. community density and not to ind^n m°rtallty responds to total species no increase In th.îr oê Î lMi'M ■*“*•« d«»«*, -onld find little „ competed, .„d thfl “ “L? “ S°* ™*» "»»“ 1«.* ». out- Thus scramhi resident genotype would become extinct. • ramble competitors moving to higher latitudes to breed are able to 634 take advantage of the greater 'reproductl ve rates there, while euch species moving to lower latitudes to winter will he unable to enjoy the higher survi¬ val rates there. The higher reproductive rates are available to all species and individuals; the higher survival rates are available only to the winners of competitive contests which normally are established residents. These scenarios produce a significant conclusion. If the hypotheses from population ecology are confirmed, and if the idea of adaptive migration is true, then the evolution of tropical- tempe rate migrants from tropical species is likely, but the evolution of such migrants from temperate species is un¬ likely. The evolution of equator-ward migrating species from temperate species can occur, but it is most likely to involve partial migrants moving into ni¬ ches where contest competition is minimal (e.g. disturbed habitats). The individual migrants which leave such populations will likely be subordinants with low potential survival in the temperate region of residency. Let me summarize the prediction from these scenarios: 1 • general, there ought to be a correlation between contest and scramb¬ le competition in winter, and migration habit, so that scramble competitors migrate more f requently(vig. 1). 2. Tropical resident species in indefensible non-breeding season niches will evolve complete temperate-tropical migrants. Temperate resident species will either not evolve temperate-tropical migrants, or will evolve incomplete migration systems (Fig. 2). 3. In migrant species, deviants tending towards residency from normal migration patterns will result in wintering individuals with lower survival, or breeding individuals with increased nest predation (Fig. 3). I close by making some observations that challenge this perspective on migration. There are many cases in North American birds where one species replaces another in their migrations. For example, the Hermit Thrush (Catha- rug_guttatus.) winters in the Southeastern U.S., and migrates to the Northern U’S* and Canada to breed. It is replaced in summer over most of its wintering range by the Wood Thrush (Hylocichla musteline), which winters in Couth Ame- * rlca. if it ls advantageous for a thrush to migrate from the Coutheas.t to Canada to breed, why does the iVood Thrush not keep on migrating and join the Hermit Thrush? And, if it is not advantageous, why does the Hermit Thrush leave? * There are many cases like this. Winter Wrens (T. troglodytes ) winter in tne central U.S. where House Wrens (T.acdon) breed, but do not winter. Yellow- throated Warblers (Dendroica dominica) only breed' in southeastern pine fo¬ rests where iellow-rumped Warblers (I'.coronata ) only winter. The simple ex¬ planation that tempts us is that these birds are seeking a uniform climate and are migrating to keep from adapting physiologically to the extremes they would experience if they were residents. However, if such climatic adaptation were important, one would expect, say, Bergman's Law to apply. However, the ./ood Thrush is larger than the Hermit Thrush, and the House ’Iren is larger than the ./inter vYren. Thus, the cold-climate species is smaller, not larger. 635 Costs -- & Benefits 0 L opt L max l.ntitude Pig. 1. Costa and Benefits of migration The costs (solid lines) and Benefits of migration are shown, plotted against latitude, with the origin being the wintering grounds. The costs, in increased death rates, stem from two sources: the. costs of actually travelling, which increase with distance traveled, and the costs of reduced contest- competitive ability on the wintering grounds. The benefits increase with latitude, but at a diminishing rate, and would actually decrease at very high latitudes. The intersection of costs and benefits set an upper limit (I'raax) to the latitude it would be advantageous to migrate to, but the difference between benefits and costs (hatched area) reaches a maximum ^opt* this determines the best latitude a migrant might achieve. Species which invest heavily in contest competition always pay more than they gain when they migrate, and so will always be resident (L ^ “ 0) . Species which have no contest competition will migrate to rather high latitudes, since the only costs they pay are those of travelling. Mixed contest-scramble competitors would stop at lower latitudes P i g. 2. Population consequences of migration The migratory habit will increase the population size on both the winte¬ ring and the new breeding grounds, increasing death rates (costs) d', and decreasing birth rates b', until b=d between lmin and 1 . Because the dif¬ ference between benefits and costs will be greatest at lQ.t, the greatest breeding population will occur there, before benefits are*" reduced to equal costs At present, I am working on a model for migration strategy which predicts the extent of migration for differing levels of contest and scramble compe¬ tition. My work so far draws on the idea that not only does the kind of com¬ petition affect whether or not a species migrates, but also affects how far 656 P 1 s* 3. Competition between a migrant into a region, and a resident spe¬ cies already there Prom the previous figure, the migrant into a region lowers the birth rate there by b' , causing residents in that region to lower their populati¬ ons until their birth rate equals their death rate. The benefits-costs cur¬ ves for these other species (2) are shown, similar to those of Pig. 1 , with the origin displaced to the higher latitude where they are resident (02^* Other species (2) with a lesser investment in contest competition, hence, a lower slope to their costs curve, will find it advantageous to migrate even further north it goes. The model suggests that the Wood Thrush and House Wren are more con¬ test competitors than the Hermit Thrush and Winter Wren, and that the benefits of migrating within the temperate zone do not outweight the costs for the for- mer species, but do for the latter. Also, the northern species may have been forced into migration by the invasion of their breeding grounds by the more southern species, which would lower reproductive rates there. The larger size of\ the southern species is interpreted as a reflection of their greater in¬ vestment in contest competition. Of course, these speculations need to be developed so that predictions are generated and tested before they can be regarded as very plausible. SUMMARY Two contrasting hypotheses explaining why some birds migrate and others do not involve competition and physiological flexibility. The competition hypothesis argues that fluctuations in community carrying capacity force 3ome birds to leave areas where they bred to winter elsewhere, and some to leave areas where they winter to breed elsewhere. The physiological flexibi¬ lity hypothesis argues that some birds develop narrow physiological require¬ ments but high efficiencies, and. migrate to keep in a constant environment, while other birds develop flexible physiological requirements, trading off efficiency, to take advantage of a broader niche. In thi3 report, I develop the competition hypothesis to the point that it can be readily tested, and offer several tests of predictions. I conclude that while most temperate bird species are winter limited, competition for nesting sites, both intra and interspecifically, is the major selective for¬ ce behind migration. K BIBUQTKÈC mm . «. sic. c^.;- 637 HABITAT PHENOLOGY AND SPRING MIGRATION SCHEDULES Tore Slagsvold University of Trondheim, Royal Norwegian Society of Sciences and Letters, the Museum, Erling Skakkesgt. 47A, N-7000 Trondheim, Norway INTRODUCTION Most temperate species of birds live in seasonal fluctuating environments, subject to annual changes in climate and photoperiod, and in food quality and quantity. The birds have developed a timing programme which adjust the onset of important events, such as migration, breeding and the moult, to the most favourable periods of the year. The reproductive cycle exihibits the greatest degree of environmental dependence. Migrant birds therefore have to time their return to their breeding areas in spring so as to be able to utilize to the full the spring flush of food, for reproduction. A balance exists between op¬ posing selection pressures: firstly, selection for as early an arrival, as pos¬ sible, because this will increase their chances of occupying an optimal breed¬ ing territory and nest site and of getting a mate (von Ilaartman, 1968). This is probably the reason' why the males of many species return before the females (Schüz, 1971); secondly, the opportunity for early breeding, which seems to be favourable for the raising of more offspring, of larger broods, and of several successive broods, increases the survival rate of the juveniles and allows more time for the preparations for the autumn migration (Perrins, 1970; Mac- Lean, Pitelka, 1971; Hussell, 1972; Sokolov, 1975). Early departure also helps to minimize the competition for food in their wintering areas (Lack, 1968). On the other hand, there is a concomitant risk of the renewed onset of low temperatures, rain and snowfall later in spring which may greatly reduce the availability of food, with widespread bird mortality in consequence (Nisbet, Drury, 1968; Sealy, 1975; Ojanen, 1979). An early arrival to the breeding grounds may also involve a depletion of those stored food reserves which should have been available for reproduction, e.g. for egg production by the females. A relationship seems to exist, for instance, between clutch size and the con¬ dition of the females on their arrival in spring (Picula , 1976; Silverin , 1981 ) . In studies of bird migration much attention has been paid to the factors underlying the start of the migration from the winter quarters and also to those v/hich stimulate or suppress the rate of migration itself; e.g. such fac¬ tors as physiological changes induced by day-length variation, weather condi¬ tions and food availability. Few studies have been paid to the variation in the arrival times of birds in relation to the environmental conditions which they encounter on arrival. In the present paper I shall concentrate attention on the latter subject. ENVIRONMENTAL VARIABILITY AND BIRD ARRIVAL AND BREEDING TIMES In temperate and arctic regions plants grow and fruit only at certain times of the year, and the biomass of invertebrates also changes seasonally (Dani- levskii, 1965; Bradshaw, 1974; Lieth, 1974). In addition, these phenophases are subject to annual displacement in different geographical areas due to fluctuations in the physical environment. According to the "bioclimatic law" of Hopkins (1938) there is a general re¬ tardation in season of four days for each degree of northern latitude in the 638 northern hemisphere, for every five degrees of eastward longitude across a continent, and for every 100-125 m of altitude. One would therefore expect to find that bird breeding times will be displaced in a similar manner (Im- melmann, 1971). This does not, however, seem to be true. Baker (1938) conc¬ luded that there is a general tendency for the egg-laying season, for all kinds of birds, to start later and later the further north one goes, to the extent of some 2-3 days per degree of northern latitude (1.8 days for passe¬ rines). The culmination of the egg-laying season in general is only retarded by about 1.4 days per degree of latitude. The latitudinal retardation in the breeding times of passerine birds in Fennoscandia also seems to be less than that of the developmental stages of the vegetation (Slagsvold, 1975, 1977), although exeptions are found (Slagsvold, 1975, 1976a). Observations on the timing of the annual phenophases of different plants (time of leafing, flower¬ ing and fruiting), i.e. phenology, enjoys a long tradition among botanists in many countries, as also observation of the arrival dates of the different birds from their spring migration does among ornithologists. However, the in¬ terrelationships of these two types of phenological studies have seldom been studied. I have made such a study of the phenological data for Norway, and came to the conclusion that the latitudinal and altitudinal retardation in the arrival dates of birds is less than the retardation in the developmental stages of the vegetation (Pigs. 1, 2, 3); viz. only about 6 days in arrival time for evei^r 10 days retardation in vegetational development (Slagsvold, 1976b). The development stages of invertebrates are also closely related to the environmental temperature and to the stages of vegetational development. Thus, the latitudinal retardation in the arrival times of the birds would also seem to be less than the equivalent retardation in the timing of the va¬ rious phenophases of the invertebrate fauna in the same areas (Slagsvold, 1976b, 1977). It should be noted that the northward progression in the dates of the first appearances of birds is far less than that which is theoretical¬ ly possible, based on recorded flight speeds (von Haartman, 1956; Salomonson, and that the arrival times on their breeding area are not directly re¬ lated to the actual distance travelled (Stresemann, 1948), although there is a tendency for the winter ranges of late-returning species to lie further south (Hemmingsen, 1951; Weydemeyer, 1973). As seen from Pig. 2, the phenophases of the plants which start growing early on in the year are more retarded than those which commence growth la¬ ter, and that such a tendency also holds true for the arrival dates of the birds studied. Although the arrival dates of the majority of the bird species In the Norwegian Btudy showed less latitudinal retardation than that found for the phenophases of the plants, exceptions were found, particularly among "early" arrival birds such as the Thrush Turdus species. In Finland, for in¬ stance, the spring arrival of the Song Thrush Turdus philomelos is said to follow the 0° isotherm, which is about two weeks before the local snowmelt oommences (Siivonen, 1939). The time of the snowmelt probably represents the Primary limitation to the possible arrival times of many early -arriving spe- cles of birds (Stresemann, 1948; von Haartman, 1956; Irving, I960; Pikula, 19?1; Slagsvold, 1977; Mikkonen, 1981a, b), although in Sweden the Skylark Alauda arvenai s has been reported as arriving contemporaneously in localities 639 F 1 g. 1. Five gradients in Norway for which hira • , °f Plant phenophases have been compared arrival dates and dates "Ärr r:iientinus* mo)- The a— - - — of ice cover Is a pie f ?" °f areaB’ — the breakup rants (Irving i96o- win +7 the arrlval «mes of aquatic mig- nrving, i960; Wallentinus, 1970; vSisänen, 1974). less relarJI ^»laMon^ DOrmally return late lB ™>t only those which return earlv th Creas 5 northern latitude and altitude than holds true both in the south^ SUbJeCt to less anrmal variation. This well-known phenomenon (e g Jx ^ “ °f ^ <** a”< a times of the "early" specie h ! ’ 1970; Wetdemeyer, 1973). The arrival weather conditions by h «“ ^ *° * lnfl—ed by tba 1967 ; Schüz 197i-’weid ^ ^ air temperature in Particular (Salomonsen, theirmiSr ; ? ;rI SUCh Sp-laa ^ -en reverse Pendent upon the environ! Ü ï T arrlVSl are "0t arrival, but are also relat I C°n ltlons prevailing in the breeding areas on migration and to those which ° t °SS 10 the areas traversed during the sprin * late spring the X II T T ** ^ ^ air temperature is generally higher, and the birds may be 640 birds during the spring migration (closed circles) and in plant phenopha- ses (open circles) along the coast of Norway. The gradients referred to are those indicated in Pig. 1. The respective regression lines are added, a solid line for bi.rd arrivals and a dashed line for plant phenophases (from Slagsvold , 1976b) iöss susceptible to fluctuating temperatures while on migration (Slagsvold 1976b). The time elapsing between arrival and egg-laying is hort in "late" seasons at hieb latitudes and altitudes, as well as for late arriving birds (Slag- Ev°ld, 1975, 1976b, 1977). For a late-arriving species, the Pied Flycatcher j-jcedula h.ypoleuca. not only is a low correlation between arrival time and habitat phenology typically recorded (von Haartman, 1956), but also a rather low correlation between the time of appearance of the first birds to arrive in the spring and the onset of egg-laying, in particular at high latitudes (Slag- 8vold, 1976a). The males of this species arrive before the females, and it is the arrival time of the latter, of course, which determines the onset of breed¬ ing. It is noteworthy that whereas the annual variation in the date of the °hset of egg-laying by the Pied Flycatcher in Finland is only slightly corre¬ lated with the ambient air temperature and habitat phenology, it is closely correlated with the onset of egg-laying, and thus of female arrival, much further south, viz. in Dresden in ■ GDK (Slagsvold, 1976a). In comparison, ihe time of egg-laying by those bird species which arrive early (the "weather ®fgrants") seems to be much more closely correlated with habitat phenology and 5-3ai<. 981 641 F i g. 3 '.s for Fig. 2, but in b the plain interval in days between the respective events is used, without being previously divided by the dif¬ ference in latitude, because altitu¬ dinal difference!: also exist between areas (from " lags void , 197 the annual variation in the arrival and breeding times the tfrantS 18 1608 at hlgh than at low latitudes. It would thus appear that tit ri1"6 °f thS °nSet °f sprins 18 more Predictable at high than at low la- b “ de8’ in the 8ense that the duration of the optimal period for arrival and ing seems to be shorter. According to Alerstam and Hogstedt (1980) this awaCUmStanCe peraiits th08e birds which breed at high latitudes to winter far migrati*1 thU° Pr°Vlde an exPlanation for the phenomenon of "leap-frog ten;1 haVe" 8tUdied the Mnual variation in the date on which a certain air annmaatUre l6Vel 18 attained for the flrst t5me ln spring, and also the svold Variatl°n in the dally air temperature on certain days in spring( filag¬ ree i 1976a)* 1 found that these annual variations were not of a lesser deg- tem ater on rather than early. on in spring. However, even though the air is ^eratUre£I I" lute spring also varied consideralby , the mean temperature cat eVertheleas then higher end so the chances of such climatic disasters as ustrophic late snowfalls are reduced. ' liliY 1)01:3 3UCH A LOW CORRELATION EXIST BETWEEN THE ARRIVAL TIMES 0i BIRDS AND THE STAGES OP HABITAT PHENOLOGY? °h theiBPring mieratiorl of birds appears to be. so timed that the birds arrive r breeding grounds at almost the earliest possible moment at which they o43 have a reasonable chance of surviving there (Lack ,1960). It therefore seems reasonable to expect to find that the northerly displacement in the arrival dates of the birds will parallel the annual and geographical displacement of the onset of spring. However, this does not seem to be the case for all spe¬ cies of birds, and why not? Hour do they manage to survive after such a phe- nologically speaking, early arrival in a "late" year and at higher latitudes, despite the low temperatures and -the retardation in vegetational development, and how even to defend their territories, build their nests and lay eggs? This is probably an adaptation to the delayed and short spring season in such "late" years and in such "late" areas. But why then do they not also arrive correspondingly earlier in their more southern breeding areas? The northern populations depart from their winter quarters some time after the more southern populations have already left. The former thus remain lon¬ ger in areas subject to high air temperature and advanced vegetational deve¬ lopment, and their winter quarter may be situated farther south as well. The northern populations may therefore be in a better physiological condition at the time of arrival on their breeding grounds even though they have to fly further to reach them. Studies of body fat content may provide an answer to the question whether the birds belonging to the more northern populations are able to replenish their fat reserves on arrival or en route north (flagsvold, 1976b). For inotance, there may be relatively more food available the further north one goes, when similar stages of vegetational development are compared, because of longer days and of a lower diversity of the food items (von Haart- man, 1973; Levin, Turner, 1977). This may be a food supply ouch as plant seeds from the preceding year, which is not directly dependent upon air temperature and the requisite vegetational and invertebrate development in spring. Arthro¬ pods produced in the previous year may also he of great importance. Ac one progresses northwards the life-cycle type of many insects changes, with con¬ sequences in their appearance times and availability (Bradshaw, 1971), ',7eid- emeyer (1973) has suggested that the annual variation in migrant arrival dates should be less for bird species which rely mainly upon seeds left over from previous seasons, or on aquatic foods, than for insectivorous species (Nisbet, Drury, 1968; bealy, 1975). However, over a 50-year observation period, he found that in fact the reverse was true. For each explanation provided for the early arrival of migrants in nort¬ hern areas, the question must be answered: why is this not also the case for bird populations breeding in the more southern, due to natural selection for early arrival? In these areas, too, the birds return from wintering In warmer areas, with a more advanced state of vegetational development, and they also have a shorter distance to travel. Plant seeds and aquatic foods may also be available there on arrival. Detailed feeding and food supply studies are the¬ refore called for. The relatively early arrival and breeding of birds at high latitudes seems in particular remarkable, because food supply constraints have frequently been put forward as setting a limit to an early, otherwise favou¬ rable, onset of breeding (Perrins, 1970; Jones, Hard, 1976; Drent, Daan,1980). An early arrival of birds at high altitudes, phenologically speaking, is more easily understandable from an energetic standpoint than an early arrival at high latitudes, since the birds inhabiting mountain areas can rapidly retreat 644 to lower-lying localities if the weather subsequently turns bad. A possible explanation for the low degree of annual variation found in the arrival dates of "late-returning" species is that at this time of year enough food is gene¬ rally available for survival, even if the weather subsequently turns bad (Salomonsen, 1967). However, further feeding and food supply studies are re¬ quired and a further question reguires an answer, viz. why don't these spe¬ cies, at least some individuals or flocks, arrive et a still earlier date if it is so favourable, ultimately, to settle early and start breeding early? Consequently, the time of arrival and the onset of breeding of birds may not be as early in spring as the energy demand would allow. Other biotic fac¬ tors, such as predation pressure and the degree of intraspecific compétition are also important. For instance, the rate of nest phedation is generally higher early on than later on in the breeding season, and is also higher at low than at high latitudes (Elagsvold, 1982). In other words, the selection pressure for an early onset of breeding may be relaxed in more southerly com¬ pared to more northerly areas (Byrkjedal, 1980). On the other hand, the com¬ petition for breeding territories is probably more severe at southern lati¬ tudes, and this will favour those birds which arrive early. Thus, whereas the main problems for birds which occupy breeding areas at low latitudes are nest predation and competition for territories, nest sites and mates', the impor¬ tant factors for those breeding at high latitudes are food availability and the length of time available for any successful breeding at all to take place. In Norway the various migrant bird species arrive in about the same order each year, and also from place to place, forming separate temporal groups (e.g. species 7-15 in Pig. 5). A close relationship exists between arrival time, food availability and food requirements. Species which arrive early utilize the seeds which have been left over from the previous year, those ar- • . » riving late are typically insectivores. However, there appear to be certain exceptions which call for further study. Studies of congeneric species in Particular are to be recommended, e.g. the Chaffinch Fringilla coelebs and the Brambling F.monti fringilla (Slagsvold, 1979; Mikkonen, 1981a, b), as well as the different Phylloscopus species. Por instance, among those birds which are mainly insectivorous, the Chiffchaff P.collybita arrives relatively early on in spring in Norway, whereas the closely-related Willow Warbler P, trochi- ius arrives two or three weeks later (Pig. 5) but starts egg-laying only a tew days later than does the Chiffchaff (Haftorn, 1971). SUMMARY The spring migration of birds appears to be so timed that the birds arrive on their breeding grounds at almost the earliest possible moment at which they have a reasonable chance of surviving there. It therefore seems reaso- Pable to expect to find that the annual and geographical displacement in the arrival dates of the birds will parallel the annual and geographical displa¬ cement of the "onset of spring". Por many species this does not seem to be the case, and this raises questions of proximate and ultimate character: how do the northern populations manage to survive and breed after such a, pheno- 1ogically speaking, early arrival at high latitudes, and why do not the southern populations of birds arrive earlier, due to strong natural selection early arrival and breeding? Probably, answers to the questions are found 645 Dramrrwn Bergen Tropdhjhrn Mosjoen S Varang«r 59.7°N 6Q4°N 634°N 6&fl°N 605°N 2 ll. 4,5 3 6 36 16 22,23 19 24 22,23 25,26 20 29,30 5^32 2125 34 i 33 33 35 36 31,35 9,10,11,15,16 8 18 12,15 13 17 14 5 20 18 8 ns 21 &23 ft 26,29 28 10 33 m27 33 34 31,33 i 34 35 29 Fig. 5. The arrival dates of migrant passerine from Haftorn, 1971) Species 1. Sturnus vulgaris 2. A lauds ar van tit 3. Plactrophanax nivalis 4. Turdut marula 5. Fringilla coaleba 6. Acanthia cannabina 7. Erlthacua rubacula 8. Mota cilia alba 9. Turdut philomalos 10. Turdut pilaris 1 1 . Turdut iliacua 12. Cardualis tpinut 13. Prunalla modular it 14. Turdut torquatus 15. Fringilla montllrlngllla 16. Phylloacopus collybita 17. Embariza schoeniclua 18. Anlhus pratensis 19. Oenanlha oananlha 20. Flcadula hypolauca 21 . Phoanicurut phoenicurut 22. Ant hut trivial la 23. Pbyllotcoput trochllua 24. Embarixa hortulana 25. Saxlcola rubatra 26. Hlrundo rustics 27. Motacllla flava 28. Lutcinia svacica 29. Dalichon urbica 30. Phylloacopus sibilatrix 31 Sylvia atrlcapilla 32. Sylvia curruca 33. Mutcicapa striata 34. Sylvia communia 35. Sylvia borln 36. Hippo lait ictarlna birds in Norway (data in the differences in basic conditions for reproduction: whereas the main problems for birds which occupy breeding areas at low latitudes are nest pre¬ dation and competition for territories, nest sites and mates, the important factors for those breeding at high latitudes are food availability and the length of time available for any successful breeding at all to take place. References Alerstam T., Hogstedt G. - Omis Scand., 1980, p. 196-200. Baker J.R. - In: Evolution: essays on aspects of evolutionary biology / Ed. by G.R. de Beer. Oxford, Univ. Press, London; New York, 1938, p. 161-177. Berthold P. - In: Grundriss der Vogelzugskunde / Ed. by E.Schüz. Parey, Ber¬ lin und Hamburg, 1971, p. 257-299. Bradshaw W.E. - In: Phenology and seasonality modeling (Ecological Studies 8)/ Ed. by H.Lieth. Berlin; Heidelberg; NY : Springer-Verlag, 1974, p. 127-137. 646 Byrkjedal I. - Omis Scand., 1980, 22* p. 249-252. Danilevskii A.S. Photoperiodism and seasonal development of insects. Edin¬ burgh; Londons Oliver and Boyd, 1965. Drent R.H., Daan S. - Ardea, 1980, 68, p. 225-252. Haartman L. von. - Soc. Scient. Penn. Arsbok, 1956, 33B, p. 1-23. Haartman L. von. -Omis Penn., 1968, 45, p. 1-7. Haartman L. von. - In; Breeding biology of birds / Ed. by D.S.Famer. Natl. Acad. Sei., Wash., D.C., 1973, p. 435-437. Haftorn S. Norges Fugler. Oslo: Universitetsforlaget, 1971. Hemmingsen A.M. -Proc. Int. om. Congr. , 1951, 22, p. 289-294. Hopkins A.D. - U.S. Dept. Agr. Mise. Publ., 1938, 280. p. 1-188. Hussell D.J.T. - Ecol. Monogr. , 1972, £2, p. 317-364. Högstedt G. -Omis Scand., 1974, 5, p. 1-4. Immelmann K. - In: Avian Biology / Eds. D.S.Pamer, J.R.King. N.Y.: Academic Press, 1971, p. 341-389. Irving L. - U.S. Natl. Mus., Bull., I960, 217. p. 1-409. Jones P.J., Ward P. - Ibis, 1976, V18» p. 547-574. Hack D. - Auk, I960, 77, p. 171-209. Lack D. - Oikos, 1968, 2!» p. 1-9. Levin D.A. , Turner B.L. - In: Evolutionary ecology / Eds. B. Stonehouse, C. Perrins. L. : Macmillan Press, 1977, p. 215-222. Lieth H. - In: Phenology and seasonality modeling (Ecological studies 8)/ Ed. by H. Lieth. Berlin; Heidelberg; New York: Springer-Verlag, 1974, p.3-19. Maclean S.P. Jr., Pitelka P.A. - Arctic, 1971, 24, p. 19-40. Mikkonen A. - Omis Penn., 1981a, 58, p. 78-82. Mlkkonen A. - Omis Scand., 1981b, 22iP* 194-206. Myers J.P. , Pitelka P.A. - Arct. Alp. Res., 1979, 22* P* 131-144. Nisbet I.C.T., Drury W.H. Jr. - Anim. Behav., 1968, 16, p. 496-530. Ojanen M. - Omis Penn., 1979, 56, p. 148-155. Perrins C.M. - Ibis, 1970, 222» P- 242-255. Pikula J . - Zool. Listy, 1971, 22, p. 165-180. Pikulaj. _ zool. Listy, 1974, 23, p. 163-174. Pikulaj. - zool. Listy, 1976, 25, p. 65-72. Salomonsen P. Pugletrae kket og dets Gader. Kobenhavn: Munksgaard, 1967. Schuz E. Gmndriss der Vogelzugskunde. Parey, Berlin; Hamburg, 1971. Sealy S.G. - Auk, 1975, 92, p. 528-538. Siivonen L. - Suomal. elain - ja kasvit. Seur. van. elain. Julk., 1939, 7, P. 1-289. Silverin B. - Omis Scand., 1981, 12, p. 133-139. Slagsvold T. - Norw. J. Zool., 1975, 23, p. 213-218. Slagsvold T. - Omis Scand., 1976a, 7, p. 127-145. Slag avoid T. - Norw. J. Zool., 1976b, 24, p. 161-173. Slagsvold T. - Omis Scand., 1977, 8, p. 197-222. Sokolov L.V. - Zool. Zh., 1975, 54» P« 257-265. St re semann E. - Var Pagelvarld, 1948, 7, p. 1-18. Maisänen R.A. - Omis Penn., 1974, 52. P« 61-84. Wallen tinus H.-G. - Var Pagelvarld, 1970, 2 £, p. 160-178. Weydemeyer W. - Condor, 1973, 75, p. 400-413. Williamson K. - Bird Study, 1975, 22, p. 143-164. 647 SOCIAL BEHAVIOR AND FORAGING ECOLOGY OF NEOTROPICAL MIGRANTS Russell Greenberg Department of Zoological Research National Zoological Park" Smithsonian Institution Washington , 'D.C. 20008 , USA INTRODUCTION Migrant birds often move between havitats that are dramatically different in structure and food resources. They must function efficiently to raise young in food rich breeding habitat , as well as survive possible food shor¬ tages in winter habitats. How birds are adapted for the seasonal occupation of different habitats can best be approached by examining the foraging be¬ havior, social behavior, and morphology of individual species. The large num¬ ber of migrant species, each with its unique combination of winter and breed¬ ing distributions and food habits, provides a rich pool to explore for cross- seasonal correlations. I have selected neotropical- migrant passerines as the focus of a review of the social organization and feeding ecology of species on their wintering grounds. I will focus on the relationship of sociality and foraging and how these relate to other aspects of species' biology. SOCIAL ORGANIZATION Eaton (1953) first noted the consistent difference in social behavior of different Bpecies of migrant parulids in Cuba. Since his initial observations, many other observers have noted the species-specific diversity of winter so¬ cial organization in neotropical migrant birds (Skutch, 1957; Willis, 1966; Lack, Lack, 1972; Rappole, Warner, 1980; Greenberg, 1979, in press; Hespen- heide, 1980; Morton, 1980; Tramer, Kemp, 1980). Most neotropical migrant species characteristically occur solitarily ; the occurrence of single species flocks is a relatively uncommon phenomena found commonly in about a dozen species (Table 1). The intraspecifically gregarious migrants span the taxonomic categories including Tyrannldae , Vlreonidae , Tur- didag , Paralidae. Icteridae . and Fringillidae . For most of these species flock size is small ( < 20 individuals), but some groups may be huge, such as those found in Tyrannus tyrannus (Morton, 1972). The most intriguing Bocial grouping for migrant birds is the non-breeding male/female pair (Table 1). The occurrence of pairs of neotropical migrants was discovered recently (Leek, 1872; Morton, 1980; Greenberg, Gradwohl, 1980) , although winter pairs are well known for certain partial migrants in the tem¬ perate zone (Lack, 1943; Zahavi, 1971; Davies, 1977). The mechanism of pair formation is not known and the handful of species that are known to occur in winter pairs remains too disparate to support a simple adaptive hypothesis. Formerly, the occurrence of territorial defense was a noteworthy event (Schwartz, 1967; Emlen, 1973), but it is now viewed as a dominant theme in the life of neotropical migrants (Rappole, Warner, 1980; Morton, 1980). Ter¬ ritoriality, however, is a rubric that covers at least two distinct phenomena in wintering migrants: the long-term defense of a patch of habitat through an entire winter; and the short-term defense of a specific resource. 648 Table 1. Winter social behavior of some neotropical migrant passerines Single species flocking Tyrannus tyrannus Morton, 1972; Fitzpatrick, 1980; Leek, 1968 Hylocichla ustalata Willis, 1966; Rappole and Warner, 1980; Vireo olivaceus Morton, 1980 Vermivora peregrins Gri8com, 1932; Skutch, 1957; Tramer and Kemp 1979; Morton, 1980 Vermivora ruficapilla pers. obs. Protonotarea citria Morton, 1980 Dendrolca coronata MacArthur, 1958; Wilz and Giampa, 1978 Dendroica palmaram Eaton, 1953 Dendroica tigrina pers. obs. Dendroica castanea Greenberg, 1979; in' press Dendroica striata DeSchauensee and Phelps, 1978 Icterus spurius Hamilton, 1961; Morton, 1979: Rappole and Warner, 1980 Pheucticus ludovicianus Rappole and Warner, 1980 Passerina cyanea r* Rappole and Warner, 1980 Pairs Protonotarea citrea Morton, 1980 Dendroica cerulea pers. obs. ^ilsonia canadensis Greenberg and Gradwohl, 1980 Piranga rubra Leck, 1972 Icterus galbula Leck, 1972 Vireo solitarius Morton, pers. comm. Vireo phildelphicus ? Tramer and Kemp, 1980 Can occur in flocks Long-term territoriality will probably be found to be a dominant social system of migrant birds when many more studies of color-marked individuals are completed (Rappole, Warner, 1980; Greenberg, in press). Short-term de¬ fense has attracted considerable attention in the "notes" section of ornitho¬ logical Journals. Species that otherwise are not territorial, and in fact are often intraspecif ically gregarious, often display short-term defense. Consider that the phenomena has been reported in the following species also listed in Table 1; Vemlvora peregrins (Morton, 1980; Tramer, Kemp, 1979), Dendroica tirrrina (Kale, 1967; pers. obs.), D.coronata (Woolfenden, 1962), Djcastanen (Morton, 1980), D.palmarum (Wunderle, 1978), Icterus galbula (Schemske, 1975; Cruden, Hermann-Parker, 1977). FORAGINIG BEHAVIOR Most species of migrant birds that breed in forests and woodlands search for insects that rest on foliage (Holmes et al., 1979). A smaller number of species forage in the leaf litter for soil arthropods (Turdidae) or sally to oaputra aerial insects (Tvrannidae) ; one species searches the bark of trees i0r insects (Mniotilta). During the non-breeding season, most migrants remain foliage insectivores. 649 Table 2. Omnivorous species of neotropical migrant passerines Tyrannus tyrranus Morton, 1973; Fitzpatrick, 1980; Willis, 1966; Rappole and Warner, 1980; Morton, I960 Hylocichlus ustulata Willis, 1966; Leek, 1968 Vireo olivaceus Morton, 1980 Vermivora peregrine Griscom, 1932; Skutch, 1957; Tramer and Kemp, 1979; Greenberg, 1980; Morton, 1980 Vermivora ruficapilla pers. obs. Protonotaria citria Morton, 1980 Dendrolca coronata Dendrolca palmarum MacArthur, 1958; Wilz and Giampa, 1978 Dendrolca tigrina pers. obs. Dendrolca castanea Morton, 1980; Greenberg, 1979; in press Piranga rubra Leek, 1972 Piranga olivacea pers. obs. Icterus spurius Morton, I960 Icterus galbula Schemske , 1975; Crudend and Hermann-Parker, 1977; Leek, 1974 Pheucticus ludovicianus Morton, pers. comm. Passerina cyanea Rappole and Warner, 1980 but both Inter- and intraspecific variation in niche increases. In some birds this increased variation involves shifts in what microhabltats are searched, and in other species this consists of feeding on new kinds of food, particularly fruit and nectar. Migrant birds can be placed into three categories based on their use of fruit or nectar: restricted insectivores (0% omnivory); partial omnivores (0-10%); omnivores (>-10%). Most specieB remain mostly or wholly insecti¬ vorous and the known omnivorous species are listed in Table 2. Whereas behavioral plasticity has been considered the hallmark of migrant bird behavior (Morse, 1971; Willis, 1966), it may be a rather rare strategy of migrant birds to be extremely generalized. If attention is paid to the foraging ecology of birds in one community (such as in Rappole, Warner, 1980; Willis, 1966; Tramer, Kemp, 1980; Lack, Lack, 1972; Greenberg, in press), migrant birds show a degree of specialization comparable to resident birds. A few species of migrants stand out as being extremely generalized in where they search for food. No species displays this plasticity more conspicuously than Dendrolca coronata which forages in a broad range of habitats and sub¬ strates. On the other extreme, a few species of migrant birds regularly spe¬ cialize on certain typically tropical microhabitats. Helmitheros vermivora and Vermivora chrysoptera in lowland tropical forest forage out of dead cur¬ led leaves that hang in the forest understory. In highlands, V, chrysoptera specialize upon foraging from epiphytes (Powell, 1980; pers. obs.). These species may forage out of dead curled leaves in the Temperate Zone to a lesser degree. 650 THE RELATIONSHIP OP FORAGING BEHAVIOR AND SOCIAL BEHAVIOR The diversity of social systems of wintering migrant birds reflects a diversity of foraging strategies. The correlation is similar to the one found hy Crook (1965) for Ploceidae. The species that occur in single species flocks are those species that are most omnivorous (X^ = 31.5. d.f. = 2, P^.001). While these omnivorous species occur in flocks, they often aggres¬ sively defend certain fruiting and flowering trees. These species are best characterized as having labile social organization (Tramer, Kemp, 1979). The dichotomy in social organization of omnivorous versus more insecti¬ vorous migrants is probably related to the defensibility of home-range suf¬ ficiently large to contain a winter's food supply. The patchy and ephemeral nature of fruiting and flowering trees probably requires an animal to range over a large area to use these resources throughout the winter. It may re¬ quire birds to move large distances. Insectivorous migrants can presumably survive the winter on a particularly good patch of habitat provided that conspecific interlopers are excluded. Single species flocking is a possible, hut not necessary consequence of the large overlapping home ranges of the omnivorous species. The important point is that the omnivorous species, freed from a commitment to a long-term territory, can show greater lability in social organization. CORRELATES OP WINTER DIET The most profound and readily identifiable ecological division among wintering migrants is their degree of omnivory. Finding features of the bio¬ logy of migrant species that allow us to predict how omnivorous it will be on the wintering grounds should prove of particular interest. The following generalizations can be advanced: Size: Larger species of migrants have a much greater chance of being om- biyorous than smaller species. Of the migrant species over 15 grams (for which some data are available) 11 of 17 are omnivorous of migrants weighing *5 grams or less, eight of 40 are omnivorous (X2 « 4.8, d.f. = 1, p ^c.,05). Phylogenetic Relationships: Certain taxonomic classes of migrants consist of restricted insectivores. Within Parulidae, for example, most of the genera (Wilsonia. Orporornis. Sciurus, Mnloltllta, Helmltheros. Setophaga) contain species that probably never take plant products. Dendrolca and Vermlvora have numerous species that at least occasionally eat fruit and nectar. While a dependence upon plant foods may require a large shift in winter social behavior, the low-level UBe of fruit often occurs in basically in¬ sectivorous specieB of tropical birds. A complete restriction to insectivory ®ay be based on some rigid psychologically— based restraints. Breeding Habitat: Within Dendrolca and Vermlvora most of the omnivorous species are restricted boreal forest breeders (V. peregrine, D.tlgrina. D.cas- D. corona ta and D.palmarum) ; three of these species are major budworm species (Kendeigh, 1945). These patterns suggest that a highly omnivorous diet Is selected by spe- cies unable to persist as strict insectivores during the non-breeding season; a) Large species should be less likely to subsist on insects because large 651 active tropical arthropods are probably disproportionately more difficult for less specialized insectivores to capture. b) Birds restricted to boreal forest, and particularly those species that depend heavily upon superabundant budworms, are probably species less able to efficiently glean insects from, broad-leafed foliage during the non-breeding season (Greenberg, 1979) CONCLUDING REMARKS As homogeneous as most temperate forest passerines are during the breeding season, both ecologically and socially, they show great variation during the non-breeding season. However, the divergent winter behavior of some species, such as the waxwing-like flocks of Tyrannus, and "beach-combing" of Dendroica coronata, belie the more typically conservative behavior of most neotropical migrant passerines. Most species remain insectivorous, exploiting microhabit¬ ats similar to those used in the breeding season. Many species defend small territories throughout the winter. Perhaps the driving force behind the increased variation in foraging behavior in the winter months is the break-down of the monogamous territorial social system (in most species) and the increase of alternative food sources during the winter months, particularly in tropical areas. The omnivory-insectivory dichotomy is fundamental to the diversification of winter ecology of migrant species. Why some temperate zone insectivores remain insectivorous, while others become more omnivorous is a critical ques¬ tion to answer both in an ultimate and proximate sense. Since most small fruit are relatively easily procurred, omnivory may allow some successful temperate-breeding insectivores to winter in areas where they are unable to subsist on insects. ACKNOWLEDGEMENTS My field work on migrants has been supported by Prank M. Chapman Pund, the Smithsonian Tropical Research Institute, the Museum of Vertebrate Zoology, the Friends of the National Zoo, Phi Beta Kappa, the John Tinker Foundation and the Center for Latin American Studies at University of California, Berkeley. I have been assisted in all aspects of my work by Judy Gradwohl. Ref erences Bond J. - In: The Warblers of North America / Eds. L.Griscom, A.Sprunt. N.Y.: Devin-Adair, 1957, p, 257-263. Crook J. - Symp. Zool. Soc. London, 1965, p* 181-218. Crudend R.W., Hermann- Parker S.M. - Auk, 1977, 94, p. 594-596. Davies N.B. - J. Anim. Ecol., 1977, 46, p. 37-57. Deschauensee R., Phelps W. A guide to the Birds of Venezuela. Princeton, N.J. Princeton Univ. Press, 1978. Eaton S.W. - Wilson Bull., 1953, 65, p. 169-174. Emlen J.T. - Wilson Bull., 1973, 85, p. 71-74. Pitzpatrick J. -In: Migrant Birds in the Neotropics: Ecology, Behavior, Distribution and Conservation / Eds. A.Keast, E. Morton. Wash., D.C., Smithsonian Press, 1980, p. 67-78. 652 Greenberg R., Gradwohl J. - Ibis, 1980, 122. p. 509-512. Greenberg R. - Auk, 1979, 96, p. 756-766. Greenberg R. - Biotropica, 1981, Jjî» P* 215-223. Griscom L. - Bull. Amer. Mus. Nat. Hist., 1932, 64, p. 3-24. Hamilton T. - Am. Nat., 1961, 95, p. 121-124. Hespenheide H. - In: Migrant Birds in the Neotropics: Ecology, Behavior, Distribution and Conservation / Eds. A.Keast, E. Morton, Wash., D.C., Smithsonian Press, 1980, p. 227-239. Holmes R. T., Bonney R.E. , Pacala S.W. - Ecology, 1979, f>0, p. 512-520. Kale H. - Auk, 1967, 84, p. 120-121. Kendeigh C.S. - Auk, 1945, 62, p. 418-436. Lack D. The Life of the Robin. L.« H. P. and G.Witherby, 1943. Lack D., Lack J. - Living Bird, 1972, JJ., p. 87-95. Leck C.P. - Bird Banding, 1968, J9, p. 318. Leck C.P. - Auk, 1972, 89, p. 842-850. Leck C.P. - Auk, 1974, 21» P* 162-163. Macarthur R. - Ecology, 1958, 39, p. 599-619. Morse D. - Annual Review of Ecology and Systematics, 1971, 2, p. 177-200. Morton E. - Auk, 1971, 88, p. 925-926. Morton E. - Ann. Miss. Bot. Garden, 1979, 66, p. 482-489. Morton E. - In: Migrant Birds in the Neotropics: Ecology, Behavior, Distri¬ bution and Conservation / Eds. A.Keast, E. Morton. Wash., D.C., Smithso¬ nian Press, 1980, p. 437-466. Powell G. - In: Migrant Birds in the Neotropics: Ecology, Behavior, Distri¬ bution and Conservation / Eds. A.Keast, E. Morton. Wash., D.C., Smithsonian Press, 1980, p. 477-485. Rappole J., Warner D. - In: Migrant Birds in the Neotropics: Ecology, Behav¬ ior, Distribution, and Conservation / Eds. A.Keast, E. Morton. Wash., D.C., Smithsonian Press, 1980, p. 353-395. Schemske D. - Auk, 1975, 92, p. 594-595. Schwartz P. - Living Bird, 1964, J, p. 169-184. Skutch A. - In: The Warblers of North America / Eds. L. Griscom, A.Sprunt. N.Ï.: Devin-Adair, 1957, p. 275-286. Timken R.L. - Wilson Bull., 1970, 82, p. 184-188. Tramer E„, Kemp T. - Auk, 1979, 96, p. 186-187. Tramer E., Kemp T. - In: Migrant Birds in the Neotropics: Ecology, Behavior, Distribution, and Conservation / Eds. A.Keast, E. Morton. Wash., D.C., Smithsonian Press, 1980, p. 285-296. wHlis E. - Living Bird, 1966, 5, p. 187-231. Wllz K., Giampa V. - Wilson Bull., 1978, 90, p. 566-574. Woolf enden 0. - Auk, 1962, 79, p.713-714. Wunderle J. - Wilson Bull., 1978, 90, p. 297-299. Zahavi A. - Ibis, 1971, 113. p. 203-212. 653 THE ROLE OP HEREDITY AND OP COLLECTIVE AND INDIVIDUAL EXPERIENCES IN SEASONAL DISTRIBUTION AND MIGRATION OP BIRDS Yu. A. Isakov Institute of Geography, USSR Academy of Sciences, Mpscow, USSR Every Bird species can be regarded as a complex population system charac¬ terized by relatively stable links with the areas they populate, these links being consolidated not only eco-morpho logically , but also via inherent col¬ lective stereotypes of behaviour, as well as collective and individual ex¬ perience. The most essential feature of large geographical populations of avian species is a common major direction of seasonal migrations. This feature is one of the elements of the species behaviour stereotype as has been proved by a number of well-designed experiments on avian orientation. The inherent directions of avian migrations are invaraibly Justified biologically as the most rational routes from nesting to wintering sites. These routes are pre¬ sented diagrammati cally in Pig. 1. Examples of large geographical populations of birds in the USSR are provided by: Atlantic populations, migrating west¬ ward and southwestward; populations migrating southward, i.e. to the Near East and India; those migrating south-eastward, i.e. to China and Japan and others. Many of the above-mentioned gross populations may be further speci¬ fied and divided into several minor populations. For several duck species such a study was performed by T.P.Shevareva (1968, 1970), and for a number of other birds - by A. A. Ki st chinsky (1978, 1979). It should be noted that the natural conditions of the nesting areas of birds pertaining to a single geographical population may differ considerably. The next hierarchical grade in the species population structure is re¬ gional geographical populations. Their common feature is similarity of eco¬ logical conditions in the breeding areas. At the same time, the major routes of seasonal migrations, and partially, their major trends may differ within the nesting area occupied by the same population depending on the ecological conditions favourable for migration. Examples of regional geographical po¬ pulations are furnished by some waterfowl species of the Pre-Caspian Lowland, lake forest-steppe of the Trans-Urals, Western Siberia, Northern Kazakhstan, etc. Each of them is largely independent. Their common feature is primarily their individual behaviour stereotype adapted to the particular conditions of respective breeding areas. In addition to the above-mentioned categories, local populations should be mentioned. They emerge in localities favourable for a particular species and are normally isolated and separated from one another by localities that are less favourable ecologically. Such are large tracts of well-preserved mature forests among young stands, steppe plots among ploughed up land, isolated lakes, built-up areas and their neighbourhood,, sea bays. The popu¬ lations of such localities are consolidated through the so-called phylopat- ry, i.e. development of common behavioural responses, which are rigidly adapted to the life in a particular area. Such populations are maintained through a merge of several such groups into a common flock or several flocks, and also through following seasonal migration routes determined by 654 P i g. 1. Division of species range into distribution regions of major geo¬ graphical populations. The nesting zone is cross-hatched, while zones of migration and wintering are clear. Arrows show major directions of seasonal migrations characteristic of large geographical populations similar ecological conditions. Thanks to that, the experience acquired by individual population members is passed on to the population as collective experience. The sharper the contrast between the areas occupied by local populations end surrounding landscapes, the more independent such populations. The most vivid examples are provided by nesting colonies of the Rook, Heron, Swift and other species, as well as by local populations which also develop in birds nesting singly. One of the factors promoting the formation of such po¬ pulations is spring songs of males. They not only communicate that the ter¬ ritory has been taken up by a nesting couple, but also that the given area is favourable for nesting. According to N.B.Birulya (I960) these acoustic cues are conducive to the regularity of nesting couples dispersal in nu¬ merous species throughout the area suitable for nesting. Of interest are also some particular sites that are regularly used by individual couples or small groups as nesting ranges and places for feeding and rest on migration routes or in wintering areas. These sites are charac¬ terized by a set of ecological conditions which are favourable for the given species. Many such sites are used by birds for many years running. As an il¬ lustration, in 1949, V. V.Nemtzev found and mapped in the Darwin Reserve, 16 nesting ranges of the Crow, which were located within 7 kilometres from the Reserve's research station. They all were located on the; edge of a forest, commonly on the banks of a reservoir. In 1982, 15 nesting couples oi the Crow were recorded there, out of which number 10 had been stationed at the same sites used for oesting as early as 24 years ago. Another 3 nesting ranges showed some displacement of nests (by 200-300 m) due to various rea- 3°ns, and another 2 nests appeared- at new sites over that period where clus¬ ters of birches had grown among 'the meadow, and only 3 nesting ranges were abandoned because they had been overgrown by a thick forest (Pig. 2 i. It is hoteworthy that in 1951-1954, in an experiment the Crow population was eli¬ minated almost completely, the birds having been shot near the nests. The Priment resulted in the number of nesting couples being reduced to 4. ^us, it was new bird couples that populated the temporarily vacant nesting Ganges. It can be inferred from the above that! (1) nesting ranges have 655 Pig. 2. A diagrammatic representation of species range landscape structure of that of its large geographical population Zones of seasonal location of species: A- nesting sites; B- wintering sites, C- seasonal migration zo¬ nes. Regions and areas varying in favourableness for species: 1 — unfavourable, 2 - favourable, 3- par¬ ticularly favourable, 4- particular points which are regularly used by species and densely populated some natural properties that distinguish them from the surrounding terrain and that the birds leave behind some traces of their occupancy, primarily, old nests which communicate to new residents that the range is favourable for nesting. Bird wintering areas dating many years back are well known. These are primarily roosting sites. In Moscow, multi-thousand Crow and Jackdaw flocks have had a roosting site in the centre of the city in the park near the Kremlih walls for over one hundred years. In the Kyzyl-Agach Reserve on the Sara island a roosting site for a numerous wintering Milans and some other birds of- prey located in a small smooth— leaved elm grove dates back to 60 years ago. In the same area in dense thickets of wild pomegranate trees and blackberry, the roosting site of a large association of Long-Eared Owls was found in 1930. V.V.Nemtzev and myself saw Owls at the same site after 28 years. Without giving further example I shall point out that such favourab¬ le concentrations of birds exist along every route of seasonal migrations. In fact, Starlings spend the night in a definite area of reed thickets, while migratory Swifts bed in the growns of old willows, v/hile migratory spotted Woodpeckers use the same feeding trees, etc. The same feature of bird behaviour is utilized in hunting migratory Oeese from permanent huts set up on their route. Such constancy in visiting and use of the same sites by birds is of great significance in maintaining the unity of elementary and local populations. This unity is maintained via traces of past activity left. behind at every such site. The permanence of response to these cues is provided through collective experience being passed over from generation to generation. The peculiarities of ecological conditions of particular sites regularly used by birds are often hard to detect, but occasionally these can be de¬ termined and verified experimentally. A study of this type was performed by ornithologists of the Darwin Reserve. All the bird nests found there •were described in a definite pattem to characterize: general features of 656 the biotope where nesting birds were recorded (forest and its type, meadow, tog, etc.); the particular small site where the nest was found, stating in a detailed manner its features, if only minor, to distinguish it from the surrounding sites; location and structure of the nest (e.g. a cluster of taller grass, a juniper shrub, a tree with a dense crown on forest edge, etc.). A large amount of data accumulated over a number of years were sta¬ tistically treated, using a number of indices, which made it possible to develop a model for the nesting range in several bird species, reflecting, among other things, the peculiarities of nest location. The next stage was an experimental verification of such models via const¬ ruction of aritificial nesting ranges and attracting nesting couple. The ex¬ periments proved successful for Anas platyrhynchos. Anas penelope. Larus ca¬ ms . Sterna hirundo, Haematopus ostralegus, Sylvia curruca. Sylvia communis and Ardea cinerea. I shall only mention 2 experiments that lend themselves to some general inferences. To establish a Heron colony, a cluster of arti¬ ficial nests were constructed in tall pines on an island within several hundred metres from the laboratory. None of them were occupied by Herons which built their own nests near the man-made ones, the latter being used for construction material. The experiment has clearly demonstrated the cue significance of the experimental site. To attract the Common Gull (and also Duck and Soipel) for nesting, a portion of one of the islands was cleared of young pines and tall willow bushes, the turf was disturbed with a rake, and patches of sand soil cleared. The Gull colony formed at the site had 42 nests after 8 years. It existed for 25 years despite the fact that over those years both dense shrubs and trees were restored so that the site be¬ came quite unfavourabl“ for Gull3. The colony had been maintained by force of "tradition" upheld by the population's collective experience. Our concept of the hierarchical structure of an avian population and its territorial relationships with the range structure are represented diagram- «'atically in Table 1. Concurrently, a graphical illustration is provided ih Pig. 2, which represents the phy Biographical structure of a species range °f its large geographical populations. The Figure shows one of the possible combinations of regions and areas favourable for given species in definite seasons. The diagram in Fig. 3 shows a possible form of combination of va¬ rious areas particularly favourable for the species in terms of their ecolo¬ gical conditions with ranges of regional and geographical populations. The mechanisms determining the boundaries of such ranges are shown diagrammati- °ally in Fig. 4. Another series of diagrams demonstrates consequitive changes of the ranges °f regional populations due to the modification of the area by man. Felling, complete ploughing up of steppes and other forms of transformation of natural landscapes reduce areas particularly favourable for the species in different aeasons (Fig. 5, 6). In a number of cases, the advent of anthropogenic land¬ scapes (large waterbodies, forest plantations in steppe, etc.) promote de¬ viation of migration routes and displacement of wintering sites (Fig. 7). But occasionally a situation arises when the distances between favourable areas become so great that migratory flocks are unable to cover them. In auch cases, the ecological conditions peculiar to the route are disturbed 6 3aK. 981 657 Pig. 3. Interrelationship of regions with ecological conditions particular¬ ly favourable for species and ranges of associated geographical populations; dashed line designates ranges of regional population, solid line - regions with particularly favourable conditions Pig. 4. Routes of seasonal migration between neighbouring points of con¬ centrations of migrating individuals, as a basis for the development of ranges of regional geographical populations 1 - regions particularly favourable ecologically; 2— points of concent¬ rations of migrating birds; 3— migration routes between points of concent¬ rations Pig. 5. Reduction in the number and area of regions particularly favoura¬ ble for birds due to modification of the landscape by man. Disappearance of some routes. Designations as in Pig. 3 P i g. 6. Further reduction in regions favourable for migrating birds and emergence of fully-isolated populations. Designation as in Pig. 3 658 Table 1. Hierarchical and spatial structure of species and range in birds Population structure of species Range structure Population Landscape-geographical Entire population of species Large geographical Populations of spe¬ cies Entire area populated by Species Portions of range populated by species in different years, seasons and stages of biological cycle Portions of range populati¬ ons having considerable in¬ dependence, characterized by definite nesting and wintering ranges, and also major directions of seaso¬ nal migrations Range whose borders are de¬ termined by physiographical (climatic and landscape) boundaries Parts of range with diffe¬ rent ecological, primarily, climatic conditions Areas, occasionally similar with respect to landscape. Often, they are separated by physiographical ob¬ stacles repesenting land¬ scapes alien to species. Each of them has characte¬ ristic ecological conditions determining seasonal mig¬ ration routes Regional geographi- Regions populated by spe- cal populations cies at a greater density than adjoining areas. The populations are less iso¬ lated geographically than large geographical ones Local populations Regions with populations having common behavioural features adjusted to local conditions and maintained thanks to flocking Elementary, occasio- Sites regularly populated naLly , seasonal com- by individual couples or Unities small groups of a given species thanks to a sys¬ tem of visual and audial cues created by birds _ themselves Regions whose landscapes are much more favourable for species than adjoining areas Regions particularly fa¬ vourable for species in different seasons due to their ecological conditions Particular sites attractive for nesting, wintering or resting route to ouch a great extent that this endengers the existence of particular geog¬ raphical populations. The only feasible solution is establishment of man- made sites favourable for species concerned along migration routes and in Entering areas (Pig. 8). 659 P i g. 7. Deviation of migration routes as a result of disappearance of natural biotopes and emergence of thropogenic areas used by species (triangle - favourable anthropogenic biotopes) Triangles- anthropogenic areas, other designations as in Pig. 3 Pig. 8. Situation when it is necessary to create artificial sites along migration routes and in wintering areas for preserving regional populations of species. Cross, regions where such sites are to be created The following inferences can be made. The major directions of seasonal migrations of large geographical populations are very stable and can hardly be apprecaibly modified by man. At the same time number control and terri¬ torial management of regional geographical populations is quite feasible through management of avian summer and winter habitats, as well as of ter¬ ritories along the major seasonal migration routes. SUMMARY Pour groups of ethological mechanisms control seasonal distribution of avian populations as well as their flight paths; they are: (1) individual pe¬ culiarities of behavior; (2) experience acquired by individuals; (3) "collec¬ tive experience" accumulated within local populations and maintained by learning of young birds from old ones; and (4) by innate reflexes of the total species and of its large geographical populations. Innate reflexes determine choice of the main direction of seasonal migra¬ tions thus contributing formation of flight paths of the large geographical populations. Individual experience is acquired by trial and error during an individu¬ al's life. The role of the period terminated by the first breeding season is of particular importance. The individual experience leads to emergence of birds populations having specific connections with breeding localities and habitats during the nonbreeding seasons. 660 Symposium ecology of raptors Convener: I. NEWTON, UK Co-convener: V. GALUSH1N, USSR GALUSHIN V.N. ADAPTATION OF PREDATORY BIRDS TO ALTERED ENVIRONMENTAL CONDI¬ TIONS KENWARD R. PROBLEMS OF GOSHAWK PREDATION ON PIGEONS AND OTHER GAME DOROFEEV A. M., IVANOVSKY V.V. THE ROLE OF PREDATORY BIRDS IN THE ECOSYSTEMS OF THE BYELORUS¬ SIAN LAKE REGION MEYBURG B.U. MANAGEMENT ZUR ANHEBUNG DES GREIFVOGELBESTANDES NEWTON I. RECENT DEVELOPMENTS IN THE STUDY OF RAPTOR POPULATIONS SPITZER P. R., POOLE A.F., SCHEIBELM. INITIAL POPULATION RECOVERY OF BREEDING OSPREYS (PANDION HALIAETUS) IN THE REGION BETWEEN NEW YORK CITY AND BOSTON ADAPTATION OP PREDATORY BIRDS TO AI/TERED ENV IRONMEHTAL CONDITIONS V. M. Ga lus hin Lenin State Pedagogical Institute, Moscow, USSR The future existence of any group of birds, including the birds of prey, depends on their ability or inability to adapt themselves to the current changes in the surroundings, caused by human activities. Diff erentiative ana¬ lysis of this ability is expected to allow estimation of the reasonable ex¬ tent of anthropogenic impact tolerated by different species of predatory birds. The results of such investigations would provide a basis for the ela¬ boration and implementation of the most efficient strategy for managing the predatory birds' surroundings. In India more than ten years ago, I happened to observe an unique case of a perfect adaptation of some birds of prey to the urban environment. The city of Delhi harboured at that time as many as 3 thousand pairs of predatory birds within 150 sq. km of its territory, including about 2,400 pairs of black ki¬ tes, over 400 pairs of lappet-faced vultures, nearly 100 pairs of Egyptian vultures, and odd pairs of other species. The average density of predatory birds in the city was 19.3 breeding pairs per sq. km. The maximum density in some large districts of the Old Town reached an incredible(f or birds of prey) figure of 70 pairs per sq. km. An extremely high density of breeding pairs was reported in some settlements in the rural areas of northern India. The well-being of the predatory bird populations in the city of Delhi can chief¬ ly be accounted for by food abundance and - which is of an greater signifi- oance-by the Indians traditionally favourable attitude to every living thing. Peaceful co-existence of man and birds of prey seems to constitute the main feature of life both in the countryside and in urban areas throughout India. It testifies to the ability of these birds to adapt themselves to some inde¬ structive forms of anthropogenic influence. It takes them, however, much more time to overcome a deep-rooted fear of man as compared to passerine birds or gulls, for that matter, which did not suffer such persistent victimization. The Indian tradition of a benevolent attitude to every living creature is thousands of years long while tolearance of predatory birds in this country, in particular, dates back from the middle of the 1960s. There are nevertheless prerequisites for the adaptive faculties of some predatory birds to be revealed, their direct extermination having been dras¬ tically reduced and sometimes completely abolished by the current protective measures. Evidence to this effect has been obtained all over the world, including our country. In the middle of the 1960s and 1970s we carried out a comparative survey of a region about 150 km east of Mosoow using identical techniques. Over ten years, the number of six breeding Bpecies of predatory birds increased here from 23.3 to 27.5 pairs per 100 sq. km of woodlands, i.e. by 18% on average. The common buzzard, sparrow-hawk, goshawk, and kestrel were the species that had mostly contributed to this increase. 662 A similar tendency to an increased or maintained population density of predatory birds has been observed in many other regions in our country; this ground can be covered by specialists who dealt with this problem there. It is important to emphasize, however that this trend is valid chiefly or exclu¬ sively in so far as the number of rather common birds are concerned, e.g. the common buzzard, pern, goshawk, Bparrow-hawk, hobby falcon, all the har¬ rier species, long-eared and march owls, and sometimes black kite process to be currently underway in many European and North American countries. There is quite a different and, in fact, situation as regards rare predatory birds - entries to the USSR Red Data Book or the Red Data Books of the Soviet Union Republics. The number of these birds in many regions keep decreasing. In-depth studies of this process and its causes were undertaken in Estonia using the peregrine population as a model. Against this background there are encouraging reports published in the last two or three years on the renewal of some aeries of the peregrine, golden and white-tailed eagles as well as bearded vulture. These are, however, but rare instances. The differences in the present-day status and trend in the numbers of the¬ se droups of predatory birds - rare and rather common - appear to testify to their different response to a variety of anthropogenic factors. The majority of species can be subdivided roughly into two groups accord¬ ing to their response to a direct destruction by mao, which has the moat dele¬ terious effect upon the populations. a significant lessening of this influence in the late 1960s and early 1970s brought about a somewhat positive sequel i°r a number of birds while it failed to affect the others. The first group embraces many common birds of prey that are known to be Perfectly adapted to the limited alterations of the landscape caused by man (common buzzard, pern, hawks, harriers, hobby falcon, and presumably some others). Some of these birds have been shown to distinguish people as safe or dangerous by their appearance or behaviour. This ability is to be regarded as indicative of the adaptive faculty in these birds. Of no small account is the fact that many birds of prey are capable of living under the pressure of the habitual anthropogenic disturbance, hut do not sustain its sudden impact. On ihe whole the species in this group are not expected to he negatively affect¬ ed by man's presence. The second group compises rare species, which are highly susceptible to an i®pact from any modification of their surroundings. These birds are least of aH resistant to human impact. Many species cannot be classed with group and are supposed to occupy an Intermediate position as the data on their status are far from sufficient. This tentative scheme makes it possible to appraise the prospects for each group of birds and elaborate the appropriate measures for maintaining their °Ptimal living conditions in the future. The species in the first group are expected to enjoy their adaptive capabi- 1Uy to the utmost, provided that the modern legislation protecting all birds prey from extermination will remain in force for an infinitely long time. Populations of these birds would grow progressively until the ecological ^eir habitats is saturated. The existence of their viable popu- °ne under conditions of rapid socio-economic development does not seem to 665 require any special governmental measures except for strict enforcement of the legislation on nature conservation and ecological decorum whenever a man gets in touch with Nature. Survival of the second group of birds is still doubtful unless urgent mea¬ sures are taken to this effect. Special programmes are Deeded to prevent their extinction. They should envisage setting up protected areas wherever breeding grounds of rare species are preserved, conserving separate aeries, erecting artificial platforms to support nests, establishing feeding points, and breed¬ ing birds in open-air cages to secure an emergency genetic fund and subse¬ quent release of the young birds to revive failing populations. Measures to prevent the mortality of predatory birds caused by pesticides and by stumb¬ ling on overhead power transmission lines are of primary importance. Effici¬ ent nature protection and conservation are the two main approaches to ensure the existence of birds of the second group. One should bear in mind that most common species in the first group have been victimized by man for a relatively short span of 100 to 150 years, while the rare species in the second group have been suffering human impact for ma¬ ny centuries. Golden and white-tailed eagles are known to have been killed in Europe from as early as the 16th century on the pretext of their preying on lambs. Nestlings of large falcons have been collected from aeries for the pur¬ pose of falconry from time immemorial. Shy individuals avoiding contacts with man appear to have survived in the process of natural selection in populati¬ ons of this birds. To sum up, the following conclusions can be drawn from the foregoing. Rea¬ sonable transformation of the natural environment does not preclude normal existence of predatory bird populations. As birds are gradually getting the better of their shyness, their adaptive potencies, hampered by all kinds of human destructure activities, are. supposed to he revealed making it possible for the populations to adjust themselves to present-day or future levels of anthropogenic influence. Strict enforcement of the current legislation pro¬ tecting birds of prey and implementation of special programmes for the mana¬ gement of rare species are major prerequisites for this trend to continue. It can be inferred that measures to be taken to secure optimal conditions for birds of prey are not in conflict with society's socio-economic progress. Me have good reason to consider the last decade and the present moment in particular to be the turning points in the dynamics of the status and numbers of predatory bird populations. It is up to us to determine whether this favourable trend will continue and how rapidly. There are still many problems of concern, but we bave also good reason to be optimistic, all the more so that I can see a lot of youpg faces here both among those presenting reports and those listening to them. I am sure that birds pf prey do have genuine friends to take care of their well-being in the future. 664 SUMMARY Future of raptors depends on their ability to adapt themselves to envi¬ ronmental changes mostly induced by man. There are extreme examples of both full adaptation of raptors to living in big cities (for instance, about three thousand breeding pairs in Delhi, India) and entire disappearance of some species from great x’egions. In recent yeai’s the most negative forms of man's impact upon raptors, i.e. direct persecution, pesticides, nest destruct¬ ion etc. are weakened. Therefore a study of such relatively moderate forms as habitat changes, disturbance, influence on food supply and so on becomes important to ensure a stability and increase of their populations. According to adaptive capability to modified environment, raptors can be divided into two provisional groups: 1) relatively tolerant to man's acti¬ vity, i.e. common buzzard, honey buzzard, sparrowhawk, goshawk, harriers, hobby and some others; 2) intolerant to man's presence, i.e. most of rare species like eagles, big falcons, vultures, osprey and others. Some species occupy intermediate position (black kite and kestrel in our conditions) or their attitude to a man is unknown. Species of the first group react positively when persecution and other severe forms of negative influence are abolished. In many regions of the USSR after a legislative act in the middle of sixties their populations be¬ came stable or increased slightly. To be fully adapted to a modified environ¬ ment, raptors of the first group need some measures, mostly local, to soften disturbance of them especially during nesting period. Raptors belonging to the second group could not exist in a changing envi¬ ronment without a special programm of their conservation which includes establishment of permanent or temporary reserves, help in nesting and feed¬ ing. strict protection against disturbance and other measures as well as captive breeding for réintroduction of rare raptors to the wild. 665 PROBLEMS OP GOSHAWK PREDATION ON PIGEONS AND OTHER GAME Robert Kenward Institute of Terrestrial Ecology, Monks Wood Experimental Station, Abbots Ripton, Huntingdon Cambs PE17 2LS,UK INTRODUCTION Raptors have long attracted man’s antipathy for killing poultry, and seve¬ ral species gained the local or even national name of "chicken-hawk". In more modem times, raptor predation on game has caused considerable concern. At¬ tention has focussed especially on the Goshawk (Acclplter gentille), because its numbers have recently increased in several parts of Europe (Kalchreuter, 1981; Thissen et al., 1981; Marquiss, Newton, 1982) and it takes more game then most raptors. This paper reviews some past studies of raptor predation on game, describes recent results obtained by radio -tracking Goshawks, and sug¬ gests ways of approaching predation problems in the future. A PAST VIEW OP PREDATION For the last 40 years our view of predation has been strongly influenced by the work of Paul Errington. Prom studies of Muskrat (Ondata zibethlca) and Bobwhite Quail (Colinus vlrginlanus). Errington (1946) concluded that predat¬ ion was unimportant in population regulation of herbivores because its vietims were "so often the immature, the ill-situated, the restless, the wanderers or the otherwise handicapped" and that predation therefore merely compensated for other types of population loss. Many other studies showed that raptors tended to select weak or "odd" prey (Dice, 1947; Eutermoser, 1961; Pielowski, 1961; Mueller 1974), but Errington' s study and the later work on Red Grouse ( La go- pus lagopus scotticus) by Jenkins et al. (1964) put this selection into the context of population dynamics. The view became established that predators take mainly the "doomed surplus" from prey populations. The idea that raptors have little long term impact on game populations was supported by the first extensive studies of raptor communities and their food suppiy. Craighead, Craighead (1956) estimated that a North American raptor guild killed only 5-18% of the autumn game bird populations, and accounted for 18% of the total Pheasant (Phasianus colchicus) winter mortality. Brüll (1964) concluded that raptors in Northern Germany took too few Pheasants and Partrid- Ses (Perdlx perdix) to affect their breeding populations. The territorial be¬ haviour found in Buteo species (Pitch et al., 1946; Dare, 1961) and Tawny Owls (Strlx aluco) (Southern, 1970) was assumed to restrict the foraging areas of many raptors, so that their numbers would not usually build up to increase predation pressure in an area unless resident raptors were removed (e.g. shot or trapped). Evidence was accumulating that bird populations were limited by their food supply, not by predation (Lack, 1954, 1966). The views were there¬ fore promoted that raptors could not reduce game populations, that they might sometimes act as beneficial "health police" by rapidly destroying diseased prey (Leopold, 1933), and that resident raptors should be preserved because they would keep others out of their territory (Brüll, 1964) and avoid taking prey near their nests (Schnurre, 1935). 666 techniques for studying goshawk predation -J“* °f predion to. b.ca la,sa aa al.t ,t ».s rrf"' i952': -1”'* »'»•"*«<»» •»* «..!». « - , S.™ Sour “T ””t‘ B1,,'r*' ,5’51 "5gl”M- ’«4, “ aiotolPfi»» ounlculus) re-aln,. On a, other hand, nu" :i: r "t””” f"1*«» »» ■»«»«» ^ CBl, t0 “ !"* “1 ®“” G°»b“k pellet, .re e,tr,».ly dim- d away from nests, because hawks seldom roost regularly In one cl... “ r;.n™rrre prei ,hici a” ab”a“, *• ■ «» pellets too may not -represent the general diet. *Ærr- ":,h “'‘”e aiet ,o •* *»** «P ‘»to kill jr r “a ”■“** *" n”aM *° “”,Crt «•*"» frequencies »b..»» .10 : * ,r:: r :: °r ""t6*r poor quaii,y p”y *■ b'ing 1, ,sl, Î ’! '■ l‘‘- r'»»l»a. G««r, I960; Oe.r, 1981). but record, ihg ..le ! / ““ °f lh' “a “t necessarily ,h. dl« af noll_hre.d_ »«« J . *1“’ ”°r of b»««aer. If »an, prey ere eaten a.a, fro, the ... b,«„n „.r,",... ,989). n.r of harts a, o,h„ of tecta !“ "I °V'"b” bl b..k. or their prey. Both fresh H I measurement of kill-rates and facilitate recovery of (Dumke lnB ml nSbPry Pr0VldeS datS °D a11 S0UrCeS °f Prey mortalit* not thêmeel V ’ requlres large «»1»» of transmitters, which must hawks requires TeTT P"f VUlnerabmty to preda«°a (Mech, 1967). Tracking fresh r feWer transmitters, enables the most immediate analysis of tality :aBea; rd Pr0VldeS addlti0nal data on ba"k de*sity, behaviour, mor- Widén Tsl T I8'10"0 (Dl6trlCh’ E11-eDberS. 1981; Kenward et al., i98i ; lativêly omIuenWa mb98!5 'leBemer’ 1982)* but blases aealPBt recording re- atlimale weifthin"3 It tech"iq«e ls ldeal for assessing Goshawk predation on “«eh ana f ' m°re ” Sb°Ut 25°g (1*e* game)* H°Wever* coraPa-d with sto- "■oottored i 8’ Ir61* “ half thS Bmaller Prey Bay be recorded if hawks are m°ditorin 688 ab°Ut °”Ce a" hour ^onward et al., 1981). More continuous l°n at thp eanB fr°m f6Wer haWk8' EVe" concentrating entirely on predat- nth sue * 6Xpenee of °ther information, and monitoring several hawks equipped 1982) . ^1U transmitters which indicate when they are feeding (Kenward et al. 8ervationedIyUld 6XPeCt t0 record more than one Goshawk kill per ob-' ^reda0^1 STUDIES 0P G0SHAWK PREDATION ~on ^oodpigeon populations: the effects and mechanism of selection 6 Wo°dplgeon (Columba palumbus ) can cause serious damage to brassica and 66? pea crops in Britain (Murton, 1965). In W1 T started to investigate whether the Goshawk, which was recolonising Britain (Marquiss, Newton, 1982), could help to prevent this damage, either by reducing pigeon numbers or by scaring t pigeons from vulnerable crops. Hawks marked with tail-mounted radio-transmitters (Kenward, 1978a) were released in a lowland area with much brassica cultivation, and followed in¬ dividually to record their kills. The bodyweight of captured pigeons was es¬ timated from one supracoracoideus (pactoralis minor) muscle, which could usually be excised intact from part-eaten carcases and correlated very strong¬ ly (*105 = °*®97) with bodyweight (Kenward, 1978b); there was no correction for bodysize because variation in stemum+coracoid span accounted for only 1% of bodyweight variation. Compared with pigeons shot at roosts of the local population, Goshawks showed selection for birds of below average bodyweight, but not for any particular age or sex category outside the pigeon breeding season (Table 1). If the hawks had killed only the thinnest pigeons, the predation would have had a negligible effect on the population size, because most such birds were dying anyway. The observed selection was more subtle, however, with some high bodyweight pigeons being killed, but low weight birds being taken more fre¬ quently relative to their presence in the population. The degree of compensat¬ ion for other mortality associated with low weight (e.g. food-shortage, di¬ sease) could be estimated from ffoodpigeon marking data collected in similar habitat but without Goshawk predation by Murton et al. (1971), As a survival index, the probability (y) of resighting a pigeon of bodyweight (x) more than one month after marking in mid-winter (correcting for emigration) was: y = 0.0019x - 0.60 for adults, and y = 0.0012x - 0.28 for juveniles. Using these equations, the mean survival prospects of pigeons captured by the hawks were 72% those of shot samples. Thus if the hawks killed 100 pigeons, their net removal from the population -at that time would have been 72, because 28 would have soon died away. As well as removing pigeons that were already dying, the hawks were also killing pigeons which might subsequently have suffered food-shortage. This meant that although a pigeon was killed every four "hawk-days", a natural Goshawk population would have been able to reduce the large lowland Woodpi- geon population substantially below the limiting February food supply (Murton p et al., 1964, 1966) only at winter Goshawk densities above 0.4 hawks/km . Such Goshawk densities do occur, but have only been recorded in areas with high Table 1. The sex and estimated bodyweight (g) of Woodpigeons captured by Goshawks or shot in Oxfordshire between November 1974 and March 1975 ■lex structure Adults Juveniles Sex subtotals Bodyweight Bodyweight Total Female Male 7 N Mean Range N Mean Range Captured 21 8 7 6 14 471 396-579 5 443 342-317 Shot 38 19 17 2 22 540 415-589 16 528 487-587 668 densities of released Pheasants (see later). Removal of pigeons in early win¬ ter might also have left more food for February, and thus increased their breeding population (Lack, 1954). To investigate the value of hawks for scaring Woodpigeons from vulnerable Bites, a Goshawk trained for falconry was flown at flocks feeding on winter brassicas. Large flocks were difficult for the hawk to approach undetected, so a the bird eventually showed some reluctance to attack them, and the pi¬ geons often resettled on their food immediately after an attack. Approaching humans were slightly (but not significantly) more effective for scaring pi- geons away than was a hawk attack (Kenward, 1978c). Although pigeons would not tie while a hawk soared nearby, the actual attacks were of little value for SCar;r 2hem’ bUt dld provide data on selection mechanisms. Attacks were most successful at small flocks and single pigeons, partly eeause the approaching hawk was detected earlier when more pigeons were pre- ent and partly because singletons were often too weak to outfly the hawk ( enward, 1978b). tfoodpigeons could nomally outfly the Goshawk if they took f when it was more than about 20m away, so early detection of the predator s important for the prey. If the pigeons took off with the hawk close at olrr TV*6 °ften S ChaBe’ and “ WaS then that 8electi°n "eak Pigeons rred, because the hawk caught those that lagged behind. When the hawk rprised the pigeons where they sat, the condition of those taken représen¬ te 3 rT°m Cros8-8ectlon °f blrd ^ tbe flocks (Figure 1). Selection of r quality pigeons thus occurred only after a chase. This effect was ap- P rent among pigeons killed by the radio-tagged hawks too, because 7 birds Wp,e” n °r near °0Ver’ where surprise was likely, had significantly higher ghts than 3 killed in open fields (P = 0.04). Predation on Pheasants; the response to prey availability G inveatigate predation on Pheasants (Phasianus colchicusl by a wild jos awk population, hawks were trapped and radio-tagged initially at a Swe- s estate where more than 4,000 captive reared Pheasants were released an- a “ y (Kenward, 1977). Since Goshawks took 1-3 hours for their first meal on 0r eaaant- an<* subsequently returned until the carcase was cleaned of meat r scavenged, up to six hawks could be monitored at a time by checking each of 1-2 h0Ur intervals to see if it had killed. This resulted in some kills t‘h ama11 prey beinS missed, but provided many more data on Pheasant predation ^ an if single hawks had been followed continuously; few, if any. Pheasant ha le would have been missed. A Pheasant was killed, on average, every 1.7 ^awk-days in August and 2.3 hawk-days in October. The kill-rate declined to aft and 8*7 hawk-day0 per Pheasant in December and January, respectively, ■er the prey population had been substantially reduced by shooting, trap- ^ up breeding stock and hawk predation. theThe nUmber °f hawke hunting in the study area could be estimated by using Al® radio transmitters as markers in a modified Lincoln-Index calculation. hawke seen while not being radio-tracked were immediately checked for the ^esence of a transmitter. The .total number present was derived from the ra- Wg of radiotagged to untagged hawks seen when a known number of tagged hawks re present. The validity of the estimate was confirmed by Pheasant kills 669 JM'- 5= - --L- - 1 - 1 _ L__ 0 /& JO JO W F i g. 1. The bodyweight of Woodpigeons captured by a Goshawk from flocks at brasslca sites, compared with the mean (+1 and 2 x 3.C.) for pigeons shot from flocks at the same sites. Low bodyweight pigeons were selected when a chase occurred found independently by the gamekeepers: the ratio of tracked hawk kills to "unknowns" was the same as the ratio of tagged to untagged hawks in sightings Knowing also the proportion of the radio-tagged hawks' time which was spent in the study area, and assuming the same for untagged hawks, the average den¬ sity of all hawks in the area was estimated during October, when the released pheasants had reached full size but before numbers had been reduced by shoot¬ ing. The total predation on Pheasants in the area, given by (the average kill- rate per radio-tagged hawk) x (the number of hawks hunting the area), was about 1% of the released birds (40 Pheasants) per week in October, and would not have been less earlier in the autumn when the predation rate was higher. This 1% per week may underestimate the potential loss of game, because 11 of 23 trapped hawks had been removed from the estate in the previous 2 months to preserve more Pheasants for shooting. The large number of hawks present reflected a total’ lack of territoriality. The ranges of five radio-tagged males were essentially superimposed, rather than overlapping at the edges, and the area used by all five (encompassing 8 of 9 Pheasant feeding sites) was used by them 3—5 times as frequently as ex¬ pected if they used all parts of their ranges equally. Occasional mildly agg¬ ressive encounters were seen between hawks, but in this and subsequent stu¬ dies they never resulted in radio-tagged hawks leaving an area. Similar work was done in a wild-Pheasant study area, censusing the Phea¬ sants in autumn and spring to estimate the over-winter loss (Kenward et al., 1981). Goshawks killed Pheasants much less frequently than at the estate with released game, but female Pheasants in particular suffered a high winter mor¬ tality, of which 889? was due to Goshawks (Table 2). Male Pheasants were’ kil¬ led mainly by shooting, which was directed at the cocks to preserve hens for breeding. The female Pheasants were reduced to a level at which they could only have reproduced the original autumn population by breeding at the single highest rate (4 young per hen) recorded in four study years of three Scandi¬ navian Pheasant populations (Goransson, 1980). In fact the Pheasant populat¬ ion has declined to near extinction in this study area, with no marked chan¬ ges in land use during- the last decade. The most likely cause was the Goshawk predation. . 670 L;+\;+e 2- The -“^tbution of Goshawk predation and shooting to winter rtality of wild Pheasants at an estate In central Sweden i«:: -e” Mi: *° ** « »... -‘«1«. 1« o‘«o L "m,!,lne 10 * ■*“■>*"> ‘•ly.U. tecauoe v„- Released Pheasants: Remales, shot or captured at same release sites between October, December Males, shot or captured at same release sites in October Males, shot or captured at different sites in January wild Pheasants: Remales, trapped or captured between October, March ^ales, trapped or °aptured between October, March Males, shot or Captured between October, March Cap- tu red by hawks Shot or trapped H Mean Range N Mean Range • 22 957 758 -1110 298 967 701-1200 3 906 650- -1106 * 6 1109 1031-1116 4 1294 1226- •1388 43 1288 1047-1500 11 972 854- 1064 23 984 799-1190 5 1311 1215- 1413 5 1242 1120-1342 5 1311 1215- 1413 13 1307 1090-1450 Diffei 671 rieon there was evidence for selection of low weight cocks. This does not mean that no selection for low bodyweight occurred among hens, because any preda¬ tor must occasionally benefit from prey weakness and there may have been some selection in shooting or trapping (though probably not in roost shooting), but this selection was certainly much less marked than in Woodpigeons. The reason for this species difference is indicated by the Pheasant feeding beha¬ viour and escape tactics when attacked • Pheasants seldom fed more than about 10m from cover, into which they ran or flew when a hawk appeared, and only 4% of 79 kills were more than 5m from cover (with another 14% in light cover which would not have protected them Dut could have hindered their view of an approaching hawk). These observations showed that, if hawks did not surprise the Pheasants, the prey could easily escape without a chase in which selec¬ tion for weakness could have occurred. In this strongly dimorphic prey, however, a marked selection of hens de¬ veloped during autumn, in the area with released Pheasants (Table 4), des¬ pite a 1 : 1 sexratio maintained from release to first shooting in mid-Novem¬ ber. With Pheasants in groups, the hawks probably chose to attack hens be¬ cause they are smaller and easier to subdue than cocks. Similar selection of hens among wild Pheasants developed during snowcover, but this has not been found among Pheasants killed by Goshawks elsewhere (Goransson, 1975; Marc- ström, Widen, 1977; Ziesemer, 1982), possibly because hawks can only choose hens when (a) Pheasants are very abundant, or (b) the camouflage of hens is rendered less effective by snow. Goshawk predation on Pheasants has also been studied by radio-tracking in two areas of northern Germany (Ziesemer, 1982) and in three more areas of Sweden, all with fairly similar habitat. Thus data from seven areas are now available from which to investigate the Goshawk response to changes in the density of this one prey. The functional response of the average individual kill-rates (Figure 2) is a typical "Type 2" response (Holling, 1959), the limiting "handling time" being the rate of predation needed to obtain all food requirements from Phea¬ sants. A Pheasant provides 3-4 days of food for a Goshawk (Kenward, 1977), equivalent to a limiting kill-rate of 0.25-0.33 Pheasants per hawk-day, but Table 4. Selection of female Pheasants by Goshawks at two estates in central Sweden Number c aptured by hawks Male F emal e ]% Female Released Pheasants: August October November 10 25 1 5 51 14 * ** 33 67 93 Wild Pheasants: During snowcover Without snowcover 2 4 19 2 90 33 Trend significant, P< 0.001; ** difference significant, P = 0.011. 672 Fig. 2. The functional response of Goshawk kill-rates to change in Pheasant density bï «™ssrs ™»°vmg Hed ,0J. ^i^LlTUlZ 1 :„”l‘h s"a,e“ ph'a>“1 '•»•«». ».« Predator kill rates h ** SUtUmn rates* becaUEe prey densitiee and kills and Uen\ly d0Cllned m0re th8n at the 0ther Bites, where estimates. Variation inhabit t^b ^ Pr0dUC® BeParate autumn and winter hility and hence availabilÏ ty" Unael^T"^ ^ VUlne- c resting variation in Z ' ° hahly not affect the genera] Û ! & density* but this would pro¬ duce of a switcVÎo nredatl ^ **" reSP°nSe °UrVe* There "aa - -i- give rise to a sig^o d "ype " th6lr denSity in — which were a preferred orev aT „ ! re8ponae* P^bably because Pheasants atrong convex functional Y y* Wikman, linden (1981) showed a similar (Tetraoni da» 1 +„ by breedlnß Goshawks to Woodland Grouse < wtÄ™ «ZtlZ. °T TdUs ty K-ltt •* la*. Robertson, i978). 8 raptore have generally been weaker (ae- 1978^ "pt"’Btudle" <**««». 1974. review in Phelan, Robertson, eity (Pit, T S "e G0BhSWk numerical response to changes in prey den¬ sity obs^d îni^0 fUnCtl0n8 are 8hown* one based °n the autumn hawk den- eity Dred1 1 /\St the Slte Wlth m°St Pheasants and one based on the den- aa i h a r « :he 11 hawks removed fr°n the site had «» -c be Till ! ™di0tagged 311(1 ralaaaad on site. The response appears to dation^ i ^6 a 38 f0Und ^ 8°me °ther fi6ld Btudles °f vertebrate pre¬ nne about ' G088-CU8tard- 1970). hut it is impossible to be pre¬ date Z ! ! P6 the fUnOWOn Wlth0Ut m°re data for hl8b a«d interme- s ant d^ deD8ltleB- Chanced Goshawk densities may occur at low Phea- Rabbite WM 7lf W "* ablmdant> 38 in 3 S"«* 3rea <*> where ere 71% of 56 recorded prey. ”f *°“1 „ PH...«,, for si, areas sant populate W6re reCOrded in the 8evepth)* Values of 5-6% of the Phea- ween L n PeP m°nth are e9ulvalent to the highest losses recorded bet¬ as grea^T^ °f 34 Snd 35f°" T°tal predation wae vei^ variable, and could be high in l0W SS.at hlgh Pheasant densities. Predation was particularly gUre 31 6 8rea With abuildant Rabbits, which appeared to draw in hawks (Fi- fern .I thU8 Crease predation on Pheasants instead of acting as a ”buf- PI’edatlZPOld’ 1933)* Perhaps an increase in alternative prey only reduces on species which are less vulnerable than the alternative. '• 3a*. 981 673 1 ff ff 4 ff Z / /ffff Zffff ffffff rffff Fis 3* The numerical (gathering) response of Goshawks to change in Pheasant density. Rabbits were a very abundant alternative prey at one site(.) p i g. 4. The total predation of Goshawks on Pheasants at different prey densities DISCUSSION As a simplification, three degrees of intensity can be distinguished in the impact of a predator on its prey. The first occurs when the predation entirely compensatory for other density dependent mortality, such as winter food-shortage, and the prey breeding population is not -^uced Second ^ree predation is intense enough to reduce the subsequent breeding population to lower level, and third degree predation produces a continued decline to the extinction of the prey. The category found will depend both on prey vulnera- , , t-p «rpv in onlv vulnerable when young or in bility and on predator density. If prey is only vulnera poor condition, or predators are very scarce, only 1 predat (Errington, 1946). If prime prey is vulnerable in some locations. ' Iten far fro m cover, then 2° predation is possible if there are enough pre¬ dators, but a limit may be reached if prey vulnerability de*r®“” (^E*rey to experience avoiding predators or less need to feed ou 0 possible numbers fall (Gauss. 1934; Schnell. 1968). Third degree preatio.spo si only if prey are very vulnerable or relative predator density is ve^ g Pr.JJ. » «»»I« ». .«l»c«.n ^ is alternative prey,al though local prey extinctions can occur extinction if there are many prey subpopulations with some movement of pre¬ dators between them (Huffaker, 1958). This categorisation helps in considering the impact of predation, but artificial in the sense that continuous variation in predator ens prey vulnerability imply continuous variation in predation pressure. There is also no consideration of variation in the availability oi alternative prey, which may influence predator density and compete for predator a ,t -n with the investigated prey. Although a number of recent studies have shown that predators can markedly reduce the number of young birds produced, this has still mainly been found not to greatly reduce the size of subsequent breeding populations (Duebbert, Lokemoen, I960; Perrins, Geer, 1980; Potts, 1980); it is 1° predation. There is far more evidence of bird populations being limited by their food. supply (Newton, 1980), and most predation on birds is 1 . Evidence for temporary or permanent prey population reduction, 2 predat¬ ion, has so far been found mainly among mammal prey. Pitelka et al. (1955) recorded very heavy predation by Skuas ( Stercorariidae ) and Owls (utrigidae ) 674 «U.«â îâïëra,1th' l"1I"M ,,’a, •ho.» ho» predator. », te.por.rllv , , ) b« >>"• ;::rpiï - ^ —» «^•«s.rsrLixs. nr::,“v*ra r™ 1970; Powell 1980} v ’ L establishment of predators (Mech, recorded in Ireas with naturally dm "rtng^rTÏ P°PUlatl°nB haVe aleo been lack of similar data for M rrt i P^dator pressure (Kruuk, 1970). of adult birds to fly awavT P°PUlati°nS pr°bably reflects (1) the ability state of raptor populations LtT^L “d (11> the depressed str: re r;niLe* * — - trel“ H H “VLT d“d “1S b6COme b— of ex- Predation sel LuÎ .£££% ’T? ^ ^ ^ 3° it coulrf v, * ly betweeD 8Peeies have co-existed for millenia, ■>* J“i=n “.rr: '"uj * -«« «*»0., Goehawka p„, h„vll, „ ' VTt-W.„ "l,v,oio„,-. p0r America, depressine fro» v Grouse (Bonasa umbellnal in North - »./cjrs r“uThmk -■*■ <*«• -»«>. »M Goshawk lritiptlons • rraTr "*eh* ,1" le rsa“*a a- —• 4 3 indicates Z \ 6 °f Rabblts at one study area (Figures 3 thus increase predatJor^^00^ ^ lncrease G°«hawk density a^d nerable than PheÜ ! T mleBB altornative prey is also more vul- th0USbi to dam!!! “1 ; raTCh 18 needed iD m°re areaB Where are autumn kin rat T ^ Uslng radl°' -tracking techniques to estimate r^es and hawk densities need not take more than 2-3 man-mont"! 675 . -, rrrnciuallY reveal much more about Goshawk predation mechanisms. a" Pheasants are introduced in norther Europe, but their high vulnerability to Goshawks is probably not explained by a lack of natural defence *gaiMt this predator, because Goshawks are found in the original Pheasant range On the other hand, Pheasant vulnerability is probably greatly increase * destruction of cover in modern facing (GSransson, 1980). Several sugg , h"« been made for improving cover and reducing at sites favoured by Pheasants (Kenward, Marcstrom, 1981; Ziesemer, 9 ), this may be enough to prevent Goshawks reducing Pheasant breeding numbers in Tst areas. Of cLse/the hawks may still be a P-blem ^*.»^0^,.*- ing for the harvestable post-breeding surplus. Where Goshawks are enough for serious competition with hunters, however, their national bree population is unlikely to suffer if the local density is reduced in a few areas (and see Haukes, Haukioja, 1970). Live-trapping Pheasant kills is then to be recommended, because it se ec a «+■ oi and trapped birds can be rei killing Pheasants (Kenward et al., a*1* « »„I»., r- ”” *h» 30 ■" "" ‘“r° rom, Kenward, 1981). SUMMARY B„l, .lull.. of raptor pradatioo ««••»•* *“* “““ d„c, pr„ br.adlng »4 1«M S*” iaTpro- .Mi., mo.tly d.rivd »11-»«. » .boat »«or due. biased ..tint., of pr.d.tio» on game, .lth .W®» »“"* r*P“r food requirements and wastage. 2. Radio-tracking enables direct measurement of kilt-rates, « of fresh kills for selection effects, and can also be used to tor densities outside the breeding season. tor densities^ ^ Britain aelected low weight Woodpigeons wh * reduced the predator impact on this prey. Arranged attacks on pip«- showed that this selection depended on the occurrence of a chase, «■ pigeons with normal bodyweight were taken when a hawk surpr se • 4. Goshawks tracked in Sweden did not select poor quality Pheasa , escape behaviour provided little chance of a chase, but apparen y 0 attack hens rather than cocks when possible. Hawk predation on w sants was very heavy, and was probably reducing their breeding populatio . 5. The Goshawk functional response to changing Pheasant density in Swe¬ dish and Geman studies indicated that Pheasants were a preferred prey in these areas, and hawks accumulated where Pheasants were abundant, mus ng serious competition with hunters for this game. High availability of a er native prey in one area did not "buffer” the Pheasants against Goshawk pre¬ dation, but increased predation on them by increasing hawk density. ACKNOWLEDGEMENTS I am very grateful to Drs. I. Newton and A. Village for help in preparing this paper, to P. Ziesemer for permission to use unpublished data, to J.Holm. for drawing the figures and to J. Stokes for typing. The data from Sweden were obtained thanks to the generous assistance of Dr. V. Marcstrom and M.Karlbom. 676 Ref erenc e e p. 227-242. 144-177; 2T. (3), p. 221- Brull H. Das Leben deutscher GreifvSgel. Stuttgart: Fischer 1964 TsT, ?9 Ï: Crai6head F'C- HaWkS# 0lS and Wildlifft* Inst., Dare P.J. Ph.D. Thesis. Univ. Exeter., 1961. Duce R.L. - Cent. Lab. Vert. Biol. Univ. Mich. , 1947, 34 p , ?0 TlZI:; “r;: H; ïrri: understanding ndsay . Int. Ass. Falconry Cons. Birds of Prey, 198I n 16t itr ' D,pt- or ^ »1.. Duebbert H.R., Lokemoen J.T. - J. Wildl. Mgmt, 1980, 44, p 428-437 Einarsen A.S. Determination of some predator species to field aira,’ n State Monographs 10, 1956# ° ^ * Oregon -Iton C.S. The Ecology of Invasions. L. : Methuen, 1958. ™g R*1“' sillon C.W. _ Wilson. Bull., 1962, 74 Errington P.L. - Condor, 1932, 34, p. 75-86. Errington P.L. - Quart. Rev. Biol., 1946, 21 (21 245. — " Euterrcoser A. - Vogelwelt, 1961, 82, p. 101-104. itch H.S., Swenson P. , Tillotson D.P. - Condor, 1946, 48 p 205 2^7 Galushin V.M. - ibis, 1974, 116, p. 127-134. ~ Cause G.p. _ The struggle for Existence. N.Y.: Hafner, 1934. " er -• -J. Zool, Lond., 1981, 295, p. 71-80. Wbb J.A., ward C.P., Ward G.D. - D.S.I.R. Bull., 1978, 223 Goransson 0. - Anser, 1975, U, p. 11-22. - Coransson C. Ph.D. Thesis, Lund University, 1980. Goss-Custara J.D. - J. Anim. Ecol., 1970, 39, p. 91-113. au 10, ja E., Haukioja M. - Finnish Game Res., 1970, 31. p p 2 0 "“f“ - "*<»., 1964. 2 (5). p. 27i:32s. P 2°- i1"8 C,S* _ Can* Entomologist, 1959, 91, p. 293-320. aker C.B. - Hilgardia, 1958, 27, p. 343-383. ‘9P. 1964, P. 183-195. 8av H* ■ In: Under8tandinS the Goshawk / Eds. R.E.Kenward, T.Lind- Keith t ? Falconry Cons. Birds of Prey, l98l,p. 18-28. L.B., Todd A .W., Brand C.J. et al. - in- Proc XITT L-. 1977, p. 151-175. 1 C°ng* Game Bio1* elWildlifI "indberg L’A* A dem°graphic analysis of the snowshoe hare cycle Kenward R e vfT* Wlldllf6 WaSh* °C* USA- K a K*E* * Viltrevy, 1977, JO, p. 79-112. K&nward R'S* " 0rnis Scand., 1978a, 9, p.220-223. Kenv ard R'E* ~ J* Anlm* Ecol*> ^Sb, £7, p. 449-460. y nward R,S* ~ Ann* appl. Biel., 1978c, 89, p. 277-286. Kenlard R‘E‘ " J‘ 'taitn‘ Eco1*' 1982* II» P- 69-80. Ward R.E., Hirons G.J.M., Ziesemer Fi - Symp. Zool. Boo, P« 129-137. ward R.E., Marcström V. - In: Understanding the Goshawk / Eds. R.E.Ken- EenÜard' I*LlRdsay* Int* Assoc* Falconry and Cons.iBirds of Prey, 1981,i52_l62 ard R,E*» Marcström V., Karlbom M. - J. Wildl. Mgmt, 1981, 45, p. 397.40a* Lond., 1982, 49, 6 77 Kruuk H. - In: Animal Populations in relation to their food resources / Ed. by A. Watson. Symp. Brit. Ecol. Soc. 1C, 1970, p. 359-374. Lack D. The natural regulation of animal numbers. Oxford Univ. Press, 1954. Lack D. Population studies of birds. Oxford Univ. Press, 1966. Leopold A. Game management. Charles Scribners Sons. N.Y., 1933. Î.Iarquiss M., Newton I. - British Birds, 1982, 75, p. 243-260. Marcstrom V. - Svensk Jakt, 1982, 120, p. 102-105. Marcstrëm V., Kenward R.E. - Viltrevy, 1981, _1_2, p. 3-35. Marcstrëm V., Widen F. - Svensk Jakt, 1977, 115, p. 98-101. Mech C.D. - J. Wildl. Mgmt, 1967, 31 (3), p. 492-496. Mech C.D. The wolf. Nat. Hist. Press. N.Y., 1970. Mueller H.C. - Auk, 1974, 91, p. 705-721. Mueller H.C., Berger D.D., Allez G. - Auk, 1977, 94, p. 652-663. Murton R.K. The 'Woodpigeon. L. : Collins New Naturalist Series, 1965a. Murton R.K., Isaacson A.J., Westwood K.J. - J. appl. Ecol., 1966, 3, p. 55-96. Murton R.K. , Isaacson A.J., Westwood N.J. - J. Zool. Lond., 1971, 165, p.53-84. Murton R.K., Westwood N.J., Isaacson A.J. - Ibi3, 1964, 106, p. 482-507. Newton I. - Ardea, 1980, 68, p. 11-30. Newton I., Marquiss M. - J. Zool. Lond., 1982, 197 , p. 221-240. Opdam P., Thissen J., Verschuren P., MÜskens G. - J. Orn., 1977, 118, p.35-51. Pearson O.P. - J. Anim. Ecol., 1966, 35.» p. 217-233. Perrins C.M. , Geer T.A. - Ardea, 1980, 68, p. 133-142. Phelan P.J.S., Robertson R.J. - Can. J. Zool., 1978, j>6, p. 2565-2572. Pielowski Z. - Ekologia Polska Ser A, 1961, 9, p. 183-194. Pitelka P.A., Tomich P.Q., Treichel G.W. - Ecol. Monogr. , 1955, 25, p.85—1 17. Potts G.R. - Adv. Ecol. Res., 1980, 1 1 , p. 1-79. Powell R.A. - Am. Nat., 1980, M_5, p. 567-579. Schnell J.H. - J. Wildl. Manage., 1968, 32, p. 698-711. Schnurre 0. - Mitt. Ver. sächs. Omith., 1935, 4, p. 211-225. Schnurre 0. - Z. Jagdwissenschaft, 1965, 21, P* 121-135. Siewert H. - J. Orn., 1933, 81_, p. 44-94. Southern H.N. - J. Zool. Lond., 1970, J_62 (2), p. 197-285. Sulkava S. - Aquilo, Ser. Zool., 1964, 3, p. 1-103. Thissen J., MÜskens G., Opdam P. - In: Understanding the Goshawk / Eds. R.E. Kenward, I. Lindsay. Int. Assoc. Falconry Cons., 1981, p. 28-43. Uttendörfer 0. Neue Ergebnisse über die Ernährung der Greifvögel und Eulen. Stuttgart: Eugen Ulmer, 1952. Von Bittera J. - Aquila, 1915, 22, p. 216-218. Widen P. - In: Understanding the Goshawk / Eds. R.E.'Kenward, I. Lindsay. Int. Ass. Falconry Cons. Birds of Prey, 1981, p. 114-120. Wikman M. - Viltrapport, 1977, 5, p. 59-72. Wikman M.f Linden H. - In: Understanding the Goshawk / Eds. R.E. Kenward, I. Lindsay. Int. Assoc. Falconry Cons. Birds of Prey, 1981, p. 105-113. Ziesemer F. - In: Understanding the Goshawk / Eds. R.E. Kenward, I. Lindsay. Int. Ass. Falconry Cons. Birds of Prey, 1981, p. 144-151. Ziesemer F. Untersuchungen zur Lebensweise von Habicht und Mäusebussard und zu deren Bedeutung fiir einige Niedeiwildarten. Unpublished research report, Staatliche Vogelschutzwarte Schleswig-Holstein. Berlin, 1982. THE ROLE OP PREDATORY BIRDS IN THE ECOSYSTEMS OP THE BYELORUSSIAN LAKE REGION A.M. Dorofeev, V. V. Ivanovaky S.M. Kirov Vitebsk State Pedagogical Institute, Byelorussian Society of Hunters and Fishers, Vitebsk, USSR The study of the role of predator? birds in ecosystems is of great scientific and practical interest in developing optimal methods of manag¬ ing animal populations and ecosystems as a whole. The present communication is based on data on predator? bird ecology in Northern Byelorussia obtained in 1962-1982 (Dorofeev, 1966; Dorofeev, Iva¬ novsky, 1980; Ivanovsky, Umanskaya, 1981 and others). The total census route was 1450 km, and the aircraft census covered an area of 28 000 km2. To reveal territorial relationships of predator? birds, their nesting ran¬ ges were mapped annually at biological stations. Over 4 000 individuals of vertebrates were identified in pellets and prey remnants. Prey censuses were "»de, and selective morphological and parasitological analysis of populati¬ ons of certain species was performed. The methods applied are similar to hose described elsewhere (Golodushko, 1961; Galushin, 1962, 1971; März, 1972). The study area (40 1000 km ) is in the mid-course of the Zapadnaya Dvina river. Forestland accounts for a large proportion of the territory; there is I I8"186 network of rivers (25 km per 100 km2 of territory), there are many a es (up to 1 2%) and bogs (10.6%). Farming lands constitute 50% of total (G the 18 ZS1 coni dormes species nesting in the Lake Region, 6 are common Hobb r*’ Sparrow~Havvk’ Common Buzzard, Lesser Spotted Eagle, March-Harrier He y 5.Sre 3111511 numbered (Honey Buzzard, Black Kite, Montagu’s Harrier, ^en Harrier, Kestrel), 7 rare or very rare (Osprey, White-Tailed Eagle, Potted Eagle, Golden Eagle, Short-Toed Eagle, Merlin, Peregrine Falcon). te errit°rial and trophic relationships of birds of prey are largely de- the d11611 ^ t^le oomPlexity °T the forestland-lake-marshland landscape and ® egree of its modification. Anthropogenic succession of ecosystems re- S in the re(iuction of the area and modification of the structure of the the n^ habltats of the "»Jority of birds, which, in its turn, determined high ^tUrS 01 tnter- and itraspecific relations associated with nesting. In habit °8S’ Whi0h ^ lea3t modified man> the stability and diversity of sites'^3 8XClude8’ almost completely, interBpecies competition for nesting Year3" 01 Merlins neatins there occupy the same nesting ranges every thre* Whereas in a "»n-modified landscape- only 40%. The nesting territory of 2 M9rliD 00UPlea in the high bog Obol averaged 1.200 ha, while that of high^108 ln a °Ultural landacape was 1.800 and 2. 000 ha respectively. In in a °8S' it iS Merlln alone that uses the nests of the Hooded Crow, whereas Nared0^1^1^1 landacape* its competitors are the Kestrel, Hobby and Long- The the n egree °T habitat transformation is determined to a greater extent by Ure of tropich relationships. The diet of Golden Eagles nesting in a whiieyt™°di^ie while among the 70 Black Grouse and 20 Capercaillies taken by hunters - only 1.0%. In the kill of Goshawks, Jay individuals with various defects, ac¬ counted for 33-3% (9 out of 27) while in a sample - 5.0% (2 out of 40). In the kill of a couple of Goshawks that specialized in hunting Rock-Do- Ves> individuals with deviant colouration constituted 40, 0%, while in flocks 681 in the countryside settlement where this couple hunted - only 5.0. In Vi¬ tebsk, where Hawks do not hunt during the nesting period, the value in ques¬ tion was 14.7%. In the kill of 5 couples of Kestrel and 3 couples of Long- Eared owls, the incidence of occideiasis and helminthiases among common vo¬ les was 4.6 times as frequent (23 Individuals out of 1 60) as in control samples (5 individuals out of 160). In the course of conjugated evolution of both elements of the predator - prey system, the trophic relations are the major faotor limiting the number of predatory birds (Newton, 1980). An important factor of stabilizing se¬ lection, predatory birds are conductive to equilibrium in the ecosystem and to an optimal structure of prey populations. SUMMARY The study of predatoiy birds in the ecosystems of Northern Byelorussia (1962-1982) has revealed that in undisturbed ecosystems their overall im- p«t où pre, populations doe. not exceed 6.7*. In hlghlp-.odlli.d ecoW. e»s. tlti. value a» attain 8.0-15.0* in copie. «Ui • Zatpopiilations ol nan. predator, *»= ■«•«* ^ 5.6 lessen extent than oo-on bird.. A narked „l.ctlv.nes. ol on the part ol predator, to .orphologlo.il, or phj.iologlc.ll, d.f.otive pre, ha. been revealed. In disturbed eoo.j.te.s, the predator- pre, relation, are .ore strained. References Dorofeev A.M. - In: Proc. of the Vlth Baltic Ornithological Conference. Vilnius, 1966, p. 58-59 Dorofeev A.M. , Ivanovsky V.V. - Westnik zoologii, 9 , * 0,l^”n“!i. - I». »..anal, ol I.un. and .»log, .1 a»i..l.- Tran.actl.n. „1 the »0.00« Pedagogical Institute named alter V.I. Lenin. Moscow, 9 . N 186, p . . Qva state Reserve. Moscow, 1977,P.5 Galushin V.M. - In: Transactions of the Oka ouaxe 132 Golodushko B.Z. - In: Fauna Byelorussia. Minsk, 1961, Ivanovsky V.V. , Umanskaya A. and ecology of terrestrial vertebrates of p. 98-111 S. - Vest. zool. , 1981, N. 4, P- 61-65 März R. Gewäll- und Rupîungskunde. B., 1972, S. 1-287. Newton J. - Ardea, 1980, 18, N 1-4, P- 11-30. 682 MANAGEMENT ZUR ANHEBUNG DES GREIFVOGELBESTANDES Von Dr. Bemd-Ulrich Meyburg Bockumer Str.289, D-4000 Dusseldorf 31, FRG Management 1st heutzutage ein viel benutzter Ausdruck, der seinen Eingang auB dem Amerikanischen auch in die Terminologie der Biologie bzw. Ökologie gefunden hat. Ursprünglich kommt das Wort jedoch aus dem Italienischen. Die wörtliche Übersetzung lautet etwa "handhaben". Unter Populationsmanagement mochte ich hier im weitesten Sinne die bewusste Beeinflussung der Greifvögel- beatände durch den Menschen verstehen. Jahrhundertelang bestand diese fast assohliesslioh in der Reduzierung durch Abschuss, Fang, Zerstörung der Brut¬ stätten usw. Erst mit dem Wandel des menschlichen Denkens und dem rapiden Rückgang der Greifvögel begann sich auch mehr und mehr der Greifvogelschutz durchzusetzen. Unter Management wird daher heutzutage in erster Linie die positive Beeinflussung der Bestände verstanden. Geht man davon aus, da seit Beginn des vorigen Jahrhunderts in Europa ein Zusammenschmelzen der Zahl der Greifvögel auf etwa T% stattgefunden hat (Voous in Bijleveld, 1974), so steht die Notwendigkeit einer Beeinflussung der Populationen durch moderne Manage¬ menttechniken ausser Frage. Ein vollständiger gesetzlicher Schutz sämtlicher Greifvogelarten in allen Ländern der Erde ist dazu eine selbsverständliche Voraussetzung, wie dies u.a. auch in Resolution 2 der Weltkonferenz für Greifvögel 1975 in Wien gefordert wurde. Für eine Regulierung von Greifvögeln im Sinne der Reduzierung, wie sie gelegentlich noch immer von einigen Jägern gefordert wird, vermag ich nicht die geringste Berechtigung zu sehen. Für Ausführungen über die Gründe einer Ablehnung der heutigen Bejagung von Greif- v°geln ist hier nicht der Raum, auch haben zahlreiche Authoren (z.B.Sothmann, 1 978 ) hierzu ausführlich Stellung genommen. Glücklicherweise sind inzwischen in Europa in den meisten ländern alle Greifvogelarten ganzjährig geschützt. Vor jedem praktischen Versuch des Populationsmanagements von Greifvögeln muss die Beantwortung der Frage stehen, wodurch ihre Zahl begrenzt wird bzw. welches die limitierenden Faktoren sind. Es wäre vollkommen sinnlos, die In¬ dividuenzahl in einem Habitat erhöhen zu wollen, in dem die Tragfähigkeit desselben schon erreicht ist. ^ei Hauptgründe sind für den weltweiten Rückgang vieler Greifvogelarten verantwortlich: Habitatveränderungen, menschliche Verfolgung und Kontamina- ti°n mit toxischen Chemikalien. Die Tragfähigkeit eines gegebenen Lebensrau- mee wird unter Ausschluss direkter menschlicher Einwirkung normalerweise haupt- aneebot. Nur unter Beiücksichtigung dieser Grundtatsachen ist die Anwendung ®ihes Greifvogelmanagements sinnvoll. Viele moderne Greifvogelmanagement techniken im engeren Sinne - man könnte 04 _ auch aktive Managementtechniken nennen - wurden erst in den letzten 10-15 Jahren entwickelt. Sie greifen zum Teil recht drastisch unmittelbar in das ieben der Tiere ein. Wohl aus diesem Grunde werden sie teilweise noch von einigen konservativ eingestellten Vogelechützern kritisiert. Eine gewisse ^kepaig l0t ln Bezug auf mancjje Techniken sicherlich vorerst auch noch ange- ^richt. Andererseits sollte man dabei nicht vergessen, dass in einigen Fallen h erln die vielleicht letzte Chance für eine Art bestehen kann. Jahrzehntelang man in herkömmlicher Weise z.B. vergeblich versuch;, den weiteren Rück- 8an8 des Kalifornischen Kondors zu verhindern. Wird jetzt der Versuch, die 683 Vogel in Gefangenschaft zu züchten, zu spät kommen? Ein Jahrzehnt lang benö¬ tigte man für den notwendigen Kampf gegen DDT in den U.S.A. während dieser Zeit wurde der Wanderfalke nur in üblicher konservativer Weise geschützt und starb im Osten des Kontinents aus. Jetzt nachträglich wird diese Verfahrens¬ weise von einigen bedauert. Auch der Seeadler stand in Mitteleuropa um die Jahrhundertwende unmittelbar vor dem Aussterben. In Mecklenburg, seinem /erb— reitungszentrum, konnte man die Paare an den Fingern einer Hand zählen. Ge¬ rade noch rechtzeitig liess dann der Jagddruck nach und die Populationsgrösse nahm wieder einige Zeit lang zu. Nicht mehr geschafft hat es in Mitteleuropa der Bartgeier, und es bleibt abzuwarten, ob die Bemühungen um seine Wiede¬ reinbürgerung in den Alpen Erfolg haben werden. Man muss sich unbedingt vor Augen halten, dass die weiter unter beschriebe¬ nen Managementmethoden nicht etwa in Konkurrenz zu den klassischen Schutz- ma nahmen, wie Juristischer Schutz vor direkter Verfolgung und Erhaltung der Habitate (passives Management), stehen. Dies sind vielmehr nach wie vor die G rund voraus Setzlingen für das Überleben einer Population in freier Wildbahn, andererseits aber oft nicht allein ausreichend oder manchmal nicht rechzeitig erreichbar. In unserer sich rasch verändernden Welt, in der es offenbar nicht gelingt, das Hauptproblem der rapide zunehmenden menschlichen Population und all ihrer Folgen in den Griff zu bekommen, scheint für manche Greifvogelar- ten zumindest vorübergehend die vielleicht einzige Chance in dem zu bestehen, was Zimmerman (1975) mit dem Begriff "klinische Ornithologie" Umrissen hat. I. Verbesserung des Nistplatzangebotes und der Nistplatzsicherhelt Greifvögel gehören zu den wenigen Vögeln, deren Zahl und Bruterfolg in einigen Gegenden deutlich durch das Nistplatzangebot limitiert wird (Newton, 1979: 81). Hierin besteht eine bisher kaum genutzte, aber in ihrer Bedeutung kaum zu überschätzende Möglichkeit, die Brutdichte und selbst Verbreitung vieler Arten positiv zu beeinflussen. Ein Hindernis dürfte nicht zuletzt in der etwas romantischen Vorstellung vieler bestehen, Greifvögel müssten an wil¬ den und abgelegenen Plätzen nisten. Ein Steinadlerhorst gehört beispielsweise sicherlich nach der Ansicht selbst vieler Kenner in eine steile Felswand und nicht auf einen Hochspannungsmast in der Kultursteppe. Und doch fand man in den Vereinigten Staaten allein in einem kleinen Teil des Staates Idaho 32 Horste von Greifvögeln auf Hochspannungsmasten, davon mindestens 17 des Stei¬ nadlers. Durch entsprechende Konstruktionen Hessen sich diese Masten so ges¬ talten, dass die Vogel darauf sicherer alB an natürlichen Plätzen brüten konnten. Vorher waren diese Stellen überhaupt nicht besiedelbar gewesen. In Europa könnten andere grosse baumbrütende Arten wie Seeadler, Kaiseradler und Mönchsgeier, denen durch die systematische Abholzung der Altholzbestände vollständig ihre Brutbiotope entzogen zu werden drohen, auf diese Weise viel¬ leicht gerettet werden. Ausser der Horstplattform müsste wohl in manchen Fal¬ len der Horstbaum in Form eines einfachen Holzmasten ersetzt werden. Da der Umgewöhnungsprozess an derartige Horstplätze nur sehr allmählich vonstatten gehen dürfte, müsste hier sehr langfristig experimentiert und geplant werden. Da diese Vorstellung auch in Europa nicht utopisch ist, beweisen die inzwi¬ schen fast ausschliesslich auf Masten horstenden Fischadler an der Müritz in Mecklenburg. Aber auch Habichtsadler Hleraaetus fasciatus und Spanischer Kaiseradler Aqulla hellaca adalberti haben bereits auf Hochspannungsmasten gebrütet. 684 I • a • Bruthilfe durch Nistkästen BereitB 1895 wurde auf die MSglichkeit der Anbringung von Nistkästen für Turmfalken hingewiesen und vom erfolgreichen Brüten darin berichtet (Piecho- cki, 1970). Von Schmidt (1948) erschien eine ausführliche Arbeit über die Bruthilfe mit Hinweisen zum Bau von Brutkästen für den Turmfalken. Das wohl beste Beispiel in Europa, wie gross der Effekt des zur Verfügungsteilens geeigneter Nistplätze unter bestimmten Bedingungen sein kann, lieferte Cavé 1959 betrug die Zahl der Paare io seinem Uotersuchuogsge- biet 20, davon 11 in Nistkästen. Ein Jahr später, nachdem 246 Kästen angeb¬ racht worden waren, wurden auf der gleichen Fläche 109 Paare gefunden. I*b. Kunsthorste für Baumbrüter Der Greifovgelbe stand ln Mitteleuropa wird normalerweise eher durch das Nahrungsangebot als durch Mangel an Nistgelegenheiten begrenzt. Deshalb soll¬ te man zunächst nicht erwarten, dass sich der Greifvogelbestand eines Gebietes durch das Anbringen von Kunsthorsten merklich heben lässt, denn in der Regel stehen jedem Brutpaar mehrere fertige Horste in seinem Brutrevier zur Ver¬ fügung. Jedoch gibt hauptsächlich ein Umstand dazu Anlass, bestimmten Arten Kuns¬ thorste anzubietens Der bevorstehende Abtrieb eines grossen Teils der noch verbliebenen^ Altholzreste in einigen Teilen Mitteleuropas, in denen bisher viele Greifvögel zum Teil dicht gedrängt brüten, wofür sich viele Beispiele nennen lassen. Besonders See- und Fischadler, die über hundertjährige Bes¬ tände bevorzugen, sind am stärksten vom Mangel an Brutgehölzen betroffen. Zum anderen konnten viele Lebensräume für manche Arten neu erschlossen werden, wurde es gelingen, sie in grösserem Umfang zum Brüten auf künstlichen Plätzen wie z.B. Hochspannungsmasten zu veranlassen. In grösserer Zahl wurden in Europa Kunsthorste bisher nur in Schweden (Berggren, 1975) und Finnland (Saurola, 1978) errichtet. In Nord-Schweden wur- den die Horste ausser von Bartkauz und Habichtskauz vom Mäusebussard, Raufu - Bussard und Habicht angenommen. Helander (1975) gelang es in drei Fällen, Seeadler durch Anbieten von Kunsthorsten zum Brüten an ruhigeren Stellen zu Bringen. In Finnland wurden für den Fischadler über 200 Kunsthorste und weitere ?00 Kunsthorste für andere Greifvögel errichtet. 1977 beispielsweise waren einem Gebiet 60 Fischadlerhorste beflogen, davon nur 21 in natürlichen Morsten . Auch Mäusebussarde haben die Kunsthorste gut angenommen. Auf einer T robefläche fanden 26 von 50 Bruten in Kunsthorsten Btatt. Die Bruterfolge Beider Gruppen waren etwa gleichgross. In einigen Fällen wurden die Kunsthor- ate auch von Habicht, Sperber, Baumfalke und Wespenbussard benutzt. ^•c* Künstliche Nischen und Nistkästen für Felsbrüter Diese Managementtechnik kam bisher besonders systematisch in Kanada zur Anwendung (Fyfe, Armbruster, 1977). Im Rahmen eines experimentellen Nist- Platzverbee8erungeprogramm8 wurden seit 1970 über 200 Horstnischen für Prai- ■’’iefalken geschaffen oder verbessert. Mit der Hand oder einer Schaufel wur- den Löcher von 30 x 60 i 30 c Grösse hergestellt , die zu etwa ein Viertel in de:r Folge benutzt wurden. 685 Auch ln Europa werden dem Wanderfalken zusätzliche sichere Nistplätze er¬ folgreich angeboten. Es werden ln glatte und mardersichere Felswände Nischen hineingesprengt oder aus Buntsandstelnplatten hergestellte Nistkasten an glatter Wandpartie aufgehängt. Diese Kästen wiegen 200 kg und sollen 50 Jahre halten. Zu ihrer Befestigung sind acht Kletterer notwendig. Trotzdem 1st die Aufhängung dieser Nistkästen nur helb so arbeitsaufwändig wie das Heraussprengen von Nistnischen, was z.B. in stelnschlaggefahrdeten Sandetein- briichen auch kaum möglich ist. I.d. Künstliche Horstplattformen auf Masten, Gebäuden usw In baumlosen Trassen dienen die Masten von Hochspannungsleitungen dem Mäusebussard und anderen Vogelarten als Ansitz und Schlafplatz. Zum Brüten werden sie am häufigsten in Mitteleuropa bisher vom Fischadler benutzt. Tm Müritzgebiet in Mecklenburg horsteten bereits I960 14 von 20 Paaren auf Hochspannungsmasten. Es wurden bisher etwa 25-30 eiserne Plattformen auf den Masten montiert, nicht nur aus Naturschutzgründen, sondern auch um Störungen an den Leitungen zu vermeiden. In der Schorfheide (nördliche Mark Branden¬ burg) sind mir hingegen keine Horste auf Leitungsmasten bekannt. Tradition spielt also offenbar auch eine Rolle. Diese Technik verdient unbedingt , dass man sich ihr auch in anderen Ländern eingehender widmet. Durch entsprechende Gestaltung der Masten liesse sich sicherlich auch hier erreichen, dass weitere Arten in grösserer Zahl hier si¬ chere Nistplätze finden. Die Forschungsarbeit von NelBon & Nelson (1977) in den Vereinigten Staaten kann auf diesem Gebiet als richtungsweisend gelten. I.e. Sicherung von Horsten gegen Absturz Die Horste mancher Arten sind durch ihren Standort und ihre Bauweise sehr absturzgefährdet. Die proportional grössten Verluste erleidet in Europa wohl der äusserst seltene Kaiseradler durch die Instabilität seiner den Bäumen "aufgesetzten" Horstkonstruktion. Von 20 in der Ostslowakei gefundenen Hors¬ ten waren bis 1978 mindestens 9 heruntergefallen, während 3 weitere Horstbäume gefällt worden waren (Svehlik, Meyburg, 1979). Ausser durch Anbieten fester künstlicher Horste kann diesem Vogel durch frühzeitiges Befestigen abstur¬ zgefährdeter Nester sehr wirksam geholfen werden. I.f. Sicherung gegen Störungen und Zerstörungen durch Menschen und tierische Feinde Auf diesem Gebiet hat man in den letzten 10-15 Jahren mancherorts ausseror¬ dentliche Fortschritte erzielen könne. Es haben sich Arbeitsgruppen gebildet, die mit grosser Zähigkeit gefährdete Brutplätze wochen- und monatelang bewa¬ chen, wobei sie sich zum Teil hochwertiger Technik bedienen. So wird beis¬ pielsweise der Zugang zu den, wenigen Seeadlerhorsten in der Bundesrepublik Deutschland in einem Umkreis von ca. 500 m gesperrt. Die Horstbäume werden mit Kletterhindemis8en , wie Stachelringe, und mit Hilfe von Mikrofonen ge¬ sichert. 60-120 freiwillige Helfer werden jährlich für die Bewachung einge¬ setzt. Auf ähnliche Weise werden alljährlich beispielsweise die Horete von Fischadlern in Schottland und auf Korsika und die von Wanderfalken in Deut¬ schland und Frankreich bewacht. Die einer Untersuchung an in der Bundesrepublik Deutschland brütenden Wan¬ derfalken wurde in 7 von 40 kontrollierten Horsten das Auftreten der Zeckenart 686 Ixodes arborlcola nachgewiesen. Me Sterblichkeit der mit Zecken befallenen Nestlinge betrug 74$. Zur Bekämpfung der an Wanderfalkennestlingen angesaug- ten Zecken wurde mit gutem Erfolg eine 1% ige wässrige Suspension von Antor¬ gen verwandt. Die Behandlung der Horste erfolgte mit einer 3% igen Suspen¬ sion desselben Mittels. Antorgan ist ein Insektizid und Akarizid auf der Ba¬ sis eines Phosphorsäureesters mit Langzeitwirkung, das bei Haustieren einsch¬ liesslich Hausgeflügel angewendet wird. Es wird empfohlen, mit Zecken befalle¬ ne Horste Jährlich mindestens dreimal gründlich auszusprühen: Einmal kurz nach dem Ausfliegen der Jungvögel im Sommer, dann wieder im Frühjahr kurz vor Brutbeginn und ein weiteres Mal beim Beringen der Jungvögel (Schilling et al., 1981). I. g. Andere Manipulationen zur Verhinderung von Brutverlusten 1974 wurden forstliche Arbeiten in der Nähe eines Kaiseradlerhorstes in den ost slowakischen Karpaten durchgeführt, die dazu führten, dass das Weibchen nicht mehr regelmässig die noch unbefiederten Jungen hudem konnte. Da es nicht möglich war, diese Arbeiten sofort zu stoppen und andererseits der bal¬ dige Tod der beiden Jungen wegen des kalten und regnerischen Wetters zu be¬ furchten war, wurden diese aus dem Nest genommen und dafür zwei Junge Mäuse¬ bussarde in den Adlerhorst gesetzt. Diese wurden auch angenommen und von den Adlern gefüttert. Da die Jungen Bussarde schon vollständig befiedert waren, machte es ihnen nichts aus, dass eie nicht gehudert werden konnten. Bei den Adlern hingegen blieb die Bindung an den Horst bestehen. Als die Forstar¬ beiten abgeschlossen waren, wurden die Jungen wieder ausgetauscht. Beide Jun¬ gen Adler wurden daraufhin problemlos weiter aufgezogen. In ähnlicher Weise gelang es auch bei anderen Greifvogelarten (z.B. Seead¬ ler, Habicht, Sperber) gefährdete oder sogar bereits aufgegebene Bruten zu retten. II. Erhöhung der Reproduktionsrate Die Fortpf lanzung ist neben der Sterblichkeit der Hauptfaktor, der für die Populationsgrösse einer Art verantwortlich ist. Es ist daher nicht ver¬ wunderlich, dass viele Managementtechniken hier ihren Ansatzpunkt haben. Wahrend bei den im vorigen Abschnitt über die Verbesserung des Nistplatzan¬ gebotes und der Nietplatzsicherheit beschriebenen Methoden noch relativ pas¬ siv versucht wird, die Fortpflanzungsrate zu erhöhen, kommen wir Jetzt zu einigen Techniken, die sehr direkt in das Leben freilebender Tiere eingrei- fen. Verantwortungsbewusstsein und Erfahrung ist daher hierbei in besonderem Masse zu fordern. Vorausetzung für diese Methoden sind ferner die volle Ausschöpfung des Passiven oder konventionellen Managements sowie - sofern notwending - auch die Anwendung der im vorigen Abschnitt (I..) genannten Schutzmassnahmen; denn ea ist beispielsweise natürlich nur sinnvoll, den Kainismus zu verhindern, wenn auch das Überleben der gesamten Brut soweit gesichert ist. • H-a. Induzierung von Zweitgelegen Seit der frühen Zeit der Oologen des vorigen und Beginn dieses Jahrhun¬ derte wia8en wir, dass manche Greifvogelarten häufig oder teilweise sogar regelmässig ein Zweitgelege produzieren, wenn sie ihr erstes kurz nach der Eiablage verlieren (Nethersole-Thompson, 1931; Wittenberg, 1964). Diese 687. Tatsache versuchte man besonders beim Wanderfalken und Fischadler zur Steige¬ rung der Reproduktion zu nutzen. In 9 Fallen entnahmen Fyfe et al. (1978) in den letzten Jahren in Kanada frische Wanderfalkengelege. Zwei Drittel der Paare zeitigten eine Zweitbrut. Bis auf einen Fall enthielten die Nachgelege ein Ei weniger als die Erstbru¬ ten. Diese Rate stimmt gut mit den frühen Angaben von Nethersole-Thompson (1931) aus England überein. Nach Wittenberg (1964) zeitigten norddeutsche Baumbrüter häufig, teilweise sogar regelmässig, ein Nachgelege und manchmal auch ein zweites. Das 1. Nachgelege war in Norddeutschland durchschnittlich mindestens ebenso stark wie das Normalgelege. Bei deutschen Felsenbrütern scheinen unter gleichen Bedingungen Nachgelege selten zu sein, vielleicht aus Mangel an Ersatz-Horststellen. Das Ergebnis entsprechender Experimente in Ostfrankreich, kombiniert mit Adoption in Gefangenschaft, wird von Mon- neret (1978) wie folgt angegeben: Bei 10 Paaren wurden 17 Erstgelege ent¬ fernt, die alle ersetzt wurden. Die Erstgelege ergaben 17 Küken, von denen 10 flügge wurden. 20 Nestlinge aus den Ersatzbruten wurden flügge, zusammen also 30. Unter Ausschluss von 2 Paaren mit normaler Fortpflanzungsrate ergab dies 16 Junge für 8 fast "sterile" Paare, die in vier vorangegangenen Jahren zusammen nur 10 Jungvogel hochgebracht hatten. Auch aus anderen Angaben ergibt sich, da die Weibchen offenbar bei der Produktion der Erstgelege einen Teil ihrer Pestizide verlieren und dadurch die Eischalendicke des Nachgeleges grösser und die Wahrscheinlichkeit abnor¬ men Verhaltens geringer wird. Gleiches wurde auch beim Fischadler in den U.S.A. gefunden (Kennedy, 1977). Auch hier war der Schlüpferfolg der Nachge¬ lege deutlich besser als der der Erstbruten. Während diese Technik der Erhöhung der Reproduktionsrate bei Wildvögeln zum Teil umstritten ist, wird sie in der Zucht inzwischen regelmässig mit grossem Erfolg angewandt . II. b. El- und NestllngBverf rachtung Durch die Anwendung gewisser Pestizide kam es bekanntlich zu einem Rück¬ gang der Reproduktionsrate nicht weniger Greifvogelarten. Dabei sind oft nicht alle Populationen einer Art gleich stark betroffen. Dadurch ergibt sich die Möglichkeit, den Rückgang stark kontaminierter Populationen durch den Austausch der Eier und Jangen der mit in weniger betroffenen Gebieten leben¬ den Paare zu verhindern. In einem entsprechenden Experiment verfrachtete Spitzer (1978) 1968-1970 53 Eier bzw. Nestlinge des Fischadlers aus Horsten in Maryland (U.S.A.) in Nester in Connecticut. 45 der Jungadler flogen aus. Diese Rate von 85% ent¬ sprach der in Maryland. Mindestens 7 dieser Vögel kehrten in den darauffol¬ genden Jahren nach Connecticut zurück, und 3 von ihnen pflanzten sich dort erfolgreich fort. Wenn die Reproduktionsrate der jenigen Paare nicht vermindert werden soll, aus deren Horsten Junge oder Eier entfernt werden, so musses hier eine natürliche Nestlingssterblichkeit geben oder es müssen regelmässig Nachgelege produziert werden. Ein typisches Beispiel ist der Spanische Kaiseradler Aoul- la (hellaca) adalbertl. Zwischen 1971 und 1979 kontrollierte ich 39 Bruten •zur Schlupfzeit in Zentralspanien, wobei 10 mal 1, 4 mal 2, 14 mal 3 und 5 mal 4 Küken schlüpften, während in 6 weiteren Horsten die Gelege unbefruchtet 688 oder die Embryonen abgestorben waren. Zwar können bis zu 4 Junge aufgezogen werden, aber in der Regel kommen bei Bruten mit mehr als einem Küken die zu- letzgeschlüpften wahrend der ersten Lebenswochen um. Wie bei vielen Greif- vogelarten legen die Nestlinge nämlich anfangs gross Unverträglichkeit an den Tag. Da sie infolge unterschiedlicher Schlüpf termine verschieden gross sind, fallen die Jüngsten Neetinsassen in der Regel der Aggressivität ihres gröss¬ ten Geschwister8 zum Opfer. Um den Verlust dieser Nestlinge zu verhindern, müssen sie mus dem Horst genommen und in andere Nester gesetzt werden, die ein unbefruchtetes Gelege oder nur ein etwa gleichgrosses Junges beinhalten, wo sie dann aufgezogen werden. Können keine derartigen Horste zum Einsetzen der Jungen gefunden wer¬ den, bleibt nur die Handaufzucht. Sobald die kritische Phase vorüber ist, können die Jungvögel vor dem Ausfliegen in den elterlichen Horst zurückge¬ setzt oder woanders ausgewildert werden. Beim Spanischen Kaiseradler konnte gezeigt werden, dassauf diese Weise der Tod von 30% der geschlüpften Jungen verhindert und damit die Zahl der ausfliegenden Jungen um 43% erhöht werden kann (Meyburg, Garzon Heydt, 1973). Bei mindestens 27 Adlerarten der Erde sowie vielen anderen Greifvogelarten, die regelmassig mehr, als ein Ei legen, sterben zuletztgeschlüpfte Küken mehr oder weniger regelmässig. Dies eröffnet die Möglichkeit, die Portpf lanzungs- rate dieser Arten erheblich künstlich zu steigern oder Junge Vögel für Zuchtzwecke zu gewinnen, ohne der Wildpopulation Schaden zuzufügen. Entspre¬ chende positiv verlaufene Experimente wurden auch bei einer ganzen Reihe an¬ derer Arten gemacht (Meyburg, 1978). TI*o. Verhinderung des Kainismus Eine Reihe von Greifvögel-, Kranich-, Tölpel-, Raubmöwen-, Pinguin- und kaduarten legen regelmässig zwei Eier, ziehen normalerweise, aber nur eines der geschlüpften Küken auf. Bei Adlern hat Bich für diesen eigenartigen und interessanten Vorgang der Terminus "Kainismus" eingebürgert. Er ist der ait testamentarischen Geschichte vom Morde Kains und Abel entlehnt, denn der T°d des zweiten Jungen wird durch das ältere bedingt. Nahrungsmangel spielt iß diesen Pallen keine Rolle, wie experimentelle Untersuchungen ergeben haben, o® Kainismus unterscheiden wir den Pratrizid, bei dem der Tod der jüngeren Nestgeschwister eher durch Nahrungsmangel bedingt wird und die kleineren Nes- Ünsassen bei reichlichem Nahrungsangebot überleben können. Der Übergang zwischen beiden Formen ist Jedoch fliessend. Bei einer Population des Schreiadlers Aquila pomarlna in der Ostslowakei, el der in 26 erfolgreichen Horsten 42 Küken geschlüpft waren, bedingte diese r8ache den Tod von 38% aller Nestlinge, Einerbruten mit eingerechnet. Durch von Meyburg ( 1971 , 1972, 1977, 1978a, b) beschriebenen Methoden lässt sich er Verlust des zweiten Jungadlers verhindern und dieser in seinem Horst zum ^ 8fliegen bringen. Dabei wird er entweder während der kritischen Phase der stlingszeit in Menschenobhut aufgezogen oder vorübergehend zur Adoption in Horst anderer Arten (Mäusebussard, Schwarzmilan) gesetzt. Diese Techniken ZUr künstlichen Erhöhung der Portpf lanzungsrate wurden an 11 Horsten erfol- Sï’eich angewandt, erstmals 1968 bei zwei Paaren. Dabei war es lediglich die gäbe dieser Versuche, nachzuweisen, dass sich auf diesem Wege der Reproduk- 8,3aK. 981 689 tionserfolg erhöhen lässt Um einen wirklichen Einfluss auf die Population- sgroase zu. erreichen, müsste die Durchführung bei einer viel grösseren Zahl von Bruten organisiert werden. Hatte man ln der Slowakei ln Jedem Palle den Ka- lnismue verhindert, so wäre eine Steigerung der Reproduktionerate um 81* er¬ reicht worden (Svehllk, Meyburg, 1979). Verglichen etwa mit dem Aufwand, der mit der Zucht eines Jungen Greifvogels ln Gefangenschaft und seiner Auswil- derung verbunden ist, erscheint er bei dieser Technik recht gering, besonders wenn sie mit Bestandsaufnahmen und brutblologlschen Studien gekoppelt wird. In Anbetracht des starken Rückganges der Art in Mitteleuropa und anderen Tellen Ihres Verbreitungsgebietes ist eine Durchführung ln grossem Rahmen wünschenswert. , Auch bei anderen ln Europa vorkommenden Arten, wie etwa dem Schelladler, Steinadler, Seeadler, Zwergadler und Bartgeier kommt Kalniemus vor. Die Häufigkeit und die Ursachen wurden bisher noch nicht näher untersucht. Belm Steinadler scheinen etwa 30-50* der zweitgeschlüpften Küken zu überleben. Belm Bartgeier verschwinden die kleineren Geschwister normalerweise , die Grün¬ de hierfür sind nach Gefangenschaf tebeobachtungen die gleichen wie beim Schreiadler. Bei Wiedereinbürgerungsversuchen dieser Arten sollte unbedingt auf diese Todeskandidaten zurückgegriffen werden, sofern keine gezüchteten Vogel zur Verfügung stehen. Andere Nestlinge auszuhorsten ist meines Erachtens nicht zu verantworten. III. Reduktion der Mortalität der Wlldpopulatlon und der Kontamination mit Pestiziden III. a. Behandlung von verletzten und geschwächten Greifvögeln und Ihre Wiederfreilassung Das zunehmende Interesse am Greifvogelechutz spiegelt sich mancherorts auch in der Errichtung von sogenannten Greifvogelpflegestationen wider. Zwei Gruppen von Greifvögeln werden ln der Regel ln solche Einrichtungen gebracht! kranke oder verletzte Tiere und fälschlicherweise auf genommene Jungvogel. Da sich Greifvogelpopulationen in erster Linie ln Abhängigkeit von ihren Beutetieren regulieren, 1st es nicht sinnvoll, Jeden verletzten Vogel unter allen Umständen am Leben zu erhalten. Greifvögel mit verheilten Knochenbrü¬ chen, Muskel- oder Sehnenverletzungen beispielsweise haben ln der Natur nur geringe Öberlebenschancen. Trotz bester Absichten besteht leider die Gefahr, dass Greifvogelpf xegestatlonen zu Menagerien entarten und sich dann kaum noch von Jenen Schaustellungen unterscheiden, die entschieden abzulehnen sind. Sta¬ tionen, in denen Besucher Zutritt haben, sind nicht akzeptabel. Besonders dort wächst nämlich die Versuchung, unnötigerweise Tiere zu halten, um eine möglichst vollständige "Kollektion" präsentieren zu können. Die Pflege wird dann zu eigennützigen Zwecken missbraucht und hat nur noch Allblfunktlon. Die Pflege von Greifvögeln sollte sich in erster Linie auf lebenstüchtige Tiere beschränken, die nach einer gewissen Zeit wiederausgewildert werden können. Jungvögel, die während der Sstlingsphase auf den Boden geraten sind, sollten unbedingt in den eigenen, oder einen anderen Horst mit etwa gleichgrossen Jun¬ gen zurückgesetzt werden. 690 III,b* Zusätzliches Puttern lm Winter und mit pestizidarmen Fleisch Hierdurch versucht man seit einer Reihe von Jahren ln verschiedenen Län¬ dern die Populationen einiger Greifvogelarten, Insbesondere von Geiern und Adlern, zu fördern. Umfangreiche, langjährige PÜtterungsprogramme gibt es beispielsweise ln Europa besonders für die Geier ln den Pyrenäen und den Seeadler ln Schweden und Mitteleuropa. Dazu werden ganze Tiere aus Schlach¬ thäusern oder überfahrene Wlldtiere oder Plelschabfälle in den Winteraonaten an geeigneten Stellen ausgelegt. Die bedrohteste Greifvogelart der Erde, die man unter anderem durch das Auslegen von Kadavern vor dem Aussterben zu’be- wahren versucht, 1st der Kalifornische Kondor. III,C* Verhinderung von Stroaunfällen und Kollisionen mit Leitungen Stromunfalle an Hochspannungsmasten ereilen ln erster Linie grosse Greifvo. gelarten (Adler und Geier), deren Plügelspannweite grösser als der Abstand zwischen zwei Dräten ist, so dass sie beim Landen und Abfllegen gleichzeitig zwei oder mehr Drähte berühren. Ganz überwiegend immature und subadulte (bis zu 98%) Vögel verunglücken. Ein genügender Abstand von mindestens 152 cm zwischen den einzelnen Drähten 1st die wichtigste Voraussetzung zur Verhin¬ derung derartiger Unfälle. Die umfangreichste Übersicht über diese Problema¬ tik und Lösungsmögllchkeiten haben Olendorf et al. (1981) zusammenges teilt. Iv* Aufstellung von Sitzkrücken auf Freiflächen Durch diese Methode zur Schadnagereinschränkung (vor allem Feldmäuse ) durch Greifvögel (Mäuse-, Rauhfussbussarde, Turmfalken u.a.) kann diesen, besonders in futterarmen Perioden, sehr wirksam geholfen werden. Verschiedene Arten von Greifvögeln benutzen die etwa 1 m hohen und mit einem ca, 20 cm langen Quer¬ holz versehenen Sitzkrücken als Warte, um von dort aus die Nahrungssuche zu betreiben. Die in den letzten Jahren zunehmende Entfernung natürlicher Auf- baumungsmögllchkelten ln weiten Teilen der Landschaft macht den Einsatz dle- 8er biologischen Methode ln vielerlei Hinsicht sehr lohnend. Kaatz und Bich (1979) konnten ln einer Untersuchung feststellen, dass der MäusebeBatz auf suchßf lachen von 0.5 ha, die mit je 10 Sitzkrucken versehen waren, im ^rgleich zu entsprechenden Kontrollflächen ohne derartige Warten signifikant niedriger war. V. Zucht. Auswllderung und Wiedereinbürgerung Wohl etwas zu Unrecht ist die Zucht in Gefangenschaft heute ganz in den Vordergrund des Interesses gerückt und hat dabei etwas die anderen Manage- menttechniken in den Schatten gedrängt. Bisher konnte noch keine bedrohte Vogelart auf der Erde durch Zucht gerettet werden. Am häufigsten wird dies von der Hawaiigans (Branta sandv'icensls ) behauptet, von der bisher über 1600 ^züchtete Exemplare ausgesetzt wurden. Es 1st bisher nicht bekannt, ob sich bie Population nach Beendigung der Aussetzungen allein halten kann. Lediglich ei einigen wenigen säugetierarten konnte eine vollständige Ausrottung durch eltung und Zucht in Zoologischen Gärten verhindert werden. ^ehlgeschlagen ist bisher der Versuch, die vielleicht seltenste Grelfvo- ßelart der Erde, den Mauritiusfalken Palco punctatus. durch Zucht zu schüt- Zeh. Der Gesamtbestand an Wlldvögeln hält sich seit 1975 etwa glelchblelbend 1 1 5 Vögeln. Im Laufe der Jahre wurden 8 Individuen zu Zuchtzwecken gefan- 691 gen. Ein Junges wurde gezüchtet, aber alle 9 gefangenen Tiere etarben, wobei die Weibchen Anormalitäten der Portpflanzungsorgane aufwiesen. Dennoch können die bisherigen Greifvogelzuchterfolge insgesamt als ermut¬ igend bezeichnet werden. Noch vor 10 Jahren wären sie beispielsweise beim Wanderfalken wohl kaum für möglich gehalten worden. Tm Osten der USA konnten so von 1975 bis 1981 mehr als 350 in Gefangenschaft gezüchtete Junge Wander¬ falken ausgesetzt werden. 1981 waren mindestens 7 Paare ansässig, von denen 4 eigene Junge aufzogen. In Kanada wurden von 1970—1981 368 Wanderfalken gezüchtet, von denen 315 ausgesetzt wurden. Hier wurde der erste Beweis er¬ bracht, dass diese auch erfolgreich brüten können: Ein 1975 gezüchtetes Weib¬ chen, das einem wilden Paar zugesetzt worden war, legte zwei Jahre später 10 km entfernt zwei Gelege. Sechs der sieben Eier waren befruchtet, und drei hinzugesetzte gezüchtete Junge wurden aufgezogen. In Europa brütete das erste ausgesetzte Paar 1982 erfolgreich im Harz. Beide Partner stammen von demsel¬ ben Züchter und zogen zwei Junge gross ( Saar et al., 1982). Man muss sich stets vor Augen halten, dass Zucht und Auswilderung der ge¬ züchteten Vögel nur das allerletzte Mittel sein sollten, zu versuchen, das Aussterben einer Art zu verhindern. Es bleibt immer fragwürdig, wenn dazu bei nicht ganz so bedrohten Arten die insgesamt nur sehr begrenzten Mittel des Naturschutzes eingesetzt werden, die vielleicht bei anderen Projekten sinnvoller angebracht wären. SUMMARY Management to Increase Raptor Populations Not until very recently have modem methods of population management .that is to say the purposeful, positive influencing of populations, been tested and applied in the case of raptors. They have become necessary because of the decline in many species which is, in some instances, world-wide; since the beginning of the last century the European populations have, on average, decreased to about 1% of their former level. Prior to the application of a particular method, investigations must be conducted to establish the extent to which the capacity of a given habitat is utilized by a particular species and what the limiting factors are. Under normal conditions the latter are primarily the availability of food and nesting-places but today the main resons for the decrease are changes in the habitat, persecution by man and contamination by toxic chemicals. Management techniques tried out so far can be divided into four main groups: 1. Increasing the number of nesting-places and increasing their se¬ curity. 2. Increasing the reproduction rate. 3. Reducing mortality and con¬ tamination by pesticides. 4. Introducing. or re-introducing to the wild rap¬ tors bred in captivity. The ba'sic prerequisite for effective application of the individual techniques is protective measures in the classical sense, such as legal protection and preservation of the habitats. Ref erences Berggren W. - Var Fagelvarld, 1975, 34, p. 67-68. Bijleveld M. Birds of prey in Europe. L. : MacMillan Press, 1974. 692 Call M.W. Habitat Management Culdes for Birds of Prey. Bureau of Land Mana¬ gement, U.S. Department of the Interior Technical Note, Denver, 1979. Cavé A.J. - Netherlands J. Zool., 1968, _18, p. 313-407. Pyfe R.W., Armbruster H.I. Raptor Research and Management In Canada. World Conf. on Birds of Prey. Ottawa, 4977, p. 282-293. Pyle R.W., Armbruster H. , Banasch U., Beaver L.J. - In: Endangered Birds; Management Techniques for Preserving threatened Species / Ed. by S. A. Temple. University of Wisconsin Press, Madison, 1978. Helander B. Havsörnen 1 Sverige. Uddavalla, 1975. Kaatz Ch., Blch Th. - Beltr. Vogelkd., Leipzig, 1979, 25, p. 346-352. Kennedy R.S. Transactions of the North American Osprey Research Conf. 1977 p. 35-42'. Meyburg B.-U. - Beltr. Vogelkd., 1971, V7, p. 207-227. Meyburg B.-U. Conference on Birds of Prey, Vienna 1975. Report of Procee¬ dings. Vienna, 1977, p. 387-391. Meyburg B.-U. - In: Endangered Birds: Management techniques for threatened species / Ed. by S. A. Temple. Madison: University of Wisconsin Press 1978a, p. 195-200. Meyburg B.-U. - In: Geer Bird of Prey Management Techniques / Ed. by Oxford, Brit. Falconers' Club, 1978b, p. 81-93. Meyburg B.-U., Garzon Heydt J. - Ardeola, 1973, 19.» p. 105-128. Monneret R.J. - In: Bird of Prey Management Techniques / Ed. by T. A. Geer. Oxford, 1978, p. 56-61. Nelson M.W., Nelson P. Power Lines and Birds of Prey. World Conf. on Birds of Prey. Ottawa, 1977 , p. 228-242. Nethersole-Thompson D. - OoL.. Rec., 1931, 21* P. 73-80. Newton I. Population Ecology of Raptors. Berkhamsted, T. and A.D.Poyser. 1979. Oiendorff R.R., Motroni R.S., Call M.W. U.S. Dept, of the Interior-Bureau of Land Management Technical Note. N.Y., 1980. endorff R.R., Miller A.D., Lehman R.N. - Raptor Research Report N 4, 1981. ^iechocki R. Der Turmfalke. A. Ziemsen Verlag, Wittenberg-Lutherstadt, 1970. aar Gh*» Trommer G. , Hammer W. Der Wanderfalke. Bericht über ein Arten¬ schutzprogramm - Methoden, Ziele, Erfolge. Bonn, Deutscher Palkenorden 1982. * Saurola P. - in: Bird of Prey Management Techniques / Ed. by T. A. Geer. Ox¬ ford: Brit. Falconers' Club, 1978, p. 72-80. ^hilling F. , Böttcher M., Walter G. - J. Om., 1981,222, p. 359-367. idt Fh. - Schweiz. Naturschutz, 1948, 2i* P. 105-113. °thmann L. Greifvögel und Jagd. Themen der Zeit Heft 2, Kilda-Verlag Creven, 1978, ®Pltzer P.R. - ln: Endangered Birds / Ed. by S. A. Temple. Madison: Univ. of ' Wisconsin Press, 1978, p. 171-182. J6hllk J*» Meyburg B.-U. - J. Om., 1979, 220, p. 406-415. tenberg J. Nachgelege bei Raubvögeln. Vogelwelt, 1964. nBnertnan D.R. To save a bird in peril. Coward, McCann and Georghegan, New ¥ork, 1975. 693 RECENT DEVELOPMENTS IN THE STUDY OF RAPTOR POPULATIONS I. Newton Monks Wood Exptal Station Abbots Ripton, Huntingdon 2L5, UK The effective conservation of captors requires, among other things, a thorough understanding of their population dynamics. Reproduction has been well studied, but much less is known about mortality and other aspects relevant to the construction of life tables. In these respects, studies on diurnal raptors have lagged behind those on some other birds. In this paper, I shall discuss three aspects of reptor population studies, which depend on the marking of in¬ dividual birds, and on which ideas have changed recently in the light of fresh information. These include the fidelity of breeders to their nesting territo¬ ries, the mortality of breeders, and the age of first breeding. I shall draw mainly on studies of Sparrowhawks Acclpiter nlsus and other raptors by myself and colleagues in south Scotland, but will also quote some other published work where relevant. FIDELITY TO NESTING TERRITORIES Many raptor species can be found nesting in the same places over long pe¬ riods of years. Such places may be cliffs, isolated trees, groves of trees, or patches of forest or ground cover, depending on the species. Particular cliffs are known to have been used annually by successive pairs of eagles or falcons for periods of 70-100 years (Newton, 1976). Among 49 British Perigine Falco peregrlnus cliffs known to falconers between the sixteenth and nineteenth cen¬ turies, at least 42 were in use during 1930-39 (Ferguson-Lees, 1951 ). Continued occupancy may thus have held at many cliffs for centuries, long before there were ornithologists to record it. In trees, too, certain eagle nests have been used for longer than a man's lifetime and, added to year after year, have of¬ ten reached enormous size. One historic Bald Eagle Hallaetus leucocephalus nest in America spanned 8 m? on top and contained *2 waggon loads' of material, while another was 3 m across and 5 m deep (Bent, 1938)* Some Osprey Pan d ion haliaetus nests were in continued use for periods of 45, 44 and 41 years, and Red-Shouldered Hawk nests for 47 an 37 years (Bent, 1938). Certain patches of forest (though not the same nests) have been used for long periods by other species, and even patches of ground cover were used by Hen Harriers for more than 50 years (Balfour, 1957). In general, of course, sites on rock must be more permanent them those in trees, and sites in trees more permanent than those in herbaceous cover. The continued use of particular sites by certain breeding raptors has given rise to the ideas that: (a) the same individuals are present year after year, remaining faithful both to territory and to mate, and that (b) each Individual, after the death of its mate, attracts another partner to the same site, thus ensuring continuity of occupation (e.g. Tinbergen, 1946). These views gained credance from the fact that certain individual birds, which were recognised by some peculiarity of behaviour, plumage or egg type, occupied particular terri¬ tories for long periods. Only in recent years, however, have these ideas been checked by use of marked individuals. The findings have revealed wide variati¬ ons in fidelity to territory between populations. Such studies entailed trapping and marking the occupants of certain terri- 694 Table 1. Turnover of Sparrowhawka on particular territories Years between captures on the same territory: Occupant same (S) or different (D) Males. Numbers Estimated annual turnover Females. Numbers Estimated annual turnover One Two Three S D 25 33 57% 148 148 50% S D 4 16 55% 12 50 56% S 0 D 12 16 42% tories in restricted study areas.then cheking for the presence of these same birds in future years. They tell us about the turnover of birds at particular erri tories, and about shifts between territories within study areas, but they miss any birds which might have moved outside the study areas between one year and the next. Also, because female raptors spend more time near the nest than males, females are the easiest to catch and have usually provided most lnronnation. I shall start with the Sparrowhawk, which has been found nesting in the same places for periods of 30-50 years, while ever the woods concerned re¬ mained suitable. Newton and Marquise (1982) studied the turnover at parti- cu ar territories in south Scotland for ten years. Each time a bird was caught, note was made whether it was the same individual that was on that erri tory previously. From territories where occupants were identified at ome year intervale, 57% of cocks and 50% of hens had changed by the second Fear. This gave average periods of residence on territories of 1.4 and 1.5 years respectively. The fewer records from territories where birds were ^ught at intervale of 2-3 years gave roughly similar estimates of turnover ITable 1). Table 2. Periods that individual Sparrowhawka were resident on Particular territories during a 10-year study Number of birds present for following periods (years) Mean - 1 1 2 3 4 5 6 period les females 42 173 8 22 0 1 0 1 1.3 1.3 The figures just quoted gave estimates of the mean turnover of individu- f 8 from year~to-year changes, but many birds were identified in several dif¬ ferent years. Periods that individuals were known to be resident on particu¬ lar territories are given in Table 2. Only those birds which were known to a art “"d end their stay on a particular territory within the ten year study re included. Such data are probably biassed slightly in favour of short pe- th°de' becaU8e long periodB were more likely to overlap the start and end of study, and so be excluded. This may be why the mean periods of residence, ab 1,3 yeare for both sexes, were slightly shorter than the means calculated in Ve flt>m the year~t0-year changes. However, the results were interesting ^t&8ain showing the shortness of the periods involved. The majority of birds ®ined the same territories for only a year or two, and only occasional in- 695 Table 3. Fldell-ty to territory among individual raptors identified In successive years Species and sex Number of individuals in second year Reference On same territory On different territory (%) Sparrowhawk male 25 7(22) Newton, Marquise , 198 1 female 158 67(30) Kestrel* male 15 307) Village, 1980 female 5 7(58) Merlin male 9 3(25) Hodson, 1975 female 2 8(80) Peregrine male 6 0(0) Mearns, Newton, 1983 female 61 7(10) * Sex difference statistically significant on Fisher's Exact Test: Kestrel, P = 0.022; Merlin, P » 0.014. dividuals for up to four years (cocks) or six years (hens). Four other cocks had been resident for 3, 4 and 5 years when the study ended, so their pe¬ riods may have been even longer. Similarly, three other hens had been resi¬ dent for 6 years, and two others for at least 5 years, when the study ended. It came as a surprise that, in this species, whose nesting places are used over several decades, the mean individual residence periods were so short. Evidently, the continued occupancy was produced by many different in¬ dividuals occupying the same territories in quick succession, each for a short time. Some territories were occupied in all ten years of the study, but by a different hen each year. Part of this high turnover was due to mortality. More than one-third of breed log Sparrowhawks died each year, so in a stable population, one might expect that this proportion of places would become available for re-occupat¬ ion each year. In addition, however, some birds changed territories from year to year, thus further contributing to turnover. Overall, about 78% of re— trapped males and 69% of 225 re— trapped females were in the same ter¬ ritory the second year, and the remainder of each sex had moved to a diffe¬ rent territory (Table 3). These figures suggested that cocks were slightly more sedentary than hens, but in fact the difference between the sexes was not statistically significant. The nesting places of neighbouring pairs were sometimes as close as 0.4 km Many birds made only this minimum move, and beyond this, records became stead ily less frequent with increasing distance. In general, hens which changed territories moved further than cocks. The median distance moved by 96 hens was 1.5 km; most had moved less than 9 km, but one had moved 16.5 km and another 27 km. The median distance moved by 14 cocks was 0.8 km; most had mo¬ ved less than 2.0 km, but one had moved 3 km and another 19 km. Possibly the longer movements of each sex were underestimated, if they took birds out of 696 Table 4. Proportion of hens which changed territory, according to age and neat success the previous year. Birds which failed the previous year more often changed territory than did birds which succeeded, but the tendency to change territory became lese marked with increasing age Comparison between following ages (years) 1-2 2-3 3+ to following year On same terri¬ tory On diffe¬ rent ter¬ ritory On same terri¬ tory On diffe¬ rent ter¬ ritory On same terri¬ tory On diffe¬ rent ter¬ ritory After success in previous year After failure in Previous year Significance of variation within age groups 6 5 0 10 X2»5.2, P< 0.05 16 5 4 5 X2=1.6, P < 0.3 103 26 19 16 X2 -0.8. P < 0.5 the study area; in general, however, movements were short compared to those which could have been recorded in the study areas concerned (two areas measu- ring 40 x 20 km and 20 x 12 km, and 15 km apart at their nearest points). What circumstances led birds to change territory? Both sexes more often changed territories if they had failed in their breeding the previous year than if they had succeeded but this result was statistically significant °nly in hens. Thus, of 1 6 1 retrapped hens which had produced young the pre¬ vious year, 22% changed territory, while of 54 which failed, 57* had changed territory. The tendency to move after a failure was especially marked between the first and second year of life in hens, and became less marked with age (Table 4). Older hens showed a strong tendency to stay on the same territo¬ ries, whether successful or not the year before. Among cocks, the number of one-year-olds was very small, but among older birds the same trend held as In hens, with greater residence with increasing age (Table 4). In both sexes, movements became shorter with increasing age. So not only were old birds less Incluned to change territory than young ones, when they did change, they mo- ved leas far. One further factor which influenced movements was territory quality (a klgh grade territory was one where nest success during the ten year study was S°od). Both yearling and adult hens showed a strong tendency to stay on high grade territories after a success, and to move away from low grade territo- ries, irrespective of whether the previous attempt was successful or not. The frequent deaths and movements meant that most Sparrowhawks had a dif- ferent mate each year. Birds which changed territory almost invaribly changed males as well, even though in many cases the original mate was still alive, on the original or a different territory. However, some partners remained toget- ^er on the same territoi^, and four years was the longest period- recorded. Summarising, most Sparrowhawks which survived from the previous year stayed ot> the same territory, but some moved, particularly hens which failed the pre- vious year, which were yearlings the previous year, or which were on poor ter- 697 rltoriee the previous year. The alte fidelity was related to the age and pre¬ vious success of the bird, and to the quality of territory. A change of ter¬ ritory was almost invaribly associated with a change of mate. In two small falcons that have been studied in detail, some individuals also changed territories between years, again females more often than males. 4mong Kestrels Falco tlnnunculuB in south Scotland, '8 males were identified in successive years, 15 on the same territories and 3 on different territories, whereas of 12 females, 5 were on the Bame territories and 7 on different ones (Village, 1980). The sex difference in frequency of movement was statistically significant (P = 0.022, Fisher's Exact Test), but not the distances moved. In both sexes, these distances averaged less than 2 km in a study area where move¬ ments up to 1 5 km could have been recorded. Kestrels were partial migrants in this area, and males much more often stayed on their territories over winter than did females, most of which left. In the Netherlands, Kestrels varied in behaviour, according to changes in the numbers of the rodents which formed the main food (Cavé, 1968). When Kestrels were on the increase, up to 705? of adults returned to the study area from one year to the next, but when they were on the decline, as few as 105? of birds returned. Among Merlins Falco columbarius in Alberta, 12 adult males were re-trapped, 9 on the territory where they had previously bred, 2 on territories less than 4 km away and the other 12 km away. But of 10 adult females, only 2 were on the same territory, 3 were on territories less than 15 km away, 3 were 15- 30 km away, while 2 were more than 100 km away (Hodson, 1975). Again, the sex difference in frequency of moves was statistically significant (P « 0.01 4, Fisher's Exact Test). For these three species, neither of the ideas on territory and mate fideli¬ ty mentioned at the start of this section held in an unqualified manner. Al¬ though the same places were used for nesting in different years, this could not always be attributed to the return of the same individuals, and birds often changed their nesting territories, irrespective of what their former mates did. Moreover, some territories were occupied by completely different pairs from one year to the next, and others were vacant for one or more years, before being re-used. Almost certainly, the same places continued to be used for nesting because they were particularly good places within the local lands¬ cape and territorial framework, rather than through continuity of individuals. Other raptors have shown much greater fidelity to territory. Among Peregri¬ nes in south Scotland, 6 males were trapped in successive years, all on the same territories, and 68 females were trapped in successive years, 61 on the same territories. Four of the seven which moved were found on adjacent terri¬ tories, 3-10 km away, but the others had -moved further afield, up to 33 km away in an area where movements exceeding 170 km could have been recorded. Si¬ milarly, among Ospreys in eastern North America, individuals typically retur¬ ned to the same nest site, or one within 2 km, for many years in succession. Only 3% of returning adults moved further than this, up to 18 km (Spitzer, this symposium). The most extreme fidelity to territory and mate was shown by some Greater Kestrels Palco rupicoloides studied in the Transvaal (A, C. Kemp, in Newton, 1979), in which ten pairs remained on their territories over a 3-year study 698 p i g. 1. Annual mortality of adult raptors shown in relation to female body weight. Mostly based on ring recoveries, lines join different estimates for the same species period, with only one replacement of a male which died. Thus these birds show- not only great fidelity to territory and mate, but also exceptionally high survival. Similar data on smaller samples had been published for Hobbies Palco JiHbbuteo and various Buteo species, including B^platychtarus and B.galaoa^ sis (Matray, 1974, de Vries, 1975). - _ - MORTALITY Most existing estimates of annual mortality in raptors are based on the * ng recoveries of birds found dead, and reported by members of the public, ^uch estimates have revealed the general trend in Figure 1, for mortality to rrelate with body size, the smaller species showing greater annual mortali¬ ty in adult life than the larger ones. This fits the trend in other birds, an would be expected from reproductive rates. However, some of the estimates obtained in this way for raptors have long been in doubt, because in some Pecies the estimates are so large that, on known reproductive rates, the Populations concerned would soon have become extinct, yet in reality they continued to thrive. This is particularly true for species which are often °t, such as some accipiters and harriers. h The Mcent trapping of adults on nesting territories in successive years ^ae provided othér estimates of mortality among breeders, but again the data ^i-e more numerous for females than for males. In female Sparrowhawke, esti¬ mates were obtained (a) from the ratio of different age classes in the breed- Qf8 Population, in which most nestlings had been ringed during twelve years Ce study, and (b) from the recovery frequency of particular females in suc- ad sive years (Newton et al., 1983). On the ratio method, the mortality of WaUlt t'emales was estimated at 36% per year, and on the recapture method, it Pep estilnated at 34*. A similar figure obtained by recapturing individual ï'egrlnes in successive years gave a mortality estimate of 11% per year ““cams, Newton, 1983). Tbese estimates are all maxima, because they do not allow for any birds 699 Table 5. Annual mortality of adult raptor (2+ years) calculated (a) from local studies on marked breeders seen alive and (b) from widespread ringing programmes relying on reports of birds found dead Local studies of adults breeding Widespread ringing programmes Annual adult morta¬ lity Locality Source Annual adult morta¬ lity Locality Source Oßprey 10-15* E. United Spitzer, 18* E. United Henny, Wight, States 1980 States 1969 Sparrowhawk 35* S. Scotland Newton, Mar- 42* Germany Kramer, 1973 quiss.Ro- 51* W. Eu rope Tinbergen, 1946 thery,l983 40* Denmark Shelde, I960 57* Britain Newton, 1975 Peregrine 1 1* S. Scotland Mearns, 32* Sweden Lindberg, 1977 Newton, 25* United States Enderson, 1969 1983 29* Finland Mebs, 1971 28* Germany Mebs, 1971 Calculated by me from data in Kramer (1973). which may have moved outside the study areas to breed elsewhere. Nonetheless they are considerably lower than those made from general ring recoveries (Table 5). The two types of recoveries are from largely different sectors of the population. The general ring recoveries are mostly from birds found dead often killed by man, and often weighted heavily towards the younger age clas see. The estimates from particular studies refer to breeding adults in res¬ tricted areas, over shorter time periods. They thus represent the "better quality" individuals within a population. The estimate for the Sparrowhawk was from a slightly declining population, while that for the Peregrine was from an increasing population. The various estimates from national ring re¬ coveries were from populations that were fairly stable during the period from which all, or almost all, ring recoveries came. Relatively few recove¬ ries were included from the organochlorlne pesticide era, when populations declined. Perhaps the main lesson Is that estimates obtained in either of these ways cannot readily be extrapolated to the whole population, whatever its trend. Similar differences have been found in some other birds, in which mortality has been estimated in both ways (e.g. Perrins, 1971). In the absence of marked birds, the mean mortality in certain populations has been calculated from a knowledge of adult numbers over several years, and of the production of young. The method depends on the fact that, in any stable population, the birthrate must equal the deathrate. It tells us noth¬ ing of how mortality is distributed between different age classes, and beco¬ mes complicated when account must be taken of movements. It has been used on the isolated population of Red Kites Mllvus milvus in Wales, in which the mean annual mortality was estimated at 1796 (Davies, Davis, 1973), and more recently on a population of Ospreys in eastern North America, in which the •mean annual mortality of adult (2+) birds was estimated at 1 0-1 59S (Spitzer, 700 this symposium). Papulations of both species were increasing during the years concerned, and again the estimate for the Osprey was lower than one produced from general ring recoveries (Table 5). To my knowledge, no estimate from ring recoveries has been published for the Red Kite. AGE OP FIRST BREEDING A third aspect on which recent ringing has changed traditional ideas is the age of first breeding, and its relationship to plumage changes. Most ßmall and medium-sized raptors achieve definitive "adult" plumage in their second year of life, though some medium sized species probably not until their third year. Only the large eagles, vultures and condors take until their 4th-9th years, depending on species (Newton, 1979). Almost all our in¬ clination on plumage changes in large raptors has come from captive indivi¬ duals only, but in some smaller species, findings on captives have been amply confirmed on wild birds. Most raptors seen at nests are in "adult" plumage, so this has provided minimal estimates of the age of first breeding, when the age at which adult Plumage is acquired is known in the species concerned. However, many small and medium sized species have nested in "juvenile" or "immature" plumage, s owing that at least some individuals breed before the age at which they on the adult dress. This is frequent among small accipiters, falcons and others, and occurs occasionally among medium and larger raptors, including eagles (Newton, 1979). In those species studied in detail, breeding in "im¬ mature" plumage was more frequent in females than in males, more frequent in Sood than in poor food conditions, and more frequent in depleted than in sa¬ turated populations (Newton, 1949). Recent studies of ringed birds have provided more precise information, and B own that age of first breeding is highly variable within populations. In ®ach study, a bird was considered a first-time breeder, providing that (a) * was new to a particular territory, (b) it (or its mate) laid one or more (c) it was not previously known to have bred elsewhere. Because occa¬ sional individuals may have changed territories from outside the study areas, ese figures gave maximum estimates of age of first breeding, but territory changes were so infrequent in most species (see above), that the figures oRould not be greatly in error. In some of the larger species, certain indi¬ quais had occupied a territory in the previous year, without producing eggs. Among female Sparrowhawks found breeding for the first time, 49 (26$) were n their first year of life, 62 (33$) in their second year, and 78 (41$) at later age. Among male Peregrines, 4 birds first bred at 2 years old, one 3 years, and another at 4 or 5; among females, 2 birds first bred at one ^aar old, 13 at 2 years and one at 3. Another 5 yearling females were seen the breeding population without being caught, but no yearling males. These (a 0 SUggest 'that ®ales may start, on average, at a later age than females W8S found in captive Peregrines, Cade, Fyfe, 1977), but the sex difference as not statistically significant. In Red Kites, 5 birds first bred at 2 °ld> one at either 2 or 3, 3 at 3 years old, one at 4 or 5 (Davis, New- • ^SO). In Ospreys, 10 individuals bred in their third year, 3 in their 701 fourth and 2 in their fifth (Spitzer, this symposium). These four species acquire adult plumage in their second year. These various records show that age of first breeding is highly variable within species, and confirm that many birds may spend one or more years in full adult plumage before attempting to nest. In this respect, these raptors resemble some large seabirds. Factors which may lead to delayed breeding in¬ clude: (a) inability to acquire a suitable territory or mate, in an area in which all suitable territories and mates are taken, or (b) inability to accu¬ mulate the body reserves necessary to breed, itself partly a result of the food situation (Newton, 1979). Either way, the ability of a given raptor in¬ dividual to breed is not necessarily linked with gonad maturation. In small species, the gonads may be functional in the first year of life, yet breed¬ ing delayed for one or more years for the reasons just given. Some first- year male Sparrowhawks, which were not breeding, had testes as well develo¬ ped as other first-year and adult males which were breeding (unpublished da¬ ta). Thus, the age at which the gonads can produce active sperm or ova, the age at which adult plumage is acquired, and the age of first breeding are best regarded as largely independent events in raptors, only poorly correla¬ ted in any one population. The only invariable condition is that first gODad development should coincide with, or precede, first breeding. General terms such as "age of maturity" are therefore best avoided, and replaced by more specific terms, relating to the gonads, plumage or breeding, as the case may be. There may also be problems in judging age from plumage changes. In large raptors, such as Aqujla eagles, each generation of feathers may take more than one year to replace, and individuals may be in active moult for most of their pre-breeding lives. In such specieB, the age at which definitive adult plumage is acquired may itself be variable, depending on how quickly the bird has passed through previous plumages. Existing knowledge of plumage changes is based on small numbers of well-fed captive birds, as mentioned, but in¬ spection of wild and museum birds reveals vet? different rates of moult (num¬ bers of feathers in growth) in different individuals, and at different times. Thus some individuals may pass through a fixed number of plumages more quickly than others, and acquire their adult plumage at an earlier age. To my knowledge, no-one has demonstrated this in the field, but it is a clear possibility, which signals the need for caution in judging ages from pluma¬ ges in large species. CONCLUSIONS Despire the continued use of particular nesting places, which is such a striking feature of many raptor populations, the extent to which this invol¬ ves the return of the same individuals from year to year varies greatly bet¬ ween populations. Changes of territory were common among the individuals of some of the species studied, yet rare in others. In one species, movements were found only in females, and in others they were more frequent in females than in males. In Sparrowhawks and Kestrels, they also varied according to territory quality and food supply, birds staying more frequently in good tha*1 in poor conditions, and with age, with old birds staying more often than 702 young ones. On the other hand, fidelity to territory was not related to whe¬ ther a species was resident or migrant, as extremes of behaviour were found In both groups. Greater fidelity would of course be expected in populations that were stable in numbers and distribution from year to year than in popu¬ lations which were continually changing in relation to fluctuating food-supp¬ lies. None of the other phenomena discussed in this paper were unexpected, as they could have been predicted from studies on other birds. However, the mortality estimates from breeders, which are given here, are the first avail¬ able for any diurnal raptor, as are .the estimates of age of first breeding in birds in adult plumage. A major need now is for similar studies on large eagle species, as these birds are likely to be extreme by any standard in their low mortality and long pre-breeding periods. In recent years, with so many populations depleted by pesticide poisoning, attempts have often been made to model -populations, using precise statistics on breeding, but only rough approximations on other population parameters. Studies of the type des¬ cribed here should emphasise the weakness of existing models, as well as help bo improve future ones. SUMMARY 1. This paper reviews findings on fidelity to territory, adult survival and age of first breeding in raptors, based on recent studies involving marked adults. 2. The turnover of Sparrowhawks on territories was high, with 57$ of males and 50$ of females changing between one year and the next. Mean residence pe¬ riods were 1.4 and 1.5 years respectively, but some males stayed on the same territories for up to 5 years and some females for up to G. Turnover was due mainly to mortality, but partly to movement. Changes of territoi? were most frequent among young birds, among birds which were on poor territories, and among birds which failed in their breeding the previous year. 3. Among other raptors, species varied in the degree to which individuals stayed on the same territories from year to year. Changes of territories were frequent among Kestrels and Merlins, but rare among Peregrines and Ospreys. However, in all species in which the point was examined, males more often atayed on the same territories than did females. 4. Mortality based on recaptures of breeders in successive years Was es- tlmated at about 35% for Sparrowhawk females, and 11% for Peregrines (both aexea), while using a different method it was estimated that 15$ for Ospreys Hoth sexes) and at 17$ for Red Kites (both sexes). These estimates are lower *Han those obtained for adults of the same species in widespread ringing Bchemes, in which most recoveries are of birds found dead by members of the Pbblic> 5. Age of first breeding was highly variable within populations. Among “Parrowhawk females found breeding for the first time, 49 were in their first y®ar of life, 62 in their second year and 78 in a later year. Among Peregri- öee (both sexes), 2 were in their first year, 17 in their second year, 2 in Heir third year, and one in its fourth or fifth year. Among Ospreys (both 8exes) io were in their first third year, 3 in their fourth and 2 in their 703 fifth year; while in Red Kites (both sexes), 5 were in their second year, one was in its second or third year, 3 were in their third year, and one in its fourth or fifth year. References Balfour E. - Bird Notes, 1957, 27, p. 177-183, 216-224. Bent A.C. Life histories of North American birds of prey. Vol. 1, ?.. New York: Dover, 1938. Cavé A.J. - Netherlands J. Zool., 1968, _18, p. 313-407. Davies P.W., Davis P.E. - Br. Birds, 1973, ,66, p. 183-224, 241-270. Enderson J.H. - In: Peregrine Falcon populations; their biology and decline / Ed. by J.J. Hickey. Madison, Milwaukee and London; Univ. Wisconsin Press, 1969, p. 505-508. Ferguson-Lees J.L. - Bird. Notes, 1951, 24, p. 200-205, 309-314. Henny C.J,, Wight H.M. - Auk, 1969, 86, p. 188-198. Hodson K.A. The ecology of Richardson's Merlins on the Canadian Prairies. M.Sc. thesis. University of British Columbia (Vancouver), 1975. Kramer K. Habicht und Sperber. Die neue Brehm- Bücherei. Wittenberg Luther¬ stadt; Ziemsen Verlag, 1973. Lindberg P. The Peregrine Falcon in Sweden. Proceedings ICBP World Conference on birds of prey, Vienna, 1975. Vienna, 1977, p. 329-338. Matray P.F. - Auk, 1974, 9J.» P « 307-324. Meams R., Newton I. Turnover and dispersal in a Peregrine population, 1983. Mebs Th. - Die Vogelwarte, 1971, 26, p. 98-105. German, with English summary. Newton I. - Brid Study, 1975, 22, p. 35-43. Newton I. - Canad. Field-Nat., 1976, 90, p. 274-300. Newton I. Population ecology of raptors. Berkhamsted; Poyser, 1979. Newton I., Marquise M. - J. Anim. Ecol., 1982, 5_1_, p. 327-41 . Newton I., Marquiss M. , Rothery P. Age structure and survival in a Sparrow- hawk population, 1983. Perrins C.M. - Bird Study, 1971, _U3, p. 61-70. Schelde 0. - Dansk. Om. Foren. Tidsskr. , I960, 54, p. 88-102. Tinbergen L. - Ardea, 1946, 34, p. 1-123. Village A. The ecology of the Kestrel (Falco tinnunculuo) in relation to vole abundance at Eskdalemuir, south Scotland, Ph.D. thesis, Edinburgh University, 1980. Vries De Tj. - Le Gerfaut, 1975, 6^, p. 29-57. 704 INITIAI POPULATION RECOVERY OP BREEDING OSPREYS (PANDION HALIAETUS) IN THE REGION BETWEEN NEW YORK CITY AND BOSTON Paul R. Spitzer, Alan P. Poole, Michael Scheibel Section of Ecology and Systematics Langmuir Laboratory Cornell University Ithaca, N.Y, 14850; Boston University Marine Program Marine Biological Laboratory Woods Hole, Mass. 02543; N.Y. State Dept, of Environmental Conservation S.U.N.Y., Building 40, Stony Brook, N.Y. 11794, USA HISTORICAL BACKGROUND During this century and the last, the coastal zone between New York City and Boston, Ma. supported some of the highest recorded densities of nesting ospreys in the world. At least 1.000 nçsts are estimated to have been active in the early 1940’s (Spitzer, Poole, 1980). Typical reproductive rates in the 1930's and early 1940' s ranged from 1. 0-2.0 young fledged per active nest (defined as a nest in which eggs are laid) (Wilcox, 1944; Peterson, 1969 ; Puleston, 1977; Spitzer et al., 1978). During the 1950's and 1960's, this population suffered extremely poor reproduction, associated with DDE residues in eggs and abnormally thin egg¬ shells (Wiemeyer et al., 1975; Spitzer et al., 1977). The first precise ob¬ servations, made in the period 1957-1962 in portions of Connecticut and eastern Long Island, N.Y., averaged 0. 2-0.4 young fledged per active nest (Ames, Mersereau, 1964). This is though to be typical of most of the popu¬ lation at that time. With reproductive rate a small fraction of what was con¬ sidered normal, natality was inadequate to balance mortality. The population crashed ', declining at perhaps 10% each year. Concentrations of nest in the Connecticut River estuary, Ct., and NarraganBett Bay, R.I., were declining at rates of up to 30% per year (Ames, 1966), implying local adult death rates far hlgher than nonnal. By 1969, the number of active nests in the region was reduced to about 150, roughly 15% of the 1,000 estimated 25 years previously. (See map of study region - Figure 1.) THE STUDY PERIOD 1969-1981 During the period 1969-1981 .Spitzer, Poole, Scheibel, many cooperators, and atate agencies recorded active nests and young fledged in the region. The region's accessibility, the virtually complete restriction of breeding osp¬ reys to the coastal zone, and the abundance of good observers allowed near- total counts of these two population parameters (Spitzer, 1980). Trends in hese parameters can be summarized as follows (see also Figure 2); 1 ‘ ^production in 1969 was 0.53 young fledged per active nest, and had Probably already increased to about twice the rate of the early and mid- 96o’s (Spitzer, 1980). 2- Reproduction increased steadily to 1.55 young per active nest in 1981. Th 1lhi eggs have been analyzed for DDE since 1976. first part of this increase is known to have coincided with sharply dec- ng DDE concentrations in eggs (Spitzer et al., 1978). Unfortunately, no ■3aK.9Sl 705 Pig. 1. Map showing geographical isolation of the study population I - 200 plus est Maine coast, beginning at Casco Bay, Just NE of Portlandj II - 0? southern Maine coast to northern Cape Cod - no active nests known! Ill - 109 the population under study; IV - Sandy Hook + Navesink River, N.J.; V - 6 Manasquan R. to Bamegat Light, N.J.j VI - 53 southern N. J. coast (mostly Cape May County); VII - 153 Atlantic coast of Dela¬ ware, Maryland, + peninsular Virginia 1975 data are used because precise surveys of breeders were carried out between N.Y. City and Chesapeake Bay in that year (see Henny et al., 1977) + 10% Change in Breeding Population ® Size (A) -10% Productivity (Young per Active Nest) 1.5 1.0 0 * J i _ i _ i i / V- / -1 - 1 - 1 I I I I I 69 72 75 78 estimated break -even point M Year Pig. 2. A comparison of Osprey reproductive rate and change in population size, N.Y. City to Boston, 1969-1981. Points denoted by "X" on the lower graph are productivity values which include young introduced from Maryland by Spitzer (1978) 3. The active nest count showed an annual decline of about 10% in both 1970 and 1971 (Spitzer, 1980). This was a continuation of the "crash" of the late 1950’s and the 1960's, with natality inadequate to balance mortali¬ ty of breeders. 706 4. Prom 1972 through 1975, the annual decline in active nesta averaged 3%. llowing for the 3 to 5 years between fledging and first-breeding (Spitzer, 1980), we hypothesize that local natality was at levels nearly adequate to balance mortality. There was no evidence of excessive, toxin-related adult ortality in this period. In the years 1968-1973. local natality was boosted Îwwf °f 6gEB and ne8tllng8 from the Chesapeake Bay region (Fi¬ gure 2) (Wiemeyer et al., 1975; Spitzer, 1978). 5. In 1976, the breeding population stood at 109 active nests its low point for the 20th century. During the next five years, the breeding popu- :r/hor*teady aMuai increase8 **>* 6.9 10 n.5*. m* i981 count found 168 active nests in the region. ESTIMATION OP A REPRODUCTIVE "BREEK-EVEN" POINT aueI!lvTTiC,rCrea8eB in reproduction (young fledged) and subse¬ quently in breeding population size (active nests) encouraged Spitzer to exa¬ mine the relationship between these parameters. This required data on (1) elHiTi f /0UBg b6tWeen fl6dging “d breeding* (2> «S*»«! fidelity of coÎl ’ 81111 (3) age at ««t breeding, all of which had been collected during the study period. The effects of these variables can be summarized as follows (for details see Spitzer, 1980): 1. Dispersal distance was low, especially that of males (Table 1). since l jTarBJhat Bale8 SeleCt the De8t l0C8tl0n <8P“«er, unpub 1. data), this 6 6 eCt °f tieing regional reproduction even more closely to subse¬ quent change in population size. Nestling ospreys have been intensively p“ ed.ln “ arC °f coastline stretching from Virginia to Massachusetts, thus ares V l P°tenU&1 diSC0Veiy °f long-distance immigrants from nesting io f80U h °f Ne" Y°rk City* ^ere was evidence of significant immig^t- on of males from thle direction, aDd only 2 feaales were maki uch a movement. More impressive evidence of low dispersal rates came from pe May County, New Jersey, where of 24 banded breeders trapped in 1979 1 * 4* 811 femaleB. had fledged at nests 71-261 km away in Delaware, Ma^y- ' ^ Virglnia* despite 5,309 bandings in those states in the years 1955- U Ql k i 1 e 1. Relationship of dispersal to sex (Prom Spitzer, I960) e re en tage in each category Males (n = 33) rcentage in each category tee- a) Maximum female movement in sample is 520 km. b) Maximum male movement in sample is 37 km. c) Maximum distance between large-Bcale banding and trapping activi- tles, thUB maximum detectable movement, is 700 km. 707 1976 (Robichaud, in prep.). 522 bandings in Cape May County during the same time period yielded 18 of the 24 banded breeders trapped there in 1979. We realize that long-distance dispersal of both sexes occurs. Ospreys re¬ colonized Scotland, presumably from Scandinavia (österlöf, 1977). A color- banded male bred at Montezuma National Wildlife Refuge in central New York atate in 1980 and 1981, the only known active nest in this region, and 425 km from the nearest color-banding activity. However, currently available evi¬ dence suggests that long distance dispersal of ospreys is occurring at low frequency in the northeastern United States, sufficient to establish some new breeding areas but not to have large effects on subsequent population dynamics. The low fledging-to-breeding dispersal distance of a bird that per¬ forms dramatic seasonal migration is quite remarkable. The reduced density of some populations owing to DDT effect may reduce pressure for such disper¬ sal, if indeed it is density-dependent. Ospreys breeding to the north of our study area in Maine and Canada area not banded intensively, and the possibility of net immigration from that re¬ gion cannot be assessed from band recoveries. Many individuals from that re¬ gion would pass through the study area twice a year, and ospreys linger around at least one food— rich portion of the study area - the Connecticut Ri¬ ver estuary - during fall migration. We assume that net immigration from the north (as well as from the south) is negligible. This assumption will become important in subsequent calculations of the population's reproductive "break¬ even" point and in discussion of annual survivorship. 2. Potential movement of established breeders was studied by color-banding a sample of breeding birds. These individuals typically returned to the same nest site or one within 2 km for many yeare in succession. 3% of the retur¬ ning birds moved from 2 to 18 km (N=136). No greater movements were recorded. 3. Age at first breeding was estimated by Spitzer (1980). During the course of nest surveys, checks for breeding birds color-banded as nestlings were made whenever possible. When such a bird was found breeding at a site where either it had not been present the previous year, or had been a non-breeder, and when there was no evidence that it had bred previously elsewhere in the region, it was considered a first-time breeder. Prom 20 such records, the proportions of first-time breeders were estimated at 5056 three-year-olds, 30$ four-year- olds, and 20% five-year-olds. Spitzer then calculated the young per active nest figure ("productivity") that should most accurately reflect the level of recruitment of new breeders in a given year (known as year "t"). He weighted the number of young fledged 3, 4, and 5 years ago (known as Yt_3» Yt-4' 800 Yt-5^ ^y their estimated contribution to first-time breeders, thus: 0.5 Y^._^+ 0.3 yt_^+0.2 Yt_^. To adjust for change in breeding population size since these young fledged, he divided their weighted sum by the number of nests active in the year immediat¬ ely before their reciuitment, At_i. This measure of productivity (0.5 Yt-3+ +0.3 Yt_4+0.2 Yt_^) / At_i he ca:1-le(i adjusted recruitment productivity, or M A p P tf # XV # X # • Calculating A.R.P. for the years 1974-1981, we compare it to annual per cent change in breeding population size, defined as /(At-Af_1 )/At_1/ x 100 = 708 Pig. 3. Relationship between "Adjusted Recruitment Productivity" (ARP) and annual change in breeding population size, 1974-1981. Prom Spitzer(1980) This comparison is shown in Figure 3. Without any effort to apply fur¬ ther mathematics or statistics to these eight data points, we argue that they suggest a production requirement for population stability of roughly 0.8 young fledged per active nest under the particular conditions of population density and age structure during the study period. ADDITIONAL CHARACTERISTICS OP THE RECOVERING POPULATION U jgpUed High Survivorship. Using 0.8 young/active nest as the populat¬ ion's reproductive "break-even" point, Spitzer (1980) estimated annual sur¬ vivorship rates of 59* during the first year of life (sQ) and a constant 85* thereafter (s). The simple equation used to make these estimates, developed by Henny and Wight (1969), does not allow for age-specific variation in sur¬ vivorship after the first year of life, although such variation is common within and between populations of long-lived vertebrates (Miller, 1976; Caugh- ley’ 1977). However, the simple equation that uses only sQ and s is adequate to make the point that current survivorship appears to be higher, and product¬ ion requirements for population stability lower, than the estimates made by Henny and Wight (1969) based on composite dynamic life tibles constructed from recoveries of ospreys banded as nestlings in the northeastern coastal region in the years 1926-47 (and recovered over the next 20 years). Such re¬ coveries are now seldom used to estimate annual survivorship and production requirements (for details see Spitzer, 1980; Burnham and Anderson, 1979; An¬ derson et al., 1981). Although a reproductive "break-even" point of 0.8 supports estimates of 80“-59 and s-,85, the speed with which the breeding population has increased during the last 5 years means that; (1) survivorship of some age groups has teen higher than one or both of these estimates, or (b) there has been net immigration to the breeding population, or (c) some combination of these two factors has occurred. The DDT era appears to have resulted in population den- ®ity being reduced faster than habitat quality - thus very high survivorship in the expanding population is perhaps not surprising. A 90* annual survivor- 709 Bhip of breeding birds (which implies that all two-year-olds and some three and four-year-olds are still surviving at 85%/year) is one pattern which would roughly account for the observed rate of population recovery. This sur¬ vivorship pattern and others will be tested against the accumulating popu¬ lation data. 2. High Proportion of Non-laving Pairs. We define "non-laying pairs" as those which build a nest but do not lay eggs. We have observed a dramatic increase in non-laying pairs as the study population shifted from decline to growth: None were recorded in 1970, 3 in 1972, 2 in 1973, 5 in 1974, 2 in 1975, 9 in 1976, 10 in 1977,17 in 1978, 22 in 1979, 20 in 1980, and 26 in 1981. We suggest that this trend is due to the inclusion of more young birds in the population. As proportionately more young birds return, there are pro¬ portionately fewer experienced birds in need of a new mate. Inexperienced birds may be forced to pair with each other, and although they frequently build a nest, laying of eggs may be less likely to occur. This phenomenon can be modeled with our annual data of active nest (A) and young fledged (Y). s =.59 and s=.85 are used, but other survivorship schedules would yield a si¬ milar pattern. In any given year "t", we are interested in the ratio of "sur¬ viving young 3 to 5 years old", the source of new breeders, to "available ex¬ perienced birds", defined as those established breeders whose mates have died since the last breeding season (year t-1). surviving young 3 to 5 years old = sQs Yt_j available experienced birds = A^._1 j^1 - last year' s laying pairs + 80s3ït-4 + flos4*t- s2 - (1 s) neither both of the of the pair pair- dies die = At-1 D-<°‘852) - (0-152)] 0.255 At-1 ont of the pair dies This ratio provides a useful measure of age structure, and we will call it the age structure ratio, or "A.S.R.^". Calculating A.S.R. for the years 1974— 1981, we compare it to the ratio of non-laying pairs to active nests (Figure 4). When A.S.R. is near 3.0, there are few non-laying pairs. This makeB sense because only about one-third of the" "surviving young 3 to 5 years old" would initiate breeding in a single year. Thus a potential one-to-one match of these with "available experienced birds" is implied by a ratio of 3.0. (It should be noted that available experienced birds may preferentially pair with one another, especially if they are in close proximity). As the ratio rises above three, the potential new breeders would begin to outnumber available experienced birds and be forced to pair with one another. During the years 1979-81, as A.S.R. approached 4,0, the ratio of non- laying pairs to active 710 0.20 ■ Non- 0.15 Laying Pairs • ’78 010 ■ Nest • '76 ,'77 0.05 • '74 •'75 0,00 - - » 3.00 • 79 • '80 3,25 3-50 3.75 Surviving Young 3 to 5 Yeors Old / / Availoble Enperienced Bird 4.00 Ï Age Structure Ratio F i g. 4. Relationship between population aee-atnir-t-nr. ^ non-laying pairs, 1974-1981. Surviving youJ 3 tTl portion of perienced bird is tenned the age stature ratio. Lî” if or derivation of figures 6 tSXt r°r details* and nests hovered around 0.1S _ 1»«..«, tt. *.S.R. ,J ; IT" J’”4“«'1« coittioued ,0 .. 4.5. I, non-laving „am. t0T «.a LT«T IT"” " h1"' even a larger proportion relative to thP „ f t0 0,20 or continued rise in active nests. ^ ^ °f 3CtIve nests. despite a ^ • Heavy Use of Mftn—moHa Npptlno* dib+* ne8tB bee occurred on such sites Avail bllTt* ^ **“ lncrea8e of active far generally been in excess of ^opulatioTL Platf0rmS 1188 80 emphasised that nest sites »t,h / ! increase. Newton (1976, 1979) has limiting raptor ZtlllZs rt 17^ *** ^ ^ or factors ».rung .hi hn.Zg “Tl.îon*InTo” T ’"T "" —* «"* * call ties. Man-made nestln« r,iatfn / reproductive success in some lo- human activity) L7Z«\ Pr0Vldin« 8ta»le. isolated (from 4.»«uu Z I.“ Z r ZTZZV“' Thl- 1m* 1. ■«> areas 1 « JZZZZZZT ^ *” in much of the “ersereau, 1964= Reese, 19?7TpooT ^ ^ f"“* °f °apreyS m J 1 “ ta- *•» «•*•*. DIFFERENT patterns op changes «nd^ome6 f0ll0Wlng* the 8even categories are treated, and a list of s°me maps presented for each.- llst of sPecies thi"^ a° ChanK~- The Bymbola 0 m clear majority As st * does not mean that no trend er-int« , y* 8 8tates above, ?ed* Thla ia the largest category with'n^ns l*V D° treBd h8S been noti~ leaa than 63 4* „f with 134 (35.5*) species (Table 1) PUiatione K ! are pa8eerln®a. which can hardly be due to trendsa"' P8rtiCUlarly 8table. bux rather to the fact thlt 1 P°“ es ak:;;:: :r:: zzzr:- Theroruy °f the b- - - — .» »rr rcxv:“ r:::; - 717 Table 1. Species showing largely no change In range or numbers in Europe. The symbols Indicate the status of each species In different countries ( + » Increase, 0 = no change, give the number of countries - « decrease, ? • status unknown ) , the figurei Species •f 0 - ? Podiceps grlsegena 2 10 2 3 Calonectris dlomedea - 5 1 - Puffinus pufflnus - 8 2 - Hydrobates pelagicus - 9 1 - Oceanodroma leucorhoa - 5 - 1 Anas penelope - 8 - 5 A. acuta 2 14 3 5 A.clypeata 2 16 2 6 Mergus serrator 1 13 1 1 Buteo lagopus - 4 - - Palco ve8pertinus - 5 1 3 P.eleonorae - 3 - - P.rusticolus - 5 - - Lagopus mutU8 - 13 1 - Charadrius morinellue - 9 - 1 Calldris maritima 1 4 1 1 C.a.alpina - 6 - - Limicola falcinellus - 4 - - Lymnocryptes minimus - 4 1 3 Limosa lapponica - 4 - - Numeniu8 phaeopus . 7 2 - Tringa erythropus - 4 - • T.nebularla - 6 - 2 Arenaria interpres - 6 - 1 Stercorariu8 parasiticus - 5 2 - S. longicaudus - 4 - - Chlidonias hybridus - 8 1 4 C. leucoptera 1 4 - 3 Uria lomvia - 3 - - Cepphus grylle 1 9 - - Pterocles orientalis - 2 - 1 Cuculus canorus - 21 4 2 Sumia ulula 4 «. - Glaucidium passerinum — 11 1 5 Strix aluco 24 1 1 §.uralensis 1 7 _ 4 S.nebulosa 4 » 2 Asio otus 2 23 1 A.f lammeus 2 14 3 6 Aegolius funereus «. 14 2 5 Apus apus 1 24 2 • 1 A.pallidus 5 _ 1 A.melba 718 - 10 - 2 £ £ £ Species + 0 Pious canus P. viridis Dendrocopos major D. minor Picoidee tridactylus Calandrella brachydactyla Calerida theklae Eremophila alpeetris Hirundo ropestrls Delichon urbica Anthus trivialis A. cervinus A.epinoletta Motacilla alba Bombycilla garmlus Troglodytes troglodytes Prunella modularis P.collari8 Cercotrichas galactotes Erithacus rubecula Luscinia megarhynchos Saxicola torquata Oenanthe pleschanka Oe •hiepanioa Monticola solitarius Turdus torquatus T. philomeloB T. viacivorus Acrocephalus melanopogon Hippolais pallida icterina ^•polyglotta Sylvia sarda S. un da ta S.conepicillata S.cantillans s*melanocephala S. hortensia S.curruca S.borln S.atricapilla phyllo8copus borealis •bonelli •sibilatrix •collybita ph.trochilus J^gulus regulus 1 16 21 25 1 20 11 8 2 5 9 3 23 23 4 1 17 27 4 26 3 21 13 3 1 25 2 13 2 14 3 5 1 6 1 16 2 24 24 7 1 4 18 1 4 3 4 4 5 6 5 1 21 22 1 23 4 9 1 20 1 24 1 19 1 22 Table 1 (end) ? 1 3 1 2 - 1 3 ‘ 1 3 4 1 1 - 1 1 1 2 1 2 4 2 1 1 1 1 3 1 - 1 1 1 3 1 2 3 3 1 2 1 1 2 1 1 2 1 2 2 2 1 - 1 2 3 1 2 1 5 3 1 2 1 2 2 2 1 2 719 preserved, but lack of Information may also play a part. Some characteristic representatives of this category are shown in Pig. 1. 2. So change or decreasing. Roughly 20-50% of the symbols indicating decrease, the rest mainly no change. The second largest category, comprising 91 (24.156) species (Table 2). The range of the area with a decreasing trend varies from species to species, but some consistent patterns are repeated strikingly often. Several species show a decrease only in the nucleus of their range, in central Europe, but are fairly stalbe in the more peripheral areas (e.g. Tetrao tetrlx, Rallus aquaticus, Scolopax rustlcola, Actltls hypoleucos, Alauda arvensls. Hlrundo rustlca. Anthus campestrls. Sylvia communis). Another pattern, common to still more species, shows a decreasing trend in the western and central parts of Europe, but no significant change in the rest of the range (e.g. Botaurus stellaris, Ixobrychus mlnutus. Anas querquedula, Bonasa bonasla, Burhinus oedlcnemus, CharadrluB alexandrinus, Gallinago galllnago, Trlnga totanus. Alcedo atthls. Luscinla svecica, Saxicola rubertra, Lan lus collurio. L. minor, L. senator. Emberiza hortulana). In some species, decreases are reported from considerable parts of the range (e.g. Sterna hlrundo, Chll- donias niger, CaprlmulguB europaeus, Upupa epops, Galerlda crlstata, Lullula arborea. Phoenicurus phoenicurus). Pig. 2 gives some examples of these patterns. 3. No change or increasing. Rougly 20-5056 of the symbols indicating an in¬ crease, the rest mainly no change. Clearly smaller than the previous category, with 47 (12.556) species (Table 3). The most conspicuous pattern is shown by species increasing and expanding in the northern parts of their range, but having fairly stable populations elsewhere (e.g. Ardea cinerea. Circus aeru- ginosus, Gallinula chloropus, Recurvirostra avosetta, Columba palumbus, Phoe¬ nicurus ochruros, Locuatella luscinioldes, Acrocephalus palustris, Panurus biarmicus, Serinus serinus). Some species show increases over considerable parts of their range (e.g. Podlceps crlstatus. Anas strepera, Aythya ferina, Buteo buteo, Fulica atra, Vanellus vanellus, Turdus merula. Pica pica). Pig. 3 depicts some species showing different patterns of increase. 4. Decreasing in some parts, increasing in others. Both decreasing and in¬ creasing trends evident in some parts of the range, on change in the rest of area. Almost as large as the last category with 44 (11.7%) species (Table 4). Many of them show the same pattern, increasing and expanding in the north, but simultaneously decreasing in western and/or central Europe (e.g. Circus pygar- gus, CharadrlU8 dubius, Philomachus pugnax, Llmosa limosa, Steroa paradlsaea, 3treptopelia turtur, Motacllla cinerea, Locustella naevla, L.f luvlatllls , Acrocephalus scirpaceus, A.arundlnaceus, Sylvia nisoria, Lanius excubitor). A few species are on the increase, at least locally, in the western parts of their range, while decreasing in the east (e.g. Phalacrocorax carbo , Ph. aristotelis, Milvus milvus, Accipiter gentllis, A.nlsus ) . An opposite trend, increase in eastern Europe, but decrease in most other parts of the range, is shown by Gypaetus barbatus. Neophron percnopterus and Tetrax tetrax. Ex¬ ceptional patterns emerge from the maps of Ciconla nigra (decrease in SW and NE, increase in some central European countries), Milvus migrans (decrease in the central parts of the range, increase in both W and E) and Larus fus cue (decrease in N, increase in W and SW). Most of the remaining species show a 720 LlL« i t' Specles elther decreasing or showing no change in range or numbers in Europe. For explanations, see Table 1 Podiceps nigrlcollis Botaurus stellaris Ixobrychus minutus Ardea purpurea Platalea leucorodia An8er fabalis Tadorna ferruginea Anas crecca A.querquedula Aythya nyroca A. marl la Clangula hyemalis Melanitta nigra M.fusca Pernis apivoius Circaetus gallious Accipiter brevipes Aquila pomarina A.chrysaetos Hieraetus pennatus H. fascia tus Pandion haliaetus Palco naumanni P* tinnunculus P* subbut eo P*biarmicus P« cherrug Bonasa bonasia Bagopue lagopus Tetrao tetrix Alectoris chucar A*ruf inus Rallus aquaticus Porzana porzana P°rphyrio porphyrio Gl^s grus burhinus oedicnemus r,lareola pratincola Charadriu8 hiaticula c*alexandrinus Pluvialie apricaria GaUinag0 gallinago Scoiopax rusticola ^dnienius arqua ta l0- 3aK. 98) 2 10 1 11 8 1 8 1 4 2 2 15 1 15 9 4 3 5 2 14 5 2 1 7 2 8 6 2 2 5 3 20 13 1 3 8 4 10 2 2 1 17 - ii 1 7 7 5 11 10 1 5 11 2 12 2 11 7 10 5 5 4 2 3 8 8 5 3 1 2 2 6 6 1 3 9 3 2 7 6 7 10 1 3 7 4 1 1 1 3 5 5 2 5 5 2 7 6 6 1 1 7 9 3 1 3 3 1 3 1 2 1 1 1 6 4 1 1 1 2 4 1 2 1 4 1 2 1 6 8 3 2 1 1 4 3 3 721 Table 2 (continued Species + 0 - ? Tringa totanua 2 14 10 Actiti8 hypoleucos 16 5 4 lamx audouinii 2 2 Gelochelidon nilotica 5 2 2 Sterna hirundo 1 14 11 Chlidonia8 niger m 8 11 4 Uria aalge 1 7 5 Alca torda - 6 3 Pratercula arctica 5 2 Pterocles alchata 2 1 Otus scops mm 6 6 2 Nyctea 8candiaca 2 2 2 Caprimulgus europaeus mm 9 13 5 Alcedo atthis 3 10 12 2 Upupa epope 8 11 3 Merope apiaater mm 9 3 2 lynx torquilla 16 8 1 Dendrocopoa médius 12 5 3 D. leucotos m. 11 6 2 Melanocoiypha calandra _ 5 2 1 Galerida cristata 1 10 10 2 Lui lui a arborea _ It 13 2 Alauda arvensis 18 8 2 Riparia riparia 1 19 5 2 Hiiundo rustica 1 T9 e 1 Anthua campeatriB 1 14 5 3 Motacilla flava 3 14 8 1 2 Cinclue cinclus 1 15 6 Lu8cinia avecica 1 9 6 Phoenicurua phoenicurua 15 10 2 Saxicola rubetra 16 10 a. Oenanthe oenanthe 22 6 1 Oe .leucura 1 1 1 Monticola saxatilia mm 10 3 1 Acrocephalue paludlcola 4 3 8 A A. Bchoenobaenus 2 14 Sylvia communie _ 18 7 2 Parus cinctue mm 2 2 Laniua collurio L. minor 1 12 8 12 7 1 1 L. senator mm 6 8 3 Periaoreus infaustus Pinicola enucleator Emberiza citrinella 3 3 20 1 1 6 E.cirlus - 6 2 4 722 species 0 Table 2 (end ) E.hortulana Miliaria calandra R. lgnlcapillus Musclcapa striata Plcedula parva Aegl thalos cauda tus Parus palustris P- lugubrls P.montanus P.oristatus P.ater P.caeruleus P. major Sitta europaea S. neumayer Tlchodroma muraria Certhia faml llaris C.brachydactyla Oriolus orlolus Garrulus glandarlus Nuclfraga caryocatactes Pyrrhocorax graculus P»pyrrhocorax Corvus monedula C. co rone Passer domeBtlcus P»montanus Petronia petronia Montlfrlngilla nivalis Pflngilia coelebs montlfrlngilla Serlnus cltrlnella ^arduelis chlorls C.carduells C.spinus C«cannablna c«flavirostris ^xia leucoptera L.curvlrostra ^•Py tyopsittacus ^miula pyrrhula Coccothraustes coccothraustes alcarlus lapponlcus Plectrophenax nivalis ^beriza cia ^elanocephala + 9 1 1 2 8 3 14 24 1 8 1 23 1 19 4 18 1 21 1 22 1 25 4 21 1 21 3 11 21 1 14 2 19 4 20 3 14 2 8 1 6 4 19 3 21 1 25 1 21 1 5 1 6 1 26 1 4 6 2 23 3 21 3 18 2 22 - 4 3 2 19 5 24 2 21 1 4 6 1 10 4 10 1 1 2 1 1 2 1 2 1 1 1 1 3 1 1 3 1 1 2 1 2 2 3 3 2 5 2 1 1 4 2 3 1 2 3 1 5 3 3 2 4 3 2 3 2 1 2 4 1 2 2 4 2 1 5 3 2 3 1 2 723 Table 3. Species either increasing or showing no change in range or numbers in Europe. For explanations, see Table 2 Species Tachybaptus ruficollis Podiceps cristatus P.auritus Ardeola ralloides Egretta garzetta Ardea cinerea Phoenicopterus ruber Branta leucopsis Anas strep era A.platyrhynchos Netta rufina Ay thy a ferina Bucephala clangula Mergus albellus Circus aeruginosus Buteo buteo Gallinula chloropus Fulica atra Haematopus ostralegus Recurvirostra avosetta Vanellu8 vanellus Tringa stagnatilis T.ochropus Larue melanocephalus L.genei Stem caspia Columba palumbus Dendrocopoe syriacus Hiiundo daurica Luscinia luscinia Tarsiger cyanurus Phoenicums ochruros Turdus merula Locustella luscinioides Acrocephalus agricola A. palustris F.icedula albicollis F.hypoleuca Panums biarmicus Remiz pendulinus Pica pica Sturnus vulgaris S. unicolor Passer hlspanlolensis 5 13 2 3 4 13 1 2 13 6 4 13 5 1 1 1 9 5 10 8 8 12 1 4 4 2 2 7 4 3 5 2 9 12 8 1 5 3 5 9 6 6 7 1 3 0 - ? - 7 13 - 1 5 - 3 5 1 1 4 1 2 11 2 1 2 2 10 1 3 20 2 1 8 1 3 13- 2 6 1 2 - 1 10 2 2 17 - 1 21 1 17 - 1 10 2 1 8 3 1 12 3 1 2 - 1 6 2 2 9 1 1 1 1 3-2 21 - 1 5 - - 2-3 5 2 1 15 1 1 16 - 1 11 1 4 1 - 1 18 1 9-2 14- 2 6 3 3 10 1 3 19 1 1 19 1 1 2 - 1 4 1 724 Table 4. Species decreasing In some parts of Europe and Increasing In others. For explanations, see Table 1 Species •f 0 ? Phalacrocorax carbo 4 9 5 1 Ph.aristotelis 3 8 1 Ph.pygmaeus 1 1 3 Nycticorax nycticorax 3 7 2 A Egretta alba 3 2 3 4 1 Ciconia nigra 4 8 5 Plegadis falclnellus .1 2 1 1 Mergue merganser 4 10 4 Mil vus migrans 4 7 7 3 M.milvus 5 5 6 4 Oypaetus barba tu s 1 2 3 Neophron percnopterus 1 1 4 p Circus cyaneus 2 10 4 4 C.pygargus 2 9 6 c Acclplter gentille 6 5 13 J 2 A. ni sus 5 9 11 2 Buteo rufinus 1 1 1 Phasianus colchicus 9 9 0 Tetrax tetrax 1 2 P Hlmanthopus himanthopus 2 7 J 3 c. Charadrius dubius 6 1 3 p Calldrls temminckii 1 2 2 Bhilomachus pugnax 3 4 8 hlmosa limosa 5 4 1 0 Trlnga glareola 1 5 *5 Phalaropus lobatus 1 6 2 4 Stercorarlus skua 1 1 *1 1 Larus minutus 3 6 2 1 1 B.fuscus 6 6 3 Sterna sandvicensis 3 7 2 S.paradlsaea 4 8 4 Columba livla 2 1 1 / Streptopella turtur 4 14 4 p Cryocopus martius 5 15 2 p Anthus pratensis 2 13 6 p Motacilla cinerea 5 14 3 p kocustella naevla 5 1 1 4 c 4 L.fluvlatllis 4 4 3 Acrocephalue scirpaceus 5 16 3 4 2 A . arundlnaceus 3 11 8 p Sylvia nisoria 2 10 3 c p Nablus excubltor 4 6 Q c»pvus f rugllegus 8 12 5 J^iberlza schoeniclus 5 17 3 1 725 Pig. 1 . Species showing largely no change in range or numbers in Europe A - Strix aluco; B - Apua melba: C - Motacllla alba: D - Plectrophenax Qivalis; + - increase, 0 - no change, - - decrease, ? - status unknown mosaic-like distribution of + and - symbols, indicating that local changes in the availability of habitats or conservation measures have affected their status (e.g. Mycticorax nycticorax. Egret ta alba. Mergus merganser, Hlmantho- pus himanthopus, Corvus frugilegus). Pig. 4 shows some typical representati¬ ves of these different patterns. *■>- largely decreasing. More than half of the symbols indicating a decrease Twentynine species or 7.7 % belong to this category, which is especially im¬ portant with respect to nature conservation (Table 5, Pig. 5). About half of them are widely distributed in Europe and have decreased in sin alarming man- 726 F 1 g. 2. Species showing no change or decreasing in Europe. Cf. Pig. i A - Tetrao tetrix; B - Saxicola rubetra; C - Upupa epops; D - Hirundo yustica; E - Lanius minor; P - Phoenicurus phoenicurus 727 F 1 g. 3. Species showing no change or increasing in Europe. Cf. Pig. A - Columba palumbua; B - Serinua serinus: C - Podiceps cristatua; Phoenicurus ochruros; E - Anas strepera: P - Buteo hitpn 728 F i . V'SsJ» °^herô. Cf!Pp1Cg.e31deCreaSinS ln a°me PartS °r and ^creasing in y.: B ' ^cclplter Sentilis; C - Ciconia nigra: D - Acro- ^ 2_5£H£liinaçeus; 3 - Gypaetus barbatus; P - Coryus fragiles» 729 s-i ijEUMA ot t î1 i g. 5. Largely decreasing species in Europe. Cf. Pig. 1 A " Falxo peregirinus; B - Columba oenas; C - Alectoris graeca; D dix perdix; E - Athene noctua; F - Falco co lumbar ius Per- 730 p i g. 6. Largely increasing species in Europe. Cf. Pig. 1 cî,7» A - Cygnus olor; B - Corvus corajc; C - Bubulcus ibis; D - Streptoperfa dec'aocto ; E - Rissa tridactyla; P - Carpodacus erythrinus 731 Table 5. Species- largely decreasing In range or numbers In Europe. For explanations, see Table 1 Species + 0 - ? Gavla stellata - 4 5 - G.arctica - 4 5 - Pelecanus onocro talus - - 4 - P.crlspus - 1 3 - Cioonia ciconia 2 7 10 Anser erythropus - 1 3 - Marmaronetta angustlrostrls - - 2 1 Oxyura leucocephala - - 3 - Haliaeetus albicilla 1 4 9 - Gyps fulvus 1 • - 6 - Aegyplus monachus - 1 3 1 Aqulla helldca - 1 7 - Palco columbarlue - 4 6 1 P.peregrlnus 2 5 17 2 Tetrao urogallus - 5 15 1 AlectorlB graeca - 2 6 - Perdlx perdix - 5 20 2 Co tu mix coturnix - 6 18 2 Crex crex - 4 19 2 Otis tarda 1 - 9 1 Calidrls alplna schlnzii - 3 7 2 Galllnago media - 1 7 1 Sterna dougallll - - 3 - S.albifrons 2 6 14 1 Columba oenas 2 10 14 1 Tyto alba 1 8 14 2 Bubo bubo 2 4 15 1 Athene noctua - 6 14 2 Coracias garrulus - 7 9 1 ner in most parts of the range In recent time (e.g . Ciconia ciconia , Palco peregrinus, Tetrao urogallus. Perdix perdix. Coturnix coturnix. Crex crex. Sterna albifrons. Columba oenas. Bubo bubo. Athene noctua). The rest include both southern (e.g. Oxyura leucocephala. Alectorls graeca) and nothern spe- oies (e.g. Gavla stellata, Anser erythropus. Palco columbarlue ) , and western (Calidrls alpina schlnzii. Sterna dougallll ) and eastern species as well(Pe- lecanus onocrotalus, P.crlspus), some of which having a very restricted dis- tribution in Europe. 6. Largely increasing. More than half the symbols Indicate an increase. Of these 26 species (6.9^) about one half is widely distributed (e. R. Cygnus olor. Anser anser, Larus ridibundus. Streptopelia decaocto. Turdus pilaris. f1, «.*- counted f fl 77 °" 5° Bt°PS >aCh (0'8 aPart> at "»ich birds are 77 l „ * (RObbln8’ ^ VelZeD* 1969)* There is a ooordinator in each state and each Canadian province who helps select qualified volunteers by Z ni 1 * rteS* Tn8trUCtlone' maPa. printed forms are supplied y he U.S. Pish and Wildlife Service and the Canadian Wildlife Service, and frill ! 81-8 eBtered dlreCtly °nt° mSgnetlC taPe fl,0,n the reP°rts received from the observers. After going through a series of edit checks, the data are analyzed by computer to measure year-to-year changes in the population of eac species and to calculate long-term population trends. Various reports are generated for the observers, the coordinators, and for research purposes- and computer-generated maps are prepared for selected species. The illust¬ rations that follow are based primarily on Breeding Bird Survey data for the years 1966 through 1979.Because of a change in computer equipment, there has een a delay in processing the data for subsequent years. Most of the recent changes in range of North American birds fall into one of aeven categories. The first I shall discuss is introductions by man. Dist ibutional changes tend to be most rapid in situations where man has intro- uced a species into a favorable environment. There are a few species whose range is expanding so rapidly that one can connect the outlying localities y a series of concentric lines representing expansion over short intervals ° years* The expansion of the eastern population of the House Pinch (Camo¬ in8 mexlcarus) at 4-year intervals, based on the Breeding Bird Survey i8 e own in Figure 1. This western species was illegally liberated in the East by cage-bird dealers. 11 • 3aK. 981 737 Another example of an introduced species is the European 'tarling (Sturnue vulgaris). The limits of its distribution in 1966 were similar to those of today except that it has extended its breeding range a few kilometers closer to the Mexican border. However, the limits of the distribution show only a small part of the story. More important is the spread to additional locali¬ ties within the range already occupied. Rather than show only the extension of the outer limits of the breeding range, I have outlined in Table 1 those states and provinces in which an important increase took place in the percen¬ tage of routes that reported this species. The last two columns show the percentage of Breeding Bird Survey routes that reported each species in the specified geographic area in 1968 and in 1979. A similar technique will be followed for most of the other species discussed. The Mallard (Anas platyrhynchos ) is a native species that nests in almost every state and Canadian province. During the short period covered by theBreeding Bird Survey, however, the. breeding population has greatly in¬ creased over a substantial part of its range. The reasons for this include the large increase in number of farm ponds and the release of large numbers of hand-reared birds for hunting purposes. In three separate areas of the continent (Table 1 ) the proportion of routes reporting Mallards more than 738 Which selectéd^specie ^ ^ P6rCentage °f BreedinS Bird Survey *>utes on selected species were recorded, 1968 to 1979 Bubulous ibis Anas platyrhynchos Zenaida macroura Petrochelidon pyrrhonota Hirundo rustics Parus bioolor Thryomanes bewlckil Mlmus polyglottos Lanius ludovicianus Sturnus vulgaris Cardinalis cardlnalis Qui8calu8 mexicanus Quiscalus quiscula Molothrus ater Texas and Oklahoma eaat and north to Pennsylvania and New Jersey Washington, Oregon, and Idaho 18 statesi Colorado and New Mexico east to the Carolinas and Delaware Massachusetts, Vermont, New Hampshire, and Maine Massachusetts, Vermont, New Hampshire, Maine, and the Maritime Provinces 10 states: Kentucky and Alabama east to Maryland and Florida Arkansas, Tennessee, and North Carolina Texas east to South Carolina and Florida Penney lvania New York and New England (except Maine) Illinois and Mississippi east to Pennsylvania and Virginia Ontario, New York, and New England Iowa and South Carolina north to Ontario, New York, and Quebec Montana, Colorado, and Lousiana to the West Coast Massachusetts, Vermont, and New Hampshire New Mexico to Kansas and Oklahoma Alberta, Saskatchewan, and Montana North Carolina to Florida Percent of routes 1968 1979 12% 29% 18% 43% 6% 20% 3% 8% 41% 62% 2% 6% 76% 90% 23% 61% 66% 77% 10% 28% 11% 3% 8% 23% 8% 2% 52% 69% 10% 47% 5% 25% 19% 46% 38% 65% inUthed batWeeR 1968 and 1979* Even though there was essentially no change °ccurrenU " ^ breedlng di8tributlon, the doubling of frequency of importance.0"61" * 181-86 P°rtl°n °f the t0tal .bre8dln« »»«• i- of major madrîwdlB0USSlng man-a8BlBted "*»«• expansions, mention should also be soulrytSrCle8 °f eX0U° Parr0tS (P9lUacldae) have been liberated in therncaïi™ Tl: eSPeClally B0Uthera Plorlda- southexn Texas, and sou- at h0 ™ M°nk Parakeet (Myiopsltta monachus) became established concerted ll.0™11“**’ 8°me 38 f&r north 88 New York *»d New England; a of them T m8de t0 retrteVe these blrda* however, and now very few them still persist in the wild. A second major category of range expansions can be attributed to specific 739 conservation efforts. This can best be illustrated by the herons and ibises (Ardeidae and Threskiomithidae ) . Several of these species were nearly exte - minated by plume hunters during the firs't quarter of the 20th Century. Acti by conservation organizations and government agencies has resulted in giving protection to the birds and many of their major nesting colonies. As a re¬ sult. populations have expanded dramatically, especially along the Atlaati coast. The northern breeding limit of the Snowy Egret (Egret ta thuia), ° example, was southern North Carolina in 1931, souther New Jeree J in 1 957,^ and southern Maine in 1982. The Cattle Egret (Bubulcus l._s), - Florida from South America, is still spreading rapidly to the -or* « - *«t. A third category of range expansions includes those P'»»«* species that have benefited from artificial feeding. I shall give three examples. The Tufted Titmouse (Parus bicolor) reached a high the Chesapeake Bay area in 1966 and this was reflected by an expansion in o „«h«.«» ....... Th. Mockingbird (Mi»., p.lyfl.iiç.) fir.« ■„-»<> *» Z. ..«»g»». d.c. — 1» *»• ”*» >»* »• ,o .h, north h.. .1» «»«1 «» 2 decades. Thank. jartU » «■ widespread planting of Ho., nul.lflo^ hedge, and 1955;* Niethammer (1951), Mosansky (1964) vSisïnsn (1969)f von Haartman (1973 i97fU Kownv /infTC» - 9 ^sanen fiQftni n. _ . ’ 97 N k (1975>* and Jarvinen. Ulfstrand n™ - country (jSrvinen, Ulf attend, 1980). ^ ^ °*6 81580168 Pei> d6Cade and The recent spatio-temporal expansion of the Scarlet Rosefinch ty, =.U,d »...fl»«,) 1„ eu„p, ,.u aoou„„,.a (af.-“IhB°”r ““ cea therein) as i8 also .. , , oznico» i960 and referen- ber* lQ7n p * " g biology (e.g# Reinikainen, 1939; Ris- berg, 1970; Peiponen, 1974; Bozhko, 1974, 1980; Stjeraberg, 1979- Zimin Y St Jemberg (1979) has also studied its population dynamic! HL ’ 9® U :r °f the R°~*8 — extension. processes and factors causing this range RANGE expansion and increase in numbers ^oTllTellZ T thoroughly complle(1 data (up t0 1976> 0f Bozhko b, o,h.p” 1J Tr. ,XP“'1” *» "» ccu»wa, compilations 1070 . erences, see Bozhko, I960, von Haartman 1973; Stlember. ■979; recent Bnrop.« avlf.nnl.tlc U«.„.ur, al„ T*' C0”0e™‘”e “= «"»“•*« luring thl. 1. I “,he ,3°* "d "P*'*»Uï 1» «= >940. the Bo.eflneh orp.„a,a „pla_ I to the .„t and northwest of Finland. Although the first lndl»ia„.i, reached the central parts of the west coast in the 1940s it was not the 1950s and the 1960s that a rapid increase in numbers ’was recorded there Island 19 ! the R°SeflnCh eXP8nded t0 «»«»••*•» inland and Helan; lands, and to approximately 66° N lat, in northern Finland. (Helo 107? ciÜs^raT” ^ Z'i 1972;-V°n Haartman- 19?3; Rauhala, i960). How the epe- ies breeds regularly up to c. 66°30* N lat. (Fig. 1). P In parallel with the widening of the Rosefinch* s breeding ranee hn+h +* umbers and densities rose in Finland. The increase in numbers fram the mid! e o the 1940s to the middle of the 1970s was about 30-fold (Järvinen sanen, 1976, cf. also Figs. 2-4; the low densities in the coast carts’ Ostrobothnia in Fig. 4 are not real, see Fig. 2). P tS °f TT thC rapld lncreaee ln numbers and subsequent range expansion in van Tt the 19508 Md 19608 WaS Wel1 UDder Way> the exPa«sion front ad Sw!! ,1 SW6den (Plg* 5)* SlnCe 1954 the Ro8eflnoh haa bred annually in en (Risberg, 1970). In the 1950s most of the birds were found in Co. Da- "43 m< ' -'V ► ■ n. ’•.s/ Pig. 1. The distribution of Carpodacua errthrinus in Finland according to Bird Atlas data 1974-1978, plotted on a 10x10 km grid. Large dot - estab¬ lished breeding (Atlas indices 13-20), medium dot - probable breeding (in¬ dices 5-12), and small dot - possible breeding (indices 2-4) (Kalevi Hyytiä, cers. comm.). The lateral figures refer to the Uniform Grid system, Grid27°® 744 Ogßlj/O ) 4o - n JO _ Poirv' Km* zo »• /o A. /sss 1-1 t 1 1 I. ffffO mV '/»> •< Pears Fig. 2. The immigration of Carpodacua ervthrinua into a study area in Kriatineatad, western Finland, in 1952-1972. During the periods 1948-1958 and 1965-1972, an active search was made for neats (from Stjernberg, 1979) ^ i g. 3. Population trends of Carpodacua ervthrinus in Finland during three periods according to line transect censuses. Square = density 1936-1949, triangle = 1952-1963* and dot » 1973-1977. Horizontal axis = northern la¬ titudes, Uniform grid system, Grid 27°E (redrawn from Järvinen, Vaisänen, 1982) lama and Co. Gotland, but in the early 1960s Co. Gastrikland and Co. Öland were alBo occupied (Rodebrand, 1975 ,• Risberg, Risberg, 1975; Fig. 6). In the late 1960s and during the 1970s the Rosefinch spread over large areas in Sweden and the numbers increased manyfold (No. of recorded males: 31 in 1958, 101 in 371 in 1969 and 1409 in 1974 (Risberg, Risberg, 1975). The numbers of males recorded in Umea, northern Sweden, rose from 6 in 1969 to 36 in 1974 (Risberg, Risberg, 1975). 3. In the 1970s when the increase in Sweden was rapid, the first pioneers Cached Norway. Here the first Rosefinch nest was found in 1970 (Gundersen, ^70), only 12 sightings during the breeding season were known earlier, all from the 1960s (Haftom, 1971; Larsen et al., 1979). Most of the Norwegian Puirs now breed in the southeastern and southern counties, especially in Co. °Ppland and Co. BuBkerud, but nests have also been found in Co. West-Agder (Bergersen, 1975; Olsen, 1975). In the 1970s Rosef inches have also been re¬ corded during the breeding season along the west coast up to Co. More, Roms- dftl and Co.Sor-Trondelag (Sandvik, 1980; Follestad, 1981). During the late 1970s, the increase in Rosefinch numbers in Norway was Pariq. From the bird observatory Jomfruland on the outer skerries in southern Norway, the following figures were reported: during 1972-1977 1-6 birds an¬ ally, in 1978 10 and in 1979 115 (Cleve, Lifjeld, 1980). Compilation of the 745 Pig. 4. Densities (paris/km^) of Carpodacus erythrinus in Finland accord¬ ing to line transect censuses in 1973-1977. The lateral figures refer to the Uniform grid system, Grid 27°E (from järvinen, Vaisänen, 1982) breeding season observations in the Norwegian avifaunistic literature gives the following minimum numbers: in 1970-1973 annually 3-5 males, 1974-1978 17- 35 and 1979 c. 200 males. 4. The first breeding season observation of a Rosefinch in Denmark is from 1966 (Rab/1, 1966); from 1968 onwards it has been observed regularly during the breeding season and in 1972 the first nest was found on Christians^ near Bornholm (Sorensen, 1974). The second nest was found in 1976 on Falster (Franzman, 1977). Most observations are from the eastern islands, especially from Bornholm and Christians^!. The numbers of Rosefinches observed in Denmark have risen during the 1970s, concurrently with the rise in numbers in the neighbouring countries (GDR, PRG, Sweden, Norway). 5. An increase in Rosefinch numbers has also occurred in the northwestern parts of the USSR since the 1930s and 1940s; in the Carelian SSR the numbers 746 ^ i g. 5. The range of more or less regular uouui±ence of Carpodacus erythri- nua in Fennoscandia since 1955. Data from Nordstrom (1956), von Haartman (19735, Risberg (1970), Risberg, Risberg (1975), Stjeraberg (1979) and Jär- vinen, Vaisänen (1982). Avifaunistic notes made in Norway and Denmark up to 1981 are also considered; cf. also Fig. 1 have grown rapidly and high densities have been recorded during the 1960s and 1970s (Fig. 4). Now the bird's range extends up to the coast of the White Sea (Bozhko, 1980). 6. In Central Europe the Rosefinch nas extended its breeding range in two directions: westward expansion along the Baltic coast began in the 1930s and w*8 still continuing in the 1970s (Lambert, 1979); a southwestward advance became evident in the 1950s and was especially pronounounced during the 1960s 1970s, mainly along rivers and mountain valley (see Bozhko, i960 and re¬ ferences therein). The spreading, along the Baltic coast has been slow and gradual (Muller, 1973; Lambert, 1979; Bozhko, 1980), but the expansion inland has been more rapid and sudden. The Rosefinch has become a regular breeding bird in Poland (Tomialojc, 1976), and has bred in Czechoslovakia since the l96°s (Darola, Stollmann, 1977) and in Austria since the 1970s (Czikeli, In ïugoslavia the first Rosefinch nest was found in 1978 (Sere,. 1980) 111 the 1970s Rosef inches have also been observed during the breeding season 111 the southern FRG (Czikeli, 1976; Lévêque, 1981). Mark Brandenburg/GDR 747 Fig. 6. Annual numbers of loca¬ lities and new localities (white columns) where Carpodacus erythri- nua was found in the Co. Öland, E Sweden, in 1958-1974 (from Ro- debrand, 1975) (Dittbemer et al., 1979), Switzerland (in 1979, 1980, 1981; Léveque, 1981, and in. litt., Fuchs, 1980j Juon, Biirkli, 1981), France (1977; J.Sharrock, in litt.), and Bulgaria (1979; Anon, 1982). The number of Roeefinchee obser¬ ved in spring in Britain and Ireland has risen considerably during the late 1970s (Sharrock, Sharrock, 1976; J.Sharrock, in litt.), and in 1982 the first nest was found in Scotland (I. Newton pers. comm.). 7. A characteristic feature of the colonization of Fennoscandia, and of the inner parts of Central Europe as well, is that one-year-old males (grey plu¬ mage) have suddenly appeared as far as hundreds of kilometres outside the normal range of the species, or in previously unoccupied localities within it. At times local populations have been established forming centres of secondary spreading. CAUSES OP EXPANSION The expansion of the Rosefinch is largely a question of population growth; more fledglings are being produced than are needed to keep the population in equilibrium. Hence factors affecting both population dynamics and dispersal are involved (cf. also Kalela, 1955; Nowak, 1975). The following discussion will mainly concern Finland but is presumably valid for the whole European range of the species. The strong expansion in Finland observed since the 1940s must have been preceded by some earlier changes in productivity (for definition, see Stjern- berg, 1979:70). In the 1930s the temperatures in May and June were higher 'than during earlier decades (Siivonen, Kalela, 1937; von Haartman, 1973) and the vegetation was most probably more developed at the start of the breeding of the late arriving (second half of May) Rosefinch. The nesting success has been shown to fluctuate strongly from year to year (Stjemberg, 1979) and the main factor responsible is presumably the extent to which the vegetation has devellped at the beginning of the breeding season, and the consequent degree 748 of concealment of its rather conspicuous nest. Nests in closed biotopes are especially exposed to predation. The favourable summers of the 1930s there¬ fore most likely initiated a rise in the nesting success of the Rosefinch. During this century drastic changes have been caused directly and indi¬ rectly by man in the landscape of Finland, Sweden and the USSR (for details, see inter al. von Haartman, 1973, 1978; Ahlen, 1977; Jarvinen et al., 1977; Stjernberg 1979; Bozhko, 1980; Hildén, Hyytiä, 1981). These must be of decis¬ ive importance for the still continuing expansion of the Rosefinch (cf. also Jozefik, i960; Risberg, 1970). The changes creating or modifying habitats suitable for Rosefinches can roughly be summarized as follows: clearing of continuous wooded areas, regrowth on abandoned grazing or arable land, con¬ iferous plantations, and Bpreading of human settlement. These changes have occurred both within and outside the normal range of the Rosefinch. During the last few decades in Finland the Rosefinch' s biotope preference seems to have changed towards more open biotopes, approximately in parallel with the increase in numbers. In the new open biotope, the production of fledglings is much higher than in the fonner more closed biotope (Stjernberg, 1979). Thus the change in biotope preference most likely improved the product¬ ion of potential colonists and facilitated extension of the range. The sharp decline of the Finnish and Swedish Linnet (Carduells cannablna) population during the 1920s and the 1930s may have facilitated the shift in the Rose- finch’s biotope preference; the recent open Rosefinch biotope is almost iden¬ tical with the classic Linnet biotope. For possible competition between the Linnet and the Rosefinch, see Stjernberg (1979). If we take into account the changes in temperature, landscape, vegetation and productivity, and also certain species-specific characters of the Rose¬ finch, we can construct the following, partly hypothetical picture of its expansion (Stjernberg, 1979). The high site-tenacity of breeding Rosefinches combined with growing numbers, caused by an increase in the production of fledglings during the favourable breeding seasons in the 1930s, resulted in a higher population density and greater "population pressure". Earlier, the Rosefinch in Finland mainly bred in cultural groves and in the margins of luxuriant deciduous woods strongly influenced by man (Reinikainen, 1939), i.e. in relatively closed biotopes. It is not unlikely that Rosefinches for which there was "no room" in the such biotopes, still tried to breed in the vicinity of their conspecifics, due to their sociability (cf. also Bozhko, 1980), and that some of them were thus forced to settle in more open biotopes (the species does not breed in closed forests). The difficulty of finding a alte in the saturated biotopes would be particularly great for the young birds, which arrive somewhat later than the older ones, and are probably otherwise weaker in competition (Zimin, 1981 ). The alternatives open to them would be to continue their migration, to refrain from breeding or to settle nearby in another biotope. Young hatched in the new more open biotope might be imprinted on this biotope (Hildén, 1965). Since the Rosefinch is long- lived, and since the breeding success in the new biotope is twice as high as In the closed one (Stjernberg, 1979), the numbers of Rosefinches breeding in open biotopes grew very fast, giving rise to expansion (for the shift in the Rosefinch's biotope preference, see also Bozhko, 1974; Mazzucco, 1974; Czikeli, 1976). 749 High temperatures during spring migration stimulate birds to disperse more actively than during cold springs (Otterlind, 1954). Besides improving the production of fledglings, the climatically favourable springs in the 1930s may therefore have stimulated the surplus of returning young birds to disperse over larger areas, both within and outside the normal breeding range. Young Rosefinches are less site-tenacious than older birds (Stjem- berg, 1979), and, since suitable habitatB were available, no obvious ber- viers existed to hinder an expansion. Pioneering Rosefinches were observed in western Finland even before the 1930s - why did these birds not succeed in establishing new colonies? Suc¬ cessful colonization of a new area presupposes a sufficient Bupply of suit¬ able breeding biotopes in which the resistance from the existing community is not too great. Moreover, it is equally important that the sexual partners can find each other, and that chance extinctions of newly established popu¬ lations are not too frequent. Various circumstances assist the pairs to find each other: high numbers of colonists, concentration of dispersing indivi¬ duals in certain areas by topographical features or by the distribution of biotopes; whole flocks migrating too far or going astray. The river Dalälven has evidently been important ir, the colonization of Co. Dalama, central Sweden (Bylin, 1975), and the rivers and mountain valleys in the colonization of the interior of Central Europe (Mazzucco, 1974-; Czikeli, 1976; Darola, Stollmann, 1977; Bozhko, 1980). The Baltic coastline has also had a directing effect on the Roeefinch's expansion (Mazzucco, 1974), and the Finnish west coast presumably served to congregate migrating Rosefinches and thus increase the chances of successful establishment (Nordstrom, 1956). The uneven distri¬ bution of the Rosefinch in the interior of Central Europe is presumably part¬ ly the result of a patchy biotope distribution. Finally, it is worth mention¬ ing that adult male Rosefinches seem to migrate more or less singly, while birds with female-like plumage, i.e. females and one-year-old males, migrate in flocks and arrive somewhat later than the adult males. Wann springs fol¬ lowing years with a good production of young should result in an unusually high number of colonists. The fact that the Rosefinch did not succeed in colonizing western Finland before the 1930s could thus be due to the combined effect of several factors: the colonists were too few, suitable biotopes were lacking, and the resist¬ ance from the established avifauna was too great. There is hardly reason to believe that expansion was hindered by the climate per se. It is more likely that the rising temperatures in the 1930s initiated growth in numbers within the normal breeding range, whereas expansion was made possible by changing environmental factors both within and outside the range. According to von Haartman (1973), the northward shift of the isotherms is much smaller than the northward movement of the advancing front of several expanding species, which indicates that the amelioration of the North European climate since the 1930s was probably not of major importance for the range extensions. Perhaps the most important feature of the climatically favourable period in the 1930s was that almost all the summers were good for producing fledglings, and hence the number of colonists rose considerably. 750 SPECIES-SPECIFIC CHARACTERISTICS FACILITATING EXPANSION Several oharacteriatica of the Rosefinch facilitate a rapid Increase In numbers (Stjemberg, 1979; cf. also Reinlkainen, 1939; Rlsberg, 1970; Bozhko 1974, 1980; Peiponen, 1974; Czikell, 1976; Zimin, 1981). These Include. (1) low adult mortality, (2) strong site-tenacity among birds which have 'bred once, 3) a wide range of breeding biotopes, (4) a certain breeding sociabi¬ lity, (5) lack of shyness at breeding sites, (6) flock migrotion In young birds. Furthermore, It has been established that the Roaeflnch Is a relative¬ ly unspecialized forager, having a wide food and foraging spectrum and a wide register of foraging positions. The bill Is not strongly specialized and is well suited for consuming buds, seeds and Insect larvae. In other words, the species Is very versatile In many respects and is well adapted to a dynamic patchy landscape rich In ecotones. Hence the Roaeflnch exhibits most of the characteristics of a good colonist (Mayr, 1965). It must be emphasized that the Roaeflnch» s habitat selection had differed somewhat between different periods and that local variation has been common, onsequently, the recent "development" in biotope preferences demonstrated ^ Finland and elsewhere is mainly to be regarded as a process that is still continuing, being partly a reaction to a changing environment and partly the result of improved productivity and an increase in Roaeflnch numbers (Kalela, No evaluation can yet be made of the importance of the rapid changes of the landscape in the tropical and subtropical regions, and the temperate grasslands where the Scarlet Rosefinch winters. Birds of open land, like the Scarlet Rosefinch, may have profited by these changes (Jarvinen,UlfstraQd,198Cj The events or factors causing or facilitating the recent expansion of the osefinch in Europe are summarized in Fig. 7, Pig. 7. Events or factors faci¬ litating the recent expansion of Carpodacus ervthrinus in Europe, see the text SUMMARY R_ecent expansion of the Scarlet Rosefinch Carpodacus erythrinus in Europe Scarlet Rosefinch numbers have grown manyfold in Europe during the last few decadeB with a subsequent extension of the breeding range to the north, '«eat and southwest. The countries in which the species now breeds regularli include Sweden (since the 1950s), Noway (since the 1970s), Czechoslovakia since the late 1950s) and Austria (since the 1970s), and among those from ''hich it has been recorded as a breeding bird are Denmark (1972), Yugoslavia 1 978-) and Scotland (1982). S 751 Habitat changes are considered to be the main reason for the recent ex¬ pansion. The production of fledglings has latterly been much higher than is needed to keep the population in equilibrium. Both factors affecting the pro¬ ductivity and factors connected with the expansion are discussed (Pig. 7). ACKNOWLEDGEMENTS I owe a debt of gratitude to the following persons! Prof. Olli Järvinen and Dr.Risto A. Vaisänen, for permission to publish Pigs. 3 and 4; Mr. Kalevi Hyytiä, for data for Pig. 1; Mr. Yrjö Haila, Phil, lie., for translation of an article from Russian to Finnish; Dr. J.T.R.Sharrock, Mr. R.Lévêque and Dr. I. Newton, for unpublished reports; Ms. Barbro Elgert, M.Sc., for drawing the figures and Mr. R.Tyynelä for the photographs; Dr. Olavi Hildén, for com¬ ments on and Dr. Karin Hongell for help in preparing the manuscript. Ms. Anna Damstrbm, M.A., checked the English. References o Ahlen I. Faunavard. Om bevarande av hotade djurarter i Sverige, 1977. 256 p. Vallingby . Anon. - British Birds, 1982, 75, p. 268-272. Bergersen L. - Sterna, 1975, _1_4» P* 45-46. Bozhko S.I. - Acta Ornithol., 1974, _1_4, p. 39-57. Bozhko S.I. Der Karmingimpel. Wittenberg Lutherstadt, 1980. 124 p. Bylin K. Dalarnas faglar. Dalamas Omitologiska Forening. Gavle, 1975. 443 p. Cleve A., Lifjeld J. - Var fuglefauna, 1980, 3, p. 160-171. Czikeli H. - Egretta, 1976, _l_â» P* 1-10. Darola J., Stollmann A. - Biolôgia (Bratislava), 1977, 32» P* -111-120. Dittbemer H. , Dittbemer W., Sadlik J. - Palke, 1979, 26, p. 296-298. Follestad A. - Var Fuglefauna, 1981, 4,, p. 177-185. Franzmann N.-E. - Vogel der Heimat, 1977, 50, p. 262. Gundersen W.H. - Pauna, 1970, 23, p. 272-276. Haftom S. Norges fugler. Oslo; Bergen; Tromsjï', 1971. 862 p. Von Haartman L. - In: Breeding biology of birds. Proc, of a symposium on breeding behavior and reproductive physiology in birds, Denver 1972 / Ed. by D.S. Panier. Wash., D.C., 1973, p. 448-481. Von Haartman L. - Fennla, 1978, 1 50. p. 25-32. Von Haartman L., Hildén 0., Linkola P. et al. Pohjolan linnut värikuvin, 1972, XII. p. 985-1092. Helsinki. Helo P. - Kainuun linnut, 1972, 2, p. 27-75. Hildén 0. - Ann. Zool. Pennici, 1965, 2, p. 53-75. Hildén 0., Hyytiä K. - In; Proc, second. Nordic congr. omithol. 1979. Stavanger, 1981, p. 19-37. Josefik M. - Acta Ornithol., I960, 5, p. 307-324. Juon M. , Bürkli W. - Om. Beob., 1981, 78, p. 54-55. Järvinen 0., Ulfstrand S. - Oecologia (Berl.), 1980, 46, p. 186-195. Järvinen 0., Vaisänen R. A. - Omis Pennies, 1976, 53, p. 115-118. järvinen 0., väisänen R.A. Ecological zoogeography of Finnish birds. Numbers and long-term changes. Helsinki, 1982. 752 Jarvinen 0., Kuusela K., Väisänen R.A. - Silva Fennica, 1977, 11, p. 234-294 Kalela 0. - Bird-Banding, 1949, 20, p.77-103. Kalela 0. - Ann. Zool. Soc. Vanamo, 1955, _1_6 (11), p. 1-80. Lambert K. - Omithol. Rundbrief Mecklenburgs, R. P., 1979, 20, p. 1-8. Larsen B.M.. Opheim J., yfetbyee T. - vlr Fuglefauna, 1979, T,’ p. 129-135. 1. Baker, O.L.Steb- Léveque R. - Om. Beob., 1981, 78, p. 53-54. Mayr E. - In: The genetics of colonizing species / Eds. H bins. N.Y. ; L., 1965, p. 29-47. Mazzucco K. - Egretta, 1974, 17, P* 53-59. Mosansky A. - Aquila, 1964, 69-70. p. 173-194. Millier S. - Cora*, 1973, 4, p. 112-130. Niethammer G. - Bonn Zool. Beitr., 1951, 2, p. 17-54. Nordstrom G. - Omis Pennies, 1956, 22» p. 19-28. NoWak E - Zeszyty Naukowe, 1975, 2, p. 1-255. (Translation 1975, Smithsonian Institute, Washington, D.C.). Olsen K. - Sterna, 1975, H, p. 161-166. Otterlind G. - v£r Pagelvärld, 195*, V}, p. 1-31, 83-113, 147-167, 245-261. Peiponen V.A. - Ann. Zool. Fennici, 1974, 1 1 . p. 155-165. Rabfil J. - Dansk omithol. Foren. Tidsskr. , 1966, 60, p. 77-34. Rauhala P. Kemin-Tomion seudun linnusto. Kemi , 1980. 172 p. Reinikainen A.^- Omis Pennica, 1939, _16, p. 73-95. Risberg E. - Var Pagelvärld, 1970, 29, p. 77-89. Hisberg L. , Risberg B. - Var Pagelvärld, 1975, 2£» p. 139-151. Rodebrand S. - Calidris, 1975, 4, p. 3-12. Sandvik J. - Var Puglefauna, 1980, 2» p. 279-282. 5ere D. - Acrocephalus , 198O, 2, p. 13-16. Sharrock J.T.R., Sharrock E.M. Rare birds in Britain and Ireland. 1976. 336 p. -iivonen L., Kalela 0. - Acta Soc. Fauna Flora Pennica, 1937, 60, Stjemberg T. - Acta Zool. Pennica, 1979, 1 57, p. i_88. norensen ^B.M. - Dansk Omithol. Foren. Tidsskr., 1974, 68, p. 68. Tomialo je L. Birds of Poland. A list of species and their distribution. 'Trans¬ lated from Polish by Foreign Sei. Publ. Dept. National Center Sei. Techni¬ cal and Economic Inform., USA.) Warszawa, 1976. 256 p. Väisänen R.A. - Ann. Acad. Sei. Fennicae, 1969, A IV, 149, p. 1-90. Zimin V.B. - In: Ecology of vertebrate north-west part USSR, Petrozavodsk 1981, p. 13-31. ' ’ Berkhamsted, p. 606-634. l2- 3aic. 981 ?53 THE DECLINE OP THE CORNCRAKE (CREX CREX) IN EUROPE C. J. Cadbury «M. O'Meara Royal Society for the .Protection of Birds, The Lodge, ôaûdy, Bedfords hire, JÜhglaod, c/o Irish Yildbird CoQservaocy, S out hview, Church Road, Greystones, Co. Wicklow, UK The global breeding range of the Corncrake lies largely within the Western Palearctic north of the Alpe and Pyrenees to about 62°N. The species is one of the few in the region largely dependent on farmland habitats. Marked popu¬ lation declines have occurred in most regions since the late 19th and early 20th centuries following the introduction of mechanised grass-cutting. With a bird so difficult to observe, surveys have had to rely on counts of calling birds which are usually, but not inevitably, males. The relation¬ ship between numbers of calling birds and pairs is unknown. A high level of vocal activity continues from late May until early July but it is necessary to carry out surveys at night in calm weather. By the end of the 1970s the population in western Europe was largely rest¬ ricted to 1200-1500 calling birds in Ireland, chiefly in the northwest (O'Meara, 1979); about 730 in Britain, mostly on islands in northwest Scot¬ land (Cadbury, 1980); 50-600 in Sweden, mostly on two Baltic islands, Öland and Gotland (Rodebrand, 1978; Svenson, 1978); several hundred in Finland (Hilden, pers. comm.); about 100 in the Netherlands, largely in the flood plains of rivers Buch as the Waal, Rhine and Ijssel (Teixeira, 1979), and perhaps still in some of the river valleys in east and central west Prance (Yeatman, 1976) and the north-west region of the Federal Republic of Germany (Glutz von Blotzheim et al., 1973). In eastern Europe detailed information is lacking but marked declines have occurred in much of western USSR (excluding Estonia), the German Democratic Republic, Czechoslovakia, Hungary and Bulgaria (Cramp, Simmons, 1980). The Corncrake is still locally frequent in eastern Poland but has decreased in the west (Tomialojc, 1972 and pers. comm.) and probably eastern USSR. By the time of the first national survey of the Corncrake in Britain and Ireland, in 1938-39, the species had already disappeared from much of eastern England where farming was most intensive. It was still frequent in northern and western parts of Britain and much of Ireland (Norris, 1945, 1947). The British Trust for Ornithology and Irish Wildbird Conservancy survey of breed¬ ing birds of Britain and Ireland, carried out over the years 1968-72, de¬ monstrated a further retreat north-westwards (Sharrock, 1976). In the BTO and IWC surveys of 1978/79« an attempt was made for the first time to count all calling birds, bo scarce had Corncrakes become (O'Meara, 1979; Cadbury, 1980). Only 10 years after the Atlas survey the number of ten km squares in Britain in which breeding was confirmed or considered probable, declined from 528 to 160, a 70% reduction. The species had all but vanished as a breeding bird from England and Wales and was very scarce in the south-eaBtern half of Ire¬ land. In Britain, the Corncrake only remained frequent on certain of the Hebridean and Orkney islands in northwest and north Scotland. The number of calling birds was reduced from an estimated 2600 to 730. Of the ten km squa¬ res in which Corncrakes were probably breeding, only 6% supported more than 1 ^calling birds. The highest densities, which ranged between 6 and 11 per km , were all on small-holdings (crofts) with small fields, non-intensive fanning and much marginal habitat. Breeding populations of this migratory bird appear to be subject to fair¬ ly marked annual fluctuations. On the island of Tiree, off the west coast of Scotland, early July counts of calling Corncrakes in six years between 1969 and 1979, ranged between 50 and 98 with a mean of 74.0+18.8 (Cadbury, I960). The monitoring of the Irish population has indicated a continuing decline since 1978. The habitat from which Corncrakes were colling was recorded for 530 birds in Britain in 1978-79. 6l% were in graes cut for hay or Bilage. However, in the Outer Hebrides, a Corncrake stronghold, about half the 183 birds in May and June were in marshy areas where stands of tall Iris pseudacorus and Phragmltes australis were favoured. In one area the habitat of calling birds was recorded again in July, after the hay was mown. Twelve of the 16 birds which remained relatively Bedentary were in marshes. Of the 15 that shifted habitat, 9 moved to weedy oat Avena fatua/Btrlgosa crops (Cadbury, 1980). 20% of the calling Corncrakes recorded in Ireland in 1978 were in marshes (O'Meara, 1979). Over most of Britain, including Orkney, the grass in the majority of meadows cut for silage or hay, has been sown (leys) or improved with ferti¬ lizers. In the Outer Hebrides and on Tiree, where crofting still prevails, only a third of the meadows in the late 1970s were leys or otherwise impro¬ ved. Natural meadows had a greater variety of plants (an average of 11 or 12 species) than improved grass (9 or 10 species) and leys (6 species). On the other hand, in both areas, the height of the sward of "natural" meadows was only two thirds that of leys (P 0.01) when measured in June or early July. The sward in "improved" meadows was intermediate in height. In the Outer Hebrides in June, calling Corncrakes exhibited a preference for leys over "natural" meadows (P-<£ 0.02), while on Tiree, in early July, "improved" and "natural" areas were preferred (P ^10.01). Corncrakes have been recorded taking a wide variety of invertebrates as food. In the Hebrides, pitfall traps indicated that carabid and staphylinid beetles were abundant in both natural meadows and leys. Opilionids and large carabid8 occurred in large numbers in the damp meadows and marshes frequen¬ ted by Corncrakes in the Outer Hebrides. Habitat preferences of Corncrakes in the breeding season are likely to be influenced by the need for cover and food. When Corncrakes return to their northerly breeding areas in May there tends to be a lack of suitable vegetat¬ ion cover. It is not surprising that the birds seek the more luxuriant sown grass and damp fields with clumps of Iris. Leys are, however, unsuitable breeding habitat for Corncrakes because they are cut for silage in June or for hay in the first half of July when birds have nests or small young. Mo¬ reover, the dense Bward may restrict feeding activities. The improved and natural meadows favoured on Tiree in July are not only mown later than leys but may offer greater food availability for young Corncrakes. There are several reasons why Corncrakes remain frequent where farming based on small-holdings (crofts) prevails on certain exposed islands off the 755 west coast of Scotland. The small fields, many less than five ha, offer a variety of habitats. Tha^e are still many "natural" meadows and little silage is made. Corncrake nests and broods have a fair chance of escaping destruct¬ ion. The broad field margins, weedy crops and marshy fields provide alterna¬ tive habitat once the hay is cut. Though the Corncrake avoids swamps favoured by most Rallidae, it clearly has an association with damp grasslands in many of its remaining strongholds in western Europe. The species should be included among birds whose wet meadowland breeding habitat is threatened by drainage. Even in the Outer Hebrides there are many signs of a lowered water table and shrinking marshes. A proposed major agricultural improvement scheme in the Outer Hebrides, funded by EEC and British Government grants, is likely to seriously exacerbate the situation. The future for the Corncrake in Europe, even in its present strongholds, appears bleak. The bird shows no signs of being able to adopt to the envi¬ ronment created by more intensive farming. The loss of marshes and other semi¬ natural habitat on farmland may be forcing Corncrakes to frequent sown grass crops were there is little opportunity for successful breeding. SUMMARY The long-term decline of the Corncrake Crex crex in western Europe con¬ tinues. The species appears to be unable to adapt to the environment created by intensive agriculture. Though birds are attracted by the cover provided by grass leys, early mowing for silage has disasterous effects on breeding success. Damp meadows and marshes, in the flood plains of certain major ri¬ vers in the Netherlands, Prance and the Federal Republic of Germany, in se¬ veral areas around the Baltic and on small— holdings in the northwest ex¬ tremities of Britain and Ireland, afford the last strongholds of the Cornc¬ rake in western Europe. Even they are threatened by drainage. References Cadbury J.J. - Bird Study, 1980, 27_, p. 203-217. Cramp S. , Simmons K.E.L. The Birds of the Western Palearctic. Vol. 2. Oxford, 1980. Glutz Von Blotzheim U.N., Bauer K.M., Bezzel E. Handbuch der Vogel Mittel¬ europas. Vol. 5. Frankfurt am Main, 1973. Norris C.A. - Brit. Birds, 1945, 3J3, p. 142-148, 162-168. Norris C.A. - Brit. Birds, 1947, 40, p. 226-244. O'Meara M. - Irish Birds, 1979, 2» p. 381-405. Rodebrand S. - Calidris, 1978, 7, p. 91-96. Sharrock J.T.R. The Atlas of Breeding Birds in Britain and Ireland. Tring, 1976. Sveriges Faglar / Ed. by L.Svensson. Stockholm, 1978. Teixeira R.M. Atlas van de Nederlandse Broedvogels. Deventer, 1979. Tomialojc L. Birds of Poland. Warsaw. Translation: Fish and Wildlife ServicRt Wash., 1976. Yeatman L. Atlas des Oiseaux Ni’cheurs de France de 1970 à 1975. P-, 1976. 756 ANALYSIS OP DIFFERENT FACTORS CAUSING DYNAMICS OF BIRDS RANGES G.Mauersberger Zoologisches Museum, 104 Berlin, Invalidens tr. 43, 35A, GDR Thia is one of the oldest and, at the same time, most lasting questions of both zoogeographers and ecologists: which factors delimit a Species* ran¬ ge? It is dust one a combination of diverse factors, is the composition of this complex similar within a taxonomic group or not and, finally, is our knowledge sufficient to predict where an expansion process (or its very opposite) i8 likely to be stopped by external or internal conditions’ Range expansion of dramatic extent (and this means usually, or dramatic speed) occurs in groups of high mobility and high ecological plasticity - as for instance birds. Therefore, ornithology is largely apt to offer essen¬ tial clues to phenomenology and theory of chorology. On the other hand, we neglect here all those cases where most obvious li¬ mits (very steep gradients) like the borderline between sea and land, moun¬ tains and plain, desert and forest, are responsible. But, why does the Rock Bunting (Emberizacia ) not breed in the Central Ger¬ man Harz mountains or in the eastern Bavarian mountains whereas it does in the ecologically similar Schwarzwald? Why is the Palm Chat (Dulus dominicus) con-fined to Hispaniola while its flying abilities are obviously strong enough to reach Cuba just 80 km farther west? In other species, geographical discontinity does, aue to dispersial phenomena, not mean isolation between populations. What urges the Bluetall fTarsiger cyanurus). the Yellow-breasted Bunting (Bmberiza aureola) or, more recently, Cetti's Warbler (Cettia cetti) to protrude into regions where changes of habitats as required by them are not (clearly) visible? Why does one species expand its range, a second one withdraw and a third one keep its home rights as if nothing had happened? Hhy did the Scarlet Rosefinch (Caprodacus erythrinus ) expand its breeding range just in recent years and not half a century earlier? In more general terms: although range (or "area") is clearly not a status but a continued process, why then do most species, mobile as well as plastic, not expand? These are by far too many questions to be answered within a"77w minutes. This would mean to press into a ping-pong ball what would fill a medium-sized ballon. Let us see then some of the aspects involved which the author (like some other people) thinks important. Before doing so, we must confess a serious hindrance which biasses many of our considerations more severely than some of us might be willing to admit: our knowledge of specific ecology is, for the majority of bird species even in Europe, based mainly or entirely on the description of habitat as seen by human eyes, the altitude above sea level and an enumeration of food items. Theorists tend to draw conclusions of - hopefully-high significance and this is necessary. However, much has been claimed which seemed to be clearly supported by apparently convincing evidence. So it often fell into oblivion that one should look for discordant or falsifying rather than for concordant data, so-called "Instances". A reappraisal is inevitable - and the call for more basic information following other aspects than usually 757 applied. Yet, much importance has been found out recently and I cannot feel sure not to have overlooked really essential studies. The factors causing or affecting range dynamics fall onto two major cate¬ gories. The first one comprise intrinsic factors defined as physiological ecological, and psychological properties that determine way and extent of reaction to barriers of any kind. Genetic conditions and/or changes seem ob¬ vious factors of importance, particulary mutations which initiate range dyna¬ mics. The evidence, however, is limited. Although pioneer populations might be rather uniformly made up of certain genetic variants, and mutants might foim the expansive proportion of them, most phenomena can be explained with more ease. The normal recombination potential should be sufficient to yield preadapted genotypes, and in at least one case a spectacular change-over did not even test the specific valency to say nothing of a fundamental muta¬ tive change of behaviour. Physiological abilities may be fundamental prerequisites or strictly li¬ miting factors (as is temperature resistance or mobility) but not causes of expansion. However, if (for instance) the capacity of nestlings to resist co¬ oling or to respond to heat loads is changed the population will be urged to restrict or to shift its area. A high reproductive potential (in a dispersive species) raises the proba¬ bility of dispersal beyond the range limit and is the decisive prerequisite for the quick establishment and stabilization of new local populations. The impressive figures known from Worth American Cattle Egret (Bubulcus ibis), especially the population increase in Texas illustrate this. Often a widening or shift of the niche and changes of behaviour have been offered or claimed os important factors. This could be due to either genetic changes or plastic phenomena. Plasticity a3 understood by the author is "the enlargement of the frame given by the open genetical programme" as "a result of the coupling and switching pattern characteristic of the specific system of niche utilization". It thus depends on the number of system elements that are potentially connectable and of the capacity of coupling them which is de¬ termined by the central nervous system. Elements in this sense are, among others, structures and behaviour patterns (like foraging techniques) and preferences for environmental elements specifically utilized. These preferen¬ ces are directed by specific searching images and largely depend on their number and the degree of their complexity. All this defines the versatility of a species and, hence, its survival chances in other than its herediary habitats. A survey of the characteristics exhibited by successful colonists has been given long ago by Mayr (1965). They are essentially baaed upon the capacity of plastic reactions. Sociability is not of decisive significance: single breeders - like the Scarlet Rosef inch (faaprodacus ery thrinus ) and species dependent on colonies (of other species) as is the Cattle Egret may be successful intruders. Yet, traits of the social and communicative system of a species are often considered helpful in the course of expansion processes as they are in part responsible for the growth of population size which is essential for taking roots in a new area: dispersal in flocks facilitates settling success and the facts having provoked the "information centre hypothesis" lower the mortality rate in colonizing groups. 758 Migratory properties of a species cannot be meaningless here. Udvardy has summarized as early as 1969: "In addition to single pioneers... wanderings, migrations, and irruptions may -also lead to the establishement of new breed¬ ing stations, which can dewelop into new settlements. All are mass phenomena. Migration movements expose birds to unusual external factors of chorological significance (like wind drift and change). Intrinsic causes may become ef¬ fective if migratory individuals fail to obey the ortstreue principle. In one case, defective homing behaviour, they do not return from the winter quarters to their northern birth or breeding places - everybody knows the nesting of European White and Black Stores (Giconla ciconla and C. nigra) in Africa. In the other case, prolonged migration whatever the causes (cf. hor¬ monal processes, degree of philopatry; spring temperatures and development of vegetation) provides opportunity to settle in places beyond the (average) range boundary. This has enabled many bird species to settle io regions offering food supply only part of the year (what simultaneously forces them to exert periodical migrations, even in the tropics). Albeit orstreue, site tenacity and homing abilities must be, on one hand invalidated to enable that widening of range, and it is precisely these capa¬ cities which have to be effective, on the other hand, for colonists not to vanish anywhere after the first migration flight that is enforced by migrat¬ ion instinct. An instance is the European Quail l'coturnix coturnlx) introduced into the United States: they dissappeared after summer and never came back. It should be emphasized here that - notwithstanding the significance of population status - range size has no bearing on expansiveness. The most relevant intrinsic factor appears to be diepersabiliiy . This shows clearly in pairs of species which are practically identical in morpho¬ logy and mobility but differ sharply in their dispersal patterns, A well- known example is the Silvereye (ZoBterops lateralis) which got over the 2000 km of open sea between Tasmania and New Zealand and the settled on all outlying islands whereas a species on the Solomon, Zosterops rendovae, shows no ten¬ dency to overcome barriers of Just some km width. For most population, however we may assume non-uniformity as to dispersal ability. Pioneering populations like those occupying temporary areas of pulsating ranges consist of indivi¬ duals which combine dispersal with dismigration or non-philo patry. The two phenomena mi^it be under separate control but imprinting is, at least often, likely to play a decisive part as is indicated by removal experiments. In general: population phenomena and population dynamics as the relation of productivity, dispersion and mortality form not merely the most important and most closely connected intrinsic factor but also, the immediate véhiculé of range processes. Among the extrinsic factors, climate will be named mostly in the first place. Basic physical conditions like temperature, rainfall, humidity, ampli¬ tude of circadian and circannual fluctuations are considered equally impor¬ tant as are secondary phenomena dependent on them (like vegetation and food supply). Many of the changes of the European, especially the Fennoscandian avifauna have been discussed as caused or influenced by short-term fluctuati¬ ons or long-term climatic changes, the latter even as the final phase of post-glacial, reoccupation of northern regions. 759 One basic factor is of most apparent influence: wind as drifting or in¬ hibiting power. Its role should not be overestimated since the Silvereye and the Europian Hedgesparrow (Prunella modulart s) have crossed wide expanses of usually turbulent sea around New Zealand and colonized the outlying islands. This shows, however, that difficulties of an active spread cannot be offered as a hindrance in case where far smaller distances have not been bridged. Every single factor of autecological significance means simultaneously a kind of barrier. Geographical and vegetational barriers are effective in de¬ pence on species properties and abilities. Spéciation of certain groups, e.g., in Madagaskar is an irrefutable proof that barriers have not been crossed in spite of the mere physical capacity to do so (doubtlessly being given). So, these boundaries are seldom strictly exclusive for dispersable species. Yet, their breakdown or overcoming is not a daily event, and often pure chance de¬ cides for or against (see those famous Fieldfares Turduo pilaris having rea¬ ched Greenland whereas many American parulids did not establish branches in Europe ) . Often habitat changes have been alleged to explain boundary shifts. This way apply to many cases although habitat structure have rarely been analyzed to exclude that the differences are not only striking to our eyes but essen¬ tial for the bird itself. For the same reason, one should be careful before stating a "change in habitat preference". A newcomer is dependent on strictures and resources at his disposal. Two kinds of statements must be criticized in this respect. The first is the so- called "empty niche". As the niche, by defivition, is species-specific it cannot exist without the species or, in Udvardy's working, "until filled". Secondary, the "competitive exclusion principle" or Gauseian hypothesis has been made responsible for species being prevented from invasion into a new habitat by another species that allegedly "occupies the same niche". The eco¬ logical system which controls the utilization of environment is a characte¬ ristic of biological species as a result of radiative evolution and, therefo¬ re, is not likely to be shared by to different species. To Btart anew: a new comer must encouter an ecological gap comprising all requirements for his survival. This means, e.g., the absence of a serious competitor (as in the cases of the Cattle Egret in America and the Hedgespar¬ row in New Zealand), the availability of nesting places (especially for spe¬ cies preferring large mixed colonies), but also the absence of harmful pre¬ dators and parasites and, in some cases, the presence of attractive ecologi¬ cal partners in trophic relations. One of the crucial questions, the receptivity of biotopes, has been largely disputed in recent years and will be, from another point of view, indicated later. Competition mechanisms appear - to the author - to be seen sometimes in too simple a way as to reflect matural connections. In recent centuries, most obviously in the 20th, one factor has caused or biassed an increasing number of range dynamics processes. It looks like you and me has been named "the Wise man", Homo sapiens. It is hardly necessai? to enumerate all influences, direct ones such as active extermination of po¬ pulations, naturalization of specieB in other regions or strict conservation measures (see the re-expansion of the Raven Corvus corax in Central Europe) 760 and ondirect influences by changes of environment - between afforestation, deforestation and contamination. Several of the most striking cases of recent expansion have obviously been favoured or even enabled by human activities. Three basic conditions of active spread are usually regarded: I. disper¬ sion across the boundary, 2. ecological valency or an ecological gap (or a niche holder can be pushed out), and 3. a high reproductive potential. These points are not sufficient for our topic. They show, however, that hardly a single factor can be responsible. A barrier is a barrier only in relation to mobility and dispensability which in turn has to do with territoriality, site tenacity, habitat and food selection, and homing abilities. Such a choose of specific sites reinforces the barrier. The combined effect of different factors is obvious in three cases to follow. The Black-headed Gull (Larus ridibundus) has, has in many parts of its range, not only increased in numbers but established new colonies within and beyond its boundaries. Besides the increase of breeding sites fol¬ lowing eutrophication of many water bodies, it was mainly the decrease of winter mortality caused by rich food supply (feeding of refuse; feeding by humans). So the equilibrium with the reproduction rate was lost and a populat¬ ion increase started. The Hedgesparrow has been introduced to New Zealand. The decisive factors which enabled the impressive spread were the very low level of competition and immense changes of vegetation character (by destruc¬ tion of many native habitats and acclimatization of hundreds of exotic plant species) which led to new habitat types into which the bird fitted better than any of the specialized endemic species. Moreover, among the acclimatized plants there are many European shrubs and weeds on the seeds of which the bird feeds in Europe. "The colonization of remote outlying islands by a small passerine bird without specialized flight abilities may be considered a proof that neither "land-bridge" nor long terms are actually necessary". The third instance is provided by the enourmous expansion of the Cattle Egret. The population increase in Africa exposed more individuals in their dispersal phase to marine wind conditions. Those arriving in South America encoutered not only suitable habitats and mixed colonies of other areids but also a rich insect fauna and the partners required for the specific feeding strategy: herds of large mammals though not wild species as in Africa but masses of livestock bred by man. So the newcomer lighted upon really optimal conditions. Range dynamics of some extent have consequences on, firstly, the communi¬ ties of which the species involved was, or Just became a member and, second¬ ly, on the population occupying a new areas. This field, of investigation appears to have attracted less attention than it derives. The competition system within the commities is affected if a species leav¬ es a gap or if another species has to be incorporated. The changes set going should differ according to the niche character. A species may hold an unique position on all communities as is the case in the Cattle Egret whose foraging strategy keeps competition at a very low rate. Thus, the bird would leave a gap which is not likely to be filled by any other species. The picture is quite different if- the specieB is a member of a guild. Not only has it to cope with these competitors but the latter, conversely, may be urged to apply 761 more or other belts of their ecological spectra. Strength of competition or even exclusion depends, moreover, on the size of the guild (the number of member species). In many cases, this means that ecological plasticity is tested in either, but it could likewise imply an evolutionary consequence that will be discussed later. On the other hand, if a guild member abandonee the community it relieves a specific mosaic of resources from being used. As a model for the conditions to follow then we can avail ourselves of studies on phenomena of "Ecological release" on islands where one or more species of a guild lack for chorogical reasons. One of the expansion rules more or lesB generally accepted states that "optimal" habitats are occupied first of all. The meaning of "optimal" appears to have been read only as "favourable in structure and climatic conditions" whereas the most conventient competition pattern in the taxocenosis or, least, in the guild in diverse habitats might often be the responsible feature. Another kind of problems arises from the evolutionary point of view. The changes in the community as just indicated have an improtant bearing also for the popultion and, hence, for the species itself. The changes in competition pattern modify the conditions for the genotypes. Ecodlogical plasticity may, for, the first period, be helpful for survival of individuals. Meanwhile, the gene pool of the population is rather radically reorganized. Certain genotypes might fit better now than they did in the area inhabited before. Secondly, other gene combinations may become successful which fomed the (more or less handicapped) "Sleeping" reserve and could not be productive. Furthermore, new recombination types arise some of which are particulary prosperous. Lastly new mutation result in new genotypes which likewise have to expose themselves to selection. SUMMARY Range expansion of dramatic extent (and speed) occurs preferentially in animal groups of high mobility and high ecological plasticity. Analytical studies of such processes can yield essential clueB to phenomenology and theory of range dynamics no matter which taxonomic group and which type of change is involved. As range is a multidimensional space, defined (besides the 3 spatial di¬ mensions' also by habitat(s) and time, it is subject to various changes which - though each case exhibits unique traits - can be grouped into A shift of (outer) limit, B disjunction of range, C shift of inner limits (including urbanization) , and D changes of density in (marginal) populations. Factors influencing or causing fluctuations of inner or outer boundaries are of different character. One group comprises endogenous factors such as high number of the econtic system (resulting in plasticity dispersal pattern, population structure and dynamics, reproductive potential, physiological abi¬ lities, communication system). Exogenous factors of particular significance! presence of strict barriers, ecological gap in the potential new area, chan¬ ges of environment, presence of ecological partners (useful or harmful). Cau¬ sal analyses, however, are often impeded by incompleteness of ecological data. 762 EXPANSION OP AREAS BY 15 BIRD SPECIES IN BALKAN PENINSULA S.D.Matvejev Ljubljana, Milcinskega, 14, Jugoslavia During 45 years the author together with his collaborators was making ob¬ servations and analysing the process of expansion of areas by 15 bird species in Yugoslavia. Bulgarian and Rumanian ornithologists were also interested in this subject. The expansion of areas was being observed in the central, northern and western parts of Balkan Peninsula and also in the foothills of East Alps by the following bird species: Phylloscopus trochilus. Streptopelia decaocto. Dendrocopus syrlacuB. Hirundo daurica. Hirundo rupestria. Corvus frugilegus. Hippolais pallida. Penan the hispanica. Ficedula hypoleuca. Plcedula semitor- quata, Turdus pilaris. Passer hlspaniolensls. Passer italiae, Carpodacua erythrinus. Cisticolla juncidia. While the preparatory work for field investigations and summarysing of the results the insufficient study of outlying parts of the area and the dynamics of the very process of settling were taken into account. At the Fig. 1-8 you can see the dynamics of this process. Thus the data concerning areas is generalized and schematized. It was usually considered that only southern bird species expand the areas of their distribution to N and NW. In Balkan Peninsula it was observed for: Streptopelia decaocto. Dendrocopus ayriacus, Hirundo daurica, Hirundo ru- pestris, Hlppolais pallida. Oenanthe hispanica. But at present we can also see the reverse process in Balkan Peninsula - the extension of arees to Si Phylloscopus trochilus. Ficedula hypoleuca. Turdus pilaris. Carpodacua erythrinus. and Corvus frugilegus expands the area of its distribution to S and W. According to the information of Bulgarian ornithologists Ficedula semi- torquata is also expanding the area of its distribution to W. Distribution of two bird species: Cisticolla juncidis and Passer italiae from W to E was for the first time observed on the territory of Yugoslavia- according to the data based on the investigation of hybrid population si¬ tuated at the junction of areas with Passer domesticus. Passer italiae is an independent species. Two groups of reasons are known to make birds expand their areas on Bal¬ kan Peninsula: 1. Changes in the ecological position in which a man introduces most im¬ portant alterations. 2. Changes in the very bird organism. In most cases both reasons are closely interconnected and complicated with climate fluctuations. Take, for instance, Mediterranean migrating birds, their nesting outside the nesting area far to N was being observed during the years with especially warm and arid springs. -, ?°3 764 Pig. 1. Distribution of Hu rund o rupeatria (a) and Pig. 2. Distribution of Passer hiananiolenais (a) and Carpodacua erytrinus ;b) in Balcan peninsula “ ' Passer italiae (b) in Balcan peninsula 765 766 767 The following changes in the ecological position more often lead to the expansion of bird areas in Balkan Peninsula: 1) Instillation of gardens and planting of separate fruit trees into en¬ tire steppe landscapes. This process led to the penetration of Streptopelia dec a oc to and Dendrocopus svriacus into the Central Europe. 2) Felling of forests .ploughing up of virgin soil and formation of a forest-steppe landscape: Corvus frugilegus, e.g. 3) Laying out of parks and planting of the groups of trees in steppe and semi-desert landscapes: Passer hispaniolensis. 4) Destruction of bushes and trees on stony slopes of mountains and gorges: Oeaanthe hispanica. Hirundo rupestris. 5) Opening of sand-pits and quarries in the centre of a forest landscape: Oenanthe hispanica. 6) Growing shallow of dense forest complexes, i.e. increase of a number of borders: Phylloscopus trochilus. Ficedula hypoleuca, Carpodacus eryth- rinus. 7) Decrease in a number of beasts and birds of prey which leads to an increase in a number pf Turdus pilaris. 8) Less destraction of singing birds by a man - e.g. Passer italiae in Yugoslavia. References Acrocephalus, 1980-1982, 1-12. Larus, 1947-1980, 1-32. Matvejev S.D. La distribution et la vie des oiseaux en Serbie. Academie Serbe des Sciences, monographie 161. Beograd, Reisers Omis Balcanica, 1950, V. Matvejev S.D. Survey of the Balkan Peninsula Birds fauna. I pt. Piciformes et Passeriformes. The Serbian Academie of Sciences and Arts, monography 491. Beograd, 1976. Patev P. Birds of Bulgaria. Zoolog. Institute and Museum Bulg. Academy of Sciences. Sofia, 1950. Reports of the Zoolog. Institute and Museum Bulg. Academy of Sciences. So¬ fia, 1951-1971, 1-33. Reiser 0. Omis Balcanica. Wien, 1896-1939, I-IV. Vasic V.P. Zbomik Priopcenja, Prvi kongres biologa Hrvatske. Zagreb-Po- rec, 1981. 768 Symposium DENSITY REGULATION IN BIRD POPULATIONS Convener: J. van BALEN, THE NETHERLANDS Co-convener: H. MIHELSONS, USSR PATTERSON I.J. TERRITORIAL BEHAVIOUR AND THE LIMITATION OF BIRD POPULATIONS BROWN J.L. COOPERATIVE BREEDING AND THE REGULATION OF NUMBERS COULSON J.C, DENSITY REGULATION IN COLONIAL SEA-BIRD POPULATIONS DHONDT A.A. THE EFFECT OF INTERSPECIFIC POPULATIONS COMPETITION OF NUMBERS IN BIRD MIHELSONS H., MEDNIS A., BLUMS P. MIGRATOrTduS“ 0F NUMBERS IN BREEDING POPULATION OF ^.SaK.ÇSl TERRITORIAL BEHAVIOUR AND THE LIMITATION OP BIRD POPULATIONS I. J. Patterson University of Aberdeen, Culterty Field Station, Newburgh, Aberdeenshire, UK INTRODUCTION It is widely accepted that selection on behaviour operates at the indi¬ vidual rather than at the population level and that territorial behaviour, especially territory size, varies in relation to the environment so as to ma¬ ximise the fitness of the individual (Davies, 1980). This paper discusses the hypothesis that the consequence of this may adjust density to variations in environmental resources. The definition of territory as a defended area will be used here. It is useful to separate two components; attachment to a site and aggressive be¬ haviour shown toward conspecifics around the site. The maintenance ol mutual- ly-exclusive areas with rigidly defined boundaries, emphasised by some authors, does not seem necessary to the ideas presented here. The aim of this paper is to consider the effects of territorial behaviour on population density by asking three questions: a) can territorial behaviour limit population density? b) if so, does the behaviour vary with environmental resources so as to change density in relation to these resources and c) if so, how exactly does the behaviour determine the particular density achieved in a given environment? All of these questions have been widely discussed elsewhere (e.g. Brown, 1969, Davies, 1978; Klomp, 1972; Patterson, 1980). I will deal only briefly with arguments and examples which appear elsewhere and will concentrate on recent work on the Crow Corvus corone and C. comix at Aberdeen, Scotland. CAN TERRITORIAL BEHAVIOUR LIMIT POPULATION DENSITY? Watson and Moss (1970) proposed criteria for testing behavioural limitat¬ ion of breeding populations. The most important of these for this discussion are (a) that a substantial part of the population is excluded from breeding, (b) that the excluded individuals are physiologically capable of breeding and (c) that the established residents are not using up the whole of a re¬ source (otherwise the resource itself would be limiting). The classic test of criteria (a) and (b) is to remove established territorial residents to find whether they are replaced by others, which muBt previously have been ex¬ cluded by the residents. A large number of such removal experiments, demons¬ trating the presence of surplus or floater individuals, are reviewed by Brown (1969) and Davies (1978) and need not be detailed here. Charles (1972), in addition to removal experiments, extended the breeding habitat of crows to create new opportunities for settlement. He created ad¬ ditional nesting habitat by erecting small trees in previously unoccupied tree-less areas. All the trees were occupied within a week by flock pair3 which defended an area around them. Three of the pairs laid eggs In th0the8es =°uld vaiy density . re^tion t0 re8°urce levels (Patterson, 1980) but data to test them are ew. The studies of Red Grouse (Watson, 1967; Watson, Moss, 1980) supports he second. More data are clearly needed, particularly on how density is determined in long-term territory systems. SUMMARY ditioneref18 C0n8lderable eVldence’ ™°val experiments and from the ad¬ dition of resources, that territorial behaviour can and does limit populat- rttortal Th Sh0rt"te”n terrtt01^ systems there is also evidence that ter- rttortal behaviour varies with resource level so as to change density in re- he territo^r068' “T* between rT !egre88iVene8B °f lnltlal “«!•» •»« the persistence and w h "T88 t Ïter arrlValS Snd non_^errt torial individuals. Species or ÎerH to'l6^ Tt0rial 8y8tem8 8eem t0 th*lr ^essiveness Z luch / reBP0n8e t0 8h°rt-term chan«es 1» «source abundance. In such species, any adjustment of territory size to resource level must be in”î d 0V6r S l0n£ Peri°d and m°re 8tUdy 18 need6d °f the me°banisms R e f e r e n c e s Eds. Brown J.K. - Wilson Bull., 1969, 81_, p. 293-329. Charles J.K. - Unpubl. Ph.D. Thesis, University of Aberdeen, Scotland Aberdeen, 1972. Davies N.B. - In: Behavioural Ecology. An evolutional ap’proach / J.R. Krebs, N.B. Davies. Blackwell, Oxford, 1978. Davies N.B. - Ardea, 1980, 68, p. 63-74. Dill P.B., Wolf L.L. - Ecology, 1976, 56, p. 333-345. Harris M.P. - J. Anim. Ecol., 1970, 39, p. 707-713. H irons G. Unpubl. D. Phil. Thesis. University of Oxford, England. Klomp H. - Neth. J. Zool., 1972, 22, p. 456-488. Knapton R.W., Krebs J.R. - Can. J. Zool., 1974, 52, p. 1413-1420. Patterson I.J. - Ibis, 1965, 207, p. 433-459. Patterson I.J. - Ardea, 1980,68, p. 53-62. Southern H.N. - J. Zool. Lond., 1970, lè2, p. 197-285. Southern H.N., Lowe V.P.W. - J. Anim. Ecol., 1968, 37, p. 75-97. sPray c.J. Unpubl. Ph.D. Thesis, University of Aberdeen, Scotland. Aberdeen, 1978. Vines G. - Anim. Behav., 1 979 , 27, p. 300-308. Watson A. - Nature, 1967, 225, p. 1274-1275. Watson A., Moss R. - Ardea, 1980, 68, p. 103-111. Watson A., Moss R. - m: Animal populations in relation to their food re sources / Ed. by A. Watson. Blackwell, Oxford, England. 1970. Oxford, 1976, 773 COOPERATIVE BREEDING AND THE REGULATION OP NUMBERS Jerram L. Brown Department of Biological Sciences, State University of New York at Albany, Albany, New York 12222,USA INTRODUCTION The regulation of numbers in populations of birds has been studied most often in passerine species of Europe and in marine colonial species. In such cases non-breeding or surplus individuals may be difficult to monitor pre¬ cisely, because they are inconspicuous or live elsewhere from the breeders. Cooperatively breeding birds differ from such species in that the surplus is readily visible. In addition, because of their habit of living in small groups, they may provide new perspectives. The term, cooperative breeding, denotes a social system that is defined by the presence of helpers. A helper is traditionally defined as an indivi¬ dual who acts like a parent toward young that are not its own. Helpers are commonly non-breeders, but breeders may be helpers too, even simultaneously caring for their own and other young (Brown, 1970). The term communal breed¬ ing is frequently used as a synonym for cooperative breeding. Typically, a cooperatively breeding species lives in small groups of 2 to 25 - rarely more. Except in colonial cooperative breeders, which I shall not cover, these groups typically defend a group territory, are composed largely of the mem¬ bers of one family,* have a stable composition from week to week, and are re¬ sident on their territory all year. Cooperative breeders are interesting for the study of population regulat¬ ion because the surplus birds are not expelled from their natal territories and may remain there for a long period, usually with their parents. This dramatic reduction of dispersal ameliorates the regulative effect of territo¬ riality upon the population. Most field studies of cooperatively breeding birds have not been designed to study population regulation, and few have been pursued for more than 6 years. One species that has been studied long enough to reveal something of its population fluctuations is the Mexican Jay (Aphelocoma ultramarine). I shall confine this presentation to the Mexican Jay because there is so little in the literature about population fluctuation in other cooperatively breed¬ ing species, and because a long term record is available for this species. We have Just begun this analysis. I shall present here an overview of the first results. THE MEXICAN JAY General The genus Aphelocoma belongs to the family Corvidae and ranges from Cent¬ ral America into Florida and much of western United States. All species are sexually monomorphic. The range of the Mexican Jay extends from centre! Me¬ xico northward to Just across the United States border in Arizona, where my observations are made, and to Texas. 774 Habitat and Study Area Ecologically the Mexican Jay is restricted to , z»* «.n.““«.1: xrr. zzsz'rzzur tj: - elevation. iLZTiZZZZZZZZT ^ ** — » ** Steller1 s Je, --ThnT^T“' f°”“' “"M,'a to * »« Streb J.r7i:e,«rol,.J:f) 'h' ae"rt '™b «“* <» Inhabited ~-r<1 eo„P,„,g ror thl. _ wl; «r;c:r •t an elevation or l.bîoTta TZZZZLTZ *" °”<'k C“J0"1 1,8 — :‘^c=:^~”irr:r'rr;*= Of individuals from our computer files. designated group or cohort Social Organization The Mexican Jay is a social species In iqfii . we showed that the Mexcian Jay lives in flock! tb ! 8 C°lor-banded ^s, groups that behave as single social units ^wn *3” TtM territ°rlal fore, the words flock, groun and unit Q , ! y63^' 1 this PaPer,there- apply to Mexican Jays. ” USed lnterchangeably as they In a survey of 38 units in Cave Creek Canyon in 1975 UTJ Average flock size on our study area has varied “ ' reproduction. By i97l we had six units colorbanded and the/rTein^ri!'7 ^ l6*5(Pig‘2)' the territories are held by groups, loss of even two to th«" ^ed‘BeCaU8e usually cause a change in borders. Consequently terri t i n0t borders, and numbers are exceedingly stable Some b S ’* ^ °Cati°ne* 8lzee. are. ,urr°„„d.d b, the .1, previon.l, e.odled J,0. " ?! „L*"? ■he population is defined by these seven flocks The total' 979 t0 creased 9 percent, from 155 to !68 ha since 1979 "" h“ ln‘ AU data on population numbers and fractions in this paper are from * , *» “»* «- ■>»' ••=>. year. .11 bird. Kn.» 1. bV.H,,." * »«« ZTu“ m 1 ”” 111 **" “■l',r* °f -1* or ' 779 Pig 1. The surplus population of Mexican Jays on 1 May. Data are for birds" from the preceding year class or older. Birds of the year are not in- eluded. Percentage breeding was estimated for the banded birds only. The percentage of birds not banded ranged from 17* at the beginning to zero in 1982 Mexican jay Pig. 2. Yearly variation in population size is reflected closely by va¬ riation in average unit size. The number of units on the study area varied only from six to seven Plural Breeding Unlike many cooperative breeders the Mexican Jay commonly has two or more females breeding within a single social unit, a condition known as pluaral breeding • Table 1 shows that even when only successful nests are counted, plural breeding occurs in evei^ flock and almost every year. In this respect the Arizona population of the Mexican Jay differs from the Scrub Jay and possibly from the Texas population of the Mexican Jay. Since many offspring breed in their natal territory in the presence of their par¬ ents (Brown, Brown, 1980), the hazards of finding a new territory are reduce 776 T a b 1 e 1. Number of successful nests per unit in six social units of Mexican Jay from 1971-1978 and seven units from 1979-1982. Data are the Year 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 TK CO HI SW BY US Bc f Total 1 1 1 1 1 0 1 4 2 3 2 0 1 1 0 1 1 3 3 3 1 1 2 1 2 2 1 2 2 2 2 1 2 3 2 1 2 2 1 2 0 3 2 0 0 3 1 0 1 1 0 1 0 2 2 3 1 2 1 0 1 1 1 0 0 1 1 1 0 1 2 3 8 8 4 7 3 12 14 10 10 14 14 THE SURPLUS The surplus population in Mexican Jays is large and varies greatly from year to year. Fig.1 shows that the percentage of the population known to be breeding in a given year varied from 45 to 93. Those not breeding, in all likelihood, aided in care of the breeders' young. Furthermore, breeders whose nests fail revert to feeding nestlings at other nests. Therefore, the surplus fraction constitutes a minimum estimate of the fraction of the population acting as helpers. In Mexican Jays, as in other cooperative breeders and unlike most territo¬ rial species the increment to the population remains in the preexisting terri¬ tories. Roughly half of the individuals stay to breed in their natal territory and the remainder moves to a neighboring territory. In the entire study no move of more than 1000 m has been seen. No such moves have ever been recorded for this species. Pew birds are seen that appear to lack territories. At most, such vagrants amount to 5%. As a consequence of the failure of the non-breeders to leave pre-existing territories, the average size of the groups in these territories closely •tracks the population level as shown in Fig. 2. The number of territories, in contrast, is much more stable. DELAYED BREEDING In cooperatively breeding birds, some members of the population typically delay breeding. Mexican Jays of both sexes delay breeding when compared to thPe sympatric Scrub Jay, which may breed in its first year. As shown in Fig. 3 bo one-year olds have been recorded breeding, though some break twigs and carry them awhile. One-year olds have very light bills. Only 20% of two- Year olds attempted breeding. At this age the light bill color diminishes, ahd the bill becomes all black by age 3. Not until the age of 4 does the per- centage breeding level off. About 20-30% of breeding age birds may not breed °n average. Adult levels of fledging success are not reached until the age of 777 I I I _ I _ I - 1 - 1 - 1 N 191 106 85 69 59 31 25 39 p i g. 3. Age-specific reproduction. The percentage of banded birds on the study area that attempted to breed at least by beginning to build a nest is shown by the upper curve. The percentage that fledged one or more young is shown by the lower curve. The sample is restricted to birds of precisely known age; they were banded as nestlings or year-lings. YRS - age in years. N - sample size 5 years. Because of such a long delay the maximum growth rate of Mexican Jay populations must be very small compared to other passerine species. This is compensated by a relatively high annual survival rate of about 80$. In res¬ pect to delayed breeding and survival Mexican Jays differ from most passerine species of the North temperate zone. Though there are exceptions, a relative¬ ly low population growth rate is characteric of many cooperatively breeding birds. POPULATION FLUCTUATIONS AND AGE -STRUCTURE A conspicuous cause of yearly variation in numbers of Mexican Jays is the number of yearlings. A yearling in our study is a bird hatched in the preced¬ ing year who is roughly a year old on May 1, As shown Fig. 4 fluctuations in population size are largely determined by yearly variation in number of yearlings. As a consequence of the erratic production of yearlings the fact- F i g- 4. Population numbers closely parallel the number of one-year-olds 778 ion of the population composed of yearlings „ as shown in ?k5 • - yearlings vanes greatly from year to year -«*■ - £ u. t rr birt- *• u" ,h; r- »— VP 1' agG StrUOtUre °f the Population varied greatly from year to Ler\fVU~e ab0Ve ea0h °f the ages in the ***»» shows the number of ndivi duals of that age and older. The number in a given age class for a year is glven by the vertical difference between the line above and the line below the indicated age. Data are for the entire population. Included re some unbanded birds and banded birds whose age is the stated age or older. The latter categ0I7 declined steadily from 50% in 1972 to 15% in ^ i g. 6. Year classes in a population of Mexican Jays from 1972 to 1982. ata are as in Pig. 5 77 9 PRODUCTION OP YEARLINGS The number of yearlings is determined by the number of nestlings raised in the preceding year and by their survival. Each of these factors is highly va¬ riable as shown in Pig. 7. The number of nestlings reaching banding age (14 days) varied from 8 in 1976 to 50 in 1978. The survival of these nestlings varied from zero in 1970 to 69% in 1973 and 1977. The greatest production of yearlings was achieved with moderately good production but excellent survival (1973, 1977 year classes). These conditions were relatively uncommon, but when they occurred they had a long lasting effect on the population. Conse¬ quently, increases in the population tended to be few (4) and large; decreases were more numerous (6) but smaller. Reproductive success in Mexican Jays is correlated with several climatic variables. The study area lies in an arid re¬ gion whose precipitation and temperature vary widely. Table 2 shows the corre¬ lation of five measures of reproductive success and seven climatic variables over an 11 -year period. The total numbers of nestlings and fledglings in the population each year are positively correlated with the amount of precipitat¬ ion at the onset of the breeding season, in March and April. Additionally , the number of fledglings is positively correlated with the precipitation in the monsoon rainy season of the preceding July and August, the major rainy season. Winter rains (Sept. -Feb.) were not as important as the monsoon rains. Cold temperatures during the winter also have a negative effect on reproduction in the following spring. A similar pattern is found when reproductive success is divided by the number of birds of breeding age (defined here as three or more years old), as shown in Table 2. Survival of nestlings is correlated with events in their first summer. Cor¬ relations of nestling survival with monsoon rainfall (rg = +0.60») and with maximum temperature in the hottest month (June; rg = -0.60*) are significant. The mechanisms of these effects are unknown, but it is reasonable to spe¬ culate that rainfall in the preceding summer affects the water table, the leaf growth of oaks and other trees, and the abundance of insects that utilize the affected vegetation. Cold winter temperatures might till oveiwintering in¬ sects and weaken potential breeders, thus reducing their reproductive success. fledging, in June to August, probably reduce Fig. 7. Yearly variation in number of nest¬ lings produced (Y-axis) combines with variat¬ ion in survival of those nestlings (X-axia) to determine the number of yearlings in the following year. The number of yearling3 is indicated by the contour lines, which con¬ nect points having the same number of year¬ lings designated above. The actual number of yearlings in the population is larger because of immigration. Each year class is designated by a number by its corresponding point Hot dry conditions shortly after the food available to Juveniles. 6 12. iß zz yearlings 780 Table 2. Spe annan rank correlation coefficients for 5 measures of rep¬ roduction and 7 climatic variables. All correlations discussed in this paper are based on Spearman rank correlation coefficients. On a one-tailed test these are designated * for P 4 0.05 and ** for- P ^ n m Total Total Nestlings Fledglings Fledged Nest per per per Nestlings Fledglings Adult Adult Adult March-April May-June March- June Preceding July-Aug Preceding Sept.-Peb. Temperature Coldest day of Preceding Winter Coldest Monthly Ly Average Minimum in Preceding Winter .53 .55* .54* .59* .68* .17 .41 .38 .45 .41 .45 .63* .68* .74** .75** .39 .67* .40 .58* .66* .27 .45 .40 .53 .35 .56* .68* .44 .49 .49 ’2* .63* .64* .62* .73** ,a «hl” “ °f ">»**“«» — d.t.ct- uir««h I""'! ”■ ‘“'"P*’ ™ P°ssd tlvely t„m. (■«11 3*" °r ,,*r‘ old' “ *•»« »d dipected ‘ ' S ■ °-85”i rs - 0-Î9”). Some m,S.tive effect, et higher densities were noted, however, on other factors. The number of fledglings per nest when restricted to those nests that fledged young was negatively correla¬ ted with the number of three-or-more-year-olds (males, rs = -0.86**; females, rS = -°»66**) but not with the number of yearlings (r =0.45). There appear to be some density effects on survival too, but these are significant only for yearlings (rs = -0.77** with average unit size; rc =0.70* with population size). s SPACING, DISPERSAL, AND DISPERSION Group territoriality in the Mexican Jay assures that areas suitable for Permanent residence rarely become available. Although individuals are free to disperse and explore to find suitable areas elsewhere, they rarely do. Of the western North American jays, Mexican Jays are the least likely to be found out of their usual breeding habitat (Weatcott, 1969). Consequently, each group tends to fluctuate in size according to its own reproductive success. Very productive flocks (e.g., SW) are genetic exporters; their offspring may be found breeding in the neighboring units. Unproductive units are gene- 781 tic importers that receive emigrants from productive areas. These spacing mo¬ vements tend to even out the population dispersion pattern. 'Whether such spacing movements cause a density-dependent depression of reproductive suc¬ cess at times of high numbers is not known. This issue is complicated because we cannot know what reproductive success the dispersing birds would have had if they remained at home. Preliminary analyses suggest that Mexican Jays tend to move from units with an unfavorable sex ratio to units with favorable ra¬ tios. Therefore, many spacing movements may have the effect of increasing overall population growth. Furthermore, theory suggests the possibility that territorial spacing can optimize utilization of habitats of different quali- » ty, thereby maximizing population reproduction (Brown, 1969). CONCLUSIONS Mexican Jays have a low capacity for population growth because of delayed breeding, which lowers r^. Their territoriality, combined with a low growth rate and relatively stable adult survival might be expected to stabilize po¬ pulation density. Nevertheless, density-independent effects on the production and survival of young seem to be the predominant influences on Mexican Jay populations. ACKNOWLEDGEMENTS I thank the National Institute of Mental Health and the National Science Foundationfor financial support. For permission to work on the study area I thank E. Bagwell, M.Cazier, O.Bruhlman and the Southwestern Research Station of the American Museum of Natural History. I am very grateful to the many persons who aided in the field work. Of great help in recent years have been S. Strahl, C. Barkan, J. Craig and especially E. Brown. References Brown J.L. - Condor, 1963, 65, p. 126-153. Brown J.L. - Anim. Behav., 1970, J8, p. 366-378. Brown J.L. - Am. Hat., 1969, 1 03 , p. 347-354. Brown J.L., Brown E.R. - Science, 1981, 21 1 , p. 959-960. Westcott P.W. - Condor, 1969, 7_i_, p. 353-359. 782 DENSITY REGULATION IN COLONIAL SEA-BIRD POPULATIONS J .C.Coulson Department of Zoology, University of Durham, UK INTRODUCTION The effects of density in relation to size of populations of animals are intimately linked with the classical concepts of population regulation operating through density-dependent factors. These density-dependent factors increase their effect as the density of the species increases. For example fecundity, adult survival rate or both may decrease at high densities result¬ ing in total or partial stabilization of the density and hence the populat¬ ion size. This concept is the opposite in effect of 'Social stimulation" or the so- called "Frazer Darling Effect" (Darling, 1938).' where breeding success is claimed to be higher in larger or more dense colonies. It 1b abundantly clear that many colonial sea-bird species nest at den¬ sities far in excess of those found in many other birds of a similar size. This is not the place or time to consider the advantages in colonial breed¬ ing; these are to be considered in another session of this meeting, but it must be noted that breeding at such high densities would appear to facilitate the transmission of diseases and if for no other reason, it must be expected that appreciable advantages also accrue to species breeding colonially. I have taken a wide view of density regulation and considered its influen¬ ce in the following six categories, particularly from the point of possible population regulation: 1. Regulation of density in colonies. 2. Regulation of densities outside of the breeding season. 3. Regulation of colony growth. 4. Regulation of formation of new colonies. 5. Regulation of Bpatial distribution and size of colonies. 6. Regulation in relation to feeding during the breeding season. As a result of this survey, I will suggest that the classical density-de- pendent relationships between density of birds within colonies and associated mortality rates do not, in general, appear to operate. They are, however, replaced by constraints on colony growth, formation of new colonies and the age at which birds succeed in breeding, which, together, control or regulate recruitment to the breeding population. These factors are not so much cont¬ rolled by density in the breeding colony but by the size or density of the Population in a wider area occupied by the species. 1 . Regulation of density within colonies Many species of sea-birds do not vary their nesting density in small and lahge colonies (particularly if density is measured by a "nearest neighbour" method), the distance between birdB being deteimined by a short individual distance (e.g. Guillemot Urla aalge. Gannet Sula bassana and Sandwich Tern Sterna sandvicensls). The lack of considerable variation in density of many aPecies suggest that density-dependent population regulating mechanisms con- dot be effectively operating through the small variation of densities found dd colonies. 783 A 100% B 89% C 64% HS. 1.* simple diagram to In a small oo- r—Ve r.: - — aa belBg at a lower ^ Even though the nearest neighbour method may n0t between large and email colonies, there ia an apP” „here the density „«.her. oi pairs ...ting on th. periphery of -U o ^ ^ of their neighbour, is lower than in a .«.Ml f“* „uld dsn.ity-dep.nden. id..., it might b, erpeo e ^ on Kitti— breed more successfully because oi xn + wlth central rtth no predation operating). nesting terrain 1. -re import«, in detemlning ... t»S flat, rocky area, the nesting density reaches seve^l or on moorluid. It would appear that on th. las. two ment l.tively few suitable nest sites whilst the irregular nature of rocky orovides many potential nesting places. . P Between ,979 and 1961. *■ »-»re con..r,«cy Council r.„«c d th numb » of Herring Gulls breeding of the Isle of May, Scotland from about 20,000 p.i to some 3,000 pairs. The reduced numbers bred over almost the same are used in 1971 so that the density of nesting birds was reduced by about 5-6 fold. Inferences in the breeding biology could be attribute* to the re not¬ ion in nest density or the overall decrease in birds nesting in the area. Egg size increased as did the size of the breeding birds (breeding success cou not be measured as clutches were destroyed in most areas). Hecxuitment too place at a younger age and the extent of philopatry increased, cause of the reduced competition for nest sites (Coulson, Duncan and 1982). Despite these effects acting against the species in 1971 (prior onset of culling), the population had been rapidly increasing. Kittiwake colonies also show increase in density as a colony grows of the recruitment goes in expanding the limits of the colony. The max mum density of nests in a Kittiwake colony is detemined by the geology o cliffs and the density of ledges and this is the main source of the consi able variation in nest, density found between colonies (Pig. 2). 3 0% — "o I — I — I — rrl Nests within 0.8m radius Pig. 2. The density of nests in two contrasting Kittiwake Rissa tridaotyla oolonieB. The upper diagram is of the colony at Dunstanhurgh, Northumberland and the lower one is of Marsden Rock, Tyne and Wear. Density has been measured by taking the number of other nes'ts in 0.8 m radius around each nest in the co¬ lony and plotting the values as a percentage frequency in each density class. Note that all Kittiwake colonies have low density areas but vary in the freque¬ ncy distribution and particularly in the high density areas. This is mainly caused by the numbers and length of ledges on the cliff face 2. Regulation of colonial sea birds outside of the breeding season In most sea-bird species, the density of a particular species is much re¬ duced during the non-breeding part of the year compared with the breeding season. In some species e.g. Puffin Fratercula arctica, Fulmar Fulmarus gla- cialis and Kittiwake, oceanic areas are exploited to a much greater extent at this time and accordingly the density of feeding birds is typically extremely low except at favourable sites. Further, there is often extensive mixing of populations which breed many hundreds and even thousands of kilometers apart. KittiwakeB from Arctic Russia and Norway mix with those from British colonies and those breeding on the east coast of North America. The density of only a small number of species is increased in the winter months. The Herring Gull and Black-headed Gull Larus ridibundus are examples where increased winter density occurs. In N.E. England the wintering "population" consists of local breeders, birds which have moved south out of Scotland and numbers of Scandi¬ navian or Baltic breeding birds. Whilst in these two gull species, there is Reason to believe that density regulation does occur at winter feeding sites, this may be exceptional for colonial sea-birds and I do not propose to con¬ sider this further at this time. In general, mixing of populations and the extremely low density of pelagic sea-birds which have spread beyond the .limits created by their attachment to breeding sites makes it unlikely that appreciable density related effects °Perate in the winter months. 1‘t-3aK.98i 785 P i g. 3. The growth of the Klttiwake Rlssa trl dactyls breeding population at Maraden, Tyne and Wear, in compariaon with that in individual oolomea. The log plot of the data represents the rate of growth by the steepness of the line Pig. 4. The presentation is the same as in Fig. 3, hut shows growth in 3 sections of a colony (centre, sub-centre and edge). The top line is the rate of change in a nearby colony which was nearly saturated and the figure illustrates the variations of growth rates which can occur in an area where young are recruited from a common pool 3. Regulation of growth in colonies In many species of sea-birds which are increasing in numbers, the pattern of increase within colonies differs from that of the population as a whole. Some colonies grow much more rapidly than others. Since potential recruits are not limiting, presumably certain characteristics of the colony structure restrain colony growth. Nelson (1978) has shown that very small Gannet colo¬ nies (e.g. Saltee and Bempton) grow extremely slowly until they reach a thres¬ hold number after which growth is rapid, even exceeding the rate in large, established colonies. In a study of Klttiwake colonies within the same limited area, the numbers in the area as a whole increased at a constant rate, but the rate of growth of individual colonies showed a progressive slowing with age (or size) (Fig. 3 )> suggesting that the structure of growing colonies becomes progressively less attractive to recruits. These differences can also be seen simultaneously in different parts of the same colony (Fig. 4). Since philopatry is not highly 786 Table 1. Recruitment and annual growth In three parts of a growing Kittiwake colony and In a nearby colony which has no room for further growth. Based on data in Figure 4 and assuming a 20 % annual adult mortality Edge increase recruits Sub-centre increase recruits Centre increase recruits Nearby "full" increase colony recruits Recruitment Average Percent growth 8.75 85.4% 10.25 9.43 74.2% 12.71 8.63 59.0% 14.75 5.60 9.9% 56.75 developed in the Kittiwake, these differences can be interpreted as indicat- ihg selection by the young recruits. I have examined this further by consider¬ ing the total recruitment to three parts of a growing colony and to a nearby colony which was no longer expanding. From the number of breeding pairs (Pig. 4) the annual increase can be easily determined. TiC this total I have added the numbers needed to replace adult mortality, assumed to be 20%, giving the total recruitment. Table 1 summarizes the results. Despite the difference in growth in the three sub-sections of the colony, total recruits were simi¬ lar but the proportion of recruits needed to replace adult mortality was less at the edge so that a much higher proportion of the total recruitment was al¬ located to increasing the number of breeding pairs. As a colony increases in aize, more recruits are needed to replace adult mortality and proportionally less contribute to colony growth. (It must be emphasized that the young pro¬ duced in a colony of Kittiwakes contribute only a small proportion of the necruits to that colony; most come from other neighbouring colonies.) The young of many sea-bird species do not find it easy to recruit into a dolony. Near-saturation exists in the centre of the colony and new places aPpear there only as a result of adult mortality. At the edge of the colony °dly a narrow area can be used by recruits (apparently because they need sti¬ mulation). This often results in a large number of birds capable of breeding but failing to obtain and retain suitable sites. This problem of finding a Place to breed is similar to that of forming new colonies. 4* Regulation of the formation of new colonies Pulmars are well known for their ability to colonize new areas. The whole the expansion around Britain is characterised by the formation of many new Pfeeding groups. This is in marked contrast to many other sea-bird specieB wPere there is clearly considerable difficulty or resistance to forming new c°lonies. For example, between 1909 and 1969, the North Atlantic numbers of 787 the Gannet increased threefold but the number of colonies only doubled (Nel¬ son, 1978). Similarly the expansion of the Kittiwake in Britain between 1900 and 1922 resulted in the doubling of their numbers but no new colonies were formed. Only when the population growth continued further were new colonies formed (Coulson, 1963). It is evident that solitai? breeding does not occur in many sea-bird spe¬ cies and a group of individuals have to collect together before breeding is successful. Typically, new Kittiwake colonies are formed by 30-100 birds but in the first year that breeding takes place only 5-10 pairs actually build nests and lay. Similarly breeding is mainly unsuccessful in the Rannet until about 20 pairs are established in a new colony (Nelson, 1978). This difficulty in establishing new colonies is important since it is ob¬ viously not easy for birds which fail to obtain a suitable site in an estab¬ lished colony to move and set up a new colony. This results in an appreciable number of birds of potential breeding age failing to do so, thus increasing the mean age at first breeding. 5. Regulation of spatial distribution and size of colonies Some species of sea-birds breed in colonies which contain hundreds of thousands of individuals but others clearly do not build up such large colo¬ nies although they are as numerous. For example the two species whose nest¬ ing colonies are shown in Fig. 5 show a marked contrast in the frequency and size of their colonies. The Gannet has few colonies, many of which are large and the British population. in 1969 was about 138,000 pairs. In contrast the Cormorant has a British population of just over 8,000 pairs but nearly 9 ti¬ mes more colonies. The most obvious explanation of this difference is rela¬ ted to the ability of the two species to exploit feeding areas around the British Isles. Nelson (1978) believes breeding Gannets have a feeding range of about 320 km whereas Pearson (pers. comm.) considers that breeding Cor¬ morant are restricted to a range of about 30 km. Obviously if the Cormorant is to exploit the potential feeding sites in Britain it must form many, small colonies. The food resources used by the Gannet can be exploited either by a small number of large colonies or a large number of small ones; and the species has selected the former strategy. I have examined the relationship between maximum colony size and feeding range during the breeding season for 15 colonial sea-birds exploiting fish stocks around the British Isles. Species present in small numbers have been excluded as has the Razorbill Alca torda since I have no information on its feeding range. To avoid bias, I have taken the largest British colony for each species reported in the national Bea-bird census carried out in 1969 (Cramp et al., 1974). The maximum feeding range (when rearing young) of each species has been taken from Pearson (1968 and unpublished data) with the ex¬ ception of the Manx Shearwater where I have taken the range from Harris (1966) and the Gannet, from Nelson (1978). The inter-relationship between feeding range and maximum colony size, is shown in Fig. 6 and the correlation is high. Perhaps the relationship is 788 Pig. 6. The relationship between ma¬ ximum colony size in the British Is¬ les in 1969 and the individual maximum feeding range during the breeding sea¬ son of 15 sea-bird species ( Fa-Prater cula arctica.Pp- Puffinua puf firing. sb- Sula bassana. Pg-Pulmarus_glaçlalis, Ua- Ur la aalge. Rt-Rissa tridnc^i., La-Larus argentatus. Lf-L.fuscus. Sp-Sterna paradisaea. SS-S.sandvicer.- sis, Sh-S.hirundo. Pa- Phalacrocorax arlatotelis, Pc-P. carbo. Cg-Cepphun g*?116 and Sa-Stema albi f 789 obvious; it clearly suggests that sea-birds are attempting to utilize poten¬ tial food resources. What is not clear, however, is why those species with long feeding ranges opt for large colonies. The implication is that, provid¬ ing food resources are adequate, there is an advantage in a large rather than in several smaller colonies. Apart from the possible shortage of suitable nesting sites in some species, advantages in forming one colony of, say, 100,000 pairs rather than five of 20,000 have not been considered previously. 6. Regulation in relation to feeding density during the breeding season One of the implications derived from Pigs. 5, 6 is that food and feeding influence the size and perhaps the position of breeding colonies. The impli¬ cation of food is of interest and begs the question "Can feeding bring about the control of breeding numbers?". In simple terms, one is looking for an ef¬ fect which causes food shortage in large colonies but not in smaller ones. This leads to the question of whether sea-birds greatly reduce the stocks of their food. It is difficult to believe that surface feeders and those which dive just below the surface can exploit fish to the extent that they markedly reduce the fish density even if the birds are present in large numbers. Diving species can approach their foood supply more effectively. Furness (1978) has estimated that the sea-bird populations may take up to 30% of the food supply during a breeding season, but this is in regions of very high sea-bird numbers This is a field which needs more research. Apart from the direct interac¬ tion between food and predator there is also the possibility of interaction between feeding individuals, which is probably more intense in those species with a short feeding range. DISCUSSION AND SUMMARY Too little is known about sea-birds in their wintering areas to be able to comment with any certainty as to whether density regulation takes place at this time. Many species are spread out to a greater extent at this time and usually the density of individuals is much lower than during the breeding season, when the birds are limited by the feeding range from the colonies. Except in a few species, such as some gulls which accumulate at high densities in some localities in winter, there may not be much density, regulation out¬ side of the breeding season. Since many species form mixed-population flocks or groups, any regulation which does occur is unlikely to regulate the size of the breeding populations. In those see-bird species which nest at incredibly high densities, packing closely together, there is little variation in nesting density and the densi¬ ty in each species is determined by its characteristic individual distance. The only source of variation is colony size and hence the proportion of birds nesting at the periphery. Even in those species which show variation in nes¬ ting density, much of this variation can be subscribed to variation in the nature of the nesting area and the availability of nest sites. Most sea-birder do not form colonies each of which is a closed population and some recruitment takes place from the young reared in neighbouring colo- 790 «... However there i. , .ld, of pMlops,tc> .„_blrd „Mc„ 1. particularly high in l.nnete, Shag. „d Corrorant. .! low in S.nd»ich Of seVblLlear thBt lndlVldUal C0l0nles d° «* — ny regulate the density of sea-birds on an area but there Is evidence that they exert a restraint on he growth of the breeding population In an area through the social conventi- ehort^rofT Hth reCrUltment* In effect’ the social behaviour Induces a èin o«.r ™ r.; ■*<« «. « aance iCoulson, 1971; Potts et al., 1980). breIdLreMat!°nehiP b6tWeen maXlmUm C°l0ny BlZe “d the feedlnK ™ge of reeding birds suggests an interaction between food, the ability to exploit food resource and the distribution of colonies. There ie need for ZÎ Ire research n this field but here is a possible mechanism which could reg^e sibl \! !* 8ea'blrd0 feedlne around areas used for breeding. Is it pos- fe d h v depl6te thelr f00d ^PPlies sufficiently to result in a this'dlffiruît tlnflTCeS th6ir 8UrVlVal °r thClr breedlDg 8UCCe8E* 1 «»d lust envisage for surface feeding species and those which plunge Just below the surface. So much of their potential food supply is out of reach any one time that factors affecting the availability of food would appear to be more important. This restraint is less severe in deeper diving species land”0 6 ! PUrneSS 0978) that sea-bird colonies in northern Scot¬ land were taking about 30% of the total fish eduction each year. This in itself, does not deplete the available food within the breeding season to a SWtlT Z8 r pr0dUCti0D is continulng throughout the breeding season. ex^omn°UthT IVer’ 1Srge fl8h’ mariDe “la Snd man are also actively • IT* ^ production. Overexploitation of the stock will reduce the L^ion siD “d thI m08t lik6ly °r8aniSm t0 d° thl8 18 man* If sea-^rd popu- fishin !! !" determined by feed-back through the food supply, then man-s hing activities are going to have widespread effects in the next few de- References coulson J.C. - Bird Study, 1963, 22» P* 147-179. Coulson J.C. - In: Proc. Adv. Study Inst. Dynamics Numbers Popul. (Ooster- beek 1971). 1971. Coulson J.C. , Duncan N., Thomas C. - J. Anira. Ecol., 1982. Cramp S., Bourne W.R.P., Saunders D. The Seabirds of Britain and Ireland. 1. i Collins, 1974. Carling P.P. Bird flocks and the breeding cycle. Cambridge: University Press , 1938. ^Urness R.W. - j. Anim. Ecol., 1978, £7, p. 39-53. Harris M.P. - Ibis, 1966, 108, p. 17-33. kelson J.B. The Sulidae: Gannets and Boobies. Oxford: University Press 1978. Parson T.H. - J. Anim. Ecol., 1968, 37, p. 521-522. P°1ts G.R., Coulson J.C., Deans I.R. - J. Anim. Ecol., 1980, 49, p. 465-484. 791 THE EFFECT OF INTERSPECIFIC COMPETITION ON NUMBERS IN BIRD POPULATIONS André A.Dhondt Department Biologie Universitaire Inetelling Antwerpen, B-2610 Wilrijk, Belgium INTRODUCTION Very few papers on interspecific competition in birds have considered if the competition which was observed or inferred had any effect on the numbers in the population. The definition of interspecific competition, however, says that competition has a negative effect on all species-populations involved, as made explicit by its mathematical formulation (equation 1). This states that the growth rate of a population per unit time (dN/dt) is reduced by the presence of individuals of the same species (intraspecific competition) and by the presence of individuals of another species (inter specific competition) dNt dt U (1) i, j : species; N; population size; ts time; rm intrinsic rate of natural in¬ crease; e( : competition on the per capita growth rate r » dt (1 - - «( ij Ni -i) (2) Using this approach it is clear that very few papers that talk about compe¬ tition have really shown that interspecific competition takes place. For in¬ terspecific competition to be proven the author must provide evidence that the population growth rate or the per capita growth rate of species i is re¬ duced by the presence of species j, or is a function of the density of spe¬ cies j, and vice versa. If sufficient data are available zero-growth isocli¬ nes can be drawn. Owing to the limited space I will not exhaustively review all bird papers on interspecific competition assessing them in the light of the above equati¬ ons. Rather I will (1) expand the traditional equations based on the logistic model to a simple non-linear model, (2) provide some evidence that the per capita growth rate can be a non-linear function of population density in birds, (3) discuss some implications of this non-linear density dependence on the effect interspecific competition has, and (4) use data on Belgian Tits to illustrate some of the points made. ON NON-LINEAR DENSITY DEPENDENCE Smith (1963) showed that in a laboratory population of water fleas the per capita growth rate was a non-linear function of population density. The same is true for some fruit-fly species (Ayala et al., 1973). In both these examples the relationship is concave. In reanalysing the Pheasant data from Protection island (Einarsea, 1945) a similar concave curve appears (Fig.1)* As shown in the bottom part of the figure this is the result of the non-li¬ near density dependence of recruitment*. The Lotka-Volterra equations (cf. eq. 1 and 2) are clearly inadequate to model these non-linear relationships* * Fowler (1981) has given examples of convex curves 792 1.6 ® rm 600 1000 200 600 1000 1000 p i g. 1. Re-ana lyais of the Pheaaant PhaaianuB oolchicua data of Protection Island (Einaraen, 1945) (see also text) °»e of the more complete explorations of what mathematical model best des¬ cribed experimental results was made by Ayala et al. (1973). They considered twenty different models and selected the following one (equation 3). 1 dN., N.' _ N. (3) r • — • - » r (1 - — 10 . - a -i) Nt dt mi 'kj 1 « K. One of the attractive things about this model is that the Lotka-Volterra equation is a special case for 0. 1. As shown in Fig.2 the model produces concave curves ( f>< 1), convex curves ( 9 > 1 ) as well as a straight line By introducing the power the model implies a non-linear intra- sPecific effect, but a linear interspecific effect. I am fully aware of the fact that this model has its shortcomings: it does, •i. not take into account the Allee effect. I will nevertheless use it in the remaining part of this paper. Any conclusions drawn remain at least quali¬ tatively valid for other non-linear models. It is important now to consider in what species ß would be large and in *hat specieB ß should be small. Gilpin et al. (1976) explored this and con¬ cluded that in stable environments high values of 0 would be favoured, whe- reas low values would be optimal in unstable environments. In a different ai"gon this means that low values of Q ( ■C 1 ) are typical for r-selected spe- 68 whereas large values ( > 1) of J must be found in K-selected species. 793 Fig. 2. Curves obtained for different values of 0 usiDg the model shown in equation 3. The full ourves show the effect of intra- specific competition only on the per capita growth rate. All curves go from r = rm, N = 0 to r = 0, N = K. The stippled curves include the effect of interepeolf lo com¬ petition. They all start at r^ ( is large. In fact the smaller the value of 6 , the larger the difference between K and K'" becomes. This model thus shows that r-selected species suffer heavily from inter¬ specific competition, whereas K-selected species suffer only mildly. Where do the birds now fit? Blueweiss et al. (1979) have shown that a close relationship exists between the intrinsic rate of natural increase r and body weight over all animal groups. Although birds on the whole are K-selectec species the maximal growth rate calculated from Blueweiss' formula can vary f.i. between 4.19 per annum for a 20 g bird (e.g. a Great Tit), over 1.51 per annum for a 1000 g bird (e.g. a Pheasant - this value is shown as r in Fig.1), to 0.87 per annum for a 8500 g bird (e.g. an Albatross). Within the group of birds we therefore undoubtedly find Bpecies that are more r-selected (the email songbirds with large clutches, several broodB per year and a high mort¬ ality rate) and species that are more K-selected (the large seabirds with a long delay in reproduction, a clutch of 1 and low mortality rates). If the model is correct I would expect concave curves for small songbirds, but con¬ vex ones for large seabirds, raptors, etc. Small songbirds exposed to inter¬ specific competition would then strongly be affected, but the «.-selected bird species would show only a slight numerical response to interspecific compe¬ tition. NON-LINEAR DENSITY DEPENDENCE IN THE BLUE TIT Earlier I stated that in order to prove interspecific competition it is necessary to Bhow that the per capita growth rate at a given density of a species varies inversely witH the population size of the competing species. In Figure 3 I have plotted the per capita growth rate of different Blue Tit po¬ pulations in relation to population density: the population "Zevergem" (16 ha, mainly oak) over the period 1959-1977, showing an inverse relationship bet¬ ween r and N and the points for a second area "Gontrode" (18 ha, mainly oak) for the years 1972-1976 lying very close to this line. As described by Dhondt, Eyckenman (1980) an experiment was performed in Gontrode resulting in a de¬ crease of the Great Tit population size and an increase in the size of the 794 dN Ndt K' K' K' K N Pig. 3. Per capita growth rate in relation to breeding density (per 10 haï for different Blue Tit populations (see text) P i g. 4. Blue Tit isoclines estimated after experimental reduction of Great Tit popu atioo at Gontrode (see text) Blue Tit population. The four points for the experimental years 1 977-1 qai all lie clearly to the right of the line for the normal years, including that for the cold winter 1978-79. When Great Tit population size is reduced to about 8 pairs/10 ha, the per capita growth rate for the Blue Tit population incre¬ ases and the Blue Tit equilibrium value (K) lies at around 16 pairs/ 10 ha, as compared to 10.5 pairs/10 ha when the Great Tit population size is not mani¬ pulated (Great Tit density: 16.2 pairs/10 ha). If we could exclude all Great Tits the Blue Tit population size would increase still further. But to what Level? In an earlier paper (Dhondt, 1977) I have estimated the size of a Blue Tit Population in the absence of Great Tits using linear isoclines. I obtained a K-value of 13 pairs/10 ha for the Blue Tit. In Figure 4 I have redrawn the isoclines from that paper adding the points for the pre-experimental and the experimental years in Gontrode. The four points for the pre-experimental years fit the Blue Tit isocline for the other area quite nicely. The points for the experimental years, with a reduced Great Tit population size, however, all 5 fall well above the linear isocline. I have therefore added to the figure a curvilinear isocline for the Blue Tit (drawn by eye). This line is concave, indicating a value of 0 smaller than 1, as would be expected for this small songbird. Such non-linear isoclines have also been found by Ayala et al. / 1 9 7 3 ) for Drosophila spp. CONCLUSIONS Very few studies on bird populations show that through interspecific compe¬ tition population size is reduced, or that growth rates are effected. Using a fcathematical definition of competition this implies that in these studies in¬ terspecific competition has not been proven. It is probable that in many cases the r/N is non-linear. The simple model used shows that more r-selected species will suffer very heavily from inter¬ specific competition, whereas more K-selected species Will be only mildly af¬ fected. It is quite concievable that in studies of such K-eelected species it will be almost impossible to show an effect of interspecific competition even if it occurs. The new equilibrium level reached after the level of interspeci¬ fic competition has been changed must lie closely to the old equilibrium le¬ vel. Since the environment is never completely stable and micro-evolutionary changes could affect population parameters the original K-value will fluctuate so that the new equilibrium level could easily fall within the range of va¬ riation of the original one and no interspecific competition can be shown. In the neighbourhood of the equilibrium level K the slope of the curve des¬ cribing the r/N relationship differs for r- and K-selected species (with va¬ lues of 0 respectively ^ 1 and 7- 1). The steeper the line, the more rapidly the population will react to small disturbances from the equilibrium level. K-selected species, that have a steeper slope around K, should therefore react more rapidly to small disturbances than r-selected species, in which the slope is smaller (see figure 2). K-selected bird species normally have a delayed maturation period with a non-breeding population of subadult birds. Since these birds, even in subadult plumage, are often capable of breeding (see f.i. Newton, 1980, for a review of birds in prey) there is a reserve po¬ pulation that makes it possible for such a population at equilibrium to react directly to, for example, an adult dying. In r-selected species, in which all birds breed in their first year, this non-breeding reserve is not available (or limited to one sex only), so that it is only after the next breeding season that losses can be replaced. SUMMARY The mathematical definition of interspecific competition states that for interspecific competition to occur it must have an effect on the numbers of all competing species. Using a model proposed by Ayala et al., which is a simple expansion of the Lotka-Volterra equations and produces non-linear cur¬ ves to describe the r/N relationship it is shown that the effect of interspe¬ cific competition on r- and K-selected species is very different. The belgian Tit data are used to illustrate some of the points made. References Ayala P.J. , Gilpin M.E., Ehrenfeld J.G. - Theor. Popul. Biol., 19-73, 4, p. 331-356. Blueweiss L. et al. - Oecologia (Berl.), 1978, 37, p. 257-272. Dhondt A. A. - Nature (London), 1977, 268. p. 521-523. Dhondt A. A., Eyckerman R. - Ecology, 1980, 6l_, p. 1291-1296. Fowler C.W. - Ecology, 1981, 62, p. 602-610. Gilpin E.M., Case T.J. , Ayala F.J. _ Mathematical Biosciences, 1976, 32, p. 131-139. Newton I. Population ecology of raptors. Berkhamsted, 1979. Smith F.E. - Ecology, 1963, 44, p. 651-663. 7 96 REGULATORY MECHANISMS OP NUMBERS IN BREEDING POPULATIONS OP MIGRATORY DUCKS |R.A. Mihelsooal , A. A. Mednia, P.N. Blums Institute of Biology of the Latvian Academy of Sciences, Riga, USSR A great number of laboratory experiments have shown the presence of densi¬ ty-dependent regulation of numbers in various populations of animals. This important phenomenon has been considerably less studied under natural conditi¬ ons. Investigations on natural bird populations mainly deal with non-migrato- ry territorial species (e.g. Dhondt, 1971? Kluyver, 1971; Boag et al., 1979. Zwickel, 1980). We present here our main findings on regulatory mechanisms (intrinsic control) of numbers in relatively small breeding populations of exploited migratory ducks. Tufted Duck (Aythya fuligula) and Shoveler (Anas çlypeata) were chosen as the main model species. Long-term investigations on the population ecology of migratory ducks were carried out at the shallow overgrown coastal Engure Marsh, Latvia. Since 1961 nest counts and subsequent mapping were carried out annually on the islands and some slough area. Almost all incubating females and newly hatched duck¬ lings were trapped and ringed at the trial plots. Different trapping and ring¬ ing methods were used (Lejins, 1964; Mednie, Blums, 1976; Mihelsons, Blums, 1976; Blums et al., 1983). During 21 year 42550 newly hatched ducklings of 13 species have been ringed. Prom these 790 incubating females were retrapped the succeeding years, mostly as one-year-old birds during their first breed¬ ing season, and 3340 random recoveries were received. Including retrappings, about 6200 captures of incubating females were registered. At the same time environmental changes in nesting habitats were registered and a number of mé¬ nagement measures were performed to improve the nesting habitats and to cont¬ rol the predators. The main method of analysis was the calculation of correlation coeffici¬ ents between the indices of density and survival of young birds or adults. Numbers of counted nests expressed as a percentage of a moving average (i.e. deviation from moving average) were used as index of density. In our opinion a moving average of the number of counted nests (for example from 3 years) reflects to a certain degree changes in the carrying capacity of the nesting habitate over a more prolonged period. It is extremely important to consider these changes in population studies because number of breeding females (or Pairs) per area not always can be used as criterion of "biological density" (see Mihelsons, 1980: 58). The random recovery rate during different periods of life and the recruitment rate of young females to first nesting were used 88 index of survival. In two main species under investigation the same phenomenon has been obser- Ved, i.e. the self -regulation of numbers of nesting females (Mihelsons, 1976, ^80; Mihelsons et al., 1981a). First of all the self-regulation is expressed ky a change in mortality rate among the population members, mainly among young kinds, depending on variations in biological density in breeding periods. Com¬ paring years with different density of the nesting population the post-hatch- survival of young ducks increases with the decrease of density index ^pig. 1 ). Calculation of correlation coefficients between the indices of densi- 797 Rezr/o) me/.) Fig. 1. Relationships between density index (see text and Table 2) and post-hatching survival of juveniles in breeding population of Tufted Duck on islands of Engure Marsh, Latvia, 1961-1979 Re2 - random recovery rate during second calendar year of life; Rt2 - recruitment rate to first breeding of one-year-old females. Both indices were calculated from the total amount of ringed one-day-old ducklings of unknown sex in preceding year ty and the random recovery rate of young birds in various autumn periods revealed that elimination of the excess amount of juveniles by shooting in the Tufted Duck occurs most intensively at the end of the breeding period and it is finished mainly before their departure from the natal area. In the Shoveler, the process of elimination goes on also during autumn migration and in the beginning of the wintering period. In juveniles of both species this process is almost completed at the end of the first calendar year (the¬ refore we usually use the random recovery rate after the first of January of the second calendar year as an index of survival). In the Tufted Duck there are facts suggesting that in the absence of hunt¬ ing the surplus birds perished. We compared the recovery rate of birds ringed in the same years in two neighbouring populations - Engure Marsh (with autumn hunting) and Matsalu Reserve (without hunting) (Table 1). It was found that the random recovery rate of juveniles after departure from the natal area is the same for both areas (Fisher Test, p ^ 0.05) whereas the local recovery rate of the hunted population was much higher than that of the population without hunting. This means that autumn hunting on the Engure Marsh does not affect the size of the breeding population in the following year, as a large number of juveniles perishes due to unknown natural causes whether the birds are hunted or not. Thus we suggest that natural and hunting mortality are not additive but mutually compensatory (Mihelsons et al., 1981b, 1981c). A similar phenomenon was found for the Mallard (Anas platyrhynchos ) in North America by Anderson and Burnham (1976) . The physiological mechanisms depressing the vitality of birds at increased density have not yet been studies. High density probably increases the stress 798 J * ‘ 1 ! ’■ C°">’*rl»'>n °f rcmdom recovsry »te In Tufted Dnd fro. two «ff.~t wa.tl«. with (Enw„ »,„h, um.) «d without hunting IMatsalu Reserve, Estonia), 1969-74 Age and sex at ringing Ringing place N of birds ringed N of recoveries (%) During 1st During 1st and calendar 2nd calendar L“ - year < 60 km year > 60 km Pulli, indet. Adult females Adult females Engure Matsalu Engure Matsalu 4171 3754 604 651 257 (6.2) 14 (2.3) 1 (0.2) 61 (1.5) 48 (1.3) 17 (2.8) 18 (2.8) situation in birds through competition, by which they become more susceptible to unfavourable environmental conditions. In the Tufted Duck we- have investigated the demographic regularities caus¬ ing a decrease in the survival of ducklings in situations of high density. us, along with the increase in numbers the proportion of one-year-old local iemales and immigrants among the nesting females is also increasing. The sur- th6lr dUCkllng8 is considerably lower than that of the older females (Mihelsons, Mednis, 1976; Mihelsons, i960). The increase in numbers of nesting females usually causes prolongation of the breeding period. The overall post¬ hatching survival decreases, because the survival of ducklings from late clut¬ ches is inferior, as has been found in all duck species studied so far (Mihel- aons et al., 1970). Both phenomena lead to a decrease in the survival of duck¬ lings when the number of nesting females increases. Long-term data on the Tufted Duck were collected not only on islands of the Engure Marsh where mass ringing was started in I960, but also on slough area where ringing was started in 1966. Correlation coefficients between the den¬ sity indices in separate limited marsh areas and the indices of post-hatching survival, i.e. the random recovery rate during the second calender year of Ufe (Re2) and the -recruitment rate of autochtonous females on the Marsh (Rt) were calculated. The results appeared to be different for the two survival in¬ duces. For Re2 the highest negative correlation coefficient of the survival in each separate area occurs with the index of density exactly from the same area where ducklings were hatched (Table 2). This allows us to suggest that in the initial stages Belf -regulation occurs mainly autonomically in each de¬ finite area, i.e. the survival of ducks during the first calendar year of life is affected especially by the increased density of nesting females at the imited hatching sites, more than by the density in the marsh as a whole 'Mihelsons, 1981). The recruitment rate of autochtonous one-year-old females (Rt2) and one- ïear and two-year-old females (after two years) together (Rt 2+3) gives in ®ost cases the best correlation with the density indices for the whole marsh able 3). The difference from random recovery rate may be due to various pauses and further investigations are needed. We suggest that Re2 and Rt2 0I> Rt characterize the post-hatching survival in various periods. Re2 799 Table 2. Correlation between the indices of density0 and relative survival rate (Re2)b of juvenile' Tufted Ducks in 6 limited areas (A-P) of Engure Marsh, Latvia, 1967, 1969-1976 Re2 in area Index of density in area A B C D E P Total area A -0.48 0 -0.03 -0.40 + 0.22 +0.51 -0.06 +0.25 B V-0-3Ô1 -0.79 -0.62 -0.57 CVJ • o 1 -0.43 -0.44 C +0.04 -0.63 -0.67 -0.42 +0.09 -0.44 -0.27 D +0.08 -0.31 -0.23 -0.67 -0.45 -0.58 -0.44 E -0.11 1 o • o -0.12 -0.51 -0.58 -0.54 -0.50 P -0.13 -0.16 -0.23 -0.38 -0.10 1-0.44| -0.08 Total area -0.06 -0.46 -0.50 -0.49 -0.16 (-0.541 -0.37 0 Total number of neete in the given year expressed as a percentage of the 3-year moving average; b Random recovery rate during second calendar year of life; c The highest negative value of correlation coefficient in each row is encircled; = p •<. 0.05. Table 3. Correlations between the indices of density0 and the recruit¬ ment rate to first breeding of autochtonous one-year and two-years-old (Rt 2+3) female Tufted Ducks in 6 limited areas (A-P) of Engure Marsh, Latvia, 1967, 1969-76 Rt 2+3 Index of density in area in area A B C D E P Total area A -0.52 -0.22 -0.60 -0.27 -0.32 [ -0.63 b -0.62 B' -0.09 l^o^TI -0.04 1-0.60 -0.26 -0.57 -0.55 C -0.24 -0.36 -0.57 -0.49 -0.35 1 -0.68 -0.62 D -0.43 -0.26 |-0.54| -0.09 -0.20 -0.38 -0.49 E (-0.501 -0.12 -0.44 -0.04 -0.39 -0.36 -0.62 P -0.46 -0.27 -0.61 | -0.28 -0.28 f -o.6i| -0.59 Total area -0.46 -0.22 -0.55 -0.28 -0.40 L-0-591 -0.67 0 As in Table 2; b The two highest values of corrélation coefficients in each row are encirc¬ led ; « p <■ 0.05. shows the relative survival rate of young ducks during first months of postr hatching period (i.e. mainly till the end of first calendar year of life), Rt2 embraces more prolonged period (mainly during almost all first year of life till the first breeding). Data from the literature on other species sug¬ gest that more or less intense regulation of numbers may continue also during 800 Table 4. Correlations between the index of the absolute number of survived juvenile3 Tufted Ducks and the recruitment rate (Rt2) of autochto¬ nous one-year-old females in 3 area6b wifi different survival of juveniles, Engure Marsh, Latvia, 1967, 1969-76 Rt2 in area Index of the absolute number of survived juveniles in area A D G A -0.53 -0.05 +0.68* D -0.62 -0.33 +0.78* G -0.77* -0.28 +0.49 Q See text for explanation; Areas with different survival of juveniles; A - high, D - medium, G - low; « p < 0.05. migration and in winter quarters, for example, due to competition for better feeding places within the population. In such cases it should be more reflec¬ ted in the Rt2 than in Re2 and a relationship should exist between competiti¬ ve ability and survival. As we do not know the competitive ability of juveniles we compared the survival of ducklings of three female groups which differ in their mean com¬ petitive ability (or social rank) in choosing their nest sites! 1) the hig¬ hest (A) - from island A with the highest mean survival of offspring; 2) me¬ dium (D) - from 4 small islands, and 3) the lowest (G) - from slough area of the marsh where the survival of ducklings usually is the lowest. Instead of the unknown absolute number of juveniles surviving till their migration from the marsh, relative indices were used in the calculations. The indices were obtained by correcting the number of recoveries during the period bet¬ ween the first exodus from the marsh till the end of the second calendar year to allow for 100% ringing. Correlation coefficients were calculated bet¬ ween the obtained data on juveniles of each category and the corresponding Rt2. The results turned out to be convincing (Table 4). With the increase of the absolute number of migrating offspring produced by females of the highest social rank (A), the next spring Rt2 in all three categories decreases and the highest decrease of the return rate was for females from the lowest so¬ cial rank (G). The number of surviving juveniles from the medium rank has a smaller negative effect but from the lowest rank even significant positive correlation was observed. The latter phenomenon is not yet understood. Besides there are other indications confirming that ducklings produced by females of the highest rank are really more capable of competition than those produced by females of the lowest rank. In the Tufted Duck and especially in the Shove- ler the juveniles of one-year-old females in years of high population density w®re significantly more often recovered outside the natal marsh than juveni- lea of the same age in years of low population density (Mihelsons, Mednis, l5-3aK. 981 801. 1976). Evidently if competition is higher the juveniles have to leave the En- gure Marsh earlier. In summary, the given facts on the Tufted Duck prove indirectly that popu¬ lation self-regulation is a prolonged step-by-step process with various dyna¬ mic stages, in which migrational homing of adult females and their ability for competition, i.e., hierarchial rank in the population, are especially important. References Anderson D.R., Burnham K.P. Population ecology of the Mallard. VI. The ef¬ fect of exploitation on survival. U.S. Dept. Int. Pish Wildl. Serv. Resour. Publ., 1976, 128. Blums P.N. , Reders V.K., Mednis A. A., Baumanis J.A. - J. Wildl. Manage, 1983, 47 (1). Boag D.A., McCourt K.H., Herzog P.W., Alway J.H. - Can. J. Zool., 1979, £7, p. 2275-2284. Dhondt A.A. - In: Proc. Adv. Study Inst. Dynamics Numbers Popul. (Oosterbeek 1970), 1971, p. 532-547. Kluyver H.N. - In: Proc. Adv. Study Inst. Dynamics Numbers Popul. (Oosterbeek 1970), 1971, p. 507-523. Le jins G. - The Ring, 1964, 44, p. 75-76. Mednis A.A., Blums P.N. - In: Ringing in the study of bird migration in fauna of the USSR / Ed. by V.D. Ilyichev. Moscow, 1979, p. 157-167 Mihelsons H.A. - In: Proc. Int. conference on conservation of wetlands and waterfowl, Heiligenhafen 1974. 1976, p. 394-400. Mihelsons H.A. - Acta Om., 1980, 12, p. 45-62. Mihelsons H.A. - In: X Baltic Ornith. Conf. Riga 1981. 1981, P* 120-125 (in Russian). Mihelsons H.A., Blums P.N. - Lintumies, 1976, 21» P* 98-106 Mihelsons H., Le jins G., Mednis A. - In: VII Baltic Ornith. Conf. 3, Riga 1970. 1970, p. 43-47 Mihelsons H., Mednis A. — In: IX Baltic. Omith. Conf. Vilnius 1976. 1976, p. 164-168 Mihelsons H., Mednis A., Blums P. - In: Proc. Ii)t. Symposium on the mapping of waterfowl distributions, migrations and habitats, Alushta 1976. 1981a, p. 293-311. Mihelsons H., Mednis A., Kastepold T., Kastepold E. - In: Proc. Int. sympo¬ sium on the mapping of waterfowl distributions, migrations and habitats, Alushta 1976. 1981b, p. 312-321. MihelsonB H.A., Mednis A.A., Kastepold E., Kastepold T. - In: X Baltic Omithol. Conf. Riga 1981, 1981c, p. 126-130 Zwickel P.C. - Can. J. Zool., I960, 58, p. 896-905. Symposium ONTOGENY AND PHYLOGENY OF COGNITIVE PROCESS Convener: P.P. BATESON, UK Co-convener: L. KRUSHINSKY, USSR DELIUS J. COMPLEX VISUAL INFORMATION PROCESSING IN THE PIGEON KAMIL A.C. THE EVOLUTION OF HIGHER LEARNING ABILITIES IN BIRDS BOGOSLOVSKAYA L.S. HOMOLOGOUS RELATIONSHIPS IN THE CENTRAL NERVOUS SYSTEM OF BIRDS AND MAMMALS KRUSHINSKY L.V. STUDY OF CONSCIOUS ACTIVITY AND ITS MORPHOLOGICAL BASIS IN BIRDS V COMPLEX VISUAL INFORMATION PROCESSING IN THE PIGEON Juan D. Delius t Experimentelle Tierpsychologie, Psychologisches Institut Ruhr-Universitaet , D 4630 Bochum, FRG INTRODUCTION In the normal environment of an animal one and the same object can yield vei^ different patterns of retinal activation depending on the particular lighting conditions and on the relative orientation and distance the object has with respect to the animal's eyes. It is nevertheless imperative for the sake of evolutionary fitness that animals positively recognize at least a range of objects in spite of this apparent variability. Furthermore it is equally important that different objects be recognized by some abstract cri¬ teria as belonging to one of several classes of objects. To these classes the animal can then respond with relatively unitary sets of responses in spite of the individual diversity of the member objects. We humans of course make cons¬ tant use of such capabilities in the course of daily life with respect to scores of objects. Psychologists give the collective names of perceptual in¬ variance and perceptual concepts to the phenomena underlying these competen¬ ces. Engineers have recently made efforts to provide robots with comparable performances. While their implementation is feasible in principle it has been found that they require an inordinate amount of computing power. Small-brained animals such as birds are necessarily short of information processing capacity and may thus have to forgo some perceptual invariance and concept capabilities. But the impression of field students of avian behaviour is that, if anything, the visual performance of most birds outclasses their own. For some basic functions this impression has indeed been supported by formal research. Pi¬ geons (Columba livia) for example have colour vision that is more sophistica¬ ted than ours in being at least tetrachromatic with a spectral sensitivity ex¬ tending into the near-ultraviolet and an additional abilty to detect the pola¬ rization plane of light (Emmerton, Delius, 1980; Delius et al., 1976). ROTATION INVARIANCE We have recently begun to examine experimentally the extent of pigeons' vi¬ sual invariance abilities. With Valerie Hollard (Auckland, New Zealand) we studied their performance in a situation that demands the visual identificat¬ ion of specific forms when these appear at various angular orientations. This requires a mechanism that ensures a rotational invariance of pattern recognit¬ ion. More specifically, the birds had to repeatedly recognize a predetermined target out of pairs of mirror-image shapes when these were displayed at angu¬ lar orientations coinciding or not coinciding with the target's alignment. To get the pigeons to perform the task we employed an operant discrimination lear¬ ning paradigm known as matching-to-sample (Carter, Werner, 1978). The food- deprived birds were placed in a three-key Skinner-box. An automatic slide pro¬ jector displayed shapes on the back of the translucent Keys. The opening of a shutter first allowed the pigeons to view the target or sample shape pro¬ jected on the middle key. The birds were required to acknowledge this stimu¬ lus by pecking the key a number of times. This caused the two side-key shut¬ ters to open, exposing the two comparison patterns on them. One of these 804 patters was geometrically identical to the sample pattern. The other pattern in« the T8"* Plge0nS °f °ne gr°UP had theD t0 P@ck the ke* "***•- matchÎn h r’r ^ th°8e °f another of birds, the odd, non- to foo? iTth* h dld S° C°rreCtly they were rew^ded "ith brief access of lit Z Wr°ng Shape they W6re punlshed »*«1 a brief period of darkness The next trial began with the presentation of the next sample and forth. The daily sessions consisted of 40 such trials. After training for some 40 sessions with sets where the orientation of sample and comparison timuli were the same, series of 10 sessions were conducted with sets of sti¬ muli that systematically explored the effect of angular disparities between samples and comparison shapes. The order in which the various stimulus sets occurred was randomized, as was of course the sequence in which the correct and incorrect stimuli appeared on the left and the right response keys. The e proce ure was controlled by a suitably programmed microcomputer which .1.0 *.»*.. .11 ,h, ln partlsulsr th> oomct I inco^t re.Dondln T T"" *“ ^ “ **U ,h* °r cor- responding to each response. This is the time interval between the onset of D^;:™ 8tlmUli 011,1 the P60k t0 °ne °f them f0r each trial (Holland, It was found that pigeons could master the task quite efficiently. Error ; ;V0Ul; b: aS l0W as 10* and ~a‘«°« times as fast as 0.7 sec. The most important result however was that the error rates and the reaction times were nearly constant, that is neither varied significantly as a function of e degree of orientation disparity between the samples and the comparison patterns. In other words the pigeons found it equally easy to identify the matching (or non-matching) comparison patterns, regaxMless of whether these were oriented the same way as the sample (0 degrees) or tilted by 45, 90 135 or even 180 degrees clockwise. This was so irrelevantly of whether the pigeons were dealing with patterns and their mirror images with which they had had ex tensive previous experience or with totally new patterns. Essentially the same results were also obtained if the comparison stimuli were always shown in the s andard orientation but the samples were presented in varying angular positi ons between 0 and 180 degrees (Pig. 1). This result is remarkable because previous experiments (Cooper, Sheppard 978 as well as our own using students instead of pigeons (Holland, Delius’ 982), have shown that the performance of humans in this kind of task is mark¬ edly dependent on the degree of rotation of the comparison patterns. Particu- arly the reaction times are a monotonically increasing function of the dis¬ parity angle. Overall, humans were also much slower in responding than the Pigeons. The interpretation supported by introspective accounts is that humans ave to rotate a memory representation of the sample stepwise, each time com¬ paring it for coincidence with the comparison stimuli. This sequential proce¬ dure, known as mental rotation, has all the characteristics of thinking or, aa psychologists prefer to say nowadays, of a cognitive process. Pigeons o viousiy solve the problem in a different, more immediate, automatic way a in earlier times might have been labelled as reflexive or even instinc- ive. Parallel rather than sequential information processing seems to be r°ught into play by their visual system. 8O5 Pig. 1 . Latencies and error rates of pigeons and humans during rotational invariance tasks with visual patterns. The insets illustrate the apparatus employed and give examples of the matching-to-sample tasks (see text for further details) Most of the studies on mental rotation in humans, although not ours, were done with a procedure that required the subjects to refer to the sample or target as an engram, that is as information stored in memory. We considered that perhaps this might be an important factor. Experiments with pigeons in which the sample pattern was shut off 5 sec before the comparison stimuli came on, a delayed matching-to-sample procedure, led to some deterioration of performance but there was still no evidence of any dependence on the orientation disparity of the forms (Pig. 1). Now, humans yield a performance similar to that of our pigeons in an other kind of rotational invariance task where instead of mirror images the 806 odd patterns are arbitrarily different shapes (White, 1980). Just in ease, we have tested pigeons with an analogous task and found that their perfor¬ mance was the same as when they dealt with mirror-image pairs of shapes. There is considerable evidence that for humans mirro^image shapes are pe- cuiiariy difficult to distinguish (Corballis, Beale. 1976). It seems possible that for pigeons this is not so and preliminazy experiments of ours suggest that they may indeed find them easy to discriminate. This suggests that the sequential, mental rotation process might only be brought into play when the shapes to be distinguished are very difficult to discriminate. For humans there is an indication that indeed mental rotation results are obtained with non-mirror-image odd shapes only when the shapes are highly complex. Perhaps pigeons would also yield such a performance if one would select shapes that are especially hard for them to discriminate. Visual pattern discriminations as compared with colour and brightness dis¬ criminations are more difficult for pigeons than they are for humans, thus the experiment involving non-mirror images might have already fulfilled this condition but this issue needs further experimentation. Alternatively one can hypothesize that pigeons store information about shapes in an orientation- free mode. They thus should have difficulty with tasks demanding the discri¬ mination of one and the same shape at different orientations. We have found that pigeons indeed have considerable difficulty in learning to discriminate an upright cross + from a tilted cross x (Delius, Emmerton, 1978). This could have to do with the fact that pigeons operate visually predominantly on the horizontal plane where the orientation of objects is largely arbitrary rela¬ tive to the position of the observer. Humans view predominantly the vertical plane where both observer and objects tend to have an orientation determined by the effects of gravity. Pigeons have however been shown capable of discri¬ minating very small angular orientations disparities of line stimuli (Klipec et al., 1979) and thus this explanation can be only a partial one. We have further wondered whether the rotational invariance performance of Pigeons might be due to the fact that they have a visual system predominantly based on the midbrain optic tectum as compared with the mammals that have a mainly endbrain, striate cortex based system. As a first step we examined the Performance of our pigeons after they had been surgically deprived of their telencephalic Wulst, a brain area that contains the avian homologue of the mammalian visual cortex. Their invariance performance was completely unaffec¬ ted. Thus the information processing required for it clearly does not take Place there. This contrasts with the consequences of visual cortex ablations in primates who are then very nearly blind and certainly incapable of mental notation (Milner, 1970). VISUAL CONCEPTS In the research summarized above we made the assumption that pigeons are capable of detecting the identity or conversely the oddity of sample and com¬ parison shapes in a generalized, concept-like fashion. However there has been controversy as to whether pigeons really can achieve this (Carter, Werner, 1978). Since our pigeons’ matching-to-sample performance in the rotational invariance tests was maintained even when they had to deal with shapes comp¬ letely new to them (Hollard, Delius, 1982) we have no doubt that they can. If 807 previous experimenters had some difficulty with demonstrating a conceptuali¬ zation of identity/oddity by pigeons then we believe that this has been due to the employment of too few training stimuli, inviting the pigeons to use simpler strategies, and to the use of designs that allowed the strong novelty aversion that characterizes these animals to come into play. There is another way in which the issue of whether pigeons can conceptuali¬ ze is relevant here. We mentioned earlier that it is possible that pigeons in contrast to humans distinguish between mirror-images shapes just as well as between any arbitrarily different shapes. This suggests that the birds may not be able to recognize the special equivalence of mirror-image shapes. That could imply that pigeons may not recognize bilaterally symmetric shapes as a particular class of forms consisting of two fused mirror-image halves. Morgan et al. (1976) have mentioned evidence that supported this view but Delius and Habers (1978) found that pigeons seemed to be able to discriminate bilateral¬ ly symmetric from asymmetric shapes in a generalizing manner. With Brigitte Nowak we have investigated this issue more thoroughly. Pi¬ geons were trained to discriminate 26 bilaterally symmetric shapes from an equal number of asymmetric shapes using a free operant successive discrimi¬ nation procedure (Delius, Nowak, 1983). The shapes were back-projected onto the single key of a Skinner-box in a randomized sequence. Each shape was shown for a standard 30 sec. One group of pigeons was required to peck the symmet¬ ric pattern for occasional food reward and not to peck the alternative pat¬ terns to avoid extensions of the presentation time of the non-rewarded stimu¬ lus. Performance was measured by the percentage of responses to the correct stimuli out of all responses during the standard 30 sec presentations. The daily sessions involved the displaying of 40 shapes. All pigeons learned to perform at a level of or more responses correct within 25 sessions. In interspersed trials they were then exposed to test shapes with which they had no previous experience with under extinction conditions, that is where res¬ ponses had no consequences. The birds classified these stimuli with high ac¬ curacy, that is they responded with high frequency to the novel stimuli that belonged to the same class as those training stimuli that had yielded reward and much less to those that were of the same type as those training stimuli that had resulted in punishment. This was so even when the geometrical style of the test figures differed markedly from the training shapes (Pig. 2). There can be no doubt that the pigeons recognized the bilateral symmetry, o*r else the asymmetry, of the figures in a concept-like, generalized fashion. They did so regardless of the fact that in one test series the asymmetric stimuli were repeated shapes especially designed to have a redundancy at 1 least as high as that characterizing symmetric forms and that in another se¬ ries the test figures were presented with varied symmetry axis orientations, differently from the training stimuli which always had a vertical axis. The « pigeons' symmetry recognition was not impaired when they had to perform with one eye covered by an eye-patch. The competence for symmetry recognition can not thus be Bomehow ascribed to the bilateral symmetry of the nervous system. The mechanisms with which pigeons recognize symmetiy do not seem tocorresponc pond with any that have been proposed to explain symmetry identification by humans (Corballis, Beale, 1976). Rather we have put forward an alternative theory of our own. 808 g. 2. Mean correct response scores Ccloumns) of pigeons generalizing a symmetry /asymmetry discrimination to various sets of novel visual patterns samples shown). The concurrent performance on the training stimuli is in- cated by bars. The insets illustrates the apparatus employed and the suc- aive discrimination conditioning with examples of the training stimuli It is known that the visual system of both birds and mammals performs a ind of spatial Fourier analysis (De Valois, De Valois, 1980; Jassik-Gerschen- d* Hardy' 1981 If symmetric and asymmetric shapes are examined from this Point of view one finds that at the symmetry axis the Fourier components have * special phase relationship being all in-phase (0 degrees) and/or anti-phase 180 de«rees) to each other whereas such conjunction does not occur anywhere n an asymmetric pattern. There is evidence that these phase relationships ave a special status for humans (Atkinson, Campbell, 1974) and there are Reasons to expect that the same is true in birds. This has to do with the sot that both visual systems have to deal with an information surface, the ^tinal image. This can only be done with neuronal networks that have a multiply symmetrical microstructure. II such neural filters are the basis of symmetry recognition it seems un- kely that our pigeons developed them during training. Rather it must be suspected that they only learned to apply pre-existing ones to the task in sue able to learn to shift away from the previous site of reward more easily than to leara to gb back to the same site. Therefore, we set up an experiment using artificial flowers in the labora¬ tory in which the animal was required to either stay or shift. The basic de¬ sign of the experiments was quite simple. First, on each trial the animal was given one flower to feed from and it emptied that flower. Second, two flowers were presented and the hummingbird was given a choice between going back to 815 that same location or going to another location. If the bird was In the stay condition, then It had to vremember where it had just been and go back; win- stay. If it was in the shift condition, it had to remember where it had just been and go to the other location; win-shift. Eight hummingbirds were tested under both the stay and the shift conditions. The results were quite dramatic. Regardless of whether the stay learning came first or second, stay learning always took much longer than shift learning, in some cases as much as 5 to 6 times as long. The stay learning generally took place very slowly while shift learning took place very rapidly (Cole, Hainsworth, Kamil, Mercier and Wolf, in press). This demonstrates a clear connection between the natural ecology of the animal and its performance in a cognitive task. This type of result suggests that at least some of the variation in cognitive abilities may be capable of being understood in terms of adaptations to specific environments. However, we must also deal with the question of marked similarity between very different species. There are several possibilities we must investigate. One is that these genel-al types of learning, these cognitive abilities, are not really general at all. That is, they may be tied to the specific adaptati¬ ons of specific animals. In that case we must apply a comparative ecological approach and compare and contrast closely related animals of different ecolo¬ gies and distantly related animals of similar ecologies. Another possibility is that certain kinds of learning seem to be quite ge¬ neral in very disparate species because there are some very general aspects of the environment and/or the nervous system which creates this generality. In terms of the environment, it may be that the environments of many animals are so constructed that certain kinds of learning abilities Will always be of adaptive advantage. In terms of physiology, it is possible that some very basic characteristics of the nervous system, such as the fact that neurons always fire in all-or-none fashion, place constraints upon the kinds of lear¬ ning processes animals may possess. In any event, ornithologists can make important contributions to the re¬ solution of these issues. Historically, the study of complex learning has been carried out mostly in mammals. If we are to begin to test evolutionary questions about the appearance of learning, then much work needs to be done with birds. For example, if the mammalian literature suggests that certain types of learning abilities are characteristic of generalists as opposed to specialists, this hypothesis could be tested in a separate group of animals and the birds are a perfect group for such tests. Furthermore, because there are so many avian species, and they vary so much in their adaptations, many hypotheses might be generated by original research of cognitive abilities in birds. Thus I believe that research with birds could be of critical importan¬ ce in developing an understanding of the adaptive significance and evolution of the cognitive abilities of animals. SUMMARY Blue Jays (Cyanocitta crlstata) perform better than some mammals, and as well as some primates, on learning sets, a higher order learning task. The Blue Jays acquire learning sets in a manner virtually identical to that used 816 by Rhesus monkeys and chimpanzees, by abstracting a general strategy' which can be applied to novel problems. These results clearly demonstrate the existence of higher learning abilities in at least some avian species. They also raise several issues about the evolution of cognitive abilities in ani¬ mals, which further research with birds can help to resolve. References Baida R.P. - z. Tierpsychol. , 1980, 52, p. 346. Bessemer D.W., Stollnitz P. - Ins Behavior of Nonhuman Primates. Vol. 4 / Eds. A.M.Schrier, P. Stollnitz. N.Y.: Acad. Press, 1971, p. 1-58. Couvillon P.A., Bitterman M.E. - J. Comp. Physiol. Psych., 1980, 94, p. 878. 885. — Harlow H.P. - Psychol. Rev., 1949, 56, p. 51-65. Hunter M.W., Kamil A.C. - Psychon. Sei., 1971, 22, p. 271-273. Kamil A.C., Hunter N.W. - J. Comp. Physiol. Psych., 1969, 73, p. 68-73. Kamil A.C., Lougee M., Shulman R.I. - J. Comp. Physiol. Psych., 1973, 82, p. 394-405. — ’ Kamil A.C., Jones T.B., Pietrewicz A., Mauldin J»E. - J. Comp. Physiol. Psych., 1977, 91, p. 79-86. Krebs J.R. , Davies N.B. Behavioural Ecology: An Evolutionary Approach. Sunderland, MA. Sinauer, 1979. Krushinsky L.V., Zorina Z.A., Dashevsky B.A. -Zh. Vyss. Ner. , 1979, 29, p. 590-597. Pepperberg I.M. - Z. Tierpsychol., 1981, 55, p. 1 39-1 60. Ricciardi A.M. , Treichler P.R. - J. Comp. Physiol. Psych., 1970, 73, p. 314- 319. Schusterman R.J. - Science, 1962, 137, p. 422-423. Stettner L.J., Matyniak K. A. - Sei. Am., 1968, 218, p. 64-76. Vender Wall S.B. - Anim. Behav., 1982, 30, p. 84-94. barren J.M. - In: Behavior of Nonhuman Primates. Vol. 1 / Eds. A.M.Schrier, Harlow H.R., Stollnitz P. N.Y.: Acad. Press, 1965. Warren J.M. - J. Comp. Physiol. Psych., 1966, 61, p. 421-428. Welty J.C. The Life of Birds. N.Y. , Knopf, 1962. Zeigler H.P. -J. Comp. Physiol. Psych., 1961, 54, p. 252-254. ( bibliothèque j l6-3aK.98l HOMOLOGOUS RELATIONSHIPS IN THE CENTRAL NERVOUS SYSTEM OP BIRDS AND MAMMALS L.S. Bogoslovskaya Institute of Evolutionary Morphology and Ecology of Animals, USSR Academy of Sciences, Moscow, USSR Apart from the difficulties usual in this kind of studies the elucidation of homologies between the nervous centres of birds and mammals is complicat¬ ed, by a peculiar character of onto- and phylo-genesis of the brain and its parts. In my view, four factors, interrelated to a considerable extent, play a special role in studying homologies and yet they are insufficiently taken into account in comparative-morphological studies of the nervous system. 1. Intensive processes of migration of nervous elements in ontogenesis. The basic principle of ontogenetic development of the brain consists in that neurons arise in places other than those of their localization in the adult nervous centre (Sidman, Rakie, 1973). Several foci of proliferation are known to exist in the vertebrate brain from which the embryonic cells migrate to places of prospective nervous structures. Therefore, the problem of homo¬ logous relationships of any brain structures cannot be solved by merely in¬ dicating the single source of their origin. Migrational processes are very complicated and insufficiently studied, sometimes they are counterdirected. For example, the inner segment of the pale globe migrates in telencephalon from diencephalon and a part of embryonic material for the dorsal nuclei of the latter migrates vice versa, from telencephalon. Further more, the two- wave process of neuroblast migration is a most characteristic feature of neo¬ cortex development (Polyakov, 1965), and this is to be taken into account when establishing homologies between this structure and the hyper- and neo¬ striatum of birds. A comparison of the acoustic system in birds and mammals demonstrates that in the latter each level consists of a greater number of components, and each component has a wider set of neuron forms. Neurohistological analysis has shown that in birds the auditory nuclei of diencephalon are made up almost entirely of highly specialized cells, rather primitive by the organization of dendrites (Ilyichev et al., 1976). There is a special form in each nucleus which is a kind of "visiting card" for this structure. In mammals such neu¬ rons are preserved but are suppressed quantitatively by the development of more progressive specialized elements and by migration in all nuclei of a large number of granular, reticular and reticular-like elements which appear to include giant neurons related to the motor system, 2. The presence of intermediate, or temporary embryonic forms in a number of neurons. Such forms can be consolidated as definitive ones in the same brain regi¬ ons of lower animals or occur in more ancient nervous centres in different groups of invertebrates. For example, the pyramidal neurons of layers V and III, which are of different evolutionary age, arise, according to Polyakov (1979), from different temporary forms, one of which ("pyramid-spindle") is widely represented in the brain cortex of adult reptiles. Many neurons of other brain regions proceed in their development through temporary stages which are often expressed in an excessive formation of 818 dendrites and different cell shape. Similar embryonic forms were described by Zhukova (1977) for the development of large neurons of the spinal cord ge¬ latinous substance and were termed as "neural glialike". Neurons of similar form were found in the laminary auditory nucleus of diencephalon in adult birds (Ilyichev et al., 1976), the highly specialized cells of medial part of this nucleus being more like the glial cells and embryonic glial-like sta¬ ges of the large neurons of gelatinous substance in mammals. These rare in their appearance neurons are present in enormous quantities in the laminary nucleus of well locating birds (owl, harrier) and, on the contrary, are quite scarce or may even be absent from the brain of other avian species. Such cells were not found in the brain of adult mammals either. 3. Redistribution of cellular material in phylogenesis. The intensive development of evolutionarily young brain Bystems, as well as essential reorganization of sensory and motor nervous centres, are accom¬ panied by marked changes in the amount of elements involved in the formation of a particular brain division. The possibility of comparatively "rapid" (in the evolutionary sence)trans- fer of cellular material from one centre or system into another is expecially clearly demonstrated during the research of the adaptive transformations of sensory systems. For example, the closely related avian species can differ In the number of the above mentioned cells of the laminary nucleus medial Part to a greater extent than taxonomically remote species which are charac¬ terized by similar indices of hearing. The hen-harrier has 7000 such neurons and the steppe eagle only 1390, whereas the snowy owl and eagle owl have si¬ milar with the former number of neurons: 6600 and 7000, resp. This part of acoustic system is completely absent in the tufted penguin and well expressed in the gold-tufted penguin which belongs to the same genus (Barsova, 1980). Such instability of the whole part of sensory system suggests that material comes to the brain systems and, in case it is less required, migrates to other centres and transforms therein into new forms. It is as yet completely Unknown from what sources these cells take their origin in the owls and har¬ riers and into what forms they transform in the brain of those birds where the laminary nucleus medial part is greatly reduced or absent. The most important redistribution of embryonic material in the evolution of the central nervous system of higher vertebrates takes place in telence¬ phalon and determines a parallel and independent development of neocortex in ®ammal8 and that of hyper- and neostriatum in birds. In 1969 Karten proposed his model of development of telencephalon in birds and memmals from hypothe¬ tic, common to amniotes, telencephalon. It is based on hypothesis on a possi¬ bility of two ways of migration and development of cellular elements from a single source, dorsal hippopallipl tuber of reptiles: in the direction of cor¬ tical regions (mammals) and in the direction of striatum (birds). The repti- ie8 are, however, a complex, most likely, polyphyletic class comprising cro- c°diles and turtles which are of particular interest from the viewpoint of comparison with birds and mammals respectively. Even the telencephalon of these animals is characterized by a great difference in the development of °iriatum and neocortex. Seven basic features of similarity are common to the turtles and mammals. The crocodiles are closely related to birds, expecially to their primitive representatives. Before we begin to compare the telence- 819 phalon of mammals and birds, It is necessary to solve the problem of homolo¬ gies of the cortex regions between the reptiles and mammals which remains as yet open. Although turtles and crocodiles represent different directions of development of the brain hemispheres, they differ In the organization of te¬ lencephalon and, the more so, of cortex to a much leaser extent than birds and mammals. 4. The unity of principles of neuronal net organization. Karten (1969) and his followers compare quite correctly, In the functional aspect, areas of visual and acoustic projections in the avian neostriatum with corresponding areas In the mammalian neocortex. But functional similari¬ ty is that by analogy, rather than by homology; therefore, further speculati¬ ons of these authors on direct comparison of the granular fields of striatum (fields A and L), where visual and acoustic afferente terminate, with layer TV of visual and acoustic afferents terminate, with layer IV of visual and acoustic cortex of mammals, are incorrect. The isolation of layer TV as som¬ ething structurally and functionally independent of the whole section of cor¬ tex with which it is connected by the course of cortical plate development seems very artificial. The granular character of layer IV is a feature of not only these projection cortical fields but of the whole retrocentral division of neocortex (Bogoslovskaya, Polyakov, 1981). Besides, the granular character, as well as the layered structure, is inherent in general to the nervous cent¬ res of diverse origin which are related to visual perception (Zavarzin, 1950). The ideas of Karten on a single embryonic source of development of the di¬ visions of avian hyper- and neostriatum and mammalian neocortex appear to agree with the facts. But he considers the marked differences in the ultra- structure of cortex and striatum as random and insignificant, while I think they represent a regular result of different ways of development of a consi¬ derable part of telencephalon. These two independent and parallel ways became distinct in morphological aspect already at the level of reptiles. A study of the fine neuronal organization of avian striatum (Bogoslovskaya, Polyakov, 1981 ) allows me to suggest that birdB have a constructive variant of structu¬ ral organization of the brain higher centres, other than mammals. References Barsova L, I. - In; Sensory systems and a brain of birds. Moscow: Nauka, , 1980, p. 165-1 80 Bogoslovskaya L.S. , Poljakov G. J. Ways of the morphological progress in nervous centers of the higer vertebrates. Moscow: Nauka, 1981. 159 P- Ilyichev V. D. , Bogoslovskaya L. 3. , Barsova 1,1. - 3ool. J. ,197o. H,N1 , p. 89-102 Karten H. J. - Ann. N.Y. Acad. Sei. ,1969.167. 164-1 79- Poljakov G. J - In: The development of the child -'s brain. Moscow: Meditzi- na,1 965 »P- 22-52. Poljakov G J Entwicklung der Neuronen der menschlichen Grosshirnrinde. Leipzig: VEB G. Thieme, 1979- 3203. Sidman R.l. , Kakic P. - Brain Res. ,1973, o2,p. 1-35. Zavarzin A. A. The selected works. Moscow; Leningrad : Publishing house Acad. Sei. USSR, 1950, 1-320 p. Zhukova G. P. Neuronal structure and interneuronal connections in the brain stem and the spinal cord. Moscow: Meditzina,1977. 143p. 820 STUDY OP CONSCIOUS ACTIVITY AND ITS MORPHOLOGICAL BASIS IN BIRDS |l.V .Krushinsky I Laboratory of Physiology and Behaviortal Genetics, Department of Physiology of Higher Nervous Activity; Biological Faculty of Moscow State University, Moscow, USSR The views on birds' behavior have undergone radical changes in the course of the last few decades. Up to the thirties the prevailing opinion spelled that a less pronounced development of the cerebral structures, corresponding to the cortical structures of the mammals' brain, points to a primitive cha¬ racter of their behavior. According to the widespread opinion of physiolo¬ gists existing at that time birds possess the inherent type of highly develo¬ ped complex instinctive forme of behavior while their intellect is restric¬ ted (Herrick, 1924). However, as it was proved by the subsequent investigati¬ ons of ethologists and comparative physiologists, an extremely pronounced di¬ versity and behavioral flexibility in birds can hardly be distinguished from those in the behavior of mammals (Thorpe, 1956). It turned out to be paradoxical that in spite of the fact that birds dis¬ play very flexible forms of behavior their cerebrum exhibits an entirely dif¬ ferent morphological structure than is the case in the event of mammals. The laminated new cortex detected in all representatives of mammals is nonexis¬ tent in birds. Nevertheless birds appeared to be capable of assimilating dif¬ ferent complicated forms of training and solving the problems which require a certain aptitude for correlation and elementary forms of abstraction. The overwhelming majority of investigations are carried out with pigeons and hens. However, the birds belonging to the Corvidae family considerably exoel pigeons as well as some other mammals in their aptitude for an exact time discrimination (Powell, 1972). In Corvidae it is possible to obtain the trained reflexes for much greater time intervals than in pigeons. In dis¬ tinction to pigeons, the birds representing the Corvidae family do not need a^y additional stimuli to produce the correct responses (Powell, 1973,1974). According to the data presented by Gossette (1966) magpies considerably ex- cel chicks and quails in their capability to readapt the formed habits. Prom Koehler's investigations (1952, 1954) it follows that pigeons could operate *ith the quantities amounting to 5 whereas ravens and parrots - within the ^ange of 7. In his experiments performed on jackdaws and magpies Friede ^ 1 972 ) discovered that these birds are capable to opérate with such notions aa "likeness - distinction". Kamil and his collaborators (Kamil, Hunter, 1970; Kamil et al., 1973) etudied the complicated form of training for blue jays (Cyanocltta crlstata) 8110 mynas (Gracula religiose). Por a long period of time these birds were Gained with a view to create in them gradually numerous discrimination ^actions, and little" by little they learned to pick over the correct se- ■'■action. The authors appraise such a behavior as formation of "training de- valopment" and believe that this characteristics of corvidae birds may be °°®pared with those of cats, squirrel monkeys and monkeys relating to the ^rcopithecidae family. Our investigations reveal that judging by the level of their elementary c°hBcious activity Corvidae hold quite a prominent position. 821 According to our plan of work we carry out the comparison study of cons¬ cious activity in the representatives of different taxonomic groups of ver¬ tebrates (1958-1977). Proceeding from the self-evident assumption spelling that our actual habitat is represented by the objects, phenomena and laws forming the basis of the environment, it becomes possible to give a definite determination for the conscious activity: it is a capability to realize the laws which form the foundation of the medium structural organization. A clear¬ ly defined selection of the behavioral acts formed on the basis of an apti¬ tude for grasping the laws combining the objects and phenomena of the envi¬ ronment made it possible to give not only an unambiguous determination of this form of higher nervous activity but also to carry out its unprejudiced investigation. This investigation showed that the behavioral acts formed on the basis of conscious activity can be realized by the representatives of certain taxono¬ mic groups of vertebrates already in the first formulation of test. The ability of animal to make its decision at once without any preparatory behavioral training represents a unique quality of conscious activity as a fine adaptive mechanism to the multiform habitat. The effect of realization of a conscious act in animals is revealed as an extremely frequently observed pronounced neurosiB which has a distinct electrographic manifestation. Neuroses develop despite the fact that the sol¬ ved test may prove to get a favorable confirmation. As a result of our observations of animals' behavior in natural conditions of their habitat we have come to the conclusion that it is possible to make out several parameters of conscious activity. We found it possible to diffe¬ rentiate three forms of behavior which are executed by man as well as by ani¬ mals on the basis of application of empirically assimilated laws of nature that can be used for estimating the level of conscious activity in the ani¬ mals relating to different taxonomic groups. The first form is associated with animals' aptitude for extrapolation(pro- jection of a known function on a line segment into an outside area). The behavioral acts realized on the basis of extrapolation can be objectively re¬ gistered and given a quantitative assessment. The general principle, forming the basis for the conducted experiments, implies that the animal must find the bait moving rectilinearly at a constant rate. The primary line segment of motion of the stimulus is accomplished within the visual field of the ani¬ mal; then the bait disappears behind a barrier. With such a form of the ex¬ periment the animal can define the motion direction of the desired stimulant behind the barrier if it is capable of extrapolation. The second form of behavior, offering a means of estimating the level of conscious activity, is the ability of animals to operate on the empirical di¬ mensions of figures. The animals provided with adequately high-differentiated cerebrum can understand that a volumetric bait cannot be held inside a place figure; it can be held only inside a volumetric figure and thus be removed from one space area to another. The third form is associated with the ability to construct a vector, deter¬ mine the value of space rated motion of the subject (fig. 1 ). A man or an animal to be tested is suggested to make a choice in a set of cylinders (usually 12) 822 Pig. 1. Dolichoaxonic neurons from the birds' neostriatum: the Crow (right-hand) and the :’i eoa (left-hand) arranged in one line, the bait being placed under one of them. As a rule the bait is placed in the first, then in the second, the third and so on cylin¬ ders. In fact after the first two choices the tested animal obtains the re¬ quired sufficient information allowing it to assess the regularity determin¬ ing the displacement of the bait under the cylinders. In the event of men the criterion for the correct solution of this task spells that three cylinders in which the bait is replaced should be removed in succession without mista¬ kes (Krushinsky, Popova, 1978). Our experiments proved that corvidae to a certain extent reveal their capability to solve this difficult task; however, in most cases they can realize the detected regularity only in the form of "incomplete" solutions. This fact can be easily explained taking into consi¬ deration that the presented taBk proves to be difficult even for men. With due regard for such "incomplete" solutions in the first test 23% of the birds erasped the logical structure of the task, and in the repeated tests the cor¬ net solutions were registered for 32% of the birds. In individual cases the corvidae solved the presented task reaching the criterion which was introdu- Ced in the experiments with men. In the first test such solutions were de¬ leted in one bird, in the second - in two birds (Krushinsky et al., 1982). All the three forms of the experimental investigation may be used for es¬ timating the level of conscious activity in different taxonomic groups of Vertebrates. The experiments carried out by the author in cooperation with a group of bis collaborators have shown that pigeons hold a low level of conscious acti- Vit7. They may be compared with mouselike rodents, and yet their position in Aspect to the hare's species is somewhat lower. Judging by the level of cons- °i°us activity hens hold a slightly superior position than pigeons and are aPproaching to the hare's species. The behavior of birds of prey (common kes- t^els, merlins, buzzards, steppe eagles and penis) may be compared with the orie of the hare's species, though perns display a more developed ability to e*trapolation than the other birds of prey which we have studied. By the evel of development of their conscious activity the corvidae (crows, hooded 823 crows, rooks, magpies and jackdaws) may well be compared with the predatory mammals belonging to the family of doglike species, and they are even super¬ ior to them in the solution of certain tasks so that they are approaching to brown bears, dolphins and some monkey species. The investigations conducted by us are in full agreement with the data of the ethologists who have come to the conclusion on a high-grade plasticity and diversified behavior of birds that can be compared with the behavior of higher mammals. The fact that the birds which do not possess the inherent new cortex re¬ veal the ability to solve the same problem as the predatory mammals with a well developed new cortex makes it possible to conclude that the elementary conscious activity is realized not necessarily with the assistance of the new seven-layer cortex. In this connection we are facing a new problem: which particular structures of cerebrum are responsible for realization of this complicated form of behavior in birds? When examining this problem most of the investigators point to the complex of basal nuclei that make up the struc¬ ture of dorsal eminence called Wulst. This structure consists of Hyperstriatum accessorium, Hyperstriatum dorsale and Nucleus intercalatus hyperstriate, and it is covered with a thin corticoid layer. It is supposed that wulst may be considered as a single morphological structure compatible with the néopallium of the lower mammals (Kappers, 1928). Karten and his collaborators (Karten, 1969; Karten et al., 1973) made a substantial contribution to the under¬ standing of functional activity. They specified the homology of a number of structures both in mammals and birds. It was shown that the main route from thalamus to wulst is similar to the geniculostriatal route of mammals. At the same time it was also shown that wulst represents the projection zone of the visual analyzer. In Karten 's opinion the difference between wulst and the new cortex resides in the space distribution of neuronic groupings rather than in the properties of individual neurons or neuronic populations which is expressed through the absence of seven-layer cortex in birds. Karten's opinion is confirmed by the investigations of E.D.Morenkov and Do Cong Hun (1975) who have come to the conclusion that along with certain other functi¬ ons wulst is involved in the visual control of the performed motor reactions. It follows that is spite of the specific nature characterizing the structure of the birds' brain it has the same basic functional systems which despite the lack of the sevenlayer cortex provide its complicated functional activity. So we are facing the problem on a comparative morphophysiological exami¬ nation of the neuronic organization of the brain of birds displaying diffe¬ rent levels of conscious activity. Comparison between the structures of paleostriatum and neostriatum reveal¬ ed the existence of certain distinctions in the birds displaying different levels of their conscious activity (Columba« and Corvidae). When comparing the neurons of plaeostriatum with those of neostriatum in crows as well as in pigeons, L.P. Dobrokhotova (1969) revealed that the morphology of dolichoaxo- nic neurons of neostriatum is more complicated than it is in paleostriatum. The average number of dendritic endings in paleostriatum is 17-18, and the number of dendritic trunks is no more than 3. In neostriatum the average num¬ ber of dendritic endings of dolichoaxonic cells is 27-28, and the number of dendritic trunks amounts to 5. 824 The correlation of paleostriatum and neostriatum neurons in crows and pi¬ geons has shown that in these species similar groups of cells exist inside the limits of every sector of the brain. In this case one can observe certain distinctions in the fine structure of neurons in crows and pigeons. For examp¬ le, in crows the bodies of dolichoaxonic cells have an angular foim, in pige¬ ons this form is more rounded. In crows the dendrites of neurons proved to be thinner and more winding than those of >igeons; the tranks of neurons are straighter (they often have varicose enlargements) (Fig. 2). The dendrites of brachyaxonic neurons are especially thin in crows ;their distal fragments become drastically thinner acquiring a clearly defined form Among the crow-s dolichoaxonic neurons of neostriatum one can find some dend¬ rites studded with an extremely thick cover of small spines. In distinction to crows the neurons of pigeons have a coarser structure: their dendrites are thicker, less winding and covered with large-sized widely spaced small spi¬ nes. As a rule they have a primitive rod-shaped or hooked form and are pro¬ vided with varicose enlargements (Dobrokhotova, 1981). Crows have a more perfect and multiform system of interneuronic contacts as compared with the system of pigeons, and this may represent the very type of morphological structural basis which specifies a different level of cons¬ cious activity in these birds. L.S. Bogoslovskaya and G. I. Polyakov (1981) have come to the analogous conclusions. They have failed to detect any distinctions between the densely ramified neuron?, having veiy thin not high small spines, in different sec¬ tors of hyper- and neostriatum of corvidae. At the same time such type of herve cells have never been detected in pigeons. 1 2 3 H I — I — I — r Numbers o-f colons 5 6 7 8 9 1011 12 1 2 3 9 5 67 8 n — I — I I — r I I 9 101112 n — I — I — I p . 1 g. 2. Scheme for the solution of a task on determining the regular °haracter of rate of motion of the bait by Corvidae I - Correct solution of the task; II - "Incomplete" solution of the task; 1 _ selection of an empty cylinder; 2 - selection of a cylinder Obtaining the bait 825 The importance of different structures of the birds' brain in the mecha¬ nisms of their conscious activity was studied with the method of extirpati¬ ons. The use of this method made it possible to reveal the role of different sectors of brain in the realization of different forms of complicated beha¬ vioral acts. It was shown that the old cortex (archicortex) is first of all related to the memory as well as to such forms of behavior which are based on training. The relative development of these cortical hippocampal sectors of the birds' brain is low: they are substantially reduced as compared to the reptilian cortex (Kappers, 1928; Huber, Crosby, 1926), and by their cellular structure reveal only slight distinctions from the subcortical formations. In birds the old cortex occupies the dorsal and medial surfaces of hemi¬ spheres. It is isolated from the other brain structures by the ventricle ca¬ vity and differentiated in the denticulated fascia, the aramon formation and the corticoid layer. N.L.Krushinskaya (1963, 1966) investigated the role of the old cortex in the realization of higher nervous activity in birds. She obtained the clear¬ ly defined results pointing to the fact that this structure iB related to the memory to a greater extent. The investigations were conducted on nut¬ crackers which are very keen in locating the sites where they stored up their cedar nuts. In the case of removal of their hippocampel cortex these birds lost their ability to discover the sites of their stores. The conducted expe¬ riments give the ground to draw a conclusion that the old cortex plays as important role in the mechanisms of the birds' memory. We have obtained coherent results in studying the role of wulst in the realization of conscious activity of birds. This complicated integrated function of brain is certainly associated with wulst representing an analog of the cortex in the end brain of mammals. The role of this structure in the power of birds behavioral plasticity becomes especially evident when compar¬ ing the neuronic organization of the pigeons' brain with the one of the birds belonging to the corvidae family distinguished by the high level of their conscious activity. Quite definite results for the role of wulst in the behavior were obtained by the investigations based on the removal of this structure in the represen¬ tatives of the species of birds exhibiting the greatest plasticity in the forms of their behavior. The destruction of wulst in corvidae produces dras¬ tic changes in their adaptive behavior which should be regarded as reasonable. The destruction of wulst representing the sector of brain regarded as the basic integrating structure of the highest fonnB of birds' behavior resulted for corvidae in the loss of their ability to extrapolation. Instead of the adequate solutions of the presented problem one can observe certain stereo¬ typic inadequate forms of behavior (Zorina, Popova, 1976; Zinov'eva, Zorina, 1976; Zorina, Fedotova, 1981). The deterioration of corvidae's ability to the correct solution of an ex¬ trapolation problem is revealed to a greater extent in the case when these birds displayed the required experience to solve it prior to the operation. It should be noted that after the destruction of archicortex in Qorv id a 9 no changes in their ability to the solution of the presented problem have ever been detected. It is therefore safe to say that in birds the ability to ex- 826 trapolation, which is regarded as one of the most important criteria for the level of conscious activity, is not interrelated with the old cortex of brain. Quite a different picture is observed when we deal with hens which are practically incapable of solving the tests presented for determining the le¬ vel of their conscious activity. No significant changes can be detected in the behavior of these birds after their wulst is removed. In case of multiple training with the extrapolation test the operated hens along with the unoperated ones could gradually learn to cope with its solut¬ ion. However, the removal of the old cortex in the hens resulted in deterioxv- ation of their learning ability to solve a test on extrapolation. These data are consistent with the above-mentioned experimental investigations carried out by N.L.KrUBhinskaya and spell that the old cortex is interrelated with the memory. Thus as follows that the data presented here enable us to suggest that dif¬ ferent forms of birds' behavior are based on different morphophysiological mechanisms. The acts of behavior, that are formed due to the leading effect of memory, are interrelated with the old hippocampal cortex. Its destruction causes a disorder in the ability to memorize or any training perception. The complicated and extremely pliable forms of birds' behavior, which are regard¬ ed by us a conscious forms, must be related to a specific formation named as wulst ; thiB peculiar formation is inherent only in birds. In its function this formation is similar to the mammals' cerebral cortex sind its higher in¬ tegrative center, that is the prefrontal sector. For this reason similar re¬ sults can be observed after the destruction of wulst in corvidae as well as after the extirpation of prefrontal cortex in the mammals displaying a suf¬ ficiently highly developed level of their conscious activity which was de¬ monstrated by O.S. Adrianov and L.N.Molodkina (1974) in the experiments when they removed the prefrontal cortex in the predatory mammals (cats). The presented data enable us to express certain ideas on possible courses of evolution of the birds' end brain and on the peculiarities of their behav¬ ior. Considering the problem of evolution of the reptilian end brain I.N.Fi- limonov (1955) pointed to the fact that it proceeded along the two opposing courses: in the case of birds it took the direction of dominant development of the central nodes; In mammals - the development of cortex. In the function- al aspect the evolution of the birds' brain revealed itself in a greater de¬ velopment of their instinctive reactions whereas in mammals the acquired Priority became evident in their "plastic functions". In our opinion Filimonov's concept of the course of evolution of the birds' krain may be extended. The evolution of the birds' brain as well as their behavior proceeded at least along two courses. The first course is represented by the evolution of the old cortex. Despite the reduction of the lateral and boreal cortexes, present in reptiles, the old primordial hippocampal cortex baa a clearly pronounced character in birds, and as it was already mentioned above it is interrelated both with their training perception and memory. It may be safely assumed that with well developed optic lobes in birds bhe old cortex secures possibilities for migrations, locating the sites of tbeir nesting areas, finding the clutches and accomplishing numerous other f°ttae of behavior carried out on the basis of orientation and training. 827 However, the most prominent feature characterizing the birds' brain and their behavior in the course of evolution since reptiles is a powerful development of basal nuclei representing the main morphological structure of the brain which is related to the higher functions of nervous activity (Kurepina,198l ). The investigations carried out in our laboratory reveal that in such a highly organized family of passerine species of birds as corvidae the dorsal striai enlargement plays a leading role in the realization of those behavior¬ al acts that may be determined as conscious. This suggests that in addition to the routine instinctive reactions, which show up in the process of electrostimulation of the deep tumcal structures of the brain in birds (R. Holst, U.V.Sant Paul, 1963), there exist two dif¬ ferent forms of adaptive behavior interrelated with different structures of the brain. One form is related to the old cortex providing the functions of memory, the other form is related to the striatal structure which is specific for the birds' brain and considered as an analog of the new cortex of mam¬ mals. This structure provides the birds belonging to certain taxonomic groups with a possibility to realize complicated and extremely plastic acts of be¬ havior which may be considered as conscious. Despite the fact that the morphophysiological evolution of brain and the behavior of birds and mammals proceeded along the different courses in their development, it turns out that the final results of the complicated and most pliable foims of behavior are similar. The presented scheme of interrelations between the above-mentioned systems of brain in the process of realization of a conscious act offered certain op¬ portunities for the specific physiogenetical study of conscious activity. The scheme made it possible to specify this conscious activity as an independent function of brain which has a fundamental distinction from the instincts or any forms of training and at the same time provides the basis for the most prominent functional pathologies of brain. In spite of the fact that we specify the acts of behavior realized on the basis of conscious activity as an independent form of behavior, differing from the instincts or conditioned reflexes, in the actual life all the three components of behavior are in constant interaction with each other. However, in the animals belonging to different taxonomic groups their relative signi¬ ficance is different. The greatest relative significance of conscious acti¬ vity is certainly inherent in man. The social and labor-management relatione, forming the social basis for the human society, are regulated by conscious activity with the assistance of speech. SUMMARY Opinion on the plasticity of birds behavior has changed significanty dur¬ ing last 10 years. In spite of slight development of cortex and absence of neocortex at all in birds, according to the level of highest nervous activi' ty, some taxonomic groups of birds can be compared to such mammals as dogs, bears and primates. The highest behavioral prasticity is characteristic f°r Corvidae birds. It could be regarded as reasoning ability. The level of de¬ velopment of this form of highest nervous activity is correlated with comp- 828 lexity of their intragroup relations with appearence of personally directed vocalization and other complex behavioral forms, such as directed manipulat¬ ing by things, and 30 on. The complexity of morphological organization of brain corresponds to behavioral plasticity. It is shown, that elementary reasoning ability is more developed in Gorvidae birds, than in doves. The neuronal organization of Neostriatum in Corvidae birds allows more fine ana¬ lysis and proceeding of information in brain, than such in doves. Thus, in spite of difference in evolutionary ways of brains development in comparison with mammals, birds brain has all necessary neurophysiological mechanisms to cover their high level of behavioral adaptability. References Adrianov O.S., Molodkina L.N. - J. Of Higher NeVvous Activity, 1969, 29, N 4, p. 593-601. Bogoslovskaya L.S., Polyakov G.I. Routes of Morphological Progress of Nerve Centers in Higher Vertebrates. Moscow: Nauka, 1981. Dobrokhotova L.P. - In: The collection of "XXII Meeting on the Problems of Higher Nervous Activity". Abstract and summaries of reports. Ryazan, 1969, p . 87 c Dobrokhotova L.P. - Proceedings of the USSR Ac. Sc., 1981, 257 , N 1, p. 242-244. Pilatov D.P. Comparative Morphological Course in the Mechanism of Develop¬ ment, Its Subject, Goals and Routes. Moscow; Leningrad: USSR Ac. of Sc. Publishing House, 1939. Filimonov I.N. - In: Neurology Guide. Pt I. Moscow: Medgiz, 1955. Friede A. - Z. Tierpsychol. , 1972, 30, N 4, p. 383-404; Gossette R., Gossette M.G., Riddell W. - Anim. behavior, 1966, 21. P- 560- 564. Holst E., Saint-Paul U. - Anim. Behavior, 1972, 21, P« 1-20. Huber G.C., Crosby E.C. - J. Comp. Neurol., 1929, 48, p. 1-222. Kamil A.C., Hunter M. - J. Comp. Physiol. Psychol., 1970, 73, N 1, p. 68-73. Kamil A.C., Jones T.B., Pietrewicz A., Mauldin J.E. - J. Comp, and Physiol. Psychol., 1977, 92. N 1, p. 79-86. Kappers A.C.U. - Acta Psychiat. a. Neurol., 1928, 21« N 3, p. 1 1 3 . Karten H.I. - Ann. N.J. Acad. Sei., 1969, 2lZ> P* 164-179. Karten H.I., Hodos W., Nauta W.J., Revzin A.M. - J. Comp. Neurol., 1973, 150, N 3, p. 253-277. Koehler 0. - Bull. Animal Sei., 1950, 9, p. 16-23. Koehler 0. - Freiburger Dies Universitatis, 1957/1958, 6, S. 97-116. Krushinskaya N.L. - J. of Higher Nervous Activity, 1963, 22» N 6, p. 1077- 1086. Krushinskaya N.L. - J. of Evolutionary Biochemistry and Physiology, 1966, 2, N 6, p. 563-568. Krushinsky L.V., Zorina Z.A., Dobrokhotova L.P. et al. - Ornithologie, N 17, p. 22-35. Krushinsky L.V., Popova N. P. - Proceedings of the USSR Ac. sc.j 1978, 240, N 4, p. 997-999. 829 Kurepina M.M. Animals' Brain. Moscow: Nauka, 1981. Morenkov E.D., Do Cong Hun. - In: Materials of the All-Union Congress of Physiologists, Tbilisi, 1975. Polyakov G.I. The Problem of Origin of the Brain Reflex Mechanisms. Moscow: Medit8ina, 1964. Powell R.W. - The Auk, 1972, §9, V- 738-742. Powell R.W. - J. Comp. Physiol. Psychol., 1974, 86, N 4, p. 736-746. Thorpe W.H. Learning and Instinct in Animals. L. , 1958. Zinov'eva I.B. , Zorina Z.A. - J. of General Biology, 1976, 37, N 4, p. 600- 607. Zorina Z.A., Popova N.P. - J. of Higher Nervous Activity, 1976, 26, N 1, p. 127-131. Zorina Z.A., Fedotova I.B. - J. of Higher Nervous Activity, 1981, 21» M 1» p. 185-187. 830 Symposium PHYSIOLOGY OF THE AVIAN EGG Convener: D.F. HOYT, USA Co-convener: A.M. BOLOTNIKOV, USSR HOYT D.F. INTRODUCTION TO THE DIFFUSIVE EXCHANGES AND WATER OF AVIAN EGGS PIIPER J. RESPIRATORY GAS EXCHANGE OF AVIAN EGGS CAREY C. ADAPTATION OF AVIAN EGGS TO EXTREME ENVIRONMENTS SEYMOUR R. PHYSIOLOGY OF MEGAPODE EGGS AND INCUBATION MOUNDS VLECK D., VLECK C.M.,HOYT D.F. PHYSIOLOGICAL CORRELATES OF SYNCHRONOUS HATCHING IN (RHEA AMERICANA) RELATIONS RHEA EGGS BOLOTNIKOV A.M. HETEROGENEITY OF EGGS AND HETEROCHRONY OF AVIAN EMBRYOS DEVELOPMENT UNDER INCUBATION IN NATURE INTRODUCTION TO THE DIFFUSIVE EXCHANGES AND WATER RELATIONS OF AVIAN EGGS Donald F. Hoyt Department of Biological Sciences(California State Polytechnic University Pomona, California, USA INTRODUCTION Ornithologists have always been interested in bird eggs and since the midd¬ le 1700' s increadible numbers of bird eggs have been collected and catalogued by amateur oologiats. These extensive collections were utilized by the great German amateur Max Schonwetter in his monumental descriptions of egg dimensions (1960-78) and by the American amateur, Frank Preston (1969) in his quantifi¬ cation and comparative study of egg shapes. Ethologists and ecologists have always been interested in avian reproduction and incubation but one of the first such studies to include consideration of physiological aspects of in¬ cubation and eggs in a wild species, was the comprehensive study of the func¬ tional aspects of incubation in the Herring Gull (Larua argentatus) by the Dutch ornithologist Rudolph Drent (1970). At about the same time the first in a series of landmark papers dealing with the respiratory exchanges of chicken eggs was published (Wangensteen, Rahn, 1970/71). The man whom I consider to be the father of "Physiological Oology" is Dr. Hermann Rahn of the United States. Dr. Rahn and his two clo¬ sest collaborators, Dr. Charles Paganelli of the U.S.aad Dr. Amos Ar of Is¬ rael were awarded the Coues Award by the American Ornithologists Union in 1981 for their "pathbreaking insights" into the physiology of bird eggs (Anon, 1982). The purpose of this paper is to introduce the basic concepts and relation¬ ships in the area of water balance and to mention some current areas of in¬ terest. Avian embryos obtain the energy required for their development aero¬ bically: that is they must exchange oxygen and carbon dioxide with their en¬ vironment. These gases diffuse through pores in the shell (Wangensteen, Rahn, 1 970/71 ). Pores in egg3 of different species have a wide variety of shapes (Board et al., 1977). Eggs lose water by diffusion through these pores be¬ cause eggs are usually incubated at temperatures which are higher than the temperature of the surrounding air. The rate at which an egg loses water is a function of two factors: the first factor is the gradient or the differen¬ ce in vapor pressure between the air inside the egg and the air surrounding the egg; the second factor, conductance, can be thought of as the ease with which water vapor escapes from the egg. The following equation relates the rate of water loss (M^ Q - with units P, of mg per day) to the gradient (P^ h2o . T ) and the conductance (G., n) : :H20 H2° “h20 Gri A (^fl H2U AH20 - P, lh2o (1) The rate of water loss (M^q) is equal to the rate of weight loss (Drent, 1970). This is because there is no net loss of weight due to exchange of res- 832 piratoiy gases in bird eggs. Therefore, if one measures the rate of weight loss one knows the rate of water loss. P, is the vapor pressure (in torr) in the gas inside the egg and PT is the vapor pressure in the air surroun- ■“-HgO ding the eggs. Conductance has units of mg per day-torr. It is determined by measuring the rate of weight loss under conditions where the gradient is known, normally in a desiccator at 25°C (Ar et al., 1974). Conductance is partially determined by the number, length and area of the pores in the shell (Wangensteen, Rahn, 1970/71). These morphological factors are determined at the time the shell is laid down in the shell gland. There¬ fore, in most species, conductance to water vapor is constant throughout incubation. The only exception to this is an increase in conductance during early incubation in the eggs of some small passerines (Carey, 1979; Hanka et al., 1979). Since conductance is constant, the rate of water loss in natural incubation is nearly constant and eggs experience a nearly linear decrease in weight from the time incubation commences until the egg is pipped (Drent, 1970). The loss of weight leads to the formation of the air cell, a gas fil¬ led cavity at the blunt end of the egg. The rate of water loss (M^ q) varies in a regular way with initial egg weight (W, the weight of the egg when freshly laid) according to the equation (Ar and Rahn, 1980): Mho = 13.2 W0*75 (2) An even more useful generalization is obtained by expressing the total water lost during incubation as a fraction of initial egg weight. Total water lost is estimated (Rahn and Ar, 1974) by multiplying the rate of water loss (M^ Q) by the length of the incubation period (I, in days): 2 mh2o * ™ (3) Since this equation includes the length of the incubation period (I) it is important to note that there is a considerable amount of variation in incu¬ bation period between species laying eggs of the same weight (Rahn and Ar, 1 974) . For eggs of any given weight there is nearly a two-fold range in in- °ubation periods in different species. Combining this fact with equation (3) °he might expect to find a considerable amount of interspecific variation in fractional weight loss resulting from differences in incubation period. But Is not the case. As shown in Figure 1, there is some variation in mean factional weight loss between different species but the average fractional Weight loss for most species falls reasonably close to 15% of initial egg Weight (Ar, Rahn, 1980). This important generalization, first reported by Rahn and Ar (1974), leads one to ask: Why is there less variation in frac- tiohal weight loss than one might expect? The answer to this question is, qulte simply, that the rate of water loss is adapted to the length of the incubation period (Ar, Rahn, i960). If we compare two eggs of the same ini- iial weight, the egg with the longer incubation period loses weight more slowly. The precise nature of this relationship is given by the equation (4). Vo * 0*15 W/I (4) •3aK.98i 833 to IS '20 Mean fractional ureight loss ( /•>) Pig. '1. A frequency histogram of mean fract¬ ional weight loss by diffusion for 94 species of bird eggs. The average value equals 15.056+2.5% (SD). Data from Ar and Rahn, 1980 This relationship is one of the most fundamental in all of egg physiology. It is also an interesting biological phenomenon because it describes a phy¬ siological process whose rate is not only proportional to the weight of the organism but also inversely proportional to a time parameter, the incubation period. Many physiological and morphological parameters of avian eggs exhibit this complex relationship between egg weight and incubation period and, I believe, all of these relationships ultimately are linked to this one: the necessity of losing about 15% of the initial weight during incubation. Obviously, the next question to ask is: how is this relationship achieved? If we recall the physics of the process (equation 1), we can see the possible answers: if the rate of water loss is inversely proportional to incubation period, the conductance or the gradient must also be inversely proportional to incubation period. It appears from several studies that the gradient is about the same in most species with a value of about 34 torr (Ar, Rahn, 1980 Therefore, we are not surprised to find (Hoyt, 1980) as originally predicted by Rahn and Ar (1974) that conductance is related to both egg weight and in¬ cubation period: ^0 kg W/I We can rearrange this equation to give: K_ gh2o I/W (5) (6) We can calculate the value of the Conductance Coefficient (Kg) for any spe¬ cies for which we know egg weight, conductance and incubation period using equation (6). Ar and Rahn (1978) report a mean value of this coefficient for 90 species of 5.13+0.86 (SD). If we substitute this mean value into equation (5) we have a good equation with which to predict the conductance of any egg for which we know weight and incûbation period: „H2o -*•«»/! It is interesting to note that there is some interspecific variation in the value of this coefficient. Figure (2) includes values of KQ which differ rather markedly from 5-13. These eggs appear to be adapted to extreme environ- 834 Conductance coefficient ( ) » OHÎO . I/W)”or6129 Gp^ieTrf0birdaegg80ndïhetant'e (KG » presumably, adapted to humid en^ron^entHn. peeH ^V^3 ^ desiccating environnante Pecies with low values to « * . Source a a a b b c 1. Anser indlcus (Bar-headed Goose) 2* yndrocygna autumnal Is (Red-billed Whistling Duck) 3- Hendrocygna bl color (Fulvous Whistling Duck) 4. Pu llca atra (Coot) 5- Podiceps crlstatne (Great Crested Grebe) 6* Alectura lathed (Brush Turkey) 7* Gavia immer (Common Loon) 1978; d) H-Rahn^pers!^.’ ^ ^ 5 Seym0Ur and Rah- <*■***■> -e . 2). This is probably " ZlZtT I ^ (speCiGS 1 *» ®Sg3 with unusually high conductances appear ^b^YY^ altitUd6S‘ The environments. Clearly, th<= best wav to ri + ^ apted to very humid nest unusual environments is to calculate the r adaptati°ns of conductance to in gestion and compare this value with 5.13/° C°effioient for the eggs MEASUREMENT OR CONDUCTANCE r°"U“‘,y “* o, «•ta •«. in n desiccator (*r « ^ “.T”* 'te “n<‘"°t“0e »' « »*«. inductance measured during the first v, T ^ COnseoutive The rvn subsequent days- z for thisYaeY YY/T WaS first noted * ^ and Rahn and ce have trldit Y ! m ^ °f the meas^ement of conductan- be seen f*L m*“ dl3regarded lHo^ et al* • 1979). However, as can hours The s T1"6 ’ m03t 0f thiS °hanSe °CCUrs during the first twelve Ing t;e T* rre °btained by weishin* egga eve^ couple of hours dur- Hth the change which0 ^ d8sic 'ator- Thls change should not be confused the eggs of aol Y Uril!g the firSt feW da^ °f incubation in sg0 of aome small passerines (Carey, 1979; Hanka et al. , 1979) T+ • numtrTut1! T T* °hange d063 n0t reflect a chanse in pore Womet^or d^ing ’the f i 1 7 1 1038 °f eXCe3S Water fr°m thS matriX °f shell ng the first few hours in the desiccator. 835 P i g. 3. Apparent changes In conductance with time In fresh Chicken (Gallus gallus) eggs. Conductance was measured In a desiccator at 25°C on six con- t^ïïv. d.,. for 35 .dd.. Th, 11,. connects d.llf ”lu" “4 bars Udlcate on. standard deviation. Th. „ean vain, on th. flr.t da, la 3 • higher (p ^0.05) than on the second day. Because of similar changes, data from the first day of measurement are disregarded in the measurement o conductance in bird eggs p i 4. Change in conductance during the first 24 hours in a desiccator in three individual fresh chicken eggs. Most of the change, ^iche assume to be due to the loss of water from the shell itself, occurs during the firs 12 hours REGULATION OP NEST VAPOR PRESSURE A topic of current controversy is the regulation of n'est vapor pressure. Rahn et al. (1976) proposed the hypothesis that incubating adult birds can sense and behaviorally regulate the vapor pressure of the air in the nest. They based this hypothesis on the observation that, comparing species of terns nesting in a variety of environments, there is less interspecific va¬ riation in nest vapor pressure than there is in environmental vapor pressure. They point out that water which has escaped from the egg must subsequently escape from the nest or else the air in the nest will become saturated. Since measured nest vapor pressures are usually less than 50% of saturation, water vapor does escape from the nest. This transport of water could occur either by diffusion of water vapor through still air or by the convective exchange of drier ambient air for the moist nest air. They assumed that the later process, which they refer to as "ventilation", is the most important of the two mechanisms. They suggest that birds could permit ambient air to enter the nest by standing up and could control the amount of ambient air entering the nest by varying the number of times they stand up every hour. This hypo¬ thesis was evaluated by Walsberg (1980). He utilized a deterministic mathe¬ matical model to evaluate the influence of standing up on the transport of water vapor out of a fibrous cup nest. He concluded that even if an incubat¬ ing bird never stood up there would be very little difference in vapor pres- 856 P i g. 5. Frequency histogram of fractional weight loss in individual Tern eggs. Differences in mean values of the two species are signifi¬ cantly different (p < 0.001). All of these eggs hatched, in¬ dicating the ability to tolerate a range of fractional weight losses. Data from Ni'sbet, 1981 sure between ambient air and the air in the nest because water vapor could easily diffuse directly through the walls of the nest. Data collected by David and Carol Vleck (C.Vleck et al., in press) support Walsberg's predic- lon, indicating a mean difference in vapor pressure between ambient and nest air of less than 3 torn for four species of tree-nesting birds. In a more recent study Walsberg (in press) was unable to detect any change in parental behavior when he experimentally manipulated the vauor pressure of nest air in two tree-nesting species by circulating saturated or dried air through the nest. His results failed to support Rahn's hypothesis that birds behaviorally regulate vapor pressure of nest air by standing up. However, there have been no similar manipulative studies in ground-nesting species where ventilation could be more important, and Rahn's hypothesis could still he valid for these species. INTRASPECIFIC AND INTERSPECIFIC VARIATION IN FRACTIONAL WEIGHT LOSS Figure (55 contains data on fractional weight loss in two species of terns (Nisbet , 1981). These data were obtained by weighing eggs to the Nearest milligram on two occasions at least one week apart. Both species were studied at Bird Island, Massachusetts (41’40"N, 70’ 43" W). Data on the Com- m°n Tern (Sterna hirundo) were collected during May and June, 1975, and those °h the Roseate Tern (Sterna dougallii) during May and June, 1980. There are °lear differences between these two species. The mean value for the Common Tsrn is 12.3%+1.8 (SD) and the mean value for the Roseate Tern is 15.6&f2.4 (°D). These differences are statistically different (P < 0.001). These data figure 5) also reveal a reasonably large amount of intraspecific variation ln the weight loss of these eggs. Another interesting aspect of Dr. Nisbet 's liata ia tlla-|. they inoiude all of the eggs he was able to obtain for his study 837 and virtually all of them hatched. Therefore, it seems clear that the hat- chability of these tern eggs is not dramatically affected by weight losses ranging from 9 to 25%. Data from two independent studies by Dr. Kenneth Sim- kiss (1980) and Hoyt (1979), indicate that the ability to tolerate different levels of weight loss probably results from special physiological homéosta¬ sie mechanisms of the embryos. the overall budget op water loss in avian eggs Ar and Rahn (I960) point out that the average fractional weight loss of 15% does not include water lost after the shell is pipped. This 15% represents only the water lost by diffusion through the shell. In fact, there are three phases of water loss. A small amount of water is lost between the time the egg is laid and the time incubation starts. The amount of water lost during this phase is small because there is very little, if any, difference in tem¬ perature between the egg and the surrounding air. The second phase of water loss extends from the time incubation starts until the egg is pipped. This is the diffusive phase and during this time there is a nearly linear decline in weight. The rate of weight loss during this phase is the M^q referred to earlier. If we extrapolate this rate of weight loss to the time of hatching, we can estimate the diffusive loss (average value equals 15%). The third phase of water loss commences when the shell is pipped and ends when hatch¬ ing is completed. Ar and Rahn (1980) have estimated that this paranatal wa¬ ter loss averages about 5%. Therefore, the total loss averages about 20%. They have suggested that the paranatal loss in precocial species may be 1-2% higher in precocial species than in altricial species. Obviously, the amount of water lost during this paranatal phase may vary rather greatly with such factors as the length of time between pipping and hatching and other species- specific differences in the actual hatching process. SUMMARY The rate of water loss from avian eggs is determined by the conductance and the vapor pressure gradient between the gas inside the egg and the air surrounding the egg. The amount of water lost by diffusion, which can be esti¬ mated from the product of daily rate of water loss and the length of the incubation period, averages 15% of fresh egg weight. The rate of water loss is proportional to the ratio of egg weight to incubation period because con¬ ductance is proportional to the same ratio. To detect adaptations Df conductan ce to unusual environments is calculate the conductance coefficient (KQ) and compare it with the mean value of 5*13+0. 8o (SD,. When conductance is being measured the value obtained during the first 1 2 to 24 hours may be erroneously high by as much as 30%. Data on rates of water loss during natural incubation in two species of terns indicate there may be significant amounts of inter¬ specific and intraspecific variability but hatchability may not be dramati¬ cally affected by a rather wide range of weight losses. In addition to the 15% of fresh egg weight lost by diffusion, it has been estimated that another 5% are lost during the process of hatching. 8J8 ACKNOWLEDGEMENTS My research was funded by a Special Education Grant from the Cal Poly Kellogg Unit Foundation. Travel to the IOC was made possible by grants from the American Ornithologists' Union and California State Polytechnic Univer¬ sity. I am personally grateful to Diana Roberta, Pelecia Granderson-Yitref and Marilyn Steinle for their cheerful and energetic assistance. I am deeply ndebted to Dr. Ian C.T. Nisbet for permission to use his data on weight loss of the eggs of two species of Terns. References Anon. - Auk, 1982, 22, p. 183. Âr t" r"v“ r-b- •• ,i- n. ■' ' .* "• - 1» Birds, Adult and Entry unit / Ed. y J.Piiper. B. s Springer- Verlag, 1978, p. 227-236. Ar A., Rahn H. - Amer. Zool. , 1980, 20, p. 373-384. Carey l'“' ’ J**'?’ ’ * J* Z°01* L‘ * 1977> JSS. P- 251-265. Carey C. - J. nxp. Zool., 1979, 209, p. 181-186. Drent R. - Behaviour, Suppl., 1970, 17, p. 1-132. Hanka L.R., Sotherland P.R., Taigen T.L. et al. - J. P- 183-188. Hoyt D.F. - Physiol. Zool., 1979, 52, p. 354-362. Hoyt D.j,. - Amer. Zool., i960, 20, p. 417-425 Hoï» °°*ra ”'0" “° h- O.T. . P. 438-450. Lomholt J.P. - j. Comp. Physiol., 1976, _105, p. 189-196. VwT‘ ’ U'S‘ DePt' °f Interior* P-0-' 1981, N 50181-0840-9 Hreston F.W. - Auk, 1968, 85, p. 454-4Ô3. Hahn H., Ar A.- Condor, 1974, 76, p. 147-152. Schonwetter M. - In: Handbuch der Oolûgie. Vol. 1 / Ed. by Wimeise B Verlag, 1960-1978, p. 1-26. y Wlraeise* B‘ Simkiss K. - J. Zool., L. , 1980, J92. p. 1-8. ey“ R'S'’ Rahn H* “ In: Respiratory Function in Birds, Adult and WalsbeSTg 'a' by 7J‘PJiper> B*: Springer-Verlag, 1978, p. 243-246. isoerg G.E. - Amer. Zool., 1980, 20, p. 363-372. Walsberg G.E. - Physiol. Zool., Wangensteen O.D. , Rahn H. - Respir. Physiol., 1970/71, _n, p. 31-45. Exp. Zool., 1979, 210. Zool., 1979, 52, Akad. 839 RESPIRATORY GAS EXCHANGE OP AVIAN EGGS Johannes Piiper Abteilung Physiologie, Max-Planck-Institut für experimentelle Medizin, Hermann-Rein-Strasse 3, D-3400 Göttingen, FRG INTRODUCTION Since Schwann (1834), who showed that an adequate supply of 02 is needed for the successful hatching of chicken eggs, and Hasselbalch (1900), who pioneered in the measurement of gas exchange of eggs, the study of the res¬ piration of embryonic birds has been slowly and steadily evolving. Contri¬ butions which have been important for the understanding of the physics and physiology of this gas exchange have been provided by Romijn (1950) and in particular by Visschedijk (1968). A powerful advancement and stimulation was then provided by Hermann Rahn and his co-workers, in Buffalo, N.Y. , who started work on the physiology of gas exchange of avian eggs in 1968 (the important publications of this group from the period 1968-1980 have been compiled into a special issue edited by Rahn and Paganelli, 1981). The work began with chicken eggs, but was soon extended to eggs of nume¬ rous wild bird species, both by the Buffalo group and by numerous other in¬ vestigators more or less directly inspired by the Buffalo group. Various as¬ pects of current research in the area were discussed in two symposia, namely in Göttingen, 1977 (Piiper, 1978), and in Tampa, Florida, 1979 (Carey, 1980a). In this introductory report, the emphasis will be on some basic concepts of the respiratory physiology of the avian embryo. EXTENT OP RESPIRATORY GAS EXCHANGE An avian egg is a self-cootained life-support system providing all the nutrients, minerals and water required for the development and the mainte¬ nance of the embryo (Rahn et al., 1979). Only Og, C02, water vapor and heat must be exchanged with the environment. A chicken egg weighing 60 g will take up 6 1 02 ('9 g) and give off 4. 5 L CO (i: 9 g) and 11 L ( « 9 g) water vapor during its incubation time of 21 days. Because the respiratory quotient is about 0.73 the mass of 02 taken up closely equals that of C02 given off, knd the total weight change (a decrease of about 9 g) is due to water loss. Since the avian egg shell is rigid, the water loss gives rise to the formation of an air space (air cell) between the outer and inner shell membranes at the blunt end of the egg. In many species, the relationship between water loss and total cumulative gas exchange per mass of egg has been found to be similar. It follows from the measurements that production (and maintenance up to hatching) of a chick "costs" about 100 ml 02 (equivalent to about 0.5 kcal) per g of egg or 150 ml 02 (equivalent to about 0.75 kcal) per g of chick (Hoyt and Rahn, 1980; Rahn and' Ar, 1980). More accurate measurements, however, have shown that the "cost" of con¬ verting egg contents into chick tissue is lower in altricial birds as corn- 840 pared to precocial birds, in accordance with their degree of development at hatching (Ar and Rahn, 1980; Vleck et al., 1980). CHANGES DURING DEVELOPMENT The metabolic rate of the embryo shows a spectacular increase during the evelopment. In altricial bird embryos the increase of 0„ uptake is close o exponential, in conformity with the growth rate. In precocial birds the 02 uptake tends to reach a plateau during the last days of incubation, cor¬ responding to a reduction in the growth rate, and then rises again, to ma¬ ximum value, during the labor of pipping and hatching (Vleck et al. , 1980). This increasing 02 requirement is matched by an increasing performance of the gas transport system. Of decisive importance is the growth of the vascular chorioallantois on the inner surface of the egg shell. When during the latter part of the incubation time the chorioallantois has completed its growth, covering the whole inner surface of the egg shell. all the pores of the egg shell are utilized for gas exchange. During the second half of incubation the following adaptive changes of the gas transport systei have been quantitatively deteimined in chicken em¬ bryos: increase of chorioallantoic blood volume and flow, increase of blood hemoglobin concentration and 02 affinity of hemoglobin, and increase of Plasma bicarbonate concentration (Tazawa, 1980). All these changes lead to an enhanced performance of 02 and CC>2 transport within the egg. In spite of some increase in egg shell conductance during incubation Carey, 1979), its limiting role in gas exchange becomes progressively more important towards the end of incubation. The diffusion limitation leads to a steady decrease of Pq2 and increase of PCo2 in the egg, as reflected by mea¬ surements of the air cell gas (Romijn, Roos, 1938; Wangensteen, Rahn, 1970/ 71 The hypoxia developing before hatching demonstrates the limits to the gas transport performance, imposed by limited permeability of the egg shell. Thus the pipping, that is the cracking of the egg shell by the chick, and he start of lung breathing are inevitable events from the standpoint of respiration. DIFFUSION THROUGH EGG SHELL PORES The transfer of 02< C02 and water vapor across the egg shell takes place Ï diffusion through the microscopic pores. The transfer rate, M (o uptake, C02 outPut or H20 output) , is proportional to the effective partial2pressure °i the gas species x across the shell, measurable as the difference between environmental air and air cell patrial pressure, P^-P^ (Wangensteen, Rahn, 1970/71; Wangensteen et al., 1970/71; Paganelli, 1980). The conductance, G, is the proportionality coefficient: The diffusive conductance of the egg shell is determined by the effective total pore cross-sectional area, Ap, the effective pore length (approximately e9Ual to egg shell thickness), L, and the diffusion coefficient of the gas species in air, Dx(R, gas constant; T, absolute temperature): 841 The total functional pore area, A , results from the number of pores(N, and the effective pore radius (4): Ap = ~r2 . N (3) For a chicken egg (N* 7500, r~ 10 m) , Ap is about 2.3 mm2, a very small fraction of the total shell surface area (68 cm2). Since the ratio Dcc>2/D02 *0.7 is similar to the respiratory quotient R » McOg/1^* t*ie partial pres¬ sure difference Fj - PA is about the same for 02 and C02; Fj - PA increases from about 10 Torr (day 8) to 45 Torr (end of incubation) (Wangensteen, Rahn, 1970/71). For a large number of bird species Ar and Kahn (1978) have shown that there exists a remarkably close inverse relationship between the specific conductance of the egg shell to water vapor (conductance G/egg mass W) and the incubation length (I). — • I = const ^ W This relationship was established for GH2o(because this quantity is easily measured), but it must also be valid for Gq2 and Gco2 (Ar and Rahn, 1978; Rahn, Ar, 1980). It means that slowly developing eggs have a small conduc¬ tance, but as the metabolism is proportionally reduced, the Pj - PA differ¬ ences at corresponding stages of development are expected to be about the same in all avian eggs. ENVIRONMENTAL CHANGES AFFECTING DIFFUSION Under some conditions the changes in transfer of respiratory gases as predicted on the basis of the above equations are expected to be of biologi¬ cal importance. (1) Many birds lay their eggs in burrows. When the convective air move¬ ment is reduced, the 02 concentration may drop and C02 may build up, due to the metabolism of the eggs as well as that of the incubating parent and that of other organisms (Pettit et al., 1982). Much greater effects, however, oc¬ cur in such situations after hatching (White et al., 1978). Particularly large deviations of the environmental from the atmospheric air composition are found in the nests of the mound-building megapodids (Seymour, Rahn, 1978) (2) At high altitude, the reduced barometric pressure has two effects (Visschedijk, 1980) : (a) The 02 partial pressure decreases. To ensure sufficient 02 diffusion, an increase in the egg shell conductance appears to be appropriate. (b) The diffusion coefficient, D, increases for all gases, being inver¬ sely proportional to the total (barometric) pressure. This increase in D, therefore, would enhance water loss, and produce alkalosis by reducing PC02* To compensate for this, a reduction of the conductance by decrease of the A /L ratio seems to be appropriate. P In this conflicting situation, experimental evidence shows a decrease of the A /L ratio in bird eggs from higher altitudes. This may be inter¬ preted to mean that water balance (and acid-base balance) have priority over the 02 supply- A prolongation of the incubation period with a reduced 0 uptake rate and delayed growth rate are also found in eggs incubated at altitude (Rahn et al., 1977; Carey, 1980b). 842 GAS TRANSPORT INSIDE THE EGG The layers to be crossed by diffusion are: mineral shell, outer and inner shell membranes (fibrous networks containing air), endothelium, plasma and the membrane of the red blood cells in the chorioallantoic blood capillaries. nee the air cell is fonned between the outer and the Inner shell membranes its gas analysis allows to distinguish an outer diffusion barrier (mineral shell and outer shell membrane) and an inner diffusion barrier (inner shell membrane and blood capillaries). For C02 (and H20) the major resistance to diffusion lies in the outer barrier (predominantly egg shell), but for 0 the the resistance offered by the inner barrier is not negligible (Wangen¬ steen, 1972; Piiper et al., 1980). The next link in the gas transport system is convective transport by blood flow. The chorioallantoic capillaries receive blood from the allantoic arte¬ ries and the outflow is via the allantoic veins. The diffusion of 02 into red blood cells and the reaction of hemoglobin with 02, functionally included in the inner barrier, may be important limit¬ ing processes (Wangensteen, Weibel, 1982). a particular feature in the cho¬ rioallantoic gas exchange -is a large blood shunt (about 10-15%), leading to a considerable oxygenation deficit of the arterialized allantoic blood as compared to air cell gas (Piiper et al., 1980), Moreover, since the anatomical arrangement of the embryonic circulatory system leads to mixing of arterialized blood of the allantoic veins with systemic venous blood in the embryo, the 02 partial pressure and saturation n the arterial system of the embryo are expected to be further reduced (Ta¬ rawa, 1978). For example, in the chorioallantoic artery and in the arteries running to the caudal part of the body these properties are expected to be identical. In this blood (Po2 - 24 Torr), 02 saturation has been found to be 22% only. 02 saturation of arterial blood supplying the cranial part of the oay may be slightly higher, due to preferential channeling of allantoic vein blood, in a manner similar to mammalian fetal circulation (Tazawa, 1 980) . Thus the anatomical arrangement and the limited blood flow are important li¬ miting .factors for the 02 supply to the tissues. SUMMARY , Respiratory gas exchange of the avian embryo occurs in the chorioal- antoic blood capillary plexus which, when fully developed, extends over" e whole inner surface of the egg shell. Diffusion of the respiratory gases °Ugfa the pores of the e«S shell is the predominant limiting process in dijC ange of oarhon dioxide and important for 02 exchange. The diffusive con¬ ductance of the shell, determined by the number and the dimensions of the ^°re3, is adjusted to the metabolic rate of the embryo in such a manner that b adequate oxygen supply is insured in combination with an optimal acid- statue and water balance. ACKNOWLEDGMENTS Dj, For advioe and criticism I am grateful to Dr. A. Ar (Tel Aviv, • h. P. Hoyt (Pomona, CA, USA) and Dr. A.H. J. Visschedi jk (Utrecht Hetherlands), Israel) , the 843 References Carey C. - J. Exp. Zool. , 1979, 209, F- 181-186. Carey C. - Am. Zool.., 1980a, 20, p. 325-484. Carey C. - Am. Zool., 1980b, .20, p. 449-499. Gas exchange In avian eggs / Eds. H.Rahn, C. 7. Paganelll. Buffalo: State University of New York at Buffalo, 1981. Kasselbalch K.A. - Skand. Arch. Physiol., 1900, JO, p. 393-402. Hoyt D.F. , Rahn If. - Respir. ihysiol. , 1980, JJ9, p. 255-264. Paganelli C.V. - Am. Zool., 1980, 20, p. 329-333. Pettit R.N. , Grant G.S., Whitt ow G.C. - Physiol. Zool., 1932, £5, p. 162- 17°. Piiper J. , Tazawa H. , A r A., Rahn H. - Respir. Physiol., 1980, J9, p. 273 284. Ar A. - Am. Zool., 1980, _20, p. 477-484. Ar A., Paganelli C.V. - Soi. Amer., 1979, 240, p. 46-55 Garey C. , Balmas K. - Proc. Natl. Acad. Sei., 1977, 74, Rahn H. , Rahn H. , Rahn H. , 1977, 74, p. 3095- 3098. Respiratory Function in Birds, Adult and Embryonic / Ed. by J. Piiper. Berlin', Heidelberg, New York: Springer, 1978. Reunion C. - Poultry Soi., 1950, 29, ?. 42-51. Romijn C. , Roos J.- J. Physiol. (L.), 1938, 94, p. 365-379. Schwann T. De necessitate aeris atmospheric! ad evolutionem pulli in ovo incubito. Dissertation. B. , 1834. . Seymour R.S., Rahn H. - In: Respiratory Function in Birds, Adult and Embryonic / Ed. by J. Piiper. Berlin, Heidelberg, New York: Springer, 1978, p. 243-246. Tazawa H. - In: Respiratory Function in Birds, Adult and Embryonic / Ed. by J. Piiper. Berlin, Heidelberg, New York: Springer, 1978, p. 274-291. Tazawa H. - Am. Zool. , 1980, 20» p. 395-404. Visschedijk A.H.J. - Br. Poultry Sei., 1968, 9, p. 173-184, 185-196, 197- 210. Visschedljk A.H.J. — Am. Zool., 1980, .20, p. 469—476. y leck C.M. , Vleck j. , Hoyt D.F. - Am. Zool., 1930, 20, p. 405-416. Wangensteen 0.3. - Respir. Physiol., 1972, J_4, p. 64-74. Wangensteen O.D. , Rahn H. - Respir. Physiol., 1970/71, ü, p. 31-45. Wangensteen D. , 'Weibel F.R. -Respir. Physiol., 1982, 47, p. 1-20. Wangensteen O.D. , Wilson D. , Rahn H. - Respir. Physiol., 1970/71, JJ, p. 1 6-30 White F.N., Bartholomew G. A. , Kirfney J.L. - Physiol. Zool., 1973, 5 J, p. 140- 154 844 ADAPTATION OP AVIAN EGGS TO EXTREME ENVIRONMENTS Cynthia Carey Department of 3P0 Biology, University of Colorado, Boulder, CO 80309, USA INTRODUCTION Since birds breed in a remarkable diversity of habitats, their eggs serve as an excellent tool for identifying key patterns of adaptations to stress¬ ful environments. In fact, their utility for studying adaptation extends into several fields of interest. First, although adult behavior can protect eggs from certain environmental hazards, particularly thermal extremes (see Drent , 1975! Carey, 1980a, for review), avian embryos are more exposed to variation of the physical environment than are those of viviparous ver¬ tebrates. Since reproduction is often the most vulnerable aspect of the life cycle of many organisms and since reproduction must be successful in order for a species to colonize new habitats, avian eggs provide an interesting example of adjustment of reproductive modes to environmental stress. Further, avian eggs are unique in- vertebrate reproduction since they exchange gases, but not solids or liquids (with the possible exception of eggs of a few species laid in contact with liquid water, Sotherland, 1979 ), with the en¬ vironment (Wangensteen and Ha hn,>1 970-71 ). Since the gaseous environment varies in different habitats, avian eggs can be used to determine how gas-exchange systems have been adjusted to environmental variability. Finally, the avian eggshell, the barrier between the embryo and its environment, is an excel¬ lent example of a biological feature that has evolved in compromise between mutually antagonistic requirements. The eggshell must be thick enough to bear the weight of the egg contents and incubating adult, yet thin enough to be cracked by the hatching chick. And, perhaps most interestingly, the eggshell must have the appropriate permeability not only to afford adequate diffusion of oxygen into the shell to support metabolic requirements of the embryo, but also to restrict excessive losses of C02 and water vapor from the egg. Since gas exchange and the qualities of the eggshell which deter¬ mine rates of gaseous flux might be predicted to be one of the most sensi¬ tive characteristics of avian eggs to environmental variation, the purpose °f this paper is to review current knowledge concerning how the properties °i the avian egg relating to gas exchange vary within species breeding over geographical gradients or among species breeding in diverse gaseous envi¬ ronments. ENVIRONMENTAL EFFECTS ON GASEOUS DIFFUSION As described in detail in the previous papers in this symposium, avian eSgs exchange Og, COj, and HjO vapor through common pathways in the eggshell Principally by the process of diffusion (Wangensteen et al., 1970—71; Paga- belli et al. ,1975; Fagaoelli et al., 1978; Paganelli, 1980). We can predict how the physical environment can influence gaseous diffusion by reviewing the factors that determine the rate of flux of gas between the environment abd the embryo. Gaseous flux (M, in cm^STPD * sec“1) is described by a mo¬ dification of the Fick equation (Wangensteen et al., 1970-71; Paganelli et al*. 1975): 845 M = (D/RT) • (Ap/L) - 4P, (1) 2 »l where D = effective binary diffusion coefficient(cm • sec ) , RT « gas O -1 constant and absolute temperature (cnrSTPD • cm”J • torr“ ) , Ap « effective 2 pore area (cm ), 1 = length of the diffusion path, or shell thickness (cm), and AP = partial pressure difference of gas across the shell (torr). This equation points out two aspects of the physical environment that can alter M, namely D and A P. Since D is a function of barometric pressure (PB) (see below) and since environmental gas tensions comprise part of the A P for each gas, we will find the best examples of adjustments to these environmental features in eggs laid at high altitudes and in diverse gaseous environments, respectively. Before describing the problems poBed by variation in D and A P and reviewing the available data on eggs of birds living in these habitats, we must first address the following question: what evidence exists concerning whether va¬ riation in D or A P for any gas would actually influence M sufficiently that differential mortality would result and select for compensatory modificati¬ ons in eggshell structure and/or embryonic physiology? Such little information exists concerning embryonic tolerances of variat¬ ion in Mo2> MC02> 01110 Mh20 tllat it is difficult to determine what the actual impact of variation in D or A P would be under certain circumstances. However, considerable information has accumulated concerning normal patterns of gas exchange in numerous species (Rahn, Ar, 1974; Ar, Rahn, 1978; Hoyt, Rahn, 1980; Vleck et al., 1980). Such patterns are strikingly similar despite a 45,000-fold range in egg weight and an 8-fold range in incubation period among all avian eggs (Rahn, Ar, 1974). Eggs just prior to pipping lose an average of 16% of the initial weight of the egg as water vapor during incu¬ bation (Ar, Rahn, 1978), the amount of 02 consumed per gram embryo (and presu¬ mably the amount of C02 consumed per gram embryo) varies only slightly (Ar, Rahn, 1978; Hoyt, Rahn, 1980), and the A Pq2 and A Pco2 6111(1 final levels of 02 and C02 in the aircell just prior to pipping fall within narrow ranges (Rahn et al., 1974; Hoyt, Rahn, 1980). These data do not indicate that avian embryos are intolerant of wide variation in rates of gas exchange, but that development takes place in a common gaseous environment, despite large diffe¬ rences in egg and hatchling weights and incubation periods. Such similarity is attributed to the intercoordinated evolution of eggshell permeability to gases, determined by Ap and L, with the incubation period and egg weight (Ar, Rahn, 1978). Experimental determination of tolerances of avian embryos to variation in external gas tensions is limited to studies on eggs of domestic fowl (Gallus domesticus). Hatchability severely declines due to hypoxia or hyper- carbia in domestic fowl embryos if small portions of the eggshell are blocked just prior to the onset of pulmonary respiration ( Visschedijk, 1968; Tazawa et al., 1971). Freeman (1962) observed that mortality was increased from no¬ minal levels to almost 70® if air flow in incubators was increased above re¬ commended levels; he attributed such mortality to increased losses of CO^ but had no evidence to confirm his theory. Hatchability is unusually 'low in eggs of domestic fowl incubated at 02 concentrations below 15® or above 40% or at concentrations of C02 above 1% (Lundy, 1969). 846 Preliminary results from Manipulation of eggshell permeability to gases in eggs of red-winged blackbirds (Agelaius phoeniceus) indicate that embryos of wild birds may be fairly tolerant of variation in rates of gas. exchange during incubation. Eggshells were treated with waxy coatings to decrease Ap or were punctured over the aircell to increase Ap. While flux of o , CO and H20 vapor were all affected by such treatment, only rates of water loss were measured. Embryos in naturally incubated eggs were still able to hatch from these eggs despite a 3-fold variation in rates of daily water Idas and a final water content ranging from 80-89% (Carey, unpublished data). Further studies are clearly needed to establish tolerance limits of embryos of wild birds to. variation in rates of gas exchange. If we temporarily accept the assumption that variation in D or A P beyond certain limits could cause lethal desiccation or disruption of the acid- base status of the embryo, we can now ask how these features of the environ¬ ment could modify M for any gas and what sorts of solutions may have evolved by avian species to meet these challenges. EFFECTS OF THE DIFFUSION COEFFICIENT ON GASEOUS EXCHANGE According to gas laws and theoretical predictions, the effective diffusion coefficient, D, for any gas is inversely proportional to barometric pressure (Reid, Sherwood, 1966; Paganelli et al., 1975). Therefore, gases exchanged between an embryo and its environment should diffuse more rapidly at low P All other factors in Eq. 1 held equal, at rates inversely proportional to the decrement in PB below 760 torr (Paganelli et al., 1975; Paganelli, I960). Several experiments have verified that eggs of domestic fowl exposed to bypobaria exhibit enhanced rates of loss of C02 and HgO vapor and uptake of °2 at value close to predictions based on the increase in D for each gas (aee Carey, 1980b, for review). The problem for an avian embryo laid at high altitude is this: as alti¬ tude increases and Pß decreases, the increases in Dco2 and Djj20 will cause Progressively greater rates of loss of these two gases. Above certain alti¬ tudes, these enhanced rates of loss could cause lethal disruption of acid- base balances and desiccation of the embryo. Concurrently, the Pq2 of the ambient air in the ambient air decreases with Pß. Although the elevation in C°2 can ameliorate in part the effect of lower Pq2 (Vi sschedijk et al. ,1980), the embryo will be unable to obtain sufficient 02 above certain altitudes to ®eet the demands for normal growth and regulation. Therefore, the avian egg ab high altitude is confronted with a classical and striking example of conflicting requirements: restricting losses of C02 and HgO vapor from the e8g while affording diffusion of adequate levels of 02. How has this problem been solved? Shell membranes initially pose considerable resistance to diffusion of 0 bh the early stages of incubation (Kutchai, Steen, 1971; Lomholt, 1976a; Tul- bett. Board, 1976). After the shell membranes of eggs of domestic fowl drv. ne shell and the outer shell membrane (the' "outer barrier") provide about ^3 the total resistance to 02 diffusion, the other 2/3 by the "inner bar- ^ier" comprised of the inner shell membrane, water layer, and membrane of bbe chorioallantois (Bissonnette , Metcalfe, 1978; Piiper et al., 1980). No 847 comparable breakdown of the relative resistances of inner and outer barriers are available for eggs of wild birds. If maximizing Og availability to the embryo were the most important goal for optimal hatching success, we might predict that the following characte¬ ristics of eggs laid at high altitude would differ from those of eggs of the same species laid in the lowlands: 1) increase in Ap or 2) decrease in D, both or either of which would reduce resistance to diffusion of Og, 3) dec¬ rease in parental attentiveness on the nest to result in a greater A Po2 in the nest microenvironment, or 4) decrease in resistance to Og diffusion in the inner barrier, an increase in the Og carrying capacity of embryonic blood, an increase in the tolerance of embryonic tissues to hypoxia, or other physiological changes in the embryo. If modifications 1-3 have been completed in the evolution of montane populations, each or all could concei¬ vably result in adequate supplies of 02 but also increase the rate of losses of C02 and HgO. The only adjustments that would not affect COg and HgO vapor losses but would still promote normal growth and development would be those included in option 4. If minimizing losses of C02 and HgO vapor has proven to be the most es¬ sential for maximizing embryonic hatchability at low P.ß, the following opti¬ ons may have been utilized in the evolution of montane populations: 1) dec¬ rease in Ap or 2) increase in L which would increase the resistance to dif¬ fusion of these gases, 3) increase adult attentiveness on the neat to reduce A Pco2 and AP^O»«01 4) increasing the relative water content of fresh eggs and the buffering capacity. This last option would not counteract the in¬ creased rates of losses of these gases, but would ensure that the final water content and acid-base status of the pipped embryo would be similar to those found in embryos incubated in the lowlands. If options 1-3 were utilized, we would expect that rates of diffusion of these gases would be independent of P in these changes were made in direct proportion to the variation in Pß (see Rahn et al., 1977). However, if option 4 were utilized, we can expect that rates of diffusion of these gases would increase with decreasing Pß but that the final water content of the pipped embryo and its acid-base status would be independent of Pß. Finally, we might predict that if options 1-3 were adopted as measures to control rates of losses of COg and H20, the ability to take up adequate 02 for normal requirements would be compromised above certain altitudes. Approximately 21 species of birds breed between 4300 and 6500 m and many more breed between 3000 and 3000 m (Rahn, 1977). Of these, very few have populations of the same species breeding at sea level, or even more impor¬ tantly, breeding over an entire altitudinal gradient. Data are now available on eggs of 3 passerine species and 3 groups of Callus domeBticus breeding between sea level and high altitude locations above 3000 m. Since no study has yet investigated the problems of C02 diffusion at high altitude, we will concentrate our attention on the problems of Og and HgO vapor. The following results indicate that control of 1^0 vapor and C02 diffu¬ sion has been more compelling than maximizing Og uptake, at least to alti¬ tudes around 3000 m. Daily rates of water losses do not vary significantly in naturally incubated eggs of red-winged blackbirds (Carey et al. , 1983) and white-crowned sparrows (Zonotrichia leucophrys) (Carey, unpubl. data) 848 PI g. 1. Relation of relative conductance of eggs to water vapor to P Ictull aJtitude ln ^ree species of passerines. In each case, the actual mean for each population at sea level was standardized at 1.0 and mean values for populations at other altitudes were plotted as a fraction of the sea level value. The line in each drawing represents the reduction xpec ed in conductance if it were to he decreased in actual proportion to the decrease in Pfi at all altitude locations. Data are modified from Carey et al., 1983, and Carey, unpublished data g. 2. Relation of relative conductance of eggs to water vapor to P orr) and altitude (m) in populations of Gallus domesficus m Peru. The average Gh2o of the sea level population (Lima) was standardized as 1 0 and those of birds living at higher altitudes arc plotted as a fraction of e sea level value. The line represents the reduction expected in conduc- ance if it were to be decreased in actual proportion to the decrease in P at all altitude locations. Unpublished data were furnished by F. Leon-Velar- de* J.Whittembury , C. Carey, H.Rahn, and C. Monge breeding between sea level and 3050 and 3660 m, respectively. These rates are independent of Pß despite an increase in Dh2o at the highest locations of 31 and 36% for red-winged blackbirds and white-crowned sparrows, respectively Further, the final water content of pipped red-winged blackbird embryos were independent of PB over a 2900 m altitudinal gradient (Carey et al., 1983). The independence of rates of HgO vapor diffusion from variation in P appears to have been achieved by 3 passerine species (red-winged blackbirds, white-crowned sparrows, and American robins, Turdus migratorius) by a reduc¬ tion in Ap. This conclusion is based on measurements of eggshell conductance to water vapor (Gh2o) . eggshell thickness, fresh water content of eggs, and nest attentiveness of adults in populations of these species ranging from hear sea level to over 3000 m. Of these characteristics, the only significant iactor correlated with PB was Gg^fCarey et al., 1983; Carey, unpubl data). since Ap cannot be measured directly, Gh20 is measured by the method of Ar et ab (1974). Since Gh2o is a function of both Ap and L sind since, L does not v&ry significantly with Pß in these species, the change in Gjj2q can be attri- l8-3aK.981 849 P i g. 3. Comparison of decrease of the am¬ bient oxygen tension (Pj0 in torn) to cal¬ culated values of air cel,li 02 tensions (P^0o in torr) in eggs of red-winged black¬ birds laid at 4 locations.. Data are modi'— fled from Carey et al., ‘\9BZ buted to a reduction in Ap. A similar reduction in Gh20 ^a3 been described in eggs laid in montane locations in 3 groups of domesticated fowl (Wangensteen et al., 1 974 ; Rahn et al., 1 977 ; F.Leon-Velarde et al. .unpubl. data) • Gh20 decreases in approximate proportion to the decrease in Pß ini these three species of passerines to about 2400-2900 m, then begins to increase slightly (Pig. 1). A similar relation of Gj^O to Pß is found in eggs of chickens collected in Peru from sea level (Lima) to about 3900 m (Puno) (Pig. 2). The average Gh20 of three groups of eggs at the- highest location in Peru average &4„ 75 and 83% of the sea level value) tbwgh the P^ at that location is reduced to 62 of 760 torr (P.Leon-Velarde et al., unpubl. data'.. Fewer collecting sites have been used in two other studies on chickens, but a similar undercompensation for the decrease in P0 above 3000 m is observed (see Carey, 1930b). Chickens raised at 35jQ0 m in the Himalayas for about 40 years (Hahn, 1977) produced egg3 with an average Gh20 tïia1î 'He-3 72% Qf the average value, of eggs laid at sea level; the Pß at the montane site was 69% of the sea level value (Rahn et al., 1977). Mean Gj^O °f' ®@Sa of chickens maintained for at least 15 year® at 3800 m in California was 68% of the va¬ lue of lowland eggs; the Pg at this location was 63% of that at the collec¬ tion site near sea level (Wangensteen et al., 1974). A possible explanation for the increase in Gj^O at the higher altitudes above 2400-3000 m might be that a slight increase in Ap may provide some improvement in 02 diffusion, especially for the population p. 149-167. Creme EB.ÎUJ. , Brown H.E. - Emu, 1979, 79, p. 111-119. Fitze— Gachwind V. - :Ergebn. Anat. Entwickl.-Gesch. , 1973, 47(1), p. 7-52. Fleay D.H. - Emu, 1937, 21, P* 153-163. Prith H.J. — Ibis, 1956a, 98, p. 620-640. Frith H.J. - -CSIRO Wildl. Res., 1956b, 2. p. 79-95. Frith H.J. - CSIRO Wildl. Res., 1959, i7 P- 31-60. Frith 'H.J. The Mallee Fowl. Sydney: Angus and Robertson, 1962. Hoyt D.F*, Rahn H. - Respir. Physiol., 1980, 29, P- 255-264. Weyer 0. - Omith. Monatsber. , 1930, 2§, p. 1-5. Niee M.M. - Trans. ■Linn. Soc. N.Y., 1962, 8, p. 1-211. Faganeili ~C.V. - Amer. Zool., 1980, 20, p. 329-338. ‘Fiiper J. , Tazawa H. , Ar A., Rahn H.-rtespir. Physiol. ,1980,39. p.273-284. Seymour R.S. , Ackerman R. A. - Amer. Zool., 1980, 20, p. 437.447. ■ I°’ Heaplr“10^ '““««■ 1» Sira., Acul'. „a B,- Tazawa H. - Amer. Zool., 1980, 20, p. 395-404. iaachedijk A.H.J. - Br. Poultry Sei., 1968, 9, p. 185-196. sschedijdoA.H.J. _ Amer. Zool., 1980, 20, p. 469-476. C.M,, .Vleck D.,.Hoyt D.F. - Amer. Zool., 1980, 20, p. 405-416. eberg G.E. •— Amer. Zool., 1980, 20, p. 363-372. 863 PHYSIOLOGICAL CORRELATES OP SYNCHRONOUS HATCHING IN RHEA EGGS (RHEA AMERICANA) David Vleck, Carol M. Vleck, D.P.Hoyt Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA; Department of Biological Sciences, California State Polytechnic University, Pomona, California 91768, USA INTRODUCTION An individual bird does not lay more that one egg per day, therefore the ages of eggs within a clutch usually vary. In spite of this, in many species of precocial birds, all of the ages within a clutch hatch synchronously, i.e. , over a relatively short period of time. In most species of birds in which hatching synchrony occurs, including quail, ducks, pheasants, and grouse, incubation periods of individual eggs do not very by more than 1 or 2 days, normally less than 10% of the incubation period. Most of the synch¬ rony in these clutches is due to parental delay in beginning incubation. However, in a few species, incubation begins before the last egg is laid, and synchrony is produced by social interaction between developing embryos. One such species is the Common Rhea (Rhea americana). The male Rhea (who does all of the incubating) begins incubation within 2-3 days after the beginning of egg-laying. Groups of 2-15 females continue to deposit eggs in a male's nest for up to 12 days and then usually move on to another male. As a result, incubation age of individual eggs in a clutch may vary by 10 days, yet most of the 20-50 eggs in a clutch normally hatch within a few hours of each other (Faust, i960; Bruning, 1973a, 1974). The incubation period, defined as the number of days an egg is maintained at a high and constant temperature (35.5-37° C in the Rhea), varies from a mean of 37 days to as little as 29 days and as much as 43 days (Paust, i960; Bruning, 1974). That is, embryonic development can be completed in as little as 80% of the average incubation period or can be prolonged an extra 15% beyond the normal hatching time. The magnitude of variability in incubation • period, on both relative and absolute scales, makes the Common Rhea an ideal species for the study of the developmental consequences of synchronous hatching. ADAPTIVE VARIATION IN INCUBATION PERIOD Synchronous hatching is advantageous in precocial species because it en¬ ables the parent bird to make a rapid transition from behavior appropriate for incubation to the very different behavior appropriate for the care of mobile hatchlings. However, natural selection will favor embryos that shorten (or perhaps lengthen) their incubation period only when the bene¬ fits of so doing outweigh the costs. It is likely that for each individual there is some optimal incubation period, all other things being equal. By leaving the egg too early the underdeveloped chick risks inadequate prepa¬ ration for life as a hatchling, while delaying past the optimum time of hatching places excessive demands on energy, water, and nutrient resources within the egg that would otherwise be available for post-hatching growth and activity. Of course, for individual eggs in a clutch, all other things 864 are not equal. Fitness of individuals will also depend on other members of the clutch and on interactions with the parent bird. After their eggs begin to hatch, incubating male Rheas must choose bet¬ ween two mutually exclusive courses of action. They can continue incubating, in order to maximize the number of eggs that hatch, or they can lead the hatchlings away from the nest and ensure them early access to food under parental protection. The longer hatchlings remain at the nest, the more they deplete their energy and nutrient reserves, which can be replaced only by feeding. Natural selection should favor adults that leave the nest as soon as the probability of decreasing reproductive success due to loss of existing hatchlings exceeds the probability of increasing reproductive success by hatching more eggs. Male Rheas in the field behave in a way that is consist¬ ent with such an optimization process. Incubating males remain on the nest for only 24-36 hours after the first eggs hatch. They then lead the hatch¬ lings away from the nest, and abandon any unhatched eggs (Bruning, 1974). This adult behavi.or results in powerful selection for hatching synchrony within the clutch. Abandoned eggs cool and rarely hatch, and any that do hatch are subject to almost certain predation without the protection confer¬ red by an accompanying adult (Bruning, 1974). Consequently, adaptations re¬ sulting in the capability to accelerate hatching to permit leaving the nest with the rest of the clutch and the adult will always be favored, as long as the developmental costs of accelerating hatching are less than lethal. For the most advanced embryos, delaying hatching may be beneficial because it could permit conservation of energy and nutrient reserves. Chicks expend metabolic reserves at a rate more than twice that of full-term embryos still in the egg (Vleck, 1978) so it may be to an individual's advantage to delay hatching, rather than hatching long before the male leaves the nest. We have no data on Rheas, but Smit (1963) states that Ostrich hatchlings held longer than three days without food become weak. SOCIAL ENVIRONMENT AND SYNCHRONIZING MECHANISMS Hatching synchrony requires that embryos receive information about the developmental status of neighboring eggs and that rate of development vary with social environment of the embryo. Precisely how and when such changes in the developmental program occur are unknown although the information ex¬ change between eggs is probably via auditory communication as has been de¬ monstrated in several other species. There may be auditory input from the ihcubating adult as well (Hes3, 1972). Nevertheless, because synchrony of hatching does occur under artificial incubation in Rheas (Faust, I960; Pruning, 1974; Vleck et al., 1980), communication between eggs alone must be sufficient to produce alteration of the developmental program. Moat of the information on auditory communication between eggs and hatch¬ ing synchrony comes from the work of Margaret Vince and her associates. All of the eggs within a clutch of Bobwhite Quail (Colinus virginianus) or Co- ihrnix Quail (Coturnix cotumlx .japonica) normally hatch within a few hours. Thi3 synchrony is maintained even when some eggs in the clutch have been in¬ cubated for 24 hours more or less than the others (Vince, 1964a, b, 1968a). Etching time can be accelerated, and total incubation period reduced, if l9-3ai<. 981 865 younger egge are placed in contact with older ones (Vince, 1964a, b, 1973a; Vince, Chinn, 1971). It is also possible to retard hatching and increase in¬ cubation period by surrounding older quail eggs with younger ones (Vince, 1968a; Vince, Cheng, 1970; Freeman, Vince, 1974), but in general it is easier to accelerate hatching than to retard it. Ducks, geese, and chickens do not synchronize hatching as precisely as quail, but the spread of hatching times is less in eggs incubated together than in eggs incubated in isolation (B’jarvall, 1967; McCoshen, Thompson, 1968a) and hatching can be accelerated by external acoustic stimulation in these species also (Vince, 1973a; Vince et al. , 1970) . Embryos of quail, chickens, and ducks produce sounds within the egg sur¬ prisingly early in incubation, and several of these sounds are known to in¬ fluence hatching times of adjacent eggs (Orcutt, 1974). The first sounds pro¬ duced are low-frequency, low-intensity sounds produced by the irregular move¬ ments of the developing embryos (Vince, Salter, 1967). Vince (1973b) played tape recordings of such low-frequency sounds to isolated Bobwhite eggs and demonstrated delayed hatching and prolonged incubation. Near the end of in¬ cubation, pulmonary respiration begins, producing low frequency pulses at a regular rate. Artificial sounds with the same pulse rate delay hatching in Bobwhite, but do not affect Cotumix (Vince, 1968b, 1973b). Sometime after pulmonary respiration begins, embryos of all species studied so far begin to produce intermittent high-amplitude clicking sounds (Driver, 1965; Vince, 1966a; McCoshen, Thompson, 1968b). These clicks are also produced by pulmo¬ nary respiration, but differ in both frequency and amplitude from the pulmo¬ nary sounds mentioned above. Loud artificial clicks over a wide range of pulse rates accelerate hatching in quail and chickens (Vince, 1966b, 1968b; Vince et al., 1970, 1971; Woolf et al., 1976), and the respiratory clicks presumably function in the same way. After initiation of pulmonary respirat¬ ion, embryos begin to vocalize (Collias, 1952; Gottlieb, Vandenbergh, 1968; Hess, 1972; Beaver, 1978) but as yet there is no quantitative evidence that vocalizations are important in hatching synchrony. It is likely that acoustic stimuli similar to those described in other precocial birds are responsible for hatching synchrony and consequent variat¬ ion in incubation period in Rheas. Bruning (1973a, b; 1974) found that Comma11 Rhea incubation could be shortened to as little as 29 days if young eggs were placed with older eggs for the two weeks before hatching. Rhea embryos pro¬ duce audible clicks several days before hatching (Vleck, unpubl. observation' and begin to vocalize after penetration of the air cell (Bruning, 1974). Bea¬ ver (1978) described a "contact-whistle" vocalization in Rhea hatchlings and stated the same 30und is produced by embryos in the air cell before hatching* Social contact between embryos is apparently very important in stimulat¬ ing hatching in Rheas. Hatchability of eggs incubated in isolation is very low (Vleck, unpubl. observation). Bruning (19745 reported that only 25$ of isolated eggs hatched whereas 85$ of eggs incubated in groups hatched. Iso¬ lated eggs that did hatch did so only after 41 days of incubation, rather than the 36-37 days typical of eggs incubated in groups. 866 METABOLISM AND GROWTH OP EMBRYOS In Rheas, hatching synchrony is produced by variations in incubation pe¬ riod between eggs within a clutch* Consequently, the developmental program must vary between individuals. In order to study embryqnic development, ideally one should investigate the physiological and anatomical progress of the embryo directly. However, 'because we had access to a limited number of Rhea eggs, a direct study of embryo growth was not feasible. Instead, we measured rate of oxygen consumption using techniques described in D.Vleck et al. (1980) as an index of embryo growth and development. Such measurement of metabolic rate is a noninvasive technique with which growth and develop¬ ment can be monitored continuously throughout ontogeny in a single egg. Energy expenditure (metabolism) in a developing embryo is devoted prima¬ rily to two processes: biosynthesis of new tissue, or growth, and maintenance of existing tissue. The metabolic rate of a growing embryo is the sum of the energy costs of growth, which increase with absolute growth rate; and the energy costs of maintenance, which increase with embryo mass. We previously described the relationship between metabolic rate, absolute growth rate, and embryo mass in a number of bird species and showed that ontogeny of metabo¬ lism varies with growth pattern in avian eggs (C.Vleck et al., 1980). In altricial species both metabolic rate and growth rates of embryos increase continuously and at an accelerating rate throughout incubation. In precocial species embroys initially grow at a increasing rate, but reach hatchling mass as early as 80% of the way through incubation and growth rate then de¬ clines. Metabolic rates of embryos of precocial species increase rapidly until about 80% through incubation and then increase slowly, remain constant, or even decline as the metabolic expenditure devoted to growth declines. In the Common Rhea, rate of oxygen consumption increases exponentially through the first 25 days of incubation, with little variability between 6gSs the same age. Metabolic rate reaches a maximum after about 29 days of incubation, then usually declines to about 70% of the maximum value and remains low until just before hatching (Figure 1). Metabolic rate increases when the embryo penetrates the air cell and increases again after pipping. The ontogeny of metabolism in Rhea embryos is consistent with the follow- growth pattern (Figure 2). Growth rate increases continuously, perhaps exponentially, over the first 70% of incubation. Growth rate and therefore metabolic expenditure for growth then decline rapidly, resulting in the decline in total metabolic rate. We suggest that tissue growth of the Rhea embiy0 j-g neariy 00mpiete at the time of the pga^ in metabolic rate, and Qt the remainder of incubation is used for metabolically inexpensive pro- G°Ses like maturation of neural and sensory functions. One Rhea embryo that ed after 31 days of incubation appeared fully developed and was the same ®ize as hatchlings. In Emus (Dromaius novae-hollandiae) and Ostriches (Stru- 7 — 2— camelus) that have similar ontogenies of metabolism to that of the ^ea (Hoyt et al., 1978; D.Vleck et al., 1980) embryos that died about 80% Ihe way through incubation (at the time we suggest growth is complete) ^So appeared fully developed externally and had yolk-free body masses equal 0 those of successful hatchlings (Vleck, 1978). 867 Pig. 1. Rates of oxygen consumption during development of seven Common Rhea eggs incubated together. Six eggs were the same age (dashed lines) and one egg was four days younger (solid line). Time of hatching i3 in¬ dicated by a star ( Redrawn from D.Vleck et al., 1 98Q> The period after completion of tissue growth, between the peak in metabo¬ lic rate and hatching, appears to be the period that can be shortened or lengthened to permit hatching synchrony in Rheas. This suggestion is sup¬ ported by two observations. First, the shortest reported incubation period for Common Rhea eggs is 29 days (Bruning, 1974), coinciding with the peak of metabolism, that time at which we suggest growth is nearly complete. Second, the pattern of metabolism of eggs that are stimulated to hatch early does not differ from the "normal" pattern described above until near the time of the peak in metabolic rate. We accelerated hatching in some Rhea eggs by placing young eggs in an in¬ cubator in contact with a group of four to six older eggs. When one Rhea egg was placed v/ith six other eggs that were four uays oluer, the youngui -GG bad a peak metabolic rate about four days later than the older eggs, but its me¬ tabolic rate did not then decline 3ignil’ leant ly (Figure 1). The rate of oxygen consumption in this egg increased at the same time that the older eggs showed the typical pre-pipping increases in metabolism, although it did not pip un¬ til 24 hours later. Five of the other six eggs hatched essentially synchro¬ nously during a 9.4 hr interval, and the sixth egg hatched the following day* Ontogeny of metabolism of the accelerated egg paralleled that of the older eggs until the time of peak metabolism. It hatched 6 days post-peak while the six older eggs hatched 10 days poat-peak. We suggest that the absence of a decline in metabolic rate in the younger egg resulted from a relatively higher growth rate during the last few days of incubation, just as one would expect in an embryo trying to "catch up" with its nestmates. 868 I 1 S* 3‘ Rate of consumption as a function of calander date for six ommon Rhea embryos incubated together. Pour eggs were the same age (dashed Des) and two eggs (labeled A and B, solid lines) were younger. Stars in¬ dicate time of hatching t In another experiment four Rhea eggs of the same age were incubated with w° younger eggs of unknown age. When metabolic rate of each egg is plotted aa a function of calendar date (Pigure 3) it is clear that during the early Part of incubation the two younger eggs (A and B) had lower metabolic rates ^ an the older eggs measured on the same day, presumably because the younger embryos were smaller. Three of the older eggs hatched within four hours of ®ach other on June 25 and younger egg A hatched during this time as well. next day the remaining older egg hatched and the embryo in egg B was cad. When we opened egg B, the embryo appeared fully developed and had °mple tely withdrawn the yolk sac into the abdominal cavity. This embryo had Probably attempted to begin the hatching process the previous day as indica- by a large increase in lt3 metabolic rate on June 25 (Pigure 3). We can estimate the actual number of days that Rhea eggs have been in- ubated from the metabolic measurement made in the first two-thirds of in- Ubntion. TM3 is because within a species there is little variability in w, abollc rates of eggs of the same incubation age during early development, embryo sizes and growth rates are independent of egg size. By super- 869 Oxygen consumption {c/n !/h) /. P f i g. 4. Rate of oxygen con¬ sumption as a function of number of days incubated for six Common Rhea embryos. See Figure 3 for symbols. Egg B died after 31 days of incubation 0 imposing the early data from eggs A and B over that of the eggs of known age (Figure 4) we can estimate that egg A was two days younger in incubation age than the others and egg B was seven days younger. Yet they hatched or attemp¬ ted to hatch synchronously with the older eggs’. That is, whereas the four older eggs hatched after 37 days of incubation, egg A hatched after 35 days, and egg B attempted to hatch after 31 days of Incubation. After day 26 of incubation, the accelerated eggs hat higher rates of oxygen consumption, and therefore presumably higher growth rates, than most unaccelerated eggs in¬ cubated for the same amount of time (Figure 4). Presence of older eggs appa¬ rently stimulates growth of younger embryos, making early hatching possible. CONSEQUENCES OF VARIATION IN INCUBATION PERIOD To hatch successfully, avian embryos must attain a minimum level of phy¬ siological, morphological, and behavioral competence. When incubation period varies within a species, some embryos have less time to develop this minimum competence than others. The adaptive benefits of synchronous hatching are clear but the nature of any costs that are consequent to attaining hatching synchrony by altering the time spent in embryonic development remains an open question. Quail embryos whose hatching time is advanced by acoustic stimulation are not smaller than those with normal incubation periods (Vince, 1969; Grieve et al., 1973). This i3 not surprising because tissue growth rate of a preco- cial embryo is low during the last few days of incubation (Romanoff, 1967; Vleck et al., 1980) and because any nutrients not converted to embryonic tissue are retained by the hatchling as yolk. There are some suggestions, but almost no quantitative evidence, that early or late hatching chicks are less fit than chicks that hatch at the 'optimal' time. One of our Rhea em¬ bryos that apparently attempted to hatch after only 31 days of incubation subsequently died in the shell. In quail, eggs whose hatching time is acce¬ lerated or retarded produce weaker chicks with lower viability than eggs 870 that hatch after the normal incubation time (Vince, 1969; Vince, Chinn, 1971; Grieve et al., 1973). Latê Rhea hatchlings often have developmental abnor¬ malities (Bruning, 1973b). A curled toe syndrome in late hatching quail may result from prolonged containment within the shell after growth is complete (Vince, 1969). Coturnix that hatch early are often weaker, begin to stand later after hatching, and have slightly higher incidence of abnormal posture than those hatching after the normal incubation- period (Vince, Chinn, 1971). Vince ( 1973c) proposed that the clicking sound associated with pulmonary ventilation may act like a cough and function in clearing fluid from respi¬ ratory passages. Chicks that hatch early, after 'clicking' for relatively short periods, may be less efficient in ventilation and therefore weaker. Because the absolute amount of time by which the incubation period in the Rhea can be altered is so large, further study of this species v/ill provide an opportunity to examine the ecological consequences of synchronous hatching la there an optimum incubation period and do embryos that hatch sooner or later than this optimum pay a price for synchronizing hatching? We need to know more about the morphological, physiological, and behavioral consequen¬ ces to the hatchling of variation in incubation period. This will provide insight into the adaptive trade-offs involved in the evolution of synchronous hatching. SUMMARY The male Common Rhea begins incubation of eggs before the clutch is comp- lete, yet all the eggs normally hatch within a few hours of each other. Syn¬ chronous hatching is advantageous because it allows the male to switch imme¬ diately from incubation of eggs to care of mobile hatchlings. However, syn¬ chronous hatching requires that the last-laid eggs must accelerate develop¬ ment and hatching to perait leaving the nest with the rest of the clutch, incubation periods of individual eggs can vary from the mean of 37 days to &a little as 29 days or as many as 42 days. The mechanism allowing synchro- hization of hatching is probably auditoiy communication between embryos dur- ^■hg the last part of incubation. We studied the process by which embryos syn¬ chronize hatching by monitoring metabolic rate of eggs through development, ih egga with an incubation period of 37-39 days, metabolic rate, as measured by oxygen consumption, increases exponentially during the first 70% of in- '-ubation, reaches a maximum on day 29, then declines until shortly before ching. Qnbxyonic tissue growth is essentially complete on day 29, and the Une in metabolic rate appears to be due to a decline in growth rate. ever> this period of decline can be shortened or eliminated to allow syn- ^chy of hatching. The pre-hatching decline in metabolic rate is absent in eSSs that are incubated with older eggs and consequently hatch after a short- ^■^hbation period. The relatively high metabolic rate in these eggs at 8 time is presumably due to the cost of accelerated development. The mor- ogical, physiological, and behavioral consequences to the hatchings of ation in incubation period requires further investigation. acknowledgments 0j, ^ank the Phoenix Zoo, Los Angeles Zoo, and Anne Austin for the loan Common Rhea eggs. 871 References Beaver P.W. - Auk, 1978, 95, p. 382-388. B’Jarvall A. - Behav. , 1967, ^28, p. 141-148. Brüning D.F. - Nat. Hist., 1973a, 82, P« 68-75. Bruning D.P. - Intern. Zoo. Yearbook, 1973b, Jj}» P> 163-171. Bruning D.P. - Living Bird, 1974, 1 3. p. 251-294. Collins N.B. - Auk, 1952, 6£, p. 127-159. Driver P.M. - Nature, 1965, 206. p. 315. Paust R. Verhandl. Deutsch. Zool. Gesellsch. , i960, ^42, p. 398-401. Freeman B.M. , Vince M.A. - Development of the Avian Embryo. New York: Wiley, 1974. Gottlieb G. , Vandenbergh J.G. - J. Exp. Zool., 1968, 168, p. 307-326. Grieve B.J. , Wachob R. , Pelts A., VanTienhoven A. - Poult. Soi., 1973, 52, p. 1445-1450. Hess E.H. - Sei. Am., 1972, 227, p. 24-31. Hoyt D.P. , Vleck D. , Vleck C.M. - Condor, 1978, 80, p. 265-271. McCoshen J.A. , Thompson R.P. - Can. J. Zool., 1968a, 48, p. 243-248. McCoshen J.A. , Thompson R.P. - Can. J. Zool., 1968b, 46, p. 169-172. Orcutt A.B. - Behav., 1974, 50, p. 173-184. Romanoff A.L. Biochemistry of the Avian Embryo. N.Y.: Wiley, 1967. Smit D.J.v. Z. Ostrich farming in the little Karoo. - In: Bull. N 358 Department of Agricultural Technical Services. Pretoria, 1963. Vince M.A. - Anim. Behav., 1964a, V2, p. 531-534. Vince M.A. - Nature, 1964b, 203, p. 1192-1193« Vince M.A. - Anim. Behav., 1966a, J_4, p. 34-40. Vince M.A. - Anim. Behav., 1966b, J_4, p. 389-394. Vince M.A. - Anim. Behav., 1968a, J_6, p. 332-335. Vince M.A. - Brit. Poult. Sei., 1968b, 9, p. 87-91. Vince M.A. - In: Bird Vocalization / Ed. by R.A.Hinde. Cambridge: Cambridge Univ. Press, 1969, p. 233-260. Vince M.A. - Brit. Poult. Sei., 1973a, 14, p. 389-401. Vince M.A. - In: Behavioral Enbryology / Ed. by G. Gottlieb. N.Y.: Acad. Press, 1973b, p. 285-323. Vince M.A. - Comp. Biochem. Physiol., 1973c, 44A. p. 341-354. Vince M.A., Cheng R.C.H. - Anim. Behav., 1970, _1Q, p. 210-214. Vince M.A. , Chinn S. - Anim. Behav., 1971, 22» p. 62-66. Vince M.A. , Green J. , Chinn S. - Brit. Poult. Sei., 1970, _1_1* P* 483-488. Vince M.A. , Green J., Chinn S. - Comp. Biochem. Physiol., 1971, 39A, p. 769-783. Vince M.A. , Salter S.H.A. - Nature, 1967, 2J_6, p. 582-583. Vleck C.M. , Vleck D. , Hoyt D.P. - Am. Zool., 1980, 20, p. 405-416. Vleck D. The energetics of activity and growth. Ph. D. Thesis, Univ. of California, Los Angeles, 1978. Vleck D. , Vleck C.M. , Koyt D.P. - Physiol. Zool., 1980, 5^> P* 125-135. Woolf N. K. , Bixby J.L. , Capranica R.R. - Sei., 1976, J_94, p’. 959-960. 872 HETEROGENEITY OP EGGS AND HETEROCHRONY OP AVIAN EMBRYOS DEVELOPMENT UNDER INCUBATION IN NATURE A.M. Bolotnikov Department of Zoology, Perm State Pedagogical Institute, Perm, USSR EGG HETEROGENEITY IN A SINGLE CLUTCH An ever increasing attention is being paid in poultry raising to the bio¬ logical properties of the eggs of domestic birds. Eggs selected for incubat¬ ion are estimated by their mass, form, vitamin content of and other indices. The survival of embryos and nestlings of domestic birds was shown to depend on the incubation (biological) properties of eggs, Thus, in a few ornithological studies the attention was drawn to the relationship of some egg parameters, mainly egg mass in the clutch, with the hatchability of nestlings (Parsons, 1970, 1971; Syroechkovsky , 1975, etc.), studies of morphological, biochemical, biophysical parameters of egg clutches in avian species from different orders (Bolotnikov et al., 1977, 1978, 1980) Till in, to a considerable extent, the gap in this problem. Egg morphology. Among of morphological parameters, the volume and mass of the egg and its contains were under study. It was established that the mean velues of these indices show a tendency to decrease from the first egg in the J a b 1 e 1. Morphological Characteristics of Eggs with Reference to the ■Sequence of Their Laying Feature Sequence of Egg Laying n First Last x+m C% x+m cçg Larus canus Volume 10"6 m3 76 54.80+0.50 8.1 53.33+0.67 8.8 Mass io~3 kg 13 egg 58.02+0.92 5.8 56.64+1.28 8.2 yolk 13.42+0.36 9.6 12.78+0.33 9.2 albumen 40. 98+0. 67 5.9 40.35+1.08 9.8 shell 3.60+0. 08 7.8 3.48+0.07 6.8 Corvus frugilegus Volume m3 m 40 15.66+0.27 10.6 14. 23+0.26 11.5 Mass io~3 kg 10 egg 16.41+0.56 11.0 14.85+0.72 15.0 yolk 1.93+0.078 13.0 1 . 89+0. 07 12.0 albumen 13.53+0.55 13.0 12.08+0.067 18.0 shell 0. 98+0. 03 10.0 0.89+0.029 10.0 Columba livia ^°lume i o~8 m3 36 16.42+0.22 8.0 16.24+0.23 8.3 Mass io-3 kg 9 egg 17.03+0.49 9.0 1 6. 40+0. 49 9.0 yolk 2.72+0.099 11.0 2.54+0.096 11.0 albumen 13.14+0.413 9.0 12.78+0.406 10.0 shell 1.16+0.04 11.0 1 . 07+0. 03 9.0 873 clutch to the last one (Table 1). But this pattern is not absolute. E.g , a- decrease in the egg volume, mass and components from the first eggs to tie last ones was observed in Larus canus in 68%, in Columba livia in 70% and in Corvus f-ugilegus in 85%. The mass of yolk in the first eggs was greater than in the last ones in 60% of nests in the common gull, 88% in the rock dove and 70% in the rook . The quantitative estimate of calcium carbonate content in the egg shell was carried out with consideration to the place of egg in the egg laying cycle. The variations of these values (Table 2) do not allow us to draw de¬ Table 2. Calcium Carbonate Content in the Egg Shell, % Species n Sequence of Egg Laying First X+ITl Last X4_m Larus canus 15 82.3+1.1 82.0+1.0 Columba livia 31 86.2+0.4 87.7+0.4 Corvus frugilegus 25 76.3+1.8 65.4+2.1 Passer montanus 10 68.7+1.9 69.8+3.5 Turdus pilaris 15 78.1+1.4 75. 1+2.2 finite conclusions, except for the rook, on egg heterogeneity within the clutch by this parameter. Interspecific differences were also herdly expres¬ sed at all. One can only suggest that in birds with a relatively short period of embryogenesis the degree of shell mineralization is lowered and rarely ex¬ ceeds 80%. Concentration of hydrogenic ions (pH). In the eggs of avian species pH is interest both for their characteristic and possible estimation of their hete¬ rogeneity. Eggs of the common gull and of the rock dove were studied in this respect. In the former, the eggs of three groups of clutches were studied in which the first eggs appeared, respectively, on May 8, 11 and 16. A tendency was found to changes in pH of yolk and albumen in the eggs of the same clutch (Table 3). In most of the clutches, pH in the first eggs was somewhat lower Table 3. The Dependence of pH of Egg Components in Larus conus on the Time of Clutch Formation (n = 12 for every day) Time of Appearance of Clutches Egg Component First Eggs x+m Third Eggs x+m t-crit ria ? CD Yolk 6.18+0.09 6.47+0.09 2.4 May 11 6.30+0.04 6.49+0.06 2.7 May 16 6.03+0.14 6.27+0.12 1.3 May 8 Liquid Albumen 8.37+0.04 9.76^0.06 6.0 May 1 1 8.47+0.06 8.73+0. 10 2.5 May 16 8.66+0.04 8.70+0. 10 0.4 May 8 Dense Albumen 8.55+0.07 8.71+0. 08 1.5 May 1 1 8.45+0.06 8.84+0.08 3.9 May 1 6 8.47+0.04 8.72+0.09 2.6 than in the third (at t = 2) . ho distinct differences were found with res¬ pect to the time of laying and sequence of eggs. In the rock dove the reproductive period lasts from February till Septem¬ ber and can involve, in town, five cycles of breeding. pH differed in the eggs of different cycles (Table 4). Indices of volk and albuneD. The index of albumen is, to a certain ex¬ tent, a criterion of hatchability of nestlings. As noted by B. A. Sergeyev and Table 4. pH of Yolk and Albumen in the Eggs of Columba llvla During Different Cycles of the Reproductive Feriod (n = 15 for every month) Time of Formation Egg Component Pirst Eggs x+m Second Eggs x+m t-criterion February Yolk 5.93+0.05 5.89+0.05 0.6 Albumen liquid 9.00+0.02 8.30+0.04 15.5 Dense 8.72+0.07 8. 41+0. 12 2.2 April Yolk 5.50+0.02 5.80+0. 1 4 2.1 Albumen liquid 8.42+0.02 8.52+0.03 2.5 Dense 8.60+0.05 8.50+0.07 1.1 June Yolk 5.50+0.02 5. 80+0. 1 4 2.1 Albumen liquid ■8.42+0.02 8.52+0.03 2.5 Dense 8. 39+0. 05 8.42+0.05 1.4 D.Sergeyeva (1964), the increased amount of albumen is correlated with a mar¬ ked increase of its index and, as a rule, eggs with a higher albumen index have also a higher yolk index. The decrease of albumen index indicates the in¬ crease of water content in the egg albumen. These indices were determined in three unrelated avian species (Table 5). 'Vater content in the albumen in the common gull is 4 times that in the “folk judging by the ratio of indices but the heterogeneity of eggs according *0 these indices wa3 not found. In the rock dove the heterogeneity of eggs is distinctly expressed in the lower values of yolk and albumen indices of 'the last eggs as compared with the first ones. A comparison of yolk indices the rook eggs has 3hown different (by sequence) eggs. Relatively high Yolk indices, as compared with two former species, appear to be due to a Wronger yolk membrane. Carotinoid and vitamin A content. The biological value of eggs directly spends on the vitamin A and carotinoid content in the yolk (Eremeyev, 1957, 6 c*'. Vitamin A has a wide range of action. Carotinoids provide for the ‘ a b 1 e 5. The Values of Yolk and Albumen Indices with Respect to the ij^quence of Eggs in the Clutch sPecies e>Q X/t - oxui/oa First Eggs Last Eggs - - - - - „ - □ Yolk Albumen Yolk Albumen Larus canus 37 0.383+0.003 0.090+0.001 0.385+0,005 0.090+0.002 c°lumba liv la. 31 0.379+0.002 0.054+0.002 0.368+0.004 0.048+0.001 °°‘*us frugilegus 20 0.457+0.008 - 0.427 h0. 008 875 Table 6. Carotinoids and Vitamin A Content in the Egg Yolk in Corvus frugilegus (ug/g) Index Sequence of the Egg x+m- Lim Total Carotinoids 1 11.24+0.62 7.97+14.97 4 6.25+0.53 •3.51+9.99 Vitamin A 1 10.80+0.29 9.73+12.28 4 4. 26+0.32 3.00+5.83 adaptive character of responses of the organism to life conditions and in¬ crease the general level of its viability. Eggs of the same clutch were shown to be heterogenous by these parameters as well (Table 6). The differences in vitamin A and carotinoid content between the first and fourth eggs in the clutch are statistically reliable (p = 0.0001). These indices proved to be the most variable in the last eggs as compared with the first ones. Low carotinoid and vitamin A content in the last eggs of the clutch appears to be one of the causes of increased embryonic mortality in the rook. Egg strength. The strength of eggs equals, according to approximated data, 1063 km/m3 in the common gull, 1055 km/m3 in the rook, and 1040 km/m-3 in the sand martin. The strength of eggs in the same clutch varied and, hence, this index can be used to characterize the heterogeneity of eggs (Table 7). Heterogeneity of eggs and survival of birds. A high degree of mortality of the embryos and nestlings is observed in birds, ca. 40% (Malchevsky, 1959). The rook is also characterized by a high mortality rate during the nest period: 15-2055 in embryos and 30-35% in nestlings (Bolotnikov et al., 1973). In this species mortality rate early ontogenesis is related to egg heterogeneity in the clutch. Such a dependence is also found in the common gull and sand martin. H.g. , the clutches in the centre of the common gull colony are characterized by a greater egg volume as compared with its pe¬ riphery (57.0 x 10'6 in vs. 54.7 x 10”^ nr3). The survival of nestlings varied as well. In the colony centres 97% of nestlings survived till the moment of flight from the first eggs, 88)5 from the second eggs and 68% from the third eggs. And the level of mortality was distinctly higher in the colony periphery where the survival rate equalled 78 % for the first and second eggs and only 50% for the third ones. In the sand martin nestlings the mortality from the small eggs exceeded the large ones by 3.5 times (Bolotnikov, Marks, 1980). Table 7. The Strength of the Eggs from the Main and Resumed Clutches in Sequence of Egg Laying n Main x+m Clutches C% Egg Strength kg/m3 x+m Resumed Clutches C% 1 23 1053 0. 6 24 1057 1.8 2 21 1051 0.7 13 1057 1.1 3 18 1047 0.08 10 1056 1.3 4 16 1047 0.04 7 1062 1.1 5 6 1047 0.3 4 1065 0.5 8/6 Eggs of the same clutch are thus heterogenous due to a complex of morpho¬ logical, biochemical and biophysical parameters. One can suggest that the heterogeneity eggs provides for phenotypical heterogeneity of embryos and nestlings and is, probably, involved in the regulation of the population density. HETEROCHRONIES OF EMBRYONIC DEVELOPMENT IN EGGS OF THE SAME CLUTCH Birds are usually divided into three groups by the initial phase of in¬ cubation: 1) incubating after egg laying completion ( Anserif ormes. Galli- formes) ; 2) incubating beginning with the first egg (Strigiforme3. Falconi- formes) . and 3) incubating from the middle of egg laying (Piciformes. some Passeriformes) . It was believed that eggs for which the onset of incubation coincided with the completion of egg laying could be in the state of diapause 20 to 30 days. A study of incubation and embryogenesis undertaken in our laboratory al¬ lowed us to propose another explanation for the initial stage of incubation and made us doubt the presence in the eggs (more precisely, in the embryos) of a long-term diapause (Bolotnikov et al., 1968, 1969, 1970, etc.). On clutches of several dozens of birds (Anseriformes, Passeriformes, etc.) it was convincingly proved that incubation proceeded from the first laid egg. In some birds this process proceeds continuously, e.g. in Strigif ormes. Fal- Çoni formes, in others it is interrupted (Galliformes. Anseriformes) . and, fi- hally, in the third group the interrupted incubation at the beginning of egg laying is combined with a relatively incubation towards its completion. Analysis of total preparations of the early avian embryos revealed a com- m°n pattern: in the same clutch they were at different stages of growth and development. It may be illustrated by characteristics of total preparations °1 eight Anas crecca embryos (Table 8).It follows from Table 8 that there 1 a b 1 e 8. Morphological Characteristics of Embryos in Anas crecca Age ~ - a) from the moment of egg laying, days h) by the degree of 8 7 6 5 4 3 2 1 development, hours 64-68 58-62 57-60 55-58 54-57 50-54 36-40 20-30 St*ge of Development Segmentation of Mesoderm 18” 17 17” 16+ 16+ 15+ 12 10+ (pairs of somites) 32 29 28 27 27 25 16 11 a) covered by amnion b) not covered by 28 23 21 18 17 15 4 0 amnion ^Sle Between Fore- and 4 6 7 9 .10 10 12 11 Hind Brain 45° 45° 45° 52° 54° 90° 120° - ^hgth of embryo 9.0 8.3 7.5 7.2 7.7 6.7 6.3 5.8 ®Aze of Yolk Sac Vascular Viel 1 976) . Two modes of cannibalism can be distinguished: 1) neighbor ^apnibalism, where chicks are killed and often eaten when they wander onto a ^eighboring territory, and 2) specialist or intruder cannibalism, where cer- 121 individuals specialize on capturing young conspecifics for food. In ain other species, e.g., Common Terns, one may find chick-killing by ghbors, without actual consumption or cannibalism, tb Lesser Black-Jacked Gulls (Larus fuscus) Davis and Dunn (1976) reported egg predation "usually involved a straightforward aggressive encounter 885 between two neighboring birds". Davis and Dunn (1976) and Hand (1981) noted that gulls that have lost their eggs or young are more likely to become can¬ nibals, while Kirkmao (1937) believed that cannibalism of Black-headed Gulls was attributable to "unmated rogues". Hand et al. (1981) reported that a linear arrangement of nesting territo¬ ries of the Western Gull (L. occidentalis) allowed birds to reach the inter¬ tidal zone, yet return quickly to their nest if there was a threat of can¬ nibalism. They invoke this threat as an important factor influencing the shape of gull nesting aggregations. Thus it can be seen that the threat of cannibalism represents a substan¬ tial cost of coloniality in gulls, especially if cannibalism arises among recent victims producing a chain-reaction resulting in an increasing propor¬ tion of potential cannibals in an afflicted colony. PREDATION SELECTION FOR COLONIAL BREEDING A group of birds is more obvious to a potential predator than is a single individual, but although all colonial species face the potential of predation both at and away from. the colony, many have chosen nesting habitats which offer essentially complete protection during the breeding season. In addition to the formation of passive aggregations in favorable habitats, there are di¬ rect benefits to nesting in colonies. A large aggregation of birds may prove more confusing to a predator (see Hamilton, 1971). Similarly the role of huge schools of fish may relate to predator confusion (Milinski, 1977). In addition, in a large assemblage, the chance of detecting a predator early is enhanced and is spread over numerous individuals, thus allowing each individual more time to devote to feeding, maintenance behavior or pa¬ rental care. Although the recognition that a flock of birds could more easily detect a predator probably occurred in antiquity, it appears to be Lack (1954) who recognized the adaptive significance of this fact for the indivi¬ dual within the flock. Several experimental studies (Powell, 1974; Siegfried, Underhill, 1975) showed that birds in flocks respond earlier to predators than do solitary birds; up to a point response time decreased with increas¬ ing flock size. The implications for birds in colonies are that birds feed¬ ing young can rely on neighbors to signal the approach of a predator while a group of birds can detect an approaching predator at a greater distance and fly out to meet it, thus increasing the possibility of deflecting it from the colony. These implications, however, remain as hypotheses to be de¬ monstrated for most kinds of colonial birds. Mobbing and other anti-predator behavior One important benefit of coloniality is the opportunity for collective anti-predator aggression or mobbing. This has been particularly well documen¬ ted for various species of terns (Lemmetyinen, 1971) and for gulls (Kruuk, 1964). It operates also for passerine birds (e.g. , for thrushes, Wiklund, Andersson, 1 980 ; for Caciques, Peekes, 1981; and for swallows, Hoogland, Sherman, 1976). Mobbing and recognition of predators Confronted by a predator near its nest or young, adults of many species, both colonial and solitary, engage in threat or attack behavior aimed at 886 thwarting the predator and driving it away. Such behavior, often accompanied by loud and characteristic vocalizations attracts other birds, both conspeci- fics and heterospecifics, such that the attack becomes social. Such social anti-predator aggression is widely known as mobbing. In its own right mobbing behavior has been an important subject for etho¬ logists because it is a high intensity, target-oriented behavior that can be predictably released (Curio, 1978). It is now documented that the target species does not mob indiscriminately, but recognizes potential predators and most of the experimental evidence is derived from species other than co¬ lony-nesting birds, even through they provide some of the most dramatic ex¬ amples of mobbing. Hirsch and Bolles (1980) showed that laboratory-bom Deer Mioe geromyscua manlculatus could distinguish between non-predators and pre¬ dators from their own habitat, but not from predators that did not occur in their habitat. Curio (1978) has labelled this cultural transmission. Common Terns react less frequently to crows or gulls that fly over a co¬ lony in swift straight flight, than in slower flight or more indirect pat¬ tern (Burger and Gochfeld unpublished). Similarly, we found experimentally that incubating Herring and Great Black-backed Gulls responded less to our approach if it were tangential rather than directly toward the nest (Burger, Gochfeld, 1981). The effectiveness of mobbing has been mentioned in numerous anecdotes and a few detailed studies. Goransson et al. (1975) showed experimentally that large aggressive shorebirds reduced crow and gull predation on eggs set out in artificial nests. The efficacy of mobbing in protecting birds nesting in colonies has been shown for terns (Lemmejyinen, 1971), gulls (Kruuk, 1964), and swallows (Hoogland, Sherman, 1976). Burger (1981b) provides a detailed review of mobbing. Costa of Mobbing Time spent mobbing a predator detracts from incubation and parental care, and may expose vulnerable young to adverse weather conditions or to predat¬ ion. Emlen et al. (1966) give an example of such predator-induced aggressive Parental neglect. Individuals with a high response level may spend excess time fobbing and thus show reduced reproductive success. To my knowledge, this ap¬ parent relationship remains to be tested in the field. Mobbing also brings a bird close to a predator, increasing its own chance of beinS eaten (Myers, 1978). Peregrines can catch Common Terns out of a mob- bing flock (Burger, unpublished observation); with practice a human can catch a mobbing Common Tern by hand, and it is likely that carnivores could accomp¬ lish this as well. This may explain why Common Terns hover over, but do not actively mob, intruding canines (Gochfeld, unpublished observation). Similar¬ ly. Patton surd Southern (1978) .found that gulls did not effectively mob foxes. Spacing and Predation Pew studies have investigated density find anti-predator behavior. Birkhead ^977) found that Common Cuillemots (Uria aalge) in dense aggregations -success- fully repelled gulls; nests in sparse areas were vulnerable. Buckley and Ackley (1977) and Siegfried (1977) implicate high density nesting as a means of reducing predation on terns and penguins. Siegel-Causey and Hunt 88? (1981) showed lower predation on densely nesting cormorants. Density per se may be of great importance as a mechanism by which coloniality reduces rela¬ tive predation rates (Gochfeld, 1980). SYNCHRONY, COLONIALITY AND PREDATION P. P. Darling' s classic (1938) but often argued account of how gulls in co¬ lonies reduced their exposure to predation by nesting synchronously called attention to an area of both theoretical and practical interest. Elsewhere I have discussed the substance and merit of the Darling Effect in detail (Gochfeld, 1980), and here it is sufficient to mention that although several workers (e.g. , MacRoberts, MacRoberts, 1972) found no evidence for the Dar¬ ling Effect, other workers have found supportive evidence not only in birds (Nisbet, 1 975 ; Williams, 1975; Birkhead, 1977; Burger, 1979b), but in fish (Dominey, 1981), and in the mast-fruiting of plants (Janzen, 1971). CONCLUSIONS Coloniality may reduce predation passively or actively and directly or indirectly as follows: PASSIVE ACTIVE Indirect Many birds in safe place Direct Predator confusion Predator detection Dilution (safety in numbers) Mobbing I have mentioned the variety of factors which influence predation. We can guess at the following quantitative relationships (see Pig. 1). Synchrony of egg-laying will have a curvilinear relation to group size. Predation is in¬ fluenced by synchrony in different ways depending on whether predators are recruited. Group size may influence predation independent of synchrony. Struc¬ ture of a colony, its shape aod density, influence predation, as does the central or peripheral position of a nest. Mobbing behavior, itself influenced by size, density, and species composition, can be a powerful deterrent to some predators. The challenge is to put these together into a single model. It is a chal¬ lenge because the relationships between any two variables varies among spe¬ cies, among colonies of a single species, and even for a single colony from year to year. It is also a challenge because the interactions among variables such as colony size, density, age structure, mobbing, food availability, not to mention predator populations, makes it difficult to construct a convincing model for even one species. Developing such a model can be done on theoreti¬ cal grounds or empirically, by systematic compilations of data. I favor empha¬ sis on the latter. Even given its limitations the construction of models may facilitate gathering data in a systematic fashion. To the extent that mobbing is important, both spatial factors (colony structure and density) and temporal factors (synchrony) are of great importan¬ ce. Both within and between species there is great variation in the ways that habitat selection, predator detection, and mobbing interact, and the inter¬ actions of these factors with other features of resource use deserve in¬ vestigation. 888 p . roua airaiùaùiùity g. 1. Graphical relationships among variables related to reproductive synchrony and predation on colonial birds A unitary explanation, i.e. that either food-finding or predation dicta- tes a colonial way of life, though attractive, is unlikely to be useful. The nsxt decade should see increasing attention to the interaction among diverse selective factors, rather than continued reliance on simplicity. I believe ^he time has come to respectfully retire Occam's razor. summary Predation, is an omnipresent hazard faced by birds. 2* Colonies may arise as passive aggregations of individuals an- attracted to the same nesting area because it is predator-free. species 889 BIBUOTOfcQUE I 3. Aggregations of birds may be more conspicuous to predators than in¬ dividuals. 4. An individual's risk is diluted by being part of a large group. 5. Predators may be confused by the appearance of a dense mass of birds. 6. Birds in large groups may detect a predator earlier and need devote less time per individual being vigilant than those in small groups. 7. In colonies, species with cryptic nests or eggs may be spaced in a manner which thwarts the formation of an effective seardh-image by* the pre¬ dator. 8. Anti-predator aggression or mobbing is well-developed in many colonial species, while other species may take advantage of this behavior by nesting among the more aggressive species. 9. Anti-predator aggression is not without cost, for predators sometimes capture the most aggressive (or least fearful) individuals. 10. The role of predation in shaping breeding aggregations in no way pre¬ cludes an additive or synergistic contribution of information exchange, whe¬ ther passive or active. Conversely, ones inability to demonstrate the operat¬ ion of the later does not mean that in colonies birds are unable to benefit from information conveyed by their confreres (whether conspecif ic or not) . ACKNOWLEDGMENTS Through the years many people have assisted me in my field studies of co¬ lonial birds. I particularly thank Dr. J. Burger for her participation, en¬ couragement, and her comments on this paper. To the innumerable authors whose reports on the subject of predation and colonial birds space has pre¬ vented iqy citing, I extend my apology. Ref erences Austin O.L. - Bird Banding, 1948, _1_9, p. 60-65. Birkhead T.R. - J. Anim. Ecol. , 1977, 46, p. 751-764. Boswall J. - Bull. Brit. Om. Club, 1972, 92, p. 129-132. Brooke R.K. , Wallett T.S. - Ostrich, 1976, £7, p. 126. Burger J. - Condor, 1979a, 81, p. 269-277. Burger J. - Auk, 1979b, £6, p. 694-703. Burger J. - Colonial Waterbirds, 1981a, 4, p. 28-36. Burger J. - Quart. Rev. Biol., 1981b, £6, p. 143-167. Burger J., Gochfeld M. - J. Comp. Physiol. Psychol., 1981, 95, p. 676-684. Burger J. , Lesser F. - Ibis, 1978, 120. p. 433-449. Corkhill P. - Birt. Birds, 1973, JS6, p. 136-143. CoulsonJ.C. - Nature, 1968, 217. p. 478-479. Curio E. - Science, 1978, 202, p. 899-901. Darling F.F. Bird flocks and the breeding cycle. Cambridge, Univ. Press, 1938- Davis J.W.F. , Dunn E.K. - Ibis., 1976, V18, p. 65-77. Dominey W.J. - Nature, 1981, 290. p. 586-588. Emlen J.T. , Miller D.E. , Evans R.M. , Thompson D.H. - Auk, 1966, 8 J3, p. 677- 679. Feekes F. - Ardea, 198i, 69, p. 83-108. Fuchs E. - Omis Scand. , 1977, 8, p. 17-32. 890 Furness R. - rbis, 1981, VQ, p. 534-539. Gochf eld M. - Ins Behavior of Marine Animals. Vol. 4 / Eds. J. Burger, B. 011a. N.Y. s Plenum Press, 1980, p. 207-270. Goransson G. , Karlsson J. , Nilsson S.G. , Ulfstrand S. - Oikos, 1975 26 p. 117-120. ’ — ’ Hamilton W.D. - J. Theoret. Biol., 1971, 21, p. 295-311. Hand J.L. - Biol. Conserv. , 1980, _18, p. 59-63. Hand J.L. , Hunt G.L. Jr., Warner M. - Condor, 1981, 83, p. 193-200. Hatch J.J. - Auk, 1970, 87, p. 244-254. Hirsch S.M. , Bollee R.C. - Z. Tierpsychol. , 1980, £4, p. 71-84. Horn H.S. - Ecology, 1968, 49, p. 682-694. Hunt G.L. Jr., Hunt M.W. - Auk, 1975, 92, p. 270-279. Hunt G.L. Jr., Hunt M.W. - Ecology, 1976, £7, p. 62-75. Janzen D. - Ann. Rev. Ecol. Syst. , 1971, 2, p. 465-492. Johnson R.A. - Wilson Bull., 1938, £0, p. 161-170. Kepler C.B. - Auk, 1967, 84, p. 426-430. Kirkman P.B. Bird Behaviour: A Contribution Based Chiefly on a Study of the Black-headed Gull. L. s T. Nelson and Sons, Ltd., 1937. Krebs J.R. - Natl. Audubon Soc. Res., 1977, Report 7, p. 299-314. Kruuk H. - Behaviour Suppl., 1964, _n. P* 1-129. Kury C.R. , Gochfeld M. - Biol. Conserv., 1975, 8, p. 23-34. LaCÏ95i.The NatUral RegUlatl°n °f Animal Numbers. Oxford: ' Clarendon Press, Lazarus J. - Ibis, 1972, m, p. 556-558. Lazarus J. - Behaviour, 1979, J±, p. 127-145. Inzell J.D. Jr., Nisbet I.C.T. - Man and Nature, 1972, 6, p. 27-29. emmetyinen R. - Ornis Fennica, 1971, 48, p. 13-24. Lemmetyinen R. - Ann. Zool. Fennici, 1973, 10, p. 526-535. Macroberts M.H. , Macroberts B.R. - Ibis, 1972, 114, p. 93.97. McNicholl M.K. - Auk, 1973, 90, p. 92-94. Milinski M. - Z. Tierpsychol, 1977, 45, p. 373-388. 5yers J.P. - Auk, 1978, 8£, p. 419-420. Nettleship D.N. - Ecol. Monographs, 1972, 42, p. 239-268. Nisbet I.C.T.- Condor, 1975, 77, p. 221-226. Patton S.R. , Southern W.E. - Proc. Colon. Waterb. , 1977, Group 1, p. 91-101 arsons J. - Brit. Birds, 1971, 64, p. 528-537. Pitman C.R.s. - Bull. Brit. Om. Club, 1957, 77. P* 89-97, 105-110. owe 11 G.V.N. - Animal Behav. , 1974, 22, p. 501-505. ^obertson C. J.R. - Notomis, 1964, _10, P* 393-403. ^Legal-Causey D. , Hunt G.L. Jr. - Auk, 1981, 98, p. 522-531. iegfried W.R. , Underhill L.G. - Animal Behav., 1975, 22, p. 504-508. enaza R. - Condor, 1971, 7 2, p. 81-92. ^inbergen N. , Impekoven M. , Franck D. - Behaviour, 1967, 28, p. 307-321. ^een j. _ Behaviour Suppl., 1977, 20, p. 1-193. ard P. , Zahavi A. - Ibis, 1973, H5, p. 527-534. w klund C‘C., Andersson M. - Ibis, 1980, J_22, p. 363-366. ^Llliams A.J. - Ornis. Scand. , 1975, 6, p. 117-124. °ung E.C. - New Zealand J. Zool., 1978, 5, p. 401-416. 891 A NEW HYPOTHESIS FOR THE ADAPTIVE SIGNIFICANCE OF COLONIAL BREEDING IN THE KITTIWAKE RISSA TRIDACTYLA AND OTHER SEABIRDS J.C.Coulson Department of Zoology, University of Durham, UK Before considering the adaptive significance of colonial breeding in sea¬ birds there are four general points which I wish to make concerning colonial breeding and synchrony. 1 . Did colonial breeding evolve once or on several occasions? The answer to this question is that it probably has evolved several times. Not only does it occur in almost all of the major groups of birds, the most primitive to the most specialized, but it also occurs throughout the vertebrates being found in fish, amphibia, reptiles, birds and in the mammals. To argue that it evolved only onoe is to suggest that the evolution of the vertebrates (and the birds) has taken place through colonial ancestors and that solitary breeding has evolved many times as a secondary development. If it is accepted that colonial breeding has evolved several times, there is no reason to suppose that the same selective forces were operating on each occasion. Thus there is no need to suppose that there is a single adaptive significance in colonial breeding throughout the birds. 2. Once a selective pressure has brought about colonial breeding and birds breed close together, there is opportunity for secondary adaption of colonial breeding for other purposes. I will give a hypothetical example. Colonial breeding may have evolved in, say, herons as a defence mechanism but further development could then have led to social stimulation and greater synchrony which may then be an advantage to the breeding success of individuals. It Is Therefore Possible to Find More than One Factor which Is Associated with Colonial Breeding which Has a Selective Value 3. It is generally assumed that synchrony of breeding is, in itself, adap¬ tive, (otherwise it would not occuri). This is not necessarily so. It may be linked to some other adaptive factor and result as a by-product. This can be best illustrated by two examples from other animals. a) Many insects have a quiescent stage where little or no development takes place. This suspended development is referred to by entomologists as diapause and its main function is to enable the insect to withstand periods of adverse environmental conditions such as seasonal drought or low tempera¬ tures. This inactivity is ended by environmental factors such as temperature or day-length and one of the effects is that most of the individuals break diapause and start normal development at the same time, resulting in a syn¬ chronised emergence. b) There seems to be no advantage in the varying degrees of synchrony of breeding found in the Grey Seal (Halichoerus grypus) since there are no ter¬ restrial predators which might prey on the pups. The degree of synchrony va¬ ries geographically and occurs as a result of the environmental factors (be¬ lieved to be sea-temperature) which end the suspended development of the fertilized egg and start the normal gestation development. The rise in sea temperature is more rapid in certain areas and this causes greater synchro¬ ny of implantation and hence births amongst the cows. Here the primary adap- 892 tiVe value is to adjust the breeding season to an annual one; the synchrony •is secondary (Coulson, 1981). V 4. It is worth considering how difficult it would be for a bird species to eliminate colonial breeding if it was no longer an advantage. It should not be assumed that the evolution from solitary to colonial breeding is as easy to achieve in the reverse direction. First of all, many colonial breed- ng birds have given up the ability to breed as one male and one female in isolation. A further component is necessary to bring about successful breed¬ ing in many species; that is the stimulation of other individuals. Having become dependent on other individuals how easy is it to loss this dependence* It should be remembered that the evolution from situation B to A may be much’ more difficult than the evolution from A to B. Many free living species have evolved into endoparasitic species; few if any endoparasitic species have become free living. Whilst I do not subscribe strongly to the view that in some species co¬ lonial breeding may be no longer an advantage; consideration should be given to this possibility occurring in some species. THE ADAPTIVE SIGNIFICANCE OF COLONIAL BREEDING In this paper, I present a new hypothesis to explain the function and adaptive significance of colonial breeding in birds. The hypothesis does not aim any function in colonial breeding which may not be found in solitary reeding species. It merely considers that colonial breeding achieves more ective adjustment of the breeding season to the time which is optimal for young production. This is of particular importance in species which breed in imatic regions where the environmental conditions and, presumably, the ime for optimal breeding success vary from year to year. This adjustment is so of value to individuals which may not be as 'fit' as others and cannot ford to invest as much in breeding, or for example, if the individuals rade off survival against reproductive success in a particular year. The simplest explanation of the ability of a species to adjust its breed- fug season to varying environmental conditions is that there are two rates of development towards full reproductive condition in the period leading up egg laying; the slower rate operating in adverse conditions and the faster rate when conditions are favourable. Otherwise breeding would take place at he same time each year. I suggest that there are two rates of development owards reproductive condition in colonial birds; one when the birds are away from the breeding colony and the other when they are Paired, living for much of the time in the colony and are subject to social stimulation from their neighbours. The time of return to the colony is both a good measure of the reproductive potential of an individual and an indicat¬ ion of whether the conditions leading up to the breeding season favour earlv °r late breeding. I have built the model around the Kittiwake Rissa tridactvla but the im¬ portant factors in this species, return to the colony being related to laying atë and -breeding success being higher in early breeding individuals, are, ^rom my own experience, characteristic of many 3eabird species, particularly *e SilaS Phalacrocorax aristotelis and the Herring Gull Larus argentatns. 893 Pig. 1. Clutch size variation in the Kittiwake Rissa tridactyla through the breeding season. Data from the North Shields colony and four other colo¬ nies in eastern Britain. Note that whilst in all colonies clutch size dec¬ lines as the breeding season progresses, the colonies starting later than North Shields do not lay as large average clutch sizes early in the season but start laying at that appropriate to the actual date • _ I _ I _ I _ I I I / 6 15 ZZ 29 5 1Z May June Many seabirds , particularly those which breed in the Arctic, show consi¬ derable variation in breeding dates from year to year. This variation has been documented for several species by Belopolskii (1957) who shows, for example in the Kittiwake, than in four consecutive breeding seasons (1947-50) first laying varied by 18 days in eastern Murman. In contrast, Ihe same species shows much less variation in Britain. Clutch size varies with the early or late breeding. Belopolskii (1957) has recorded a mean clutch size of 2.33 in an early year and 1.53 eggs in a late breeding season. In fact the Kitti¬ wake shows a remarkably consistent pattern of clutch size change with date. Pig. 1 shows the data for my study colony at North Shields (dots and conti¬ nuous line) and that in other (later), breeding colonies in eastern Britain. Note that later breeding birds lay a lower clutch size in the same colony and also that the individuals in later breeding colonies lay clutches approp¬ riate to actual date and not to their relative date for the colony (Coulson, White, 1961). Thus late breeding produces small clutches and this is obvious¬ ly the same throughout its range. The examination of clutch size variation in the same female breeding in successive years has also revealed that there is a strong tendency for clutch size to be lower when breeding is late. Clutch size is a good indication of breeding success in the Kittiwake. Table 1 shows the breeding success in relation to clutch size; the larger the clutch, the greater the number of young fledged and clutches of three eggs have almost the same percentage success and the normal clutch of two Clutch size Table 1. Breeding success in Kittiwakes at North Shields, England, 1954-1979 based on 1406 clutches Clutch size Breeding success Young fledged %> per pair * 1 40. 0 0. 40 2 62.0 1.24 - 3 60.7 _ 1.82 eggs. The seasonal variation in breeding success is shown in Pig. 2. Apart from a suggestion of slightly lower success in the earliest breeders, the later breeding birds have a lower breeding success (mainly as a result of the ower clutch size laid by these late birds). Clearly early breeding Kittiwa¬ kes are more productive breeders. Early laying Kittiwakes are, in general, also the birds which return to he colony early. The relationship between date of return and egg laying for individual birds (data grouped) are shown in Pig. 3. m my study colony where some birds return as early as January, early return results in early reeding but the exact date of return has little effect until the end of Feb¬ ruary, after which time the later the birds arrive, the later egg laying oc- î* 1 1 S* 3. The relationship between the date of return to the colony and the ^ate of laying the first egg of the clutch for Kittiwakes Rlssa tridact.vla ^reeding at North Shields. The bars Bhow the 95% confidence limitB for each Point 895 1 slow fast 2 3 Slow slow rat un to colony fast fast Pig. 4. Three examples of the relationship bet¬ ween the onset of de¬ velopment towards rep¬ roductive condition, date of return to the colony and the date of egg laying interpreted with slow and fast rates of development Date curs. (Note that return in March is typical of most Arctic and sub-Arctic Kittiwake colonies). It is possible to interpret the situation operating from March as indi¬ cating that there are two different rates of development towards breeding condition; one in those which are solitary and another in those which are co¬ lonial. Pig. 4 illustrates the situation with 3 examples. It is an easy task to calculate the relative rates of development in the two situations, by using the relationship: (days) (slow rate) + (days ) (fast rate) = development to egg laying. Taking two different birds, the left sides can be equated and the ratio foot t C alow raie oan determined as 1-22, that is the fast rate of development takes place 22# faster in the colony. Pig. 5 shows the relationship between the duration of the pre-egg stage in the colony and the laying date in the Kittiwake (using the data from Pig. 3)* As the time of laying becomes later in the season, the period of time needed in the colony becomes less (that is, less social stimulation is needed). This also indicates that development is taking place when the birds are oceanic and have not yet returned to the colony, as well as implying that more so¬ cial stimulation from the colony is necessary if breeding is to be early. Of interest is the point where breeding would occur without returning to the colony (although the bird would obviously need a mate). The date, about 10 June, is the time of cessation of egg laying in Britain. At this time an en¬ vironmental induced barrier to later egg laying (including replacement clut¬ ches) occurs. It is possible that the combination of the slower development of reproductive condition in solitary birds and the seasonal termination of egg laying prevent Kittiwakes from breeding as isolated pairs. Changing from a slow to a faster rate of development towards breeding has two further effects on the pattern of laying in the colony. First, the in¬ crease in the rate of reproductive development results in increasing synchro¬ ny. This is a general effect found in any biological system where the rates of development increase. Secondly, the change over from the slower to the faster rate at different times in individuals results in skewing the breed- 896 i g. 5. The relationship between date of return to the colony and the ate of laying. Note: (i) the shorter period of presence in the colony of ate arriving birds before egg laying, and (ii) the date (about 10 June) when, in theory , Kittiwakes should be able to lay without being colonial in practice, egg laying is inhibited about this date 89 7 ing season. I have illustrated this in Pig. 6 by taking a symmetrical, near normal distribution of the time of return (corresponding to the actual si¬ tuation). By applying the development rates before and after the time of return the skewed distribution of breeding, with a tail of later breeder is obtained. Gochfeld (1980) has drawn attention to this typical asymmetrical pattern in seabirds and in 27 out of 28 cases examined, a skew with a tail of late breeding was found. He did not offer any explanation of this distri¬ bution. It is possible that all of these patterns stem from the change in rate of development towards breeding condition occurring at different times in different individuals. ADAPTIVE SIGNIFICANCE The more precisely an individual can adjust its breeding date to optimize its reproductive output, the greater the selective advantage. I doubt if any species can achieve this precisely; perfect adaptation does not exist. I sug¬ gest, however, that colonial breeding may achieve this to a greater extent than the methods used by solitary breeding birds. The group stimulation or social stimulation (Darling, 1938) is an essential part of this concept and there is clear evidence- of it occurring in the Kittiwake (Coulson, White, I960; Coulson, Dixon, 1979). I may have simplified the concept in referring to two different rates of development towards breeding condition, the social stimulation effects will vary between birds nesting at different densities. However this will put only a small range on mean of 22% increased development under colonial conditions, perhaps from 15% to 30%. The prime function of the stimulation between the members of the pair and, in colonial species, between neighbouring birds, is to complete reproductive development and initiate egg laying at a time which, as far as possible, ma¬ ximizes young production (or more correctly, young which survive to adulthood). The greater the ability of individuals of a species to adjust the breeding season, the greater the probability of higher young production, which is, of course, a considerable selective advantage. In many seabird species, the earlier breeders are more successful, but this is only after the birds have adjusted their breeding date in response to environmental clues. If birds bred as early in years when conditions are unfavourable as they do in other years. I suspect these early breeders would have a very low success. I be¬ lieve that adjustment of the breeding season is more important than synchro¬ ny between members of a colony. Having said this, I wish to emphasise that this does mean that, in some species, synchrony may itself be a selective advantage.. This model moves from concepts which are unique to colonial birds. It also has the advantage of explaining anomalies in other concepts or unex¬ plained effects in colonial breeding. There is no longer the difficult problem of greater spread in larger or dense* Kittiwake colonies where the selective advantage in synchrony fall down. Synchrony is a by-product of this hypothesis. If it can be adapted to the advantage of the species, as for example Parsons (1975) has shown beautifully for the Herring Gull, then the species obtains a bonus benefit; this is a secondary advantage but it does not have to occur in all species. In the Kittiwake, the synchrony is 898 ” gr0UpS tbe (Coulson, Dizon, 1979); groups which are *1' °btain benefit *«>» swamping a predator with food. seabirds61” it*, eXpl&inB the a8y™etry of the breeding season in many ea birds . It also has the merit that it does not propose a new functio^ S ir6L rgeStS that C0lOnial MrdS ad;jU8t their Ceding season to eir advantage better than solitary breeders. This last point is one which to adiuste“eb "dr" the hyPOtheSiS* Are breeders better able to adjust their breeding season than non-colonial birds in the same area’ ZlZTt ,0 Uself * *•».«« in date of laying between years in colonial species. SUMMARY reColoniaîTtSdrth/°Ur generalizati0118 ab°»t colonial breeding: . Colonial breeding has evolved on several occasions. 2. Once colonial breedisg is established in a species other secondarv selective advantages can evolve so that there could be more ttan one seSc- ve advantage found when investigating the advantage of group breeding. need* Î t* n aSSUmed that «yachroar breeding is always adaptive.This z: » °°“ia '-■» *— *- - «. oZiz. breld/' °wd l* V6Iy dlffi0Ult for a «hich has evolved colonial and ret^n t b n/* °° adaPtive> eliminate this behaviour and return to breeding as solitary pairs. It is suggested that the adaptive value in colonial breeding lies in nos- ssmg two different rates of development towards egg laying. A slow rate nrbrraiy “* a faSter rate When the b^8 - in tS low. iS s!cc r 0î the breedias Sea30n t0 a Ume Which »azimises Seed- 61 7! 6 prevalling conditions. A by-product of this is 1) syn- Boil rrg “d 2) a skewed breeding season with a taii b^- the’breld^I mT *” W6U ln Seabird8 * is illustrated by breeding biology of Rissa tridactyla. References BelcowUf 1iL'°V E0°l0Sy °f °°l0nial sea birds °f the Barents Sea. Mos¬ cow; Leningrad: AN SSSR Press, 1957. Couîir î’°* " J' Z°0l‘ LOnd” 1981 * 121* P* 553-571. Eds" r\” Dir P’ ' In’ Bi0l0gy and Systematics of Colonial Organisms/ c°ulson j*'™; B'R‘R08er1, L*: Acad* Pre8S* ’973, p. 445-458. Co, 1 ’ E‘ " rMs’ 196°* JfiS. P. 71-86. bIT Whlte E* ^ Snalysis of the Gators influencing the clutch size °f the Kittiwake, 1961. ciutch ai,Jr^ F‘n4 " Blrd Pl0°k8 *he Breeâing Cycle. Cambridge University Press. Cambridge, 1938. y oohfeld M. - m, Behaviour of Marine Animals Vol. 4. Marine Birds / Eds Par ur8er 1 B.L.Olla, H.E.Winn. N.Y. ; L. : Plenum Press, 1980. sons J. - j. Anima! geology, 1975, .44, p. 553-573. 899 EVOLUTION OP SOCIABILITY, FORMATION AND STRUCTURE OP MONOSPECIFIC AND MIXED COLONIES OP SPARROWS FROM THE SUBFAMILY PASSERINAE V. V. Ivanitsky Moscow State University, USSR Ornithologists traditionally show great interest in the family Ploceidae, and unparalleled diversity of social relationships within this group is being one of that reasons. MaDy weavers aDd sparrows are known to nest in colo¬ nies, some comprising as many as hundreds of thousands of pairs and other consisting of no more than a few dozen birds. Representing the third type of colonies, there are in fact none other than amorphous gatherings of pairs. At last, some species nest in isolated pairs. Any multispecies genus of the family is characterized by a whole range of spacial relations bet¬ ween its member-species, the key problem being how to account for this di¬ versity. We have studied representatives of the genera Passer, Petronia, Pyrgllau- da, Carpospiza, and Montifringilla. All of them are endemic to the Asiatic continent, exclusive of genus Passer occurring both in Africa and Asia. These genera are often incorporated into the subfamily Passerinae. This sub-family features a total range of behavioural patterns, from ge- niune territorial to highly developed obligatory colonial spacing. Thus occupation of the burrows of rodents by isolated pairs is the only form of nesting for the Pere David's snow finch inhabiting the relatively flat mountain steppes. Nests are usually spaced at no less than 80-100 metres even in undisrupted populations of this species, their high density and abun¬ dant nesting space sot withstanding. Snow finches, found in rugged highland, prefer solitary nesting although groups of 3-4 nests separated by 8 to 10 metres, are sometimes found. It is noteworthy that genuine display flights are inherent in both snow and Pere David’ s snow finches just as in many other species with territorial behaviour. The breeding season being over, both these species form large sometimes mixed flocks and turn to nomadic way of life. Pale rock sparrows, inhabiting foothill semideserts, form pairs that nest separately and, as observed by Adamyan (1965), also keep their territories actively guarded. Spacial structure of the rock sparrow settlements is highly variable. Most are incompact groups of 5 to 12 males, displaying shelters for the nests to be placed at a distance of 10-15 metres. Once the pair is formed and the female gets to nest-building, the male occupies another shelter, starting to display it until a new mate is gained. The settlement density is thus growing significantly. Side by side with such amorphous colonies ihere are lone males whose number can amount to about 30 per cent of the po¬ pulation. Our observations have not revealed any relationship between the time when a male gains its first female and his social environment. Apart from nesting seasons, rock sparrows live in large flocks numbering scores of birds. They can also form transitory flocks of 4 to 8 individuals when foraging during breeding periods. 900 and highly colonial spe- The genus Passer also includes both territorial cies. The saxaul sparrow was observed to defend its territoiy within a range of 40 to 50 metres. Neighbouring territories are often widely overlapping. Protracted border conflicts, involving both males and females, are a common occurrence in the areas shared by two or more pairs. The pair makes the most of the whole of its territory, and social contacts between the partners take Place all over it, being not confined to the immediate vicinity of the nest. All the shelters suitable for placing nests within the individual territory- nest boxes and other types of artificial shelters, are defended from other conspecifics. E.I.Gavrilov has reported cases of polygyny in the saxaul sparrow. The species forms flocks in winter and during migrations. In spring the irds of migratory flights were observed to inspect closely situated nest- boxes while their owners were away. These birds were apt at forming a sort of colony, but on returning the holders of the territory immediately drove away all the intruders. Thus the saxaul sparrow is likely to set up small oolonies, provided that birds simultaneously move into neighbouring hollows. Spacial structure of the tree sparrow settlements looks very much like hat of the rock sparrow. Tree sparrows are most often seen to form solitary Pairs and sometimes sparse gatherings, with nests spaced at 6 to 8 metres. Colonies of the house sparrow are by far more compact as compared to those °f the tree sparrow. Colonies of Spanish and Indian sparrows are known to number tens or hund- e s of thousands of pairs, the nests being set so close to each other as to use mto conglomerations. The Spanish sparrow places nests on trees only, hile the Indian sparrow uses cliffs and rocks as well. As regards the spacial structure of the colonies of these species, both °q them are apt at defending a limited area around the nest. Its size depends 0 a large extent on the synchrony of moving into a given section of the ter¬ ritory. Peculiar nest-clusters are usually formed in case of simultaneous settlement. Members of these settlements are very tolerant to one another Ut ^ intruders are immediately driven away. In cases of asynchronous in- lallation the density of the colony is much lower. The male of Indian sparrow occupies a portion of a tree crown up to 50 °hbic metres, with one or more forked branches suitable for nest disposition. Cq6 wllole °f the territory is continually patrolled and inspected. Border J’hfli.ots with neighbouring males àre of frequent occurrence, lasting a few mutes and accompanied by characteristic displays. t The male of Spanish sparrow occupies but one fork, immediately laying the ^asis of its would-be nest. It spends all his time in the nest or hereabout, ^aying no attention to what is going on in the closest proximity. Border r n llots in this species are non-existent, all agonistic relations being uced to short-term contacts. Nevertheless the nest is said to be defended. t c°lonies of Spanish sparrows are generally characterized by greater densi- g ttilan those of Indian sparrows. New groups of Spanish sparrows, numbering in ° 10 ma''’es’ may often move into already established colonies. They arrive and& °0lnpao1: floo3c* each bird occupying its own fork close to one another aetting in singing or displaying. Then they proceed to nest-building 901 stealing nesting materials from and one another and weaving their individual constructions together into a single conglomerate. The latter is never formed in case of asynchronous installation. The Indian sparrow is often observed to nest in solitary pairs or small colonies of 5 to 10 pairs. Isolated colonies of Spanish sparrows never have less than 30 to 4-0 pairs. Mixed colonies of Indian and Spanish sparrows on threes are most common. Rock and Indian sparrows usually form mixed colonies in urban areas while tree and Indian sparrows place their nest under house-tops in rural loca- litites. In mixed colonies member-pairs guard their own nesting sites against any passering species. Yet those claiming for a shelter occupied by a pair of different species may turn out to be very persistent, employing it while its owners are away for foraging. Indian sparrows are known to occupy the Spanish sparrows' nests already 3-4 days before they are abandoned by nestlings. At first the parents disp¬ lay a highly aggressive behaviour, while subsequently they get used to the intruders and do not prevent them from penetrating into the nests and feed¬ ing the young. Pairs of Indian sparrows are often formed in such circumstan¬ ces. We have found a few cases of interspecific stimulation of reproductive behaviour in mixed colonies. Indian sparrows, arriving rather late, are seen to form colonies first of all where resident tree and rock sparrows can be found. Odd males of both these species first and foremost attract Indian sparrows because of their ceaseless singing. The earlier nesting of Indian sparrows is observed in such mixed colonies. Another example is that of the Spanish sparrow which may form solitary nesting pairs or groups of 5 to 7 pairs within large colonies of Indian sparrows. Having now accomplished the survey of structural patterns of social sys¬ tems in representatives of the subfamily Passerinae, we proceed to the ana¬ lysis of some functional aspects of colonial nesting in Indian and Spanish sparrows. Both species arrive at the breeding ground rather late. When outside the colony during this initial period, they form compact flights and are charac¬ terized by highly synchronous comforting, foraging, defensive, and locomotor behaviour. Their nuptial, aggressive, and territorial behaviour can already be clearly seen when the birds are still in migratory flocks. Bouts of their social activity are also highly synchronized. They are most manifest when the birds are gathering at roosts in the evenings or before they leave for foraging early in the morning. The nesting colony is often formed in such places of roosting. The flock-size is highly variable. Thousands of birds can be brought to¬ gether in spring on agricultural lands with prevalent grain farming. They are foraging in the fields but never far from trees, serving as resting Pla" ces, shelters from predators, and roosts. Large flocks in excess of 40 to 50 birds are not formed outside agrocenoces. Colony territories are being settled gradually, in a sort of cyclic pat¬ tern. Such patterns of behaviour are particularly manifest in Indian spar¬ rows, nesting on rocks or cliffs. 902 During the first few days after arrival Indian sparrows can he seen at the co}ony but for a short time in the morning. For the rest of the day small dense flocks of them are foraging in its vicinity. The birds often roost on trees rather far from the would-be colony site. Later on they begin visiting the colony in the evenings, and their roosting sites are brought as close to It as possible. At last morning stay in the colony becomes even longer, and the birds can be seen there in the afternoon. There are always birds in the colony after nest-building begins. The first eggs having been laid, females roost in their nests while males spend the whole of the lighttime in the colo- leaving it only for the night to roost on the nearby trees. The flock size in the foraging habitats is consideralby reduced by this time. Synchronous behaviour is lacking, bird gatherings are but transient. When near the cliff to be chosen as a nesting site, some birds usually occupy it while others can be seen on the nearest tree. There are all kinds of social interactions between members of both groups, accompanied by conti¬ nuous interchange of birds between the two places. Birds move in groups of 5-6 individuals in a highly synchronized way. As the colony is being fonned, the birds spend more and more time on its territory, their antagonistic re¬ lations becoming, more and more pronounced. Sparrows move in and out of the colony alone irrespective of actions of other conspecifics. Trees are used only for roosting or in case of flushing synchronously when they leave the cliff being stricken by the so-called "false panic" or getting sight of a predator. In the majority of cases such flushes are supposed to occur spontaneously, hsy happen however, far more often if predators are constantly present. The frequency of such spontaneous flushes decreases anyway as the birds' attach¬ ant to the colony grows until they cease to be seen at all when nest-buil- ding is started. There is significant negative correlation between flush pre¬ valence in different, even if adjoining parts of the colony, and the duration of the birds' permanent stay in them. Flush prevalence positively correlates with the population density in a given section. We compared two types of Indian sparrow nests to elucidate the effect of the population density on bird behaviour. Some nests were placed in the midd- le of the colony, no more than 30 cm apart from each other. The rest of them occupied peripheral portions of the colony, separated from other nests by no leas than 2 metres. Male holders of the centrally located nests were observed within an hour to mate, participate in agonistic contacts with other birds, and he involved in flushing in company with their neighbours 1.5; 4 and 2.3 times as often as owners of the peripheral nests respectively. Energy consumption for flushing is the greatest. About a hundred flushes Psr day can be seen at the outset of colony formation, each lasting for 8 to seconds. This makes up 15 minutes, enough for a bird to cover a distance TO kilometres. This energy consumption rate is said to be comparable to that required for locomotor activity exhibited by foraging birds during this Period. Increased exitability Is known to develop in birds inhabiting densely po¬ lluted parts of the colony, due to their numerous social contacts. It has en established by irritating birds with sunbeams, caught in a mirror and 903 serving as a potent discomfort factor. Only 36 per cent of affected birds occupying densely populated sites could stay put for more than a minute. All others flew away much quicker. 73 per cent of males in the sparsely populated portions of the colony endured a one-minute irritation by sunbeams. The pressure of predation on a sparrow colony often results in disastrous effects. Hawks and 3mall falcons can be seen in a colony all day long, catch¬ ing both adults and fledglings. Snakes, magpies, jackdaws, and even shrikes are known to prey on eggs and nestlings. Unable to defend their nests from predators, sparrows can do little more than to try and scare them away with yells. It is interesting that birds get used very soon to the permanent pre¬ sence of predators, especially in large colonies. Breeding success is far from being equal in different colonies, largely depending on the influence of predators. Jackdaw invasions are fraught with the most disastrous consequences. T. F.Fedyanina has shown that they are able to exterminate up to 65 per cent of nestlings. Meanwhile, predators being absent, practically all nests give rise to fledglings. Thus nesting success is largely dependent on incidental factors. We have studied breeding success in Indian sparrows, nesting in the holes of a cliff, using incidence of hatching failure as an indicator. Examination of nest contents was impossible by force of circumstances, and we could not wait for the fledglings to leave the holes. We therefore considered success¬ ful pairs that proceeded to feeding nestlings. In all, 67 and 48 nests were under observation in the densely and sparsely populated portions of the colo¬ ny respectively. In the former case 18 nests were unsuccessful while only 4 in the latter, with jackdaws being the main predators. In case of arboreal nesting, densely populated sites were observed to be most attractive for predators as well. I am afraid that the data reported would seen disappointing in terms of adaptive significance of bird colonies. In fact, the greater their size and density the more attractive they appear to be for predators. Moreover, cons¬ tant excitation of birds, resulting from a great number of their social con¬ tacts considerably increases energy consumption. At last, birds have in fo¬ rage as far as 1 . 5 kilometres away from the colony. Nevertheless this is exactly the way with colonial sparrows, making the validity of hypotheses of the advantages of colonial nesting open to question* Even if this is the case, a species is certain to pay dearly for such advan¬ tages. One unavoidably arrives at the conclusion that a social system, based on obligatory colonial bonding, can be functionally efficient only within a relatively narrow range of favourable ecological conditions. 904 ADVANTAGES AND DISADVANTAGES OP MIXED-SPECIES COLONIES OP SEABIRE6 Joanna Burger Department of Biological Sciences, Rutgers University, New Brunswick, New Jersey, USA INTRODUCTION The disperson of nesting birds varies from species that nest solitarily to those that neat in densely-packed groups of thousands of individuals. The nesting pattern for species is a continuum from solitary nesting to dense groups. Thus it is difficult to define a colony, although definition is es¬ sential to understanding the biology of seabirds. I define colonies as comp¬ rised of birds that nest in close proximity to one another, interact regular¬ ly, and use their territories only for breeding activities. oeabird colony sites are usually on coastal or marine islands, and suitab- e nest sites are often limited, forcing many species to nest together (Be- lopol'skii, 1957; Bianki, 1977; Bergman, 1980). The spatial overlap of sea¬ birds is often difficult to determine. Many seabird publications do not in¬ dicate whether other species nest nearby or on the same island; or if nests of various species are intermingled. Several authors mention that different species nest in mixed-species groups, and give numbers of nests or maps showing the locations of nests (i.e. Brun, 1976; Amerson, Shelton, 1976;Fur- ness, 1981). Such studies can be used to examine the extent to which seabirds hest in mixed-species colonies (colony where birds nest next to heterospeci- fics) . Whether species separate into monospecific clusters is often impossib¬ le to ascertain, although intermixed nesting often occurs in members of the same family (i.e. gulls, penguins). Even when nests are mixed interspecifi- cally, clusters of monospecifics may be evident. On Johnston Atoll nine spe- Qies nest intermixed, but each species clumpes monospecifically (Amerson, Shelton, 1976; Table 1). Seabirds frequently form mixed-species colonies, particularly on isolated n'arme islands. Such groups may be the rule rather than the exception (Belo- Pol’skii, 1957), and some species of most sympatric seabird families someti- mes nest together in mixed-species colonies (Table 2). Exceptions occur with Pelicans, darters and skimmers, usually inland nesters in colonies with °onspecifics, larids, or ardeids. Seabirds frequently nest in colonies with non-seabirds: gulls, terns cormorants and anhingas nest with ardeids (Elli- ®°n, Cleary, 1978; Morrison et al., 1979; Burger, 1 981 ) . In this paper I aouss the benefits and costs of mixed-species seabirds colonies. ADVANTAGES AND DISADVANTAGES OP MIXED-SPECIES COLONIES The disadvantages of mixed-species colonies result from competition for 0o +“ m s * O s S S 0 0) fl) H TJ fl) fl) R R TJ •H a; & .. al o -«3 t a ci "H R M Q) co a 3 <1) 0 1 R PP 0 g K m ^ fi •H rH 0 CQ S % ® °) PR 0 O 1 V •H PR 02 TJ ■U ” +> O R QJ « 0) R •H XJ g « +i U V— Eh P bO R 03 •H rH î> I R H 0 0 P PR p » R 0 0 CO PR -p H « K X X x X X x X X X X X X X X X X X X X On co Un en en Vf ~ on cm un X X X I R 0 0 PM p 02 0 cd 03 ~ CQ O R 03 R 0 R *H 0 ^ PM Go 03 00 CM XXXI IT\ no 00 CM vf MO KHI * - MO r— C\J CM Cn M3 vo IA vo CM CM MO CM CM CM CO MO oo MO 00 MO en MO un CM vf CM MO en co T~ •> CD C- vf LT\ en vf CM O vf vf CM CO CM CO » vf CM en •> r— r •> en CM #, m CM T"* CM en 1— « * un O vf MO un un un MO •> MO MO » O un un CM C — un en en mo en MO MO rH 0 0 0 0 0 R tJ TJ 0 R p R 0 R 0 P 0 •H P •H 0 CO 0 PR ,Û 0 R & R R 0 PR R ce 0 3 0 0 •H 0 rH W ü ro p 0 R R P R p 0 a R •H 0 0 •H O 0 0 & 0 R R ■H PR •H R X) a p bD § rO P 0 !> O rH p O R R •H 0 rH 0 p •H R 0 3 O O 0 R PR c PR co P EH P 0 P O P Ph 02 3 m CO Q) EH R O I CO en en MO MO T- en cm vf on un un * in in en un en CM * * CM » vf vf 1D MO M- CM on en t- MO CM un CM CM un en co un mo r- un m co CM vf un vf en m un un en •» un tr- un en en •> CM •» Vf •» C"- H- Vf CM MO * co Vf t- CM CM un * un Vf en r— mo m cm un CM T— MO CM O L en Mût 0 •H 0 •H •H rH O H 0 a 0 P 3 T5 0 «H •H O O ü R R rH O O <; S S 907 fins on Protection Island (7/ashington) also showed specific nest site diffe¬ rences (Richardson, 1961). Similarly, Grant and Nettleship (1971) reported that Fulmars and Puffins nesting on cliffs do not restrict nest site selec¬ tion of the other species. In these cases each species used different parts of the habitat, and in¬ terspecific competition was not reported. However, habitat distribution does not always follow directly from habitat preference. Intra- and interspecific competition may exclude birds from their preferred habitats. For example, in some areas Red-tailed Tropic birds and White-tailed Tropic birds had only a 6 % overlap in nest site types (Prys-Jones, Peet, 1980), but Diamond (1975b) reported a 78% overlap on Aldabra Atoll, suggesting intense competition. On Ascension Island, Red-billed and White-tailed Tropic birds competed for nest sites, and the ownership of nest sites changed frequently (Stonehouse, 1962). Interspecific competition for nest sites can result in nest take-overs and the replacement of one species by another. In Norway Brun (1972) reported that Northern Gannets have ousted Common Murres (»Guillemots) and Black-leg¬ ged Kittiwakes from breeding sites in two of four colonies. Similarly, in New Zealand, Cape Gannets have taken over the traditional breeding sites of White-fronted Terns (Reed, 1979). On Skomer Island Manx Shearwaters exclude Atlantic Puffins from burrows they would otherwise use, particularly affect¬ ing young adult puffins unable to successfully compete for burrows (Harris, 1966). Belopol' skii(1957) also reported competition for nest sites among spe¬ cies: Thick-billed Murres sometimes take over Kittiwake nests; and Common Murres take over nests of Thick-billed Murres, Auks and Puffins, and the cliff-top nests of eiders, geese and Black Guillemot. Cassin's Auklets and Rhinoceros Auklet similarly compete for nest sites, and the density of Rhi¬ noceros Auklet burrows affects the presence of Cassin's Auklets (Vermeer, 1979). Under some circumstances, kittiwakes can replace nesting Fulmars (Coulson, Horobin, 1972). In larid colonies, the larger species often takes over nest sites of smaller species, eventually eliminating them from these colonies (Vermeer, 1970; Morris, Hunter, 1976; Furness, 1977; Burger, Shis- ler, 1979). Larger larids often arrive at the colony sites earlier than smal¬ ler species, suggesting temporal factors may play a role. Clearly size and arrival times are important factors determining the win¬ ner of interspecific competition for nest sites. However, smaller species that arrive later can acquire nest sites if they intrude as a dense group rather than as individuals. For example. Blue-faced Boobies can win against larger Laysan Albatross on Kure Atoll (Kepler, 1969), dense-nesting Arctic Terns can evict Herring Gulls (Bianki, 1977), and Sandwich Terns arriving later than Black-headed Gulls succeed in moving into the center of the colo¬ ny, displacing the two or three resident territory holders (Taverner, 1969)* For some species, there are added benefits of mixed species colonies: petrels use burrows excavated by Tufted Puffins (Boersma et al., 1980), Cas- sins' Auklets (Thoreson, 1964), and Atlantic Puffins (Cramps et al., 1974)» and Fulmars occupy the sites of Shags after the latter have bred. In summary» interspecific competition for nest sites exists in some colonies, but not others. Assuming complete displacement does not occur, a species will usually 908 have more competition from conspecifics that require similar sites than from heterospecifics with different requirements. Nest Materials: Competition for nest materials is a disadvantage of nest¬ ing in both monospecific and mixed-species colonies. Presumably interspecific competition will be intense when requirements for materials are similar (i.e. f rigatebirds, Diamond, 1975a), but will be less'where requirements differ. Thus, given the same number of pairs in a colony, the presence of heterospe¬ cifics should lessen competition for nest materials. Mates: Since competition for mates is restricted to conspecifics, mixed- species colonies of equal numbers of nesting birds as monospecific colonies will have lower levels of mate competition than monospecific colonies. Pood: Competition for food is a potential disadvantage of nesting in colo¬ nies since members do not obtain food from their individual territories but gather food in the area around the colony. The area around each colony where birds obtain their food depends on the foraging behaviour of each species, food availability, and amount of suitable foraging habitat. One advantage’ often attributed to colonial nesting is the increased potential for exploi¬ tation of patchily-distributed food resources (Ward, Zahavi , 1973). Presumab¬ ly, members of a colony obtain information about food sources from colony ma¬ tes, whereas a solitary nester might be unable to locate food patches. Por heterospecifics information transfer and local enhancement would function only if two or more species use the same foods and can obtain information about food sources from heterospecifics. Interspecific competition for food has been examined for a number of spe¬ cies, and differences in foods consumed have been shown for most species. olkman et al. (1980) found differences in size of prey items taken (Buphau- 3ia spp.) by three species of penguins breeding in Antarctica, although krill made up most of the diet of all three. Similarly, Berruti (1979) showed that Sooty and Light Mantled Albatross ate different foods; Diamond (1975a) repor¬ ted that Great and Lesser Prigatebirds are similar prey items although the latter preferred squid over fish; Nelson (1975) found that frigatebirds caught prey by surface dipping and aerial snatching, and did not exploit food in deeper ocean layers available to boobies, tropic birds, cormorants and pelicans ; Diamond (1975b) reported that on Aldabra Atoll Red-tailed Tropic birds take larger fish and feed farther from land than White¬ tailed Tropic bird, and Vermeer (1979) showed that Rhinoceros Auklets feed at night while Tufted Puffins feed on different fish during the day. Blus, Prouty, Neely (1979) showed that while nesting in the same colony 63% of the diet of Sandwich Terns was shrimp and anchovies whereas 57„, of the diet of Royal Terns was Menhaden (Brevoortia tyrannus) . Similarly, lemmetyinen (19765 showed difference in feeding habitat and foods taken bet- ween Arctic and Common Terns in Finland. Witt et al. (1981) showed that Audouin's and Herring Gulls breeding on Mediterranean Islands used different foods ; Audouin’ s Gull fed on fish (over 90%) obtained coastally by fishing while Herring Gulls fed mainly on plant material, birds, and fish obtained ffom human sources. Unlike most studies, Belopol' skii (1957) compared the aiets of several taxonomically diverse seabirds in the Barents Sea (Table 3) abd found that fish comprised 0-97% of the diet of these species, with alcids taking the highest percentage of fish. 909 Table 3. Pood Competition among seabirds at East Murman, Russia (after Belopolskii, 1957) x = > 70% diet, y = > 70%, () a % Pish Crustaceans Molluscs Insects Birds & Mammals Berri Common Eider (0) Y X Arctic Skua x (62) Y Y Y Y Herring Gull x (53) Y Y Y Y Y Black-backed Gull x (73) Y Y Y Y Mew Gull y (39) Y Y Y Y Arctic Tern x (55) Y Y Black-legged Kittiwake x (71) Y Y Y Black Guillemot x (73) Y Puffin x (875 Y Thick-billed Murre x (90) Y Common Murre x (96) Razor-billed Auk x (97) These examples indicate interspecific overlap in food items, with a reduc¬ tion in competition through differences in size and type of prey, habitat se¬ lection, foraging techniques, and time of foraging. No study has shown 100% overlap in even one of these parameters (with the possible exception of the Antarctic Penguins). Nonetheless, the overlap is less than among conspecifics. Given the same number of individuals in a colony, competition for food should be less in mixed-species colonies compared to monospecific colonies: particu¬ larly when colonies are comprised of birds from different taxonomic families. However, overlap in foods used does not prove competition, which requires li¬ mited resources. Some authors have suggested that when food is scarce it is unavailable to all birds causing general starvation, not selective starvation of those less able to "compete" (Vermeer et al., 1979). Overlap in foods makes it possible for information transfer to occur. Proofs of information transfer are difficult to obtain even in monospecific colonies, partly because this mechanism would not Have to operate at all ti¬ mes to be selected for. Krebs (1974) tested the hypotheses of information transfer in Great Blue Herons (Ardea herodias) and reported that birds depart¬ ed from the colony non-randomly , birds from neighboring nests left together, and flock feeders had higher success than solitary feeders. In seabirds, syn¬ chrony of departure from colonies has been found for murres and puffins (Ash¬ croft, 1979) although no one has examined synchronous departure of heterospe¬ cifics from seabird nolonies. Mixed species foraging flocks are very common (Sealy, 1973). Hoffman et al. (1982) found that 3ome species act as catalysts in mixed species flocks, sug¬ gesting an advantage to non-catalysts of nesting in colonies with catalysts (larids and shearwaters). Away from colonies, birds may be attracted to evi¬ dence of a food source 3uch as diving terns (local enhancement, Gochfeld, 910 Burger, 1981). Caldwell (1981) examined mixed-species heron flocks, and found that herons were attracted to the presence of models, indicating that local enhancement occurs. However, sucn experiments do not test for information transfer within colonies. Theoretically the potential for information trans¬ fer is less in mixed species colonies compared to monospecific colonies be¬ cause each species uses différait prey items and foraging techniques. Al¬ though Bayer (1982) argued that information transfer could not have been a factor in the evolution of coloniality since a colony must already exist for it to occur, I submit that mixed species colonies could have information transfer as a selective factor. Birds already using information on food sour¬ ces from conspecifics could easily begin to use information from heterospe¬ cifics. Predation and Predator Protection Birds are exposed to predators whether they nest solitarily or in mono¬ specific or mixed-species colonies. However, many predators and pirates nest within mixed-species colonies. In this section I discuss predators and pi¬ rates nesting within mixed-species colonies; and anti-predator behavior of cojony members. Predators: Two types of predators nest in mixed species colonies, colo¬ nial birds that normally associate with particular species, and those that sometimes nest in mixed species colonies but usually nest solitarily. The large, white-headed gulls are predators that nest with many other seabirds) (refer to Table 2). Herring, Great Black-backed, Glaucous, Western, Dolphin, Kelp and California gulls prey on the eggs and young of colony members in¬ cluding Jackass Penguins (Howlands, 1981), Garnets (Taylor, Wodzicki, 1958), White Pelicans (Schaller, 1964), Storm Petrels, Manx Shearwater and Atlantic Buffins (Harris, 1980; Nettleship, 1972), Double-crested Coxmiorants and King Shags (Kury , Gochfeld, 1975), Cassin's Auklet (Thoresen, 1964) and Thick- Billed Murres (Birkhead, Nettleship, 1981). The large gulls frequently eat the eggs of similarly-sized congenerics (Brown, 1967) and eggs of smaller larids such as Black-headed Gulls (Kruuk, 1964), Laughing Gulls (Burger, ^79) , Ring-billed Gulls (Vermeer, 1970), Common and Arctic Terns (Lemme- tyinen, 1 97 1 5 . Small gulls such as Laughing Gulls will occasionally prey on the eggs of terns (Blue et al., 1979; Burger, Lesser, 1978). Predation by Sulls on smaller species often leads to desertion of colony sites by smaller species (Morris, Hunter, 1976; Burger, 1979). Indeed Black Skimmers are more likely to desert colony sites after failure due to predation than to flood- Ihg (Burger, 1982). Gulls inflict considerable damage: Harris (1980) reported IRat 40 pairs of Great Black-backed^ Gulls nesting in a Puffin colony killed 1-5% of the adult breeding population annually (2600 Puffins/year). Predat¬ ion rates were highest in low density-nesting areas. Gulls cause Puffins to leave their burrows by giving alarm calls; at each disturbance departing ^nffins displace 13-17% of their eggs to burrow entrances where gulls eat them (Nettleship, 1972). I'wo other seabirds are predators on colony mates: skuas and frigatebirds. ^igatebirds take the eggs and young of other seabirds (Nelson, 1975) and °°ngenerics (Nelson, 1968; Schreiber, Ashmole, 1970). But since frigatebirds u®Ually nest in monospecific colonies, their effect on other species is di- 911 minished. Skuas, however, are formidable predators in any colony where they nest. The effect of Antarctic Skuas on penguins and petrels (Tenaza, 1971; Young, 1978) congenerics, and other seabirds (Furness, 1981) is great. The relationship between Adelie Penguins and South Polar Skuas is complex: skuas keep other skuas out of their territory, and penguins nesting within this territory are exposed to predation only from resident skuas that usually eat deserted eggs and chicks, and are unable to acquire incubated eggs, or chicks in creches (Young, 1978). Predation is greater on edge-nesting penguins un¬ protected by territorial skuas, where two or more skuas cooperate to distract parent. In eight breeding seasons. Great Skuas ate eggs and young of conspe- cifics. Puffin, Kittiwake, Parasitic Jaeger, Fulmar, Storm Petrel, shag, gulls, Black Guillemot and Arctic Tern with jaegers sustaining the highest population loss (22%) each year (Furness, 1981). Non-seabird predators also nest in seabird colonies (crows, night-herons). Crows nesting adjacent to Pelagic and Double-crested Cormorant colonies in British Columbia ate cormprant eggs (Verbeek, 1982). Black-crowned Night Herons (Nycticorox nyctlcorax) ate eggs and chicks of Common Terns at an On¬ tario colony, causing temporary desertion of adults and lowered reproductive success (Hunter, Morris, 1976). At Agassiz National Wildlife Refuge I found Black-crowned Night Herons nesting in Franklin's Gull colonies, shifting lo¬ cations with the gulls. The gulls did not eat eggs of gulls or night-herons, but the night-herons ate the eggs and young in most gull nests within 10 m of their nests. Pirates: Stealing food from conspecifics or other species occurs where birds are foraging, or feeding young at colonies. Some pirates neat in mixed species colonies. On Marion Island, Lesser Sheathbills (Chionis minor) stole most of their food from penguins feeding their chicks crustaceans, fish and squid (Burger, 1979). Red-tailed Tropic birds on Kure Atoll are often forced to disgorge their food to Great Frigatebirds (Woodward, 1972). Larids are the most frequent pirates that nest in seabird colonies: Laughing Gulls rob food from Sandwich and Royal terns (Blus et al., 1979), Herring and Great Black-backed Gulls pirate from Puffins (Nettleship, 1972), and Silver Gulls rob Lesser Crested and Crested Terns (Hulsman, 1976'. Such piracy can reduce reproductive success: Nettleship (1972) reported that where gulls nested 37% of Puffin nests fledged young compared to 90% on Funk Island where gulls did not nest with Puffins. Antipredator Behaviour : Birds sestiog in colonies have several methods of protection from predators including early warning, predator defense and pas¬ sive "predator swamping". These advantages work less well in colonies where predators nest, since birds habituate to them. But, where predators nest out¬ side* the colony, interspecific warning can occur, each species can give early warning, end the species giving the first warning may vary. I have observed this in mixed species colonies of Herring and Great Black-backed Gull; Herring and Laughing Gulls; Laughing Gull and Common Tern; and in mixed species colo¬ nies of ardeids. Further, recognition of warning signals cuts across familial lines as Black Guillomots in burrows respond to the warning cries of shore- birds, and larids (Bianki, 1977), and puffins, herons, terns, and cormorants respond to gull calls (Nettleship, 1972; Burger, unpub. data). For burrowing 912 species, the advantage of above-ground heterospecifics giving warning calls is obvious. Direct defense behaviors such as chasing or mobbing predators are effect¬ ive for several species (see: Kruuk, 1964; Burger, 1981) and should be ef¬ fective whether the mobbing is performed by one or several species. Mobbing does involve a cost, as predators sometimes take a diving bird (Myers, 1978). For most species in mixed species colonies, the effect of mobbing is equal regardless of who mobs. However, some species do not mob, and derive advan¬ tages from heterospecifics that do. Sandwich Terns depend upon the pugna- ceousness of nearby Black-headed Gulls to chase predators away, and shift colony sites along with them (Hehls, 1969; Smith, 1975). Although gulls try to eat tern eggs, the terns can defend them (Lind, 1963). Other examples of protective associations include: Caspian Terns with other larids (Bergman, 1980), Gull billed Terns with Black-headed Gulls (Möller, 1981), Common 3ulls with Parasitic Jaeger (Gotmark, Anders3on, 1980), and Black Skimmers «ith Common Terns (Burger, Lesser, 1978). Protective associations are not restricted to seabirds (see Nuechterlein, 1981). One anti-predator strategy given as a cause of birds nesting in colonies is increased social facilitation which increases breeding synchrony, results in young produced over a short period of time, and effectively "swamps pre¬ dators" (Darling, 1938; Burger, 1979; Gochfeld, 1980). Presumably some social facilitation occurs among species in mixed species colonies (Orians, 1961). Hilden (1965) noted that Little Gulls need the facilitation of colonies of ■terns and Black-headed gulls to become established, and Bergman (1980) in¬ dicated the importance of other larids to Caspian Terns establishing themsel- ves in the Baltic. The social stimulation of cormorants is essential to the establishment of Gannet colonies in Norway (Brun, 1972). I have observed lone Pairs of Black Skimmers nesting in Common Tern colonies, while solitary pairs of nesting skimmers do not occur. Obviously these birds obtained some "so- cial benefit" from heterospecifics. Disease and Parasites: Birds in colonies are exposed to increased loads °f parasites and diseases because they are in close proximity and interact ^nily. Many parasites are able to use more than one seabird species as a host (Hindwood et al., 1963) suggesting that mixed species colonies do not comple¬ tely reduce the risk of parasitism. This aspect of seabird biology needs fur¬ ther study. SUMMARY The advantages and disadvantages of mixed species colonies relate to re¬ source allocation, predation and disease. Birds in mixed species colonies c°mpete for nest sites, materials and food, and must avoid predation and di¬ sease. Colonies are obvious to predators, but they can be in inacessible aites. Colony defenses include mobbing and early warning. Social facilitat¬ ion ia a mechanism to increase breeding synchrony which lowers predation through "predator swamping"; and information transfer is a mechanism to ob- tain information about nesting sites, impending danger, and food. These ad- vantages operate -in monospecific colonies, but the disadvantages of competit¬ ion for food, nest materials and nest sites are lessened in mixed-species co- i°nies since heterospe'cifics do not have exactly the same requirements.. For 22-3sk. 981 9-1:5 many species, mixed species colonies may be a result of habitat pressure. Heterospecifics increase the effective colony size for predator detection, predator protection, social facilitation and information transfer, while lessening competition for space. Some species derive most of their predator protection from mixed-species associations, seeking out protector species. Thus, nesting in mixed-species colonies reduces the costs of competition and allows the benefits of social faciliatlon and predator protection to re¬ main constant or increase in protective associations. ACKNOWLEDGMENTS I have had many fruitful discussions on coloniality over the years with many people and I thank them: C.G.Beer, R.M. Erwin, M.Gochfeld, J. Krebs, D.W.Mock, B.G. Murray, J. Ryder, G.Shugart and W.E. Southern. APPENDIX A. Advantages and Disadvantages of Mixed-Species Colonies of Seabirds I Advantages A. Predator Protection 1 . Early warning 2. Predator defense a. mob predator b. attack predator 3- "Predator Swamping" B. Resource Utilization .1. Pood a. Decreased competition for food compared to equal number of conspecifics b. Information transfer and local enchancement of food sources c. Direct source of food for kleptoparasites or predators nesting within colonies 2. Nest site3 a. Different species-slightly different requirements b. Burrows excavated by one species can be used by another 3. Nest materials C. Colony Establishment 1. Indication of safe nesting sites 2. Nucleus for solitary or small number of colonizers II Disadvantages A. Predator and Kleptoparasite Enchancement 1. Colonies are easier to detect with diversity of cues from different species 2. Predators and Kleptoparasites often nest within cblonies, and are attracted to colonies 3. Different species might result in longer total breeding period (reduce the effect of "predator awamping") B. Competition 1. Nest sites and materials 2. Pood C. Disease Transmission D. Interspecific Aggression 914 p . ^3 Sî T) «0 01 *4 X — O - 3 p ' X) -H — c I P (0 H X U H J rH U iH — P <13 lô P U rH -H O rH CQ C -• CP MED E M O M O •H 0) 4H M (fl -H p Û4 M (A »H (fl .H ci 0) ig v (i X EJ U £ X rH x: ä to *o 2 5 3.. U — — ^1 > _ e 3 hS 2 O T3 3 0J — Æ H H 3 - I HH UJ w . . * P P H 0) h H ucjcj m h -a -h h rtj - P id .Q p ^ C O J) l U Œ P E -H C M ,o h h h i ÜC*J E rH flj M H H H H OU^t^WCOWJ (fl 2 cd ■H ,1, 0 Tl C (fl •0 2 1 O * C a ⣠M U 3 o «J K W M to C 3 2 S •H O -H fl ai CQ X 915 References Amerson A.B. Jr., Clapp R.B. , Wirtz W.O. - Atoll Research Bull., 1974, JJ., p. 174-306. Amerson A.B. Jr., Shelton P.C. - Atoll Research Bull., 197j6, 192, p. 1-479. Anderson D.W. , Bartonek J.C. - Condor, 1967, .62’ p. 311-313* Ashcroft R.E. - Omis, Scand. , 1979, 22» p. 100-110. Bayer R.D. - Auik, 1981, 99, p. 31-40. Belepol'skii L.O. - Ecology of Sea Colony Birds of the Baerents Sea. Moscow, 1957. Beck J.R. , Brown D.W. - Ihis, 1971, 113, p. 75-90. Bedard J. - Condor, 1969, 21» p. 386-398. Bergman G. - Omis Pennies, 1980, _57, p. 141-152. Berruti A. - Emu, 1979, ]2, p. 161-175. Bianki V. V. - Bulls, shorebirds and alcids on Kandalaksha Bay. Israel, 1967. Birkhead T.R., Nettleship D.W. - Auk, 1981, ,28, p. 258-269. Blus L.J., Prouty R.M. , Neely B.S. Jr. - Biol. Cons., 1979, J2., P* 301-320. Boersma P.D. , Wheelwright N.-T. , Nerini M.K. , Wheelright E.S. - Auk, 1980, 97, p. 268-282. Brown R.G.B. - Ibis, 1967, 109, p. 502-515. Brun E. - Astarte, 1971, .4, p. 53-60. Brun E. - Omis, 1972, Scand., 2, P« 27-38. Burger A. E. - Ardea, 1979, 67. p. 1-14. Burger J. - Condor, 1979, 81_, p. 269-277. Burger J. - Quart. Rev. Biol., 1981, ,56 , p. 143-167. Burger J. - Auk, 1982, 22» P* 109-115. Burger J. , Lesser F. - Ibis, 1978, 120, p. 433-449- Burger J., Shisler J. - Auk, 1978, 95, p. 252-265. Burger J. , Miller L.M., Hahn D.C. - Wilson Bull., 1978, 22, p. 359-375. Caldwell G.S. - Behav. Ecol. Sociobiol. , 1981, 8, p. 99-103. Clapp R.B. , Kridler E. - Atoll Research Bull., 1977, 20_, p. 1-102. Clapp R.B., Wirtz W.O. - Atoll Research Bull., 1975, 186. p. 1-196. Coulson J.C., Horobin J.M. - Ibis, 1972, 114, p. 30-42. Cramp S. , Bourne W. R. P. , Saunders D. - Seabirds of Britain and Ireland. New York, Taplinger Publ. Co. Darling F.F. - Bird Flocks and the Breeding Cycle. London, Cambridge U. Press, 1938. Diamond A.W. - Condor, 1973, 72, p. 200-209. Diamond A.W. - Ibis, 1975a, 117. p. 302-323. Diamond A.W. - Auk, 1975b, 21, P* 16-39. Drent R.H. , Guiguet C.J. - Occ. Paper British Columbia Mus, 1961, J_2, P- 1" 173. Ellison L.N. , Cleary L. - Auk, 1978, 22> P* 510-517. Erwin R.M. - Ani. Behav., 1979, 27, p. 1054-1062. Evans F.G.H. - Ibis, 1981, 1 23. p. 1-18. Furness R.- Brit. Birds, 1977, 70, p. 96-107. Furness R. - Seabird Report, 1981, 6, p. 5-12. Furness R.W. , Baillie S.R. - Ringing and Migration, 1981, 2> P- 137-148. Frings H. , Frings M. - Condor, 1961, 63, p. 304-312. 916 J . Bur- Gallagher M.D. - Ibis, I960, J02, p. 489-506. Gochfeld M. - In: Behavior of Marine Animals IV. Marine Birds / Eds. ger, B. 011a, H.Winn. New York, Plenum Press, '1980, p. 207-270. GochfeldM., Burger J. - Behav. Eool. , Sociobiology , 1981, J0, p. 15-17., Gotmark P., Andersson M. - Ornis, Scand. , 1980, JJ_, p. 121-126. Grant P. R., Nettleship D.N. - Ornis, Scand., 1971, 2, p. 81-87. Harris M.P. - Nature in Wales, 1963, 8, p. 56-58. Harris M.P. - Ibis, 1966, J08, p. 17-33. Harris M.P. - Ibis, 1969, JJJ, p. 139-156. Harris M.P. - Ibis, 1973, JJ5, P* 483-510. Harris M.P. - Condor, 1974, 76, p. 249-261. Harris M.P. - Ibis, 1980, J22, p. 193-209. Harris M.P. , Bode K. G. - Emu, 1981, 8J, p. 20-28. Hilden 0. - Ann. Zool. Pennici, 1965, 2, p. 53-75. Hindwood K. A., Keith K., Servently D. L. - Div. Wildlife Technical Paper, 1963 2, p. 1-44. Hoffman W. , Heinemann D. , Wiens J. A. - Auk, 1981, 98, p. 437-456. Hulsman K. - Emu, 1976, 76, p. 143-149. Hunt G. L. Jr., Pitman R.L., Jones H.L. - In: The Califomial Islands / Ed. by D.M. Powers, 1980, p. 443-459. Hunter R.A. , Morris R.D. - Auk, 1976, 9 J, p. 629-633. Jouventin P., Guillotin M. - Rev. Ecol. , 1979, 21. P- 109-127. Kepler C.B. - Auk, 1967, 84,' p. 426-430. Kepler 0.3. - Pub. Nuttall- Ornithological Club, 1969, 8, p. 1-97. Kepler C.B., Kepler A. K. - Living Bird, 1977, J6, p. 21-50. Krebs J.R. - Behaviour, 1974, 5J, p. 99-134. Krunk H. - Behaviour Suppl., 1964, J_J, p. 1-129. Kury c.R. , Gochfeld M. - Biol. Cons., 1975, 8, p. 23-34. Lemmetyinen R. - Ornis Fenn. , 1971, 48, p. 13-24. Lemmetyinen R. - Auk, 1976, 93, p. 636-640. Lid G. - Fauna Norv. 3er. C, 1980, 4, p. 30-39. land H. - Dansk Omith. Poren. Tidsskrift, 1963, 57, p. 155-175. Manuwal D. A. , Manuwal N. J. - Western Birds, J_9, p. 189-200. Coller A. P . - Ardea, 1981, 69, p. 193-198. Morris R. D. , Hunter R.A. - Canadian Field Naturalist, 1976, 90, p. 137-143. risoD M.L. , Shanley E. Jr. , Slack R.D. - Southwest Naturalist, 1979 24 P- 259-266. Ä2* Morse D.H. , Buchheister C.W.- Bird-band., 1977, 48, p. 340-349. Murbarger N. - Natural History, 1 956, p. 298-305. Myers P. - Auk, 1978, 95, p. 419-420. Nehls H.W. - Vogelwarte, 1969, 25, p. 52-57. Melson J. B. - Nature (L. ), 1967, 21 4. p. 318. Nelson J. B. - Galapagos, Islands of Birds. L. : Longmans, 1968. Kelson J. B. - Living Bird, 1975, Jl, p. 113-156. Mettleship D.N. - Ecol. Monogr. , 1972, 42, p. 239-268. Nuechterlein G.S. - Anim. Behav., 1981, 25, p. 985-989. °rians G.H. - Condor, 1961, 6 J, p. 330-337. ^ince P.A. - Ibis, 1980, J22, p. 476-488. ^s-Jones R.P., Peet C. - Ibis, 1980, J22, p. 76-81. 917 Reed S. - Nortomis, 1979, 26, p. 89-93. Richardson F. - Condor, 1961, 6j, p. 456-473. Richdale L.E. - Ibis, 1964, 106, p. 110-114. Roby D.D. , Brink K.L. , Nettleship D.N. - Arctic, 1981, 21> p. 241-248. Rowlands B.W. - Bokmokierie, 1981, 22» P- 21-24. Schaller G. B. - Condor, 1964, 66, p. 3-23. Schrieber R.W., Ashmole N.P. - Ibis, 1970, 1 1 2. p. 363-394. Sealy S. G. - Auk, 1973, 20, p. 796-802. Smith A.J.M. - Brit. Birds, 1975, 68, p. 142-156. Spellerberg I.P.- Ardea, 1971, 22, P- 189-229. Stone W. - Bird Studies at Old Cape May. New York, Dover, 1937. Storehouse B. - Ibis, 1962, 103b, p. 409-422. Taverner J.H. - Seabird Report, 1969, p. 46-47. Taylor R.H. , Wodzicki. - Notomis, 1958, 0, p. 22-23. Tenaza R. - Condor, 1971, 78, p. 81-92. Thoresen A.C. - Condor, 1964, 66, p. 456-476. Tickell W.L.N. , Pinder P. - Ibis, 1975, 117. p. 433-451. VanGessel P.W.C. - Corella, 1978, 2, p. 52-53. Verbeek N.A.M. - Auk, 1982, 9 2, p. 347-352. Vermeer K. - Canadian Wildlife Report, 1970, N 12, p. 1-52. Vermeer K. - Ardea, 1979, 67, p. 101-110. Vermeer K. , Cullen L. - Ardea, 1979, 67, p. 22-27. Vermeer K. , Vermeer R. A. , Summers K.R., Billings R.R. - Auk, 197,9, %,P-143' 151. Vemer J. - Auk, 1961, 2§> P* 573-594. Volkman N.J., Presler P. , Trivelpiece W. - Condor, 1980, 82, p. 373-378. Ward P. , Zahavi A. - Ibis, 1973, H5, p. 517-534. Warham J. - Auk, 1963, 80, p. 229-256. Warham J. - Ardea, 1972, 60, p. 145-183. Warham J. , Keeley B.R., Wilson G.J. - Auk, 1977, 21, P. 1-17. White M.G., Conroy J.W.H. - Ibis, 1975, 211» p. 371-373. Williams A.J. - Omis, Scand. , 1974,2, p. 113-121. Witt H.H. , Cresppo J. , Suana E. D. , Varela J. - Ibis, 1981, J_23, p. 519-526. Wood R.C. - Auk, 1971, 88, p. 805-814. Wdods R.W. - Ibis, 1970, 212, p. 15-24. Woodward P.W. - Atoll Research Bull., 1972, 164. p. 1-318. Young E.C. - Ibis, 1963, 105. p. 203-233. Young E.C. - New Zealand Jour. Zoology, 1978, 5, p. 401-416. SOME FURTHER COMMENTS OK THE GATHERINGS OF BIRDS A. Zahavi Institute for Nature Conservation Research, Tel-Aviv University, George S.Wise Faculty of Life Sciences, Israel I have been asked by Dr. Burger to use the available time, owing to the absence of Dr. Nettleship to add some comments on the function of the gather¬ ings of birds as information centers (Ward, Zahavi; 1973). Some of these com¬ ments are the outcome of discussions with the late Dr. P.Ward whose recent tragic death ended for me a very fruitful collaboration. Consider these com¬ ments as comments to a discussion rather than as a paper in the symposium. 1. Since we have published the hypothesis there have been a few attempts to gather evidence to test the hypothesis. A few attempts have failed to se¬ cure evidence for the hypothesis (Evans, 1982; Bayer, 1982). When locking for such evidence it is important to remember that although information con¬ cerning the location of food may sometimes be of use, birds are not necessa¬ rily in search of such information every day. In order to secure supporting evidence it may be necessary to watch at particular days following a sudden decline of food. I shall cite an observation by Dr. Pearse (pers. comm. ) to illustrate the case. Rooks (Corvus frugilegus) around Aberdeen breed in Co¬ lonies in which trey also roost in summer. But in winter several colonies gather for the night roost. In the morning the rooks fly first to their res¬ pective colonies and later always forage within the homerange of the colony, further there is evidence that food is more abundant in winter than it is in summer. These findings seem to contradict the hypothesis that the commu¬ nal roost serves for rooks as an information center. But once, during a snow storm when most of the ground was covered with snow and visibility was very low, a whole colony followed another colony, from the night roost, to feed together on a stack of com available above the snow. It is reasonable to believe that unless the rooks at that time had information about food they would not have been able to survive. It may be that such rare cases are sufficient to select for the communal roost. 2. Birds are attracted to the communal roost by the communal displays which occur in most communal roosts sometime before the birds go into the r°ost. In 1973 we suggested that the displays function as "advertisement to facilitate the assembly into a single roost of as many birds as possible, from as far away as possible. The more birds attending a particular roost, the larger is the area searched for food and the greater is the chance of good feeding places within it being decovered". Although the displays serve to advertise it is a mistake to consider the advertisement as an ul¬ timate reason (as we did) for the behaviour of the individual bird in the flock. Stated as it is, it is a group selection argument. A bird may rest ih the periphery of the roost and enjoy the outcome of the advertisement Without investing in it. Those who are not satisfied in explanations by mo¬ dels of group selection should consider an alternative explanation. I suggest that 'a bird which displays with others is able to assess its Potential to compete with its flock members when they would eventually reach tile feeding site. There is often no point to arrive at a feeding site if all 919 other members of the flook are quicker and stronger. Such a hypothesis sug¬ gest that the strength, agility and other performances of individuals in va¬ rious flocks differ to the extent that a bird may benefit from picking the flock which suits its potential. Such a hypothesis may be tested. 3. Birds watching daily the gatherings into a communal roost may acquire some information on the homerange of their roost without having to go out of their individual homerange. If the numbers of birds in the roost increases they would benefit if they Btay because if it is good for the new -arrivals the home range of the roost may still 3erve them if they loose their feeding sites, on the otherhand if numbers decline in the roost they may also do well if they leave before they are actually short of food. 4. I still believe that a gathering without active defence is not an ef¬ fective strategy to reduce predation pressure in birds. Although predation certainly affect much of the behaviour of the birds in the gathering, predat¬ ion pressure by itself has not selected birds to gather into roosts or nest¬ ing colonies. 5. In 1973 we have overlooked the importance of sexual selection as a pri¬ mary factor in selecting birds to form leks and nesting colonies. There is now some evidence to show that leks may function as advertisement for the fitness of the males. Males in the center of a lek have a much higher fitness than peripheral males. Thus leks function for females as information centers to leatn about the fitness of their potential mates and for males to adver¬ tise their fitness. Coulson (this symposium) has provided evidence to show that in Kittiwakes, Rissa tridactyla. the nesting colony may function as ad¬ vertisement to the fitness of the males and that females prefer central males to peripheral males. 920 Symposium PHYSIOLOGY OF REPRODUCTION, MOULT AND MIGRATION Convener: D.S. FARNER, USA Co-conveners: I. ASSENMACHER, FRANCE; P. BERTHOLD, FRG BERTHOLD P. ENDOGENOUS COMPONENTS OF ANNUAL CYCLES OF MIGRATION AND MOLT NOSKOV G.A., RYMKEVICH T.A. PHOTOPERIODIC CONTROL OF POSTJUVENILE AND POSTNUPTIAL MOLTS IN PASSERIFORMES JALLAGEAS M., ASSENMACHER I. ENDOCRINE CORRELATES OF MOLT AND REPRODUCTIVE FUNCTION IN BIRDS • MOORE M.C., FARNER D.S., DONHAM R.S., MATT K.S. ENDOCRINE AND PHOTOPERIODIC RELATIONSHIPS DURING PHOTOREFRACTO¬ RINESS, POSTNUPTIAL MOLT, AND ONSET OF MIGRATION IN ZONORITCHIA LEUCOPHRYS GAMBELII NOVIKOV B.G., RUDNEVA L.M., BULDAKOVA A.N., IVANOVA L.S., GARMATI- nas.m. the ROLE OF THE HYPOTHALAMO— HYPOPHYSIAL SYSTEM IN THE ANNUAL CYCLE OF MOLT AND GONADAL FUNCTION ENDOGENOUS COMPONENTS OP ANNUAL CYCLES OP MIGRATION AND MOULT Peter Berthold Max-Flanck-Institut für Verhaltensphysiologie, Vogelwarte Radolfzell, D-7760 Radolfzell, FRG INTRODUCTION During the past two decades a steadily increasing body of evidence indi* cates that endogenous components are involved in the control of annual proces^ ses in birds. Among European-African long-distance migrants in which such components have been extensively demonstrated it seems that annual periodi¬ city is based on endogenous components. The most important endogenous func¬ tions of these species are the so-called circannual rhythms. As shown at the last International Ornithological Congress (Berthold, 1980), they have been proven to be true biological clocks, i.e. self-sustained internal rhythms, at least in part with life-long efficacy. In addition, circannual rhythms have been shown to control at least seven different annual processes in birds including migration and moult (e.g. , Gwinner, 1981). More recently , convincing evidence has been accumulated that these inter¬ nal rhythms can reflect species- and population-specific temporal programs and thus are important for the detailed time course of individual annual pro¬ cesses. In some cases these control mechanisms have been demonstrated to have a genetic basis. The following sections will concentrate on innate en¬ dogenous components involved in migratory activity and moult, in the control of some morphological features associated with migration, and on the innat¬ eness of the migratory urge. ENDOGENOUS PATTERNS OP MIGRATORY DISPOSITION AND RESTLESSNESS* INSENSITIVITY TO EXTERNAL INFLUENCES Over the past nine years »e have carried out a set of eight experiments under defined conditions on the garden warbler, Sylvia boriw. to test 2 vironmental influences on the changes of body weight and migratoiy restless- lySin"eg Hh th6 miSrat7 Peri°d- THe re8UltS aPe deplCt6d thematical¬ ly in Fig. 1. The upper graphs show the time course of body weight during the migratory period, the lower those of nocturnal restlessness. Solid lines re- preaen data from control groups, broken ones those from experimental groups. All data were obtained from groups of at least the hand-raised individuals during their first autumnal migratoiy period. 1 Part A shows the normal pattern of body weight and restlessness during the migratory period from about July to the end of the year as they are ex¬ pressed in natural light conditions as »11 ». , * . , ^ 3 as wel1 as In various constant expert- ■«nt.l conditions. B refer. to » experiment, 1» »hich »inner (,974) almost completely depressed restlessness By darkening during nlgM por . „„md of t.o months. Despite this trestment. the sub»e<,„,„. of restl.Less tn the experiment. 1 group ... p.r.llel ,0 th.t of the control groÛp » prosed to be uninfluenced by the previous trestment. a two oth„ „peri- 922 Fig. 1. Schematic presentation of the normal course (A) of changes in body mass (above) and of migratory rest- lessnes (below) Id Sylvia borin. and data from seven experiments (B-H) to test the effects of environmen¬ tal influences on these patterns. Broken lines: data from experimental groups, solid lines: data from control groups. For details, see text Time of season merits - C and Û - migratory fattening was reduced by temporary starvation (Berthold, 1975, 1976). In the case of moderate starvation, shown in C, there was no influence on the pattern of restlessness. Severe starvation to a strongly depressed body weight, as shown in D, resulted in the cessation of restlessness. But again the subsequent course of body weight as well as that of restlessness in the experimental group was congruent with the control group and appeared to be uninfluenced by this severe experimental treatment. Preventing the birds from fattening at the beginning of the migratory period (E, Berthold, 1977) yielded similar negative results. The same holds true for an experiment with simulated weather conditions (F, Schindler et al. , 1981), in which restlessness was almost completely suppressed in the ex¬ perimental group on 22 completely dark and rainy nights. Except for a ten¬ dency of the experimental group to have a somewhat lower overall time of restlessness and a slightly higher mean body weight, both groups showed con¬ gruent patterns of restlessness and of change in body weight. When south-Finnish birds (from 60° N) and south-German birds (from 48° N) were hand-raised in light conditions that simulated their own breeding area or in those of the other population, all four groups of experimental birds showed almost identical patterns of changes in body weight and of restless¬ ness as shown in G (unpublished data). The only alterations of the endoge¬ nously controlled patterns of body weight and restlessness were observed when birds were kept in long-term, constant photoperiodic conditions (Ber- thold et al., 1972). Then, as demonstrated in H, birds in LD 16:8 showed pro¬ longed and flattened migratory patterns compared with those kept in LD 12:12 or 10:14. In agreement with all earlier findings, and also with those of a very recent experiment, there were no detectable influences on the migratory Patterns (unpublished data) when conditions that birds would encounter when landing in the Sahara desert were simulated. From this set of experiments it seems that, at least in the garden warb- ler, the patterns of migratory disposition, expressed by changes body weight changes due to fattening, and of migratory restlessness, are under extremely rigid endogenous control. Consequently, a direct and strict genetic basis f°r the control of these patterns appears most probable. According to these Results the patterns are assumed to be innate and highly heritable (e.g. , Jacobs, 1981), and with a sliding setpoint (e.g., Mrosovsky, Powley, 1977) that obviously determines the appropriate values. 923 GENETIC CONTROL OP THE AMOUNT AND PATTERN OP MIGRATORY RESTLESSNESS Encouraged by the results obtained from the experiments summarized in Pig. 1, we planned a long-term experiment to test the hypothesis of an in¬ nate character in the amount and pattern of migratory activity. For expe¬ riments of this type the blackcap, Sylvia atricapilla. a widespread species with marked geographical and ecological differentiation, appeared most sui¬ table. We first considered whether populations of this species showed vary¬ ing amounts of migratory restlessness in relation to the migratory distances as found in comparisons among species. Such species differences have been shown in both earlier and more recent experiments for eleven species of the genus Sylvia (e.g., Berthold, 1982, unpublished data). The question concern¬ ing different populations is answered by the data given in Pig. 2 A, B. We hand-raised nestlings of three populations of European blackcaps and one Af¬ rican population. All birds were initially raised in identical simulated na¬ tural-light conditions and their migratory restlessness was later measured in all birds under LD 12.5:11.5. The results obtained are in accordance with the distances of migratory flight in the free-living populations which gra¬ dually decrease with populations from north to south. The degree of migratory restlessness was, as the patterns of restlessness show, greatest in the Fin¬ nish birds, and progressively less in the German, French, and African birds. To test the hypothesis of innateness of migratory behaviour with respect to amount and pattern, cross-breeding was considered the most appropriate method. If the expression of migratory restlessness is under direct genetic control, it is logical to assume a polygenic basis. An intermediate expres¬ sion of »restlessness in both amount and pattern in hybrids from two parental populations, which are differentiated by their restlessness, might then be expected (e.g., Berthold, Quemer, 1981). For our cross-breeding experiment we used the birds from which the data presented in Fig. 2 A, B derived. We choose, for practical reasons, the Af¬ rican and German birds as parental stocks. We successfully hand-raised 32 hybrids and used the same methods to record their migratory restlessness as had been used for their parents (Berthold, Quemer, 1981). The results are shown in Fig. 2 C, D. As one sees, amount as well as pattern of the restless¬ ness of the F1 -hybrids are clearly intermediate in comparison to the parental populations. Thus amount and pattern of migratory restlessness in the black¬ cap are shown to be under direct and obviously strict genetic control. With these findings in mind it is no longer surprising that the pattem of rest¬ lessness in the even more typical migratory garden warbler proved highly in¬ sensitive to various environmental influences (Fig. 1). THE GENETIC CONTROL OF MOULT IN MIGRANTS While performing the cross-breeding experiment with blackcaps described above we planned to include a study of Juvenile development, including moult> and of morphological features associated with migration: wing length and body weight. 924 " i g. 2. A and B - temporal course of migratory restlessness of groups of Sglvia atrioapilla from three .European aod African populations. SFi - sou¬ thern Finland; SG - southern FRG; SFr - southern France; Cl - Canary Isl- ands; Africa. A - data for all the birds in each group. B - data for only those birds that showed restlessness. C and D - time course of migratory restlessness of hybrids (CI x SG) compared with that of the SG and Cl st- °oks SG and CI. C corresponding with A, D corresponding with B (for det- alls, see Berthold, '^uerner, 1981) As known from earlier studies with Sylvia species, moult starts at an 6arlier age and is of shorter duration in more migratory species than in more esident species (e.g. , Berthold et al., 1970). Since migratory performance n the chosen blackcap populations decreases from north to south, north to s?uth differentiations in the moult as mentioned were to be expected. pig* 3 A shows the mean durations of juvenile moult including their stand¬ ard errors for Finnish, German, French, and African birds. Indeed, there was progressively later onset o. coult in populations from north to south, at a difference in the duration of the moult occured only between German Finnish birds and not with French and African birds has the following reason: French and African birds had already been transferred to constant 1 2. 5: 11. 5 conditions before the onset of their moult. In these birds the ■^latively short day length of 12.5 hours therefore had a comparably higher accelerating effect on the subsequent course of their moult than in the experimental groups (e.g. Berthold et al., 1970), 3 B shows the result of the cross-breeding experiment: the time ^°Urse of the juvenile moult of the F.-hybrids was an intermediate between tljnj. * ' of the parental populations. All differences in onset, duration, and 925 A gC - SFr Cl l SG - - 1 - B SG*CI Cl 1 — 1_ 1 L i i i i i i i 1 1 1 1 0 20 W BO 80 100 (20 WO Age (days) F 1 B‘ 3. A — temporal course of juvenile moult of four populations lrf Sjlvla atrlcapllla with standard errors for the duration of molt. B - data from hybrida and their pa¬ rental stoolcs. Abbreviations as in Pig.2; for detc_la see Berthold, Que- mer, 1982 a termination were statistically significant except the termination of hybrid moult compared to that of the German parents. This result is in agreement with earlier findings when garden warblers of ferent populations were raised in various environmental conditions and showed a population-specific juvenile development regardless of the conditi¬ ons. These and our recent results of the cross-breeding experiment indicate that the time course of juvenile development in its adaptedness to varying migratoiy performance is under direct and obviously strict genetic control (Berthold, Querner, 1982a). THE GENETIC CONTROL OF WING LENGTH AND BODY WEIGHT IN MIGRANTS Pour years ago in Nature Boag and Grant (1978) wrote: "Ecologists use measurements of avian morphological characters to test and modify evoluti¬ onary theories. But virtually nothing is known about the inheritance of such characters..." Physiologists, among others, I would like to add, behave the same way. " In the meantime, the situation has improved insofar as some indirect or tentative approaches, since, for example, calculations of heritabili ties in feral populations have led to more or less convincing evidence that these characters were highly heritable (e.g., Boag, Grant, 1978). The approaches, however, left some uncertainties as Boag and Grant wrote: "The tests do not eliminate the possibility of genotype-environment interactions or correlati¬ ons, but ... reduce the likelihood of the most obvious biases. There remains the possibility that the values are inflated by genotype-environment corre- lations and interactions. ” Doubtless, cross-breeding experiments, perfozmed in defined conditions, provide the most reliable results concerning the genetic basis of morpholo¬ gical characters associated with migration. Since various blackcap populati¬ ons vary conspicuously with respect to wing length, wing shape and body weight (Pig. 4), instructive results from our cross-breeding experiment could be expected. As Pig. 4 shows, the German and African parental populations differ in fat-free premigratoiy body weight by about two grams and in wing length by about three millimeters. The data obtained from 33 Ï, -hybrids are intermediate. This intermediacy Indicates their direct geneticists and produces phenology vexy similar to, or even undistinguishable from, those of feral southern French blackcaps (Berthold, Querner, 1982a). 926 P 1 g. 4. Premigratory body weight and wing length (mean values and standard errors) of four popula¬ tions of Sjlvla atrlcapina and of hybrids. Abbreviations as in Fig. 2} for details see Barthold, Ouerner, 1982a 20 i- $ t9 - \ ?77 a $ 18 « is ! 17 i ! s ^ 73 1G -1 1. 1 1 1 1 $7/ Id Cl CI*SG SFl 69 "f J - 1 - 1 L SFr SG CT CI*SG SFi SFr SG POLYMORPHISM AS A CONTROLLING SYSTEM OP PARTIAL MIGRATIONS: THE INNATENESS OP THE MIGRATORY URGE -mh respect to the control of partial migration in birds there are two controversial hypotheses: Lack 0943) proposed, mainly on the basis of Til ng recoveries, a genetic determination of migrants and residents i e :r ~ = ;:r- dents. ng arSa aS nagrantS whereas dinners should be able to remain as resi- andWbilevinVe3tiSating thS miSrat0ry restleaaness of Mediterranean warblers th»w 97T',lî T°Pe" PO■'Ul“tl',”■ “d “• population (B„. «ontnol !ï , “'a ,he «"* efp.rtm.m.i ertd.no, for the that the d T 1,1 ”” tindinga aupportcd luck 'a nypothe.ia in »«.LT ir °f « experimental groupe in ..net», «- tiuîv « condition. .a. a fairly good r.fl.oti.n of tn, typical „a p.r- •o^ LTf T f*ral “»»• «he différant migra- ry habits seemed to be endogenously preprogrammed or innate. Per/6 ?6Xt m°re ooncluaive evidence resulted from the cross-breeding ex- ment with African and German blackcaps as treated above. Here, the per- age of birds displaying restlessness increased from 23 to 56 from the hext an.Parental blrdS t0 the ProffsPrinE. i-e- from one generation to the ; when the Poorly migratory African birds were cross-bred with the ex- t^sively migratory German blockcaps. The most plausible explanation for frol ^nding 18 that 311 Production of genes causing migratory restlessness the p 1 German parents increased the proportion of migratory individuals in her^1'hybrldS °r’ ln °ther words' that the migratory urge is innate and citable. herJ° tSSt thlS exPlanation we started an inbreeding experiment with sout- 0f 10, °h blaokcaPa ^ 1977 (Berthold, Quemer, 1982b). In a large sample ®igr t eXperimental individuals from this population, known to be partially hot & 0ry’ ^ f0Und that 77% displayed migratory activity whereas 23% did °f th ASStUnlng Poiyriorphism (or dimorphism in this special case) is the basis °Ohf 13 migratory habit, inbreeding the migrant and nonmigrant morphs should °«n with three predictions: the offspring of pairs of migrants should 927 show an Increase in the ratio of migrants to nonmigrants compared with the original population and to the offspring of pairs of nonmigrants. Similarly the offspring of pairs of nonmigrants should show an increased fraction of nonmigrants compared with the original population. Up to 1981, we successfully raised 39 birds of the P1 -generation and investigated their migratory activity in the same way as had been done earlier with the parent¬ al birds. The data obtained fulfilled two of the three predictions mentioned above (Table 1): the offspring of the nonmigrants showed a significant (30%) increase in the number of nonmigrants compared with the parental population. The ratio of nonmigrants to migrants was also significantly different from the offspring of migrants. Moreover, although not statistically significant, there was also some evidence in favour of the third predictions the number of migrants in the offspring of pairs of migrants was 8% greater than in the parental population. The results of this study demonstrate that in the investigated partially migratory blackcap population, the characters "migratory" and "nonmigratory" are heritable sind thus establish polymorphism as a controlling system of partial migration for the first time in birds. In addition to our results, two other collaborators in our institute ob¬ tained similar findings in an inbreeding experiment with European Robins, Erithacus rubecula, and in rearing the offspring from either migratory or nonmigratory Blackbirds, Turdus merula, respectively. Thus polymorphism may be a geoeral genetic mechaoisms io partial migration. In light of recent findings of van Noordwijk et al. (1981), that the tim¬ ing of reproduction in the great tit Parus ma.ior may change genetically with rates of up to one week per five generations, polymorphism of partial migrat¬ ion appears as a possibly highly adaptive feature. When cross-breeding and inbreeding our Blackcaps, as demonstrated above, produced alterations in the percentages of migrants and nonmigrants from one generation to the next in the magnitude of about 30%, it implicates the possibility that under high selective pressures a partially migratory population should be able to shift on a genetic basis to (almost) exclusively migratory or nonmigratory within a relative small number of generations. We have started relevant experiments to investigate this highly exciting question. Table 1. The ratio of migratory active and inactive individuals in a partially migratory population of Sylvia atricapilla and in two inbred strains of migrants and nonmigrants (for details, s. Berthold, Querner, 1982b) Original P1 -individuals F^individuals from pairing from pairing nonmigratory x migratory x nonmigratory birds migratory birds partially migratory from pairing population n = 102 h = 19 n = n = 20 number of migratory active individuals 79 9 17 number of nonmigratory individuals 928 SUMMARY aeriBU,,m . . lrst auturanal migratory. period are highly in¬ sensitive to environmental influences. In the Blackcao in wM.v, of rpsticam... j,,- . . DxucKcap , m which the amount migration ! ZyZZ't wT" aaa°°iated strains of with and without migrator behavior froTl partially ^g^I^ Blackcap population it was shown that migrants and nonmigrants «rT^i- ration e_e™lned morphs ln a (Balanced) polymorphism (dimorphism). The alte- 5 := °i:i°t;rs prosraras “* that typicai migrants «• p**»- Ref erences Serthold P. - in: Circannual clocks / Ed. by E.T. Pengelley. N Y • L Academic Press, 1974. ^ y «.Y. , L. : Berthold P. - Naturwissenschaften, 1975, 62, p. 399. erthold P. - Vogelwarte, 1976, 28, p. 26 3-266. erthold P. - Vogelwarte, 1977, 29, p. 113-116. erthold P. - Experientia, 1978, ^4, p. 1451. rthold P. -InsActa 17 Congr. iDternat. Qrn. Berlin, 1980 p.473-482 Berthold P. - orn. Pennies, 1982. ’ P'473"482* rthold P. , Gwinner E. , Klein H. - Vogelwarte, 1970, 25, p. 297-331. Klein H., Westrich P. - Z. Tieipsyohol. , 1972, ^0, Berthold P. , Gwinner E P- 26-35. ^erthold P. , Quemer U. - Science, 1981, 21_2, p. 77.79, P” Queraer U* - Experientia, 1982a, Jg, p. 801-802 Bo pld P'*’ QUerner U‘ ~ Experientia, 1982b, J8, p. 805-806 Qwin 'T’’ Grant F*R* ~ Nature’ 1978> P- 793-794. ßwintler E* - Naturwissenschaften, 1974, 6jl, p. 405. DJler E* ~ Prl! Handbook of behavioral neurobiology. Vol JacCh0rf* NSW York: Plenura Press, 1981, p. 381-389. Kai°b3 J" ~ Z * TieiT>sycho1- . 1981 . 55, p. 1-18. Back"13 ~ Alm’ Z°o1' Soc* Vanamo, 1954, .16, p. 1-30. Mroa ~ Brlt* BirdS’ 1 943/44 > 2L, P. 122-130, 143-150. v. a°vsky N. • , Powley T.L. - Behavioral Biol., 1977, 20, p 4 / Ed. by J.As- W.: '•*’ - behavioral Biol., 1977, 20, p. 205-223. ij A.J. van, Ballen J.H. van, Scharloo W. - Oecologia 1981 4P P* 158-166. ’ — ’ hdler J. , Berthold P. , Bairlein P. - Vogelwarte, 1981, !, p. 14-32 23 3aK.98l 929 PHOTOPERIODIC CONTROL OF P0STJU7ENILE AND POSTNUPTIAL MOLTS IN PASSERIFORMES G. A. Noskov, T.A.Rymkevich Department of Vertebrate Zoology of Leningrad State University, Leningrad, USSR Although the role of photoperiodic regulation of breeding activity has been well documented (Famer, 1964; Wingfield, Famer, 1980), the influence of daylength on molting requires further consideration. Apparently the earliest scientific investigation of control of molt was the work of Miyaza¬ ki (1934). Considerable light was shed on the problem by the research of V.F. Larionov (1941, 1945, 1957). The theoretical concept developed by Wolf- son (1954, 1965, 1970) of photosensitive phases in the annual cycle, furthe¬ red understanding of the role of photoperiod in control of molt. The main conclusion that can be drawn from these investigations is that shortening daylength in the fall decreases the duration of the molting process. The research carried out in Leningrad State University was designed to illuminate the characteristics of photoperiodic control in various passerine groups, as well as to work out general principles of control of molt appli¬ cable to this order (Noskov, Siletsky, 1969; Noskov, 1975, 1977, 1978; Rym- kevich, I976a,b, 1977; Noskov, Rymkevich, 1977, 1978; Noskov, Smirnov, 1979; Gaginskaya, Noskov, 1981). The effect of various daylengths on members of 42 species of the following families have been analyzed: Alaudidae, Motacillidae, Turdidae. Svlviidae. Muscicapidae. Parldae, Emberizidae, Fringillidae, Plo^ ceidae and Stumidae. The analytical methods applied to the molting process revealed not only the presence or absence of this process, but also allowed characterization of its rate, extent, and duration of shedding and growth on all feather tracts. For all species investigated it was found that photoperiodic control can affect the rate of molting. Experiments showed that this occurs in two ways: a) the growth rate of the feathers themselves changes, or b) the number of feathers molting simulta¬ neously changes. Change in the rate of feather growth was found in only a few groups, no¬ tably in the Fringillidae. Thus, growth of the third and fourth primaries in Chloris chloris was completed in 12-16 days on LD 14:10, whereas on LD 18:6 22-26 days were required. It was discovered that the growth rate of feathers being replaced at the beginning of the molt would increase on longer days than that of feathers being replaced at the end of the molt. That is, plumage being replaced in the last stages of the molt, in order to grow in at the place observed in the first stages, requires shorter days. In almost every species the shedding of old feathers depends on photope¬ riodic conditions during both postjuvenile and postnuptial molts. It was found that on longer days shedding proceeds with lesser intensity and the whole process extends over a longer period of time (Fig. 1, A, B) . If each successive stage of the molt is accompanied by. shortening daylengths, the overall intensity of the process remains constant. Therefore, if birds are 950 !» * ;:"d F'Vj'0pt'rl0i- *»' »' ■‘■•“«ns a.0«.,m considerably » “d ,hs — *• — * °°MroY«U™iT T“"! ,rl'ea: ““«*"*« **• deciding lacer in Peri ° • the rate of shortening of days, or daylength itself’ Ex- aqu^elburdi?fbirdS-Wer: SUbje0ted t0 11Sht regimes that Cha^ed"at « organi^ rl ff ^ Ut6 leVelS °f d^len«th revealed, that the ^orteroverall 1 When the «* ^lengths was *a* effected ^ “* P— exerSd’the °f theSe experiments floate that control of molt is Pho operLT Stag6,0f thS Pr0C88S* Ea°h PhSSe’ regUlat6d ty a -aotion Phase PreSentS a °ertaln ^oquirement of daylength. The beginning naed 1Wger dayS’ Wh-eas the final stages require shorter days. Se¬ cede no™rnrePrerntßUVeS °f 8 glV6n ge0graphical Population, molting pro- bird y °nly Within Q certain interval of daylengths to which the the m arS adapted- The abort er the daylength -within a photoperiodic interval that thi enSlVely the giVen phaae of ra°lting progresses. It is suggested ’ regula 3 aBleCl °f Photoperiodic control be referred to as "stage-by-stage" lation of the molting process. ^Adaptation of the molting process to specific photoperiodic conditions “‘ears * e*i8teace of a Photoperiodic interval with upper and lower thresholds roli0n ;a e °nset °f the molt, as well as its completeness, can be cont- d-J-ed by daylength. 931 Parus major, jua Fig. 2. Completeness of postjuvenile moult of Great Tits In various photoperiod le conditions: 1 - new plumage, 2 - old plumage It has Been shown experimentally that a significant shortening of dayl- ength beyond a lower threshold causes the molt to cease. In nature, this occurrence is not uncommon in the Paridae and Fringillidae. If the daylengths become too short, a postnuptial molt late in the season, ceases completely in the concluding phases, so that the plumage will then include old feathers that otherwise would have been replaoed late in the molt. For many species, during post juvenile molt accelerated shortening of daylength may decrease the proportion of plumage replaced not only at the expense of those feathers shed at the end, but also those shed in the middle of the process (Fig. 2). The adaptive significance of this is to decrease the overall time in molt and insure timely progression on to migration or to wintering conditions. The upper threshold of daylength for the postjuvenile molt in many species is determined by the age of the bird when the molt begins. The lower the ab¬ solute level of this threshold, the greater the influence of photoperiodic conditions on the onset of the molting process. This is especially true for Chloris chloris. Soinus spinus. Fringilla coelebs, Emberiza citrinella, Erithacus rubecula, and other species with two reproductive periods in one breeding season. Photoperiod plays a lesser role in instigating postjuvenile molt among single-clutch species such as Emberiza hortulana, Coccothraustes coccothraustes, Sylvia communis and Sylvia curruca. Thus, for Emberiza cit¬ rinella the maximum age at which molting can begin under maximum daylength for that species is 60 days. This critical age is determined by genetic, en¬ dogenous rhythms and cannot be increased by increasing daylength, although age of onset <5f molt can be reduced to 20 days by reducing daylength. For Emberiza hortulana, the maximum age at which molting may begin is 25 days, the minimum is 18 days. Thus, the possibility of shifting the initial molt" ing period by photoperiodic regulation spans 40 days in the first case, and only 7 days in the second (Fig. 3). Finally, for such single-clutch species as Sylvia borin. Ficedula hvpolgH" ca and a few others, photoperiod can under no circumstance change the period during which the molt is initiated because this period has already been set at the earliest possible age by endogenous factors. The onset of postnuptial molt, to an even greater degree thao that of the post juvenile molt, depends on endogenous rhythms. For the majority of species studied postnuptial molt is coupled with the end of breeding activity. For 932 Fringilla coelebs ' ad. ta Chloris cftloris ’ ad. g^SWNN^Wx^ xxxvvxvv^VVT^ //y x v xx .WWVxX VvV ^.W^'NWW////// ^ v; #77777-, Spcnt/s spinas^ ad. Emberiza citrinella •., ad mmwv S\\\\\ CAWvt//*/// „ V 777777. — I — i I I I I I I I rn ZO bO 60 dags -1 I I BO WO ™ J -, - « r CL _ _ UUUS t« various piotowrlM^Tr^L^“ " ’"'1>' “"' Ura - durations of daylength in hours Ceding activity. Fig- Carpodacus eryihrinus ; ad. TEsbzZZZZZZL 7ddbSr/)////^z/y.,o V//Z//777Z ^ i S* 5- Onset of postnuptial molt (arrows), taking place in win¬ tering area, in photoperiodic reg¬ imes subjected to decreasing day — length at various seasons H2ZZZZZZZZZZZZ ^v\\\\ ^%Z7777777. 1F//////A IB \\VV W//////EZZ ,n-V77 X^\NV,\ IB S\\\\\\}/*////70777Z SraStionSoï’hthe,rri0d ** m°ltinS beglnS iS °ften stemmed by the *°it z\ fo^r rjn rty\This type °f indirect °ontro1 — or Kin« VJ I t — Ula arb0rea’ ^-cedula hypoleuca, Parus mB.w Prin. - 2£lebs, Çarduelia c ardu el is, Acanthi s flamme« . Chloris ,,m1. ~Z~„ -lnlcola enucleatnr, Coccothrauates coccothinnätp« T-r1n ,’ ,7^ ^ °nly ln ^beriza ^trinem was i. n^». ~ ghl~p ? T c^rrrr dayiensth durine breeding acwvity (pig- £ es Jinus and mlT T ffl0lt *” th6ir winterin« areaa> Çarpodacus eritn. ^"T- T ~a auren1a were investigated. In these two species the onset Here SthePtla? T* dld “? ^ th® duratlon of Ceding activity, exclusive regulating factor was daylength (Fig. 5). consi! maHterial preSented demonstrates that the fundamental aspect to be ed in photoperiodic control of molt is the stage-by-stage nature of 933 its regulation. It is proposed that 1) the rate of molting is under photo- periodic control for the entire duration of the process; 2) each successive stage, as well as the molting process in its entirety, is adapted to a given set of photoperiodic conditions - the photoperiodic interval - within which the molt proceeds normally; 3) photoperiodic requirements in the process of the molt undergo a progressive change with each successive stage reacting to a span of shorter daylengths; 4) the rate of plumage replacement at each stage depends on the absolute levels of daylength within the photoperiodic interval - the shorter the days, the faster the replacement rate; 5) the rate of plumage replacement changes according to the extent to which old feathers are shed simultaneously, and also the rate at which new feathers develop. Thus, stage-by-stage regulation serves as a mechanism by which the molt¬ ing process can be completely interrupted or significantly slowed down if the length of the day exceeds or does not reach the thresholds of the photo¬ periodic interval, within which the rate of the molting process is control¬ led. References Famer D. S. - Amer. Sei., 1964, £2, p. 132-156. Gaginskaya A.R. , Noskov G.A. - In: Polevoi vorobei. Leningrad, 1981, p. 84-90. Larionov V.F. - Dokl. AN SSSR, 1941, 2 1 > P* 227-229. Larionov V.F. - Uch. zap. Moskovskogo Univer. , 1945, 88. 95 p. Larionov V.F. - Dokl. AN SSSR, 1957, 112, p. 779-781. Miyazaki H. - Tohoku Imper. Univ. Sei. Rep., 1934, 4, p. 183-203. Noskov G.A. - In: Issledovania produktivnosti vida v areale. Villnius, 1975, p. 106-117. Noskov G.A. - Zool. Joum. , 1977, 56, p. 1676-1686. Noskov G.A. - Ekologia, 1978, 1, p. 61-69. Noskov G.A. , Rymkevich T.A. - In: Metodiki issledovania produktivnosti i struktury vidov ptits v predelakh ikh arealov. Villnius, 1977, p. 37-48. Noskov G.A. , Rymkevich T.A. - Vestn. Leningr. Univ., 1978, 9, p. 12-22. Noskov G.A. , Siletsky V.V. - In: Omitologia v SSSR. Ashkhabad, 1969, 2, p. 456-459. Noskov G.A. , Smirnov E.N. - Biolog. Nauki, 1979, jj, p. 38-45* Rymkevich T.A. - Vestn. Leningr. Univ., 1976, _1_5, p. 19-25. Rymkevich T.A. - In: Materialy VII Vsesoyusnoi omitologicheskoi konferent- sii I, 1977, p. 154-155. Savinich I.B. - Vestn. Leningr. Univ., 1983, 2±, p. 19-25. V/ingfield J.C., Famer D.S. - Prog. Reprod. Biol., 1980, 5, p. 62-101. Wolfson A. - J. Exp. Zool., 1954, 1 25. p. 353-376. Wolfson A. - Arch. Anat. microsc. Morphol. .exper. , 1965, £4, p. 579-600. Wolfson A. - Coll. Intern. CNRS, 1970, 172. p. 93-112. 934 ENDOCRINE CORRELATES OP MOLT AND REPRODUCTIVE FUNCTION IN BIRDS Monique Jallageas, Ivan Assenmacher Laboratory of Neuroendocrinology ERA 85-CNRS, Department of Physiology University of Montpellier II, P-304060 Montpellier, Prance INTRODUCTION "f " cndlMon. the of w,o1„ or Mra< u *"•'* b°«* Physiological M Oeh.vloral «1« !l J , T', 1“ *'• 4“M”« ,hC °0“rSe °f O«!»««, th. ooogr«»- ng lologlcal rhythm In .ccordanc. with hlocllnatlc ».»sonal cyclo» a resulted in optimal adaptation of individuals and of species to varvin* environments and hence to improved chances for survival and reproduction mÎgratrT °°CUrren0e °f basic Processes such as reproduction, molt and exo i n ia exactly timed with environmental conditions. A long series of experiments has demonstrated the synchronizing role played by external fact- imo t C°^e°“0n Wlth these funotlons. But optimal programming of the most mportant biological functions also means that exact temporal relations must be maintained between these different events, which, in general! nev' tl ob!iCoeuf rUltane°Ufy dUe t0 th6ir high requirements, or simply for odious reasons of efficiency (e.g. molt and migration). In the majority of migratory species, reproduction, molt and migration thus follow a strict se¬ quence spread out over the year. Whic!g!Tine the ParUCUlar relationships between reproduction and molting, v n * f 63ePt oontributi0n will consider, the direct correlation obser- d m most species between the onset of molt and the end of the breeding 1977°Vr Jr" empha3iZed mMy times (bino°m et al., 1980; M-waldt, King, ca Li r* 1980)- M°re0Ver* fr°m a Seriea based on tiIiT ,h age’ Z" ^ breeding StatU3’ the °0n0eP-t haS emerSed that the (Dhont q °T m0lt 13 dependent on the intensity of breeding activity ont, Smith, 1980; Dittami et al., 1979; Sealy, 1979; Zwickel, Dake, 1977). .in a few selected species, breeding and molt may overlap to some extent, cun, ! generally assumed that this particular pattern merely stems from cir- atantia! reasons, such as a very limited time and energy budget available successfui reproduction, molt and preparation for migration within favo- iq«o enVironmental conditions (Cooper, 1975; Poster, 1975; Orell, Ojanen a80i Samson, 1976). For obvious reasons, partial overlap of molting and migration appears much thrS excePbiooal( Payne, 1972), since the replacement of flight feathers spans SuLenWre Peri°d °f P°stnuptial complete molt (Snow, 1967). However a few th° Cases have been reported in some short-distance migrant species, like on fblUe gr°U8e’ Pgndragopus obscuras. - which incidentally migrates largely oot (Lance, 1970) - and several species of dunlins (Perns, Green, 1979). Although many aspects of the complex mechanisms by which external factors bet lnterplay with internal factors to synchronize the phase relationships ween reproductive and molt cycles are still obscure, a leading role has ^en atributed to the annual cycle in daylength. The stimulating role of long ten,8 °n g0nad ao’tiv'a'tion is well known in a large variety of birds in both Perate and tropical regions (review in Parner, 1 970) . It has also been 935 suggested that there is a "long day" requirement for the onset of molt (As- senmacher, 1958; Chilgreen, 1978; Dolnik, 1975; Famer et al. , 1980; Verbeek, 1979), irrespective of the exact mechanism that induces it (Berthold, 1979; Dolnik, Gavrilov, 1980; Famer,. Gwinner, 1 980; Lewis et al., 1974; Zwickel, Dake, 1977). In addition to the primordial role of the annual cycles of the photoperiod in the control of molt, a supportive role may be played by ambient tempera¬ ture (Chilgren, 1978; Lewis, Famer, 1973) or seasonal variations in humidity (Frith, Carpenter, 1980; Smith, 1978; Maclean, 1973; Morel, 1973; Morton, Wel- ton, 1973; Orel, Ojanen, 1980; Payne, 1980). On the other hand, much less attention has been paid to the annual variat¬ ions in the complex hormonal balance that may afford smother set of enlight¬ ening clues for the understanding of both the mechanism of molting and its integrated timing among other biological cycles. The present contribution in¬ tends to discuss several salient findings based on hormonal measurements, in addition to morphological data discussed earlier (see Assenmacher, 1958). INTERRELATIONSHIPS BETWEEN ANNUAL SEXUAL AND THÏR0ID CYCLES Thyroid hormones have long been known Jo control the development of skin and its derivatives (Gorbman, 1963) and earlier studies indeed pointed to the thyroid gland as a possible regulator of avian molt (see Assenmacher, 1958; Payne, 1972). However, from a series of recent measurements of annual cycles in thyroid-hormone availability in relation to the sexual cycle, the concept evolved of precise interaction between both endocrine cycles as one basic concept of the sequential occurrence of reproduction and molting. With respect to the temporal relationships between the annual sexual and thyroid cycles, two patterns have been described: (1) In a few species, thyroid activity is high throughout the reproductive season, e.g. , cape cor¬ morant, Phalacrocorax capensis (Berry et al., 1970); migratory .Canada goose, Branta canadensis (John, George, 1978); and lesser snow goose, Chen hyper- borea (Campbell, Leatherland, 1980), although in the two latter species plasma concentrations of either thyroxine (T^) or triiodothyronine (Ty re¬ main elevated through the subsequent postnuptial molt. (2) More frequently, however, the annual thyroid cycle does not parallel the sexual cycle. In¬ stead, depressed thyroid activity prevails throughout reproduction and in¬ creased thyroid activity exists during molt and sexual quiescence, e.g., spotted munia, Lonchura punctulata (Ohandola, Thapliyal, 1974), or thyroid secretion displays a clearcut peak immediately after reproduction has ceased. The three species studied in our research group conform to this most common pattern: The Peking duck, Anas plat.yrhvnchos. and teal, Anas crecca (Assen¬ macher, Jallageas, 1980a; Jallageas et al., 1978; Jallagea3 et al., 1978), and the emperor penguin, Aptenodyte-s forateri (Groscolas, Jallageas, Gold¬ smith, Lelopu and Assenmacher, in press). In southern France (latitude 43°38N) Peking ducks breed from March through May, and display a complete postnuptial molt in June-July. Teal, which normally breed in Siberia (latitude 60°N) and winter in southern France from September to February, were prevented from migrating northwards in winter and studied in a large natural park oyer one year. Under these con¬ ditions, the sexual cycle culminated in May-June while the postnuptial molt 936 '°Uo"a bï * p“tl>1 boay '***■>- ■■>» i» ».v- —«•■«««. ..„ ,01i. ■"ple‘ p"4 Por ho“»* r:; rr/.:::r «« - - ::: r^r^0: *p ^■Qâbûs pt- pT i Q'TQi^ », SJ.« y in press; Jöl* from s 7 r, / ’ /I ^ ‘ ThUS’ ln the Peking duck. testosterone levels fell from 5.7+0. 6 ng/ml in April to 0.8+0. 2 ng/ml in Julv T„ +„ mental conditions, androgen levels'decreLed in til t l ! ^ enVir°n- 1« early June ,o O.H0.03 „g/„l » lZ7 l tll ^ Mî°M ™Ml concentration. Pound a, ,h. ZXZT.ZT^Zf ? aluab]”, aur1“« ■»“ (0-15*0.02 ng/ml) . Secondly,’» ». *“ i:~ s ;;rr„:;r *• - « Increase ot 75* over ,h. lo..„ i.vel oe.^ed »’“»u^ LX"»;8 cyclf». *“« 7'"Z °‘ *he 14 Pr01'’ «“» ,h* Mpha.Ic »citing’ »» ” oTt r; 7*hu°7 ;n pi*““ 14 °pp™ «»>«> ^ «•45 Z J i.,1 ! 4,7±0-3 "S/“1 “d ”"h'd “• P«“l* I» «uguet (5.42* ! b='°r. decreeing ete.dily until Kovember. 4 .econd algnitic», c * ° Pl*°e “ °*c“ler <4-90«.57 ng/»D . ttu, th. 3U_„ „JVt «îh“t.“ZPd”f *° "" PP>““'“-1 *>“ *»*« Pea* 1» pi.™ Ï turc. » thé I* »™“P«*1 ”1*1»*. but ale„ to th. lo. ambin.t t,„p,J,. •ones .... , 'PTr Ee”''J‘r'' hlSh*“t f’1'™ concentration. ol thyroid hor- bbeais „T,h , ”* "°1*’ “,h ,h* T4 P**k »ccurring during 'bquent L "hllS *h* Ti ?“k "*■ attained only » the aub- luent phase of feather loss. ^‘t’hlTLTL^r«’ ,h*‘' T* tr°" th’ "'»* P“k *» «"ter hi related + TT SeaS°nal ^ leVela °f thTroid ho™— forms t , t0 variations in environmental factors, which con¬ fer iaL *r Statements (Chandola. Thapliyal, 1974; Wilson. Far- s®Peror ni* **“ abSenC6 °f “ ln°reaae in T4 “d *3 ««8 nonmolting °°las + ? ’ aS COmpared With moltiaS specimens in the same flock (Gros! betWR.e * *’ ln preaa)« ^rther strengthens the hypothesis of a direct link Vi » !h® 3eaaonal increase in thyroid activity and molt, rather than en- It C°“dltiona- Interestingly enough, a similar correlation between ieasrri thyrold activity and molting was also noted in the wild turkey Me- ^&-fs gallopavo (Burke et al., 1977), the domestic turkey (Scanes et alTT coij-* thS Wlld mallard drake* Anas platyrhynchos (Haase, Paulke, 1980), the r0Qk red d0Ve* ^treptopelia roseogrisea (Peczely, Pethes, 1980) and in the ’ — Prvus frugllegus (Lincoln et al., 1980). ^cte21 °0ncluaion* under natural conditions the postnuptial molt appears cha- thuaeriZed ® seaaonal imbalance of the thyroxine/testosterone ratio that undergoes a steep increase (Pig. 1). The concept of a probable causal 937 •va s= s sr ! 10 I- 16) (S) §10 ~ 16) 1(f) 1 kl* Ml B ( 6 ) 4«i » « Apr CL July January June *v OJtmg/d tOOmy/d Fig* 1. Annual cycle in the plasma ratio of thyroxine/testosterone in Peking ducke. The horizontal black bar above the abscissa indicates the annual postnuptial molt. Number of birds is indicated F i g. 2. Implication of testosterone and thyroxine in molt of ducks A - while surgical thyroidectomy has no marked effect on plasma testosterone during the breeding season, it prevents the seasonal, decline of testosterone and molt in July altogether; B - castration ttvjy.l increases plasma thyroxine in January to maximal levels normally obtained in June (postnuptial molt) and induces body molt. There is no further rise in thy¬ roxine in June; C - whereas ectopic pituitary autografts |feo°o°o lead to testicular atrophy with maintained thyroid function and to a complete molt, it was always possible to prevent the forced molt by treatment with either testosterone or propylthiouracile. Number of birds is indicated in paren theses link between this hormonal imbalance and the onset of molt receives addition¬ al support from a series of experimental data. EXPERIMENTAL EVIDENCE FOR GONADOTHYROD INTERACTIONS ASSOCIATED WITH MOLTING PROCESSES Hormone supplementation or auppreasion Experimentally induced hyperthyroxinemia has long been known to induce off-season molting in a variety of avian species (review in Assenmacher, 1958). Recent studies in Peking ducks thus showed that, whatever the repro¬ ductive stage, thyroxine treatments mimicking the peak T4 levels normally occurring in June-July depressed testosterone secretion to baseline levels (Jallageas, Assenmacher, 1974). Conversely, decades ago Zawadowsky and Liptschina (1927) in the domestic fowl, Takewaki and More (1944) in the domestic canary, and Vaugien (1955) in the house sparrow. Passer domestlcus. clearly demonstrated that testosterone supplementation obliterated seasonal molting. More recently, testosterone in¬ jections monitored to mimick the high androgen levels of the breeding season were shown to depress significantly thyroxine secretion in ducks (Jallageas- 1975; Jallageas, Assenmacher, 1972) and in quail, Cotumlx cotumlx (Peczely et al. , 1 980) • On the other hand, surgical thyroidectomy, if performed several months prior to the normal onset of molt, has a blocking effect on molt in ducks (Jallageas, Assenmacher, 1979; Svetsarov, Streich, 1940) , wild mallard (Haase. 938 1980), domestic fowl (Crew. Huxlev iqm sillev 1919) an<, „ + 6y’ 9 ?)’ “agpu> ^-ca Plea (Voitkevich, Va- lev> - “ i°::~ , 1934, Jallageas, Assenmacher, 1979; Streich, Svetsarov 1916) ^ ~ when llZll*1 thyr°Xine thSt remained f°r alm0St 6ight -nthnri^ml^eieîr only durin« molting (Jallageas, Assenmacher, 1979) (P^g 2B) aviL Lee' e? ,thre demonstrate that in a .Zlro, rat^ experimentally induced increase in the thyroxine/androgen Whn 4 SupplementaWon °f by castration - promotes artificial moltine- e conversely, a depressed thyroxine/androgen ratio - by thyroidectomy or androgen supplementation - obliterates the seasonal occuLen^e "f liT Experimental molts * S T1,163 °f Deuro6ndoorine studies on the hypothalamic control of pi moites Zted°n iQ T"63’ ^ reSUlar °0C™ce a forced and complete ,Pot reVr lnevitablo side-effect of surgical disconnection of the th! ! anterior pituitaiy gland, as obtained by autograft of aatl I?0" PltUltaiV °nt° the kidney Assenmacher, Bayle, 1968). The dra- ZtlT Î ? °£ the end0Crine balance re8Ulting **» procedure was (Assenmacher^ X T "T'tT °f “ ■“»«-"«* gonadal function rcid ZcÏ, ! ’ C°ntraStlng With 811 almost completely maintained thy- ^PeriZ lînmon3eninaCher ^ ^ ’ 1970)* latl WaS SS associated rttha sudden elevation of the re- that l thyr^lne/andro«en ratio, and further investigations clearly showed ion of Zi" ! h6 C°mPletely Pre"ented> by either daily supplementat- fclookin ^ °f te3t0Steroile (Assenmacher, Baylé, 1968) or by (BayJ loSf0?!^818 "“h daUy admini3tration Propylthiouracile and D ’ . ‘ lH thS 3ame tyPe °f exPeriment, Novikov, Garmantina sir»« ni6 rsoently showed in hens that the well known picture of of VsT 13 aSS0°iated With both a decrease in plasma concentrations thv„ .Jan LH’ B resulting arrest of egg-laying and with a state of hyper- oidism as manifested by an increased PBI. theI?u°0n0lU8iOn’ U thUS aPpears that the concept of a preeminent role of hyroxine/androgen balance in the control of molting processes adequately rms with all molting situations, whether in nature or under various ex crimen tal conditions. s •£°3.sible impact of thyroid hormones and androgens in molting process»* by yr°m early observations on experimental molt and feather growth induced the hyr°Xine administration, the presumable direct effect of thyroxine on formation of new feathers has long been postulated (Cole, Reid, 1924, in 939 the domestic fowl; Hardesty, 1935, in the Guinea fowl, Numida meleagris; and Larionov, 1 931 , in the bullfinch Pyrrhula pyrrhula) . In their remarkable ob¬ servations, Kraetzig (1937), Svetsarov and Streich (1940) actually showed that from the very first day of thyroxine treatment, a wave of mitoses spread through all feather papillae, together with the neighboring epidermal cells that underwent an intense desquamation. It was concluded that the con¬ junction of active growth of new feathers and skin desquamation actively led to the shedding of the old feathers. The data collected from the emperor penguin clearly support this view, since the increased plasma concentration in T^ in molting birds (Groscolas et al. , in press) is strongly correlated with a seasonal peak in circulating free amino acids, which, incidentally, is necessary for keratin synthesis (Groscolas et al., 1975). Tj, instead, increased in later stages of the molt¬ ing process, when the old feathers were already shed, and could presumably be associated with increased thermogenesis triggered to compensate for the transient loss of thermal insulation. Regarding the possible role of androgens in molting processes, it seems reasonable to assume that they firstly account for maintaining a moderate level of thyroid activity during reproduction. Additionally, testosterone has been postulated to exert a direct protective effect on mature feathers (Assenmacher, 1958; Meier, Ferrell, 1978; Payne, 1972; Vaugien, 1955). The recent findings of Wingfield and Earner (1979), who observed concommitantly maintained high plasma levels in testosterone and delayed postnuptial molt in renesting white-crowned sparrows, Zonotrichia leucophiys gambelii, may also fit into this hypothesis. OTHER HORMONAL INTERFERENCES WITH MOLTING Even if a preeminent role may be assigned to the thyroxine/androgen balan¬ ce in the induction of molt, a number of other metabolic hormones presumably are associated in that complex mechanism. However, at the present stage, scarce information is available on their possible involvement in molt, apart from a few data on seasonal variations in plasma concentrations of several metabolic hormones during molt. Growth hormone (GH) In this connection, plasma concentrations of GH have been shown to display seasonal variations in Peking ducks and teal (Scenes et al., 1980). Maximal values were observed precisely during the molting period. Additionally, the annual cycles of GH and T^ appeared closely and positively correlated, which, in fact, may result from the stimulatory effect of TRH on OH secretion as has been observed in ducks (Pethes et al., 1979) and the domestic fowl (Harvey et al., 1978). Although Harvey, Scanes, Bolton and Chadwick (1977) showed that acutely heat-stressed chickens had elevated circulating GH levels, it is nevertheless unlikely that the seasonal elevation noted in GH levels of Peking ducks and teal was only linked to high temperature, which in the Me¬ diterranean climate spans several months. On the other hand, enhanced secret¬ ion of GH during the molting phase may be related to the concomitant annual peak of serum levels of free fatty acids, described in the Canada goose, and might facilitate thermogenesis in the defeathered bird (John, George, 1977)- 940 Prolactin (PRL) No clear statement can be drawn from earlier reports on the possible ef¬ fects of exogenous administration of PRL on molting, since, depending on authors and/or species, PRL was shown to inhibit or to promote molt, or to have no effect at all on the process (review in Payne, 1972). More recently, Scanes, Sharp, Harvey, Godden, Chadwick and Newcomer (1979), using a radioim¬ munoassay to measure endogenous plasma concentrations in PRL, actually showed a trend for increased - although not statistically significant - levels of PRL during molt in domestic turkey. An for GH, a concomitant increase in PRL and could indeed result from the stimulatory effect of TRH on PRL as in¬ dicated by Peyrot and Vellano (1980). In fact, many more investigations have been undertaken on the possible interactions between PRL and the gonadotro¬ pins than between PRL and the thyrotropic system. Inverse correlations were thus observed in a variety of avian species during the annual cycle between plasma concentrations of LH and sex steroid hormones, on the one hand, and PRL on the other (review in Bedrak et al., 1981). These correlations have often been interpreted in the light of Riddle's ancient hypothesis of an antigonadal action of prolactin, although there has been a failure to detect an antigonadal effect of PRL in several species (e.g. , Lehrman, Brody, 1961; Gourd j i} Tixier-Vi dal, 1966; Shani et al., 1973). Finally, it is worth noting than an original trend of investigations proposed that prolactio may have an important role in the determination of various annual metabolic cycles by an annual phase-shift in the diurnal cycle of PRL secretion (Meier et al., 1 969 ) associated with diurnal variations in metabolic responses to PRL (Meier, 1969). Corticosteroid hormones In spite of an ample literature on annual variations irt the histology of adrenal cortical tissue in a variety of avian species, with some additional observations on annual cycles in plasma concentrations of corticosterone (re¬ view in Assenmacher, Jallageas, 1980b), only a few data appear pertinent to the problem of possible correlations between secretion of corticosteroid hor- m°hes and metabolism, and molting processes. However, a detailed comparison of the various parameters of corticosteroid metabolism between molting and breed- thg drakes has provided interesting results (Assenmacher et al, 1975; Assen- ®acher, 1980b; Daniel, 1975). In molting birds the secretion rate of corti¬ costerone was slightly increased (+15%), whereas the total plasma concentrat- ioh in corticosterone was actually decreased (-25%), due to a 50% increase in the metabolic clearance rate of the hormone resulting from the increased le- veia prevailing during molt. On the other hand, the plasma concentrat- °h of unbound, i.e., biologically active, corticosterone appeared unchanged a® compared with the breeding state, since the decrease measured in the total ^ount of the hormone originated essentially in a lowered synthesis of corti- c°steroneblnding globulin resulting from the concomitantly depressed levels 01 testosterone. This illustrates not only the occurrence of a complex and triable multihormonal interplay within the endocrine system, but also some ma.jor difficulties in the evaluation of a possible adrenal participation in ® control of molt. So, although the adrenal gland was secreting more corti- 941 costerone during molt, no more active hormone was actually available to the target tissues, which, in fact, conforms with the main metabolic trend during molt involving protein anabolism rather than catabolism. In the same way, reduced levels of corticosterone were also measured in white-crowned sparrows, Zonotrichia leucophrvs gambelii, during both post¬ nuptial and postjuvenile molts (Wingfield, Pamer, I978a,b; Wingfield, Smith, Parner, 1980). Progesterone The original statement by Gabuten and Shaffner (1952) that administration of progesterone induced a swift and complete molt in hens was later confirmed by a number of authors (reviews in Assenmacher, 1958; Payne, 1972). However, most recent studies based on the measurement of actual levels of plasma pro¬ gesterone were unable to assign this hormone any role in the control of molt. Indeed, no significant seasonal changes in plasma progesterone concentrations were noted in wild mallard drakes (Haase, 1980), and no apparent relation bet¬ ween progesterone level and onset of molt was found in the white-crowned sparrow (McCreery, Pamer, 1979). Moreover, lowered levels of progesterone were even found in molting in comparison with 'laying turkeys and hens (Purr, 1973), although a decrease in actual plasma concentrations can tentatively be ascribed to the stimulatory effect of thyroxine of the metabolic clearance rate of all major steroid hormones (Assenmacher et al., 1975). As for the activating role of administration of exogenous progesterone on molt, it coula well be explained by an indirect inhibition secretion of gonadotropins and sex steroid, hormones* CONCLUSION If one considers that molt, and more especially the complete postnuptial molt, involves profound alterations in several homeostatic processes, e. g. , energy metabolism, both general and a few specific metabolisms of protein, and homeothermia, there can be little doubt that such a complex process requires equally complex hormonal adjustments. At the present stage, however, little is known about the possible implication and precise participation in molting mechanisms of major metabolic hormones such as GH and PRL, not to mention insulin. On the other hand, recant studies have enforced earlier as¬ sumptions in favor of the probable role of lowered levels of androgens and increased levels of thyroxine in the onset and completion of molting proces¬ ses in a variety of avian species. At least in a few selected species sub¬ mitted to a wide range of experimental schedules, it can be taken for grante that molt is primarily controlled by the annual occurrence of an increased ratio in the plasma concentrations between thyroxine and androgens. Whether this annually recurring hormonal imbalance results directly from external factors rather than from reciprocal interactions between both hormonal sys- 'tems, the latter being clearly demonstrated in a few species, remains one of the exciting tasks ’for continued research in this field. SUMMARY The yearly programming of sequentially recurring periods of reproduction» molt and migration appears to result from a complex interplay of seasonal en 942 a series of «périmé r' 1 ^teracWons- *»«« the latter, annual cycles in plasma tentn + g y he concomitant measurement of thyroxine/testosterone ^ eXperimental deration of the erone supply or thyroid blockade, led tT^T^ °! f°r°ed m°ltS by testost- a number of species of an ino™' +v, oncept of a preeminent role in Of molting processes. Th, pooslb" '^r b.lmce la the control “*■ "■ »■ »^-osteronrrpX::!“.!'”:™^!'“60110 References Assenmacher I. - Alauda, 1958, 26, p. 242-289. senmacher X., Astier H. - Gen. Comp. Endocrinol. 1965 5 Assenmacher I., Jallageaa M Tr, u ’ 9°5, p‘ ^63. Assenmacher I., Astier H. , Daniel j.v jan’„ „ 1975, 70, p. 507-520. *’ llageas M" ~ J- Rhysiol. p. , Assenmacher I., Bayle J.D. - Arch. Anat. Histol.' Embry o 1. , 1968, £,, p. 6?_ Bayle J.D. - Gen. Comp. 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Reprod., 1978a, JJ, p. 1046-1056. Wingfield J.C. , Famer D.S. - Physiol. Zool., 1978b, 51, p. 188-205. Wingfield J.C., Famer D.S. - Gen. Comp. Endocrinol., 1979, J8, p. 322-331. Wingfield J.C., Smith J.P. , Famer D.S. - Gen. Comp. Endocrinol., 1980, il. P- 372-377. zawadowsky B., Llptschina L. - Aroh. Entw. Mech. , 1927, 1 1 3. p. 432-446. Z*ickel F.C., Dake J. A. - Can. J. Zool., 1977, J5, p. 1782-1787. 24. 3a«.98i 945 ENDOCRINE AND PROTOPERIODIC RELATIONSHIPS DURING PHOTOREPRACTORINESS, POSTNUPTIAL MOLT, AND ONSET OP MIGRATION IN ZONOTRICHIA LEUCOPHRYS GAMBELII Michael C. Moore, Donald S.Famer, Richard S.Donham, Kathleen S.Matt Department of Zoology, University of Washington, Seattle, Washington, USA INTRODUCTION The annual cycles of many species of birds are synchronized with annual changes in the environment by the use of daylength as predictive information (for reviews, see Dolnik, 1975, 1976, 1980a; Earner, 1964, 1970; Famer, Fol- lett, 1979; Murton, Westwood, 1977; Wingfield, Famer, 1980). Among many smaller species, vernal and autumnal migration are each preceded by a comp¬ lete or partial molt (e.g., Stresemann, Stresemann, 1966). In such species, the termination of reproductive function, the postnuptial molt, premigratory fattening and onset of migration occur in a species-specific order and are usually temporally separated (Famer, 1964; Famer et al., and Lewis 1980;, Wingfield, Farner,1980). Although the vernal and autumnal premigratory phases are superficially similar in that each is usually preceded by a molt and premigratory fatten¬ ing, the former is accompanied by development of the reproductive system, whereas the autumnal migration follows the termination of the reproductive effort with the development of photorefractoriness (e.g., Ferner, Lewis, 1971; Wingfield, Famer, 1980). Although this similarity might suggest a common photoperiodic control mechanism, our recent investigations of Zonotri- chia leucophrys gambelii. a typical mlgratoiy passerine taxon, suggest that their mechanisms are very different (Famer et al., 1980; Famer et al. ,1981). This difference was initially suggested by comparison of the expression of vernal and autumnal functions under laboratory conditions. The suquence of the vernal events, which is induced directly by increased daylength, cam be altered by photoperiodic manipulation. For example, on 20L 4D the prenuptial molt may be coincident with premigratory fattening instead of preceding it (King, 1961) and onset of fat deposition may coincide with that of- Zugunruhe instead of preceding it (King, Famer, 1963). The autumnal sequence of functions is induced only after 40-60 long days, by which time the birds are photorefractory and the gonads are in regression. At least the development of photorefractoriness and the postnuptial molt are independent of the vernal, photoperiodically induced plasma levels of gona¬ dotropins and the development of the testes (Matt, 1982). Also, the develop¬ ment of photorefractoriness is not dependent on testicular hormones (Mat¬ tocks, 1982; Mattocks, Famer, Follett, 1976). These observations emphasize the essential independence of the autumnal from the vernal events even though both are induced by long days. The mutual independence of the systems that control the two sequences is also suggested by the observation that in¬ termediate day lengths, such as 12 hours, induce all vernal functions by fail to induce the autumnal functions (Farner et al., 1980). Unlike the vernal sequence no investigation has yet demonstrated that the natural sequence of autumnal functions can be separated by photoperiodic 946 ' manipulation after the onset of photorefractoriness and regression of the dayle^thlth0U8h ^ ^ P°Stnuptial molt can be increased hy reducing TWO HYPOTHESES e observations on Z.l. gambelii presented above suggest two complementaiy hypotheses of the nature of the photoperiodic mechanism that induces the pre- paration for autumnal migration in this taxon. The first hypothesis proposes that the late-summer functions are induced by a slow photoperiodic process hat culminates with the development of photorefractoriness and the conse- quent termination of reproductive function. The second hypothesis proposes hat the late-summer functions are induced as an internally coupled unit, n this communication we report the results of two experiments- that test predictions derived from these hypotheses. THE EXPERIMENTAL BIRDS Z» 1. gambelii has. in general, the longest migratoiy route among the races o ZJ.eucophiys. The principal breeding areas lie in British Columbia, Alas- a, and Yukon. The major wintering areas are in California, New Mexico Ari¬ zona, and northern Mexico with isolated populations in central and eastern Washington and Oregon. The males employed in our experiments were captured from wintering flocks on the Sunnyside Game Refuge in central Washington (46°N, 120°W) from where they were transported to Seattle (48°N, 122°W) where they were held in out- °or aviaries until transferred to constant-condition chambers for the ex¬ periments. THE EXPERIMENTS In Experiment I first-year males captured in October-November were trans- erred on 5 December to constant-condition chambers with a photoregimen of L 16D’ whioh 011 20 December was changed to 12L 12D. Thereafter four groups 9-12 each were transferred to long days (20L 4D) at four stages of test¬ icular development (Pig. 1), as determined by the examination of the intact eates via laparotomy (of. Pâmer et al., 1981) - at the end of the loga¬ rithmic phase of growth (ELP, combined testicular weight, ca. 200 mg), at or near maximum testicular weight (MTW, > 250 mg), midway through testicular regression (MTR, ca. 50 mg), and at or near the end of testicular regression -c 10 mg). As noted above, 12L 12D induces neither photorefractoriness a°r postnuptial molt. The results from Experiment I indicate that all four groups responded With gonadal growth on transfer to long days. This confirms our earlier ob¬ servation (Famer et al., 1980) that 12L 12D does not induce photorefracto- aibess and postnuptial molt in Z.l. gambelii. Thus this emberized species dif- era from Fringilla coelebs in which 12L 12D induces postnuptial molt, pre¬ paratory fattening, and apparently photorefractoriness (Dolnik, 1975b, 1976) 111(3 from Sturaus vulgaris in which successive gonadal cycles on 12L 12D are Accompanied by photorefractoriness and postnuptial molt (Gwinner, Dittami, ^hahirt, 1980). Whether these differences indicate that the photoperiodic ‘Ystems of these three species have evolved independently, or simply small 947 Testicular weight MTW- Maximum Testicular, Pig. 1. Schematic representat¬ ion of the stage of the testicu¬ lar cycle in which the four groups in Experiment I were transferred from 12L 12D to 20L 4D Days of 12 L 12 D adaptive differences in threshold of a common ancestral system, remains to be resolved. However, other differences suggest independent evolution, es¬ pecially in the case of S. vulgaris (cf. Farner et al., 1982). The failure of Z.l.gambelii to become photorefractory under 12L 12D is emphasized by the logarithmic growth constant, k, of group ETR after trans¬ fer to 20L 4D - 0.09 days“1 - which is comparable to that of photosensitive males transferred directly from short tû long days (Farner, Wilson, 1957). Therefore, as predicted by the second hypothesis, 12L 12D appears to induce none of the autumnal functions - photorefractoriness, postnuptial molt, and lat e-summer fattening. However, these results do not preclude the possibility that the process can begin on 12L 1 2D but requires longer days for its cul¬ mination. The prediction that males in all groups will begin molt after the same number of days following transfer to long days, was also confirmed since the onset and duration of molt were virtually identical in all four groups. Thus, transfer of birds to long days appears to initiate the process that eventual¬ ly induces the autumnal functions. The time required for induction of autum¬ nal functions is independent of the stage of testicular development at the time of initiation of this delayed process. This strongly supports the hypo¬ thesis that autumnal and vernal functions are mutually independent. However, it is useful to compare these results with those from birds trans¬ ferred directly from short to long days. The duration of molt is identical in both cases, which is consistent with an additional hypothesis that the • rate of autumnal functions is a direct function of the daylength at the time of their occurrence, which is generally consistent with the results of ex¬ periments on the postnuptial molt in F.coelebs (Gavrilov, Dolnik, 1974; Noskov, 1975, 1977). However, postnuptial molt began about 10 days earlier in all four groups transferred from 12L 12D relative to birds transferred directly from short days, indieating that this advance was independent of the duration of pretreatment with 12L 12D. This suggests that the process that induces the autumnal functions can begin on 12L 12D but requires longer days for its culmination. We also obtained data in this experiment on the environmental control of premigratory fattening. Both prenuptial molt and vernal premigratory fatten¬ ing are induced by 12L 12D. The intensity of prenuptial molt of the body feathers when plotted as a function of the duration of treatment with 1 2L 1 2Ü indicates that an apparently normal prenuptial molt is initiated and complét¬ ez P- End of logarithmic Phase of Troi MTR : Midway in Testicular degression ETR- Tnd of Testicular Regression ed on 12L 12D. Premigratoiy fattening is also initiated but apparently per- sists indefinitely, even in those birds held on 121 1 2D for over 400 days. However, when these birds were transferred to long days, premigratoiy hyper- phagia apparently ceased and body weights decreased rapidly. In Experiment II we (Moore et al., 1982) essentially reversed the manipu¬ lation of the photoperiodic regimen of Experiment I. We employed 21 adult males captured in December at the same locality as those used in Experiment I. On 1 Pebmary these birds were transferred to constant-condition chambers with a photoregimen of 8L 13D after which on 5 March it was changed to 20L 4D, Thereafter one group was transferred to 121 12D after 31 days, i.e., before testicular regression had begun. Testioular regression in this group was similar to that of controls on 201 4D, but perhaps with a somewhat earlier onset and somewhat lower rate. None, however, underwent a postnuptial molt. Furthermore, in all members of a subset of this group returned to 201 4D on day 70 testicular growth occurred, indicating that they were not photoref- ractory. This is consistent with the hypothesis that late summer set of functions can be induced only as a cluster and in an all-or-none manner. The second group in Experiment II was transferred to 121 1 2D after 60 days on 201 4D, after the onset of photorefractoriness and testicular regres¬ sion. In contrast with those transferred to 121 1 2D after 31 days on 201 4D, all of these birds molted and failed to undergo testicular growth. Therefore, molt can occur on a nonstimulatory photoregimen if photorefractoriness is first induced on longer days, which supports the hypothesis that these two functions are coupled. This is consistent with the results of experiments on F. coelebs by Noskov (1977). The results of Experiment II indicate that the transfer from 201 4D did not interrupt the sequence of late-summer events. Although further experi¬ ments are necessary, these results appear to be consistent with the conclu¬ sion of Dolnik (1975b), from experiments with F. coelebs. that photorefracto- niness begins at a constant time after the end of the "unifactoral phase", i-e. , logarithmic phase of testicular growth, even though there is as yet to physiologic rationale therefor. Data on body weight from Experiment II are consistent with those from ^Périment I, as well as with the hypotheses stated earlier in this communi- oation. The weights of the birds transferred to 12L 12D after 31 days of 20L 4D were nearly maximal. Among those birds maintained on 12L 12D body weight Remained elevated, whereas among those returned to 20L 4D after 39 days of 12L 1 2D weights decreased sharply in a manner similar to those in Experiment Body weights of control birds retained on 20L 4D and of the group trans¬ ferred to 12L 12D on day 60 both decreased conspicuously. The latter under¬ went a veiy rapid postnuptial molt followed promptly by fattening. The cont- *°1 bdx'ds on 20L 4D also molted and fattened, but more slowly. Thus all of late-summer functions proceeded more rapidly on 1 2L 12D, which supports hypothesis that the rate of the late-summer functions is an inverse func- tion daylength at the time of their occurrence, and which is consistent ^ith results reported for first-year and adult F. coelebs (Dolnik, Gavrilov, 9?2; Gavrilov, Dolnik, 1974; Dolnik, 1976, 1980b; Noskov, 1975, 1977). The e®ults of Experiments I and II both support the hypotheses proposed in the 949 Introduction and suggest strongly that essentially separate photoperiodic systems control the vernal and late-summer functions. General observations of Z.l.gambelii under natural conditions (e.g. King, Mewaldt, 1981; Mewaldt, King, 1978; Morton, King, Famer, 1969; Wingfield, Famer, 1978) lend support to the conclusion that mechanisms that control the premigratory preparation in late summer differ from those of spring. Vernal premigratory preparation is highly synchronous within a given populat¬ ion, probably because it is induced directly by increasing daylength. In contrast, the preparation in late summer is much less synchronous, probably for two reasons: (1) Because daylengths are very long and change little at this time, no source of selectively predictive photoperiodic information, comparable to that of spring, is available. (2) Renesting can cause autumnal functions to be delayed in many pairs (Wingfield, Farner, 1979). Therefore, it seems likely that reliance on both a slowly developing or delayed process and internal coupling of functions in late summer evolved because (1) little usable external information is directly available and (2) renesting is adap¬ tively more important than early, synchronous onset of preparation for migration. Our current concept of the photoperiodic control of the annual cycle of z.l.gambelii is depicted in Figure 2. As daylength increases in spring, it induces successively the independently controlled vernal functions - gonadal growth, molt, fattening, and migration. At least in part, these functions occur in proper sequence because each successive function has a slightly greater photoperiodic threshold. When the photoperiodic and local climatic conditions are suitable, northward migration begins. Our data suggest the in¬ triguing hypothesis that the rapid increase in day length experienced during northward migration has an important function in the termination of fatten¬ ing. There is also suggestive evidence that a similar response occurs during autumn when days shorten rapidly during southward migration. In any event. 950 this increase in daylength during vernal migration also initiates a delayed or slowly developing process that eventually induces late-summer functions. It is interesting that the entire reproductive effort occurs while this pro¬ cess is developing slowly. If the reproductive effort is extended due to re¬ nesting, the late-summer functions are further delayed. We have extensive evidence that this delay is produced by an inhibitory effect of high levels of sex steroid hormones (Matt, 1982; Wingfield, Faraer, 1978), although the mechanism of maintenance of these high levels is unknown. In any event, the late-summer functions are induced as a coupled functional unit. Then, probably in response to a final component of the functional unit, southward migration begins. Once on the wintering grounds, short days terminate photorefractori¬ ness. It is then possible to begin another cycle once daylength increases in spring. It will be obvious to those familiar with this subject, that this model is a specific example of the general "driver" hypothesis (Famer, Gwinner, 1980) in which the natural photocycle directly induces several independent components of the annual cycle. We include in this refined model for 2.1. i&n^elii (Fig. 2) the remote or delayed effects of long days and the internal coupling that effects the late summer-functions in their appropriate sequen¬ ce. We have proposed herein that the components of the photoperiodic system of this taxon have evolved in response to very specific environmental const¬ raints. Therefore, we expect that these mechanisms will vary greatly among species in different environments and with different evolutionary histories. Indeed, in light of these considerations, it is not surprising that other species appear to rely on entirely different mechanisms, such as entrained endogenous circannual oscillators (cf. Berthold, 1974, 1979; Parner, Gwinner, 1981; Gwinner, 1981). SUMMARY Previous observations suggested that the photoperiodic mechanisms that control the preparation for vernal and autumnal migration are very diffe¬ rent. Results of two laboratory experiments on Zonotrichia leucophrv3 gambe- Üi ^e consistent with this generalization, indicating (1) that the vernal functions are relatively independent events that are induced directly by changes in daylength, but (2) that autumnal functions are induced as an in¬ fernally coupled cluster by a slowly developing process that is induced by vernal increases in daylength. The time of onset of the latter is an in¬ verse function of daylength, but after onset the time required to complete the functions is a direct function of daylength. References herthold P. - Endogene Jahresperiodik. Konstanz: Universitätsverlag, 1974. herthold P. - Vogelwarte, 1979, ^0, p. 7-10. holnik V.R. - Migratsionnoe Sostoyanie Ptits. Moskva: Nauka, 1975a. holnik V.R. - Zool. Zhur. , 1975a, £4, P* 1048-1056'. holnik V.R. - In: Fotoperiodizm Zhivotnik i Rastenii / Ed. by V. A. Zaslavskii. Leningrad: AR SSSR, 1976, p. 47-81. 951 Dolnik V.R. - In: Problemy Koamicheskol Biologii. V. 41 / Ed. by V.N.Cher- nigovski. Biologicheakii Ritmy. Moskva: Nauka, 1980, p. 238-288. Dolnik V.R. - Zool. Zh. ,1980b, 59, p. 91-98. Dolnik V.R. , Gavrilov V.M. - Zool. Zhur., 1972, £1, p. 1685-1696. Pâmer D.S. - Amer. Soi., 1964, 52, p. 137-156. Pâmer D.S. - Environ. Res., 1970, 2< P- 119-131. Parner D.S., Donham R.S. , Matt K. S. et al. — In: Avian Endocrinology: En¬ vironmental and Ecological Perspectives / Eds. S.Mikami et al. Tolçyo: Japan Science Societies Press, 1982. Parner D.S., Donham R.3., Moore M.C. - Physiol. Zool., 1981, j>4, p. 372-378. Pâmer D.S., Donham R.S., Moore M.C. - Auk, 1980, 21< P* 63-75. Parner D.S. , Follett B.K. - In: Hormones and Evolution. Vol. 2 / Ed. by B.J. Barrington. L. : Academic Press, 1979, p. 829-872. Pâmer D.S., Gwinner E. - In: Avian Endocrinology / Eds. A.Epple, M.H. Stet¬ son. N. Y. : Academic Press, 1980, p. 331-336. Parner D.S., Lewis R. A. - Photophysiology, 1971, 6, p. 325-370. Pâmer D.S., Wilson A.C. - Biol. Bull.., 1957, JJJ, p. 259-267. Gavrilov V.M. , Dolnik V.R. - Tr. Zool. Inst., 1974, £5, p. 14-61. Gwinner E. - In: Handbook of Behavioral Neurobiology 4. Biological Rhythms / Ed. by Aschoff. N.Y. : Plenum, 1981, p. 391-410. Gwinner E. , Dittami J. , Ganshirt G. - Vogelwarte, 1980, .^0, p. 335-337. King J.R. - Condor, 196l, §2, p. 128-142. King J.R. , Parner D.S. - Condor, 1963, 65, p. 200-223. King J.R. , Mewaldt L.R. - Auk, 1982, 98, p. 752-764. Matt K.S. Doctoral dissertation, University of Washington, Seattle, 1982. Mattocks P.W. Jr. Doctoral dissertation. University of Washington, Seattle, 1982. Mattocks P.W. Jr., Parner D.S. , Pollett B.K. - Gen. Comp. Endocrinol., 1976, 20, p. 156-161. Mewaldt L.R. , King J.R. - North Amer. Bird Bander, 1978, 2> p. 138-144. Morton M.L. , King J.R. , Parner D.S. - Condor, 1969, 21» p. 376-385. Murton R. K. , Westwood N.J. Avian Breeding Cycles. Oxford: Clarendon Press, 1977. Noskov G. A. - Zool. Zhur., 1975, 54> P* 413-424. Noskov G. A. - Zool. Zhur., 1977, 61., p. 1676-1686. Stresemann E. , Stresemann V. - J. Omithol. (Sonderheft), 1966, 107, p. 1-447. Wingfield J.C., Parner D.S. - Biol. Reprod. , 1978, _1_9, p. 1046-1056. Wingfield J.C., Parner D.S. - Gen. Comp. Endocrinol., 1979, 28, P* 322-331. Wingfield J.C., Parner. - Prog. Reprod. Biol., 1980, 2. P- 62-101. 952 THE ROLE OP THE HY POTHALAMO-HY POPHYSIAL SYSTEM IN THE ANNUAL CYCLE OP MOLT AND GONADAL FUNCTION L.M.Rudneva, A. N. Buldakova, L.S.Ivanova and S.M. Garmatina Phï,I',l0S'’ Kiev 3,.,. “a °f **■ °i°”* — ‘V « ™r.s c; : srz r" °f morphogenic proc,.«, ,„lronlI«nlal 0l ■“”“1 arioua authors have demonstrated that the surgical blockade of the S~HS==:==?ä- romrt * pituitary gonadotropic function in ducks, contains a much smaller quantity of these neurons. The axons of LH RH !SE£?;™ :r ~:rr “ Y *"“n:r,4"nn.:irc:^re — — Wheir Sie!reti0n 0f eonadotrophins in male birds, as in mammals, is tonic occu aSA T CyCll° ln femaleS‘ The maximum level of LH in the blood of hens LH d + b6f0re the elation (while in cockerels the daily level of blocHe™ TZ h6"01 dim0I7hlSm iS als° reflec^d m the 1„ 31 °f PSH- As in “ale the sexual differentiation of the hypothe¬ cs is determined by androgens. However a problem arises with resp^ttY nature of this phenomenon in birds with their different genetic detes¬ tation r SeX*/e S°1Ved thlS Pr°blem U8lng th° procedure °f cross-transplan- fou^t “ 111 Ca3!rat6d male and female °f the P6kin du^lings. It was und that in the reproductive period in males with transplanted ovaries a PwYfe °f M Se0retl0n is established. In castrated females with trans- bi 63 M secretion becomes tonic. These fiodiogs suggest that in ce sexual differentiation of hypothalamus is manifested clearly in the Productive period and is determined by estrogens. fen,1? male PSkin dUCkS the bl0°d leVSl °f PSH 13 fiVe Umes higher than in Cq a es. Following castration of males with transplanted ovaries the PSH t°ntent of the blood i3 reduced to the level observed in females. The mass of geS testes relative to the total body mass in the Pekin duck is 9% while in t*eSeit is only 6.25%. The level of plasma PSH is 450% higher in male ducks an in females, but only 30% higher in male than in female geese. The ex- 953 traordinarily high blood levels of PSH in male ducks is apparently related to the development of the large testicular mass during the period of maximal sexual activity. Species and strain differences of relative testicular mass are determined by genetically fixed differences in secretion of gonadoliberin by the hypothalamus. This conclusion is based on the results of our experi¬ ments with cross-transplantation of two testes of bantham chicks and those of white leghorns, as well as between Pekin and wild ducks. In the reproduc¬ tive period the transplanted gonad3 always attained the mass characteristic of the recepient. It is well-known that the function of the reproductive system in birds is closely related to the annual cycle of daylength. A characteristic feature of photosensitive birds is that their gonads after the active period, return to a resting state. This phenomenon is related to the temporary loss of the photosensitivity of the control system. There are considerable species diffe¬ rences in the duration of the photorefractory period. The shift of the rep¬ roductive system into the photorefractory phase may be related with a seaso¬ nal feature of hypothalamic secretion of LH-RH. We made experiments with si¬ mulation incubation, in the body cavity of photorefractory house sparrows, of the inactive testes with the adenohypophyses and hypothalami of birds in various stages of the photo-induced sexual cycle. It was found that activat¬ ion of the spermatogenic epithelium occurred in only those cases in which the hypothalamus was taken from birds in the early phase of the sexual cycle. It has also been demonstrated that the injections of synthetic LH-RH led to an increase in secretion of gonadotropins in photorefractory Zonotrichia (Wingfield et al., 1979), and in ducks (Bogach et al., 1980). The increase of the level of LH in males is accompanied by a considerable increase in testosterone concentration in the blood. These findings suggest that in the refractory period the level of LH-RH in the hypothalamus is decreased. Howe¬ ver, these experiments do not answer the question whether the mechanisms of photorefractoriness are restricted to hypothalamic level. At that stage the hypothalamus probably loses its ability to secrete into portal circulation a sufficient quantity of LH-RH, or some extra-hypothalamic regulators are elimj nated. Biogenic amines are involved in' the regulation of function of the hypo- thalamo-hypophysiogonadal system. Various authors have demonstrated positive correlations between concentration of catecholamines in the hypothalamus and concentration of gonadotropins in blood. It has been shown that the deplet¬ ion of the monoamine (MA) depots in the brain by reserpine injections causes regression of the gonads in the pigeon, and prevents the gonadal response to the light in ducks (see Tienhoven, 1981). In our studies with ducks it was noted that the implantation of serotonin into the third ventricle of the brain results in a decrease of the LH level in blood plasma both in young photosensitive ducks and adult males in the reproductive phase (Rudneva et al., 1978). Adrenomimetic drugs given intraventricularly increase the con¬ centration of gonadotropins in the blood in these birds (Novikov, Rudneva, 1981). These results indicate that monoamines participate in the regulation of release of gonadotropins and are a necessary component of the hypothalamo- hypophysial regulation of gonadal function. However, the mechanisms of actioh 954 Of monoamines are still incompletely understood T+ i „ active in the process of transfer of ZlZT l ^ that they are eminence to the adenohypophysial portal veils (dner T" ^ mearabronchi , there being 'vir! y no gas exiting directly through the main bronchus, while cranial i -c gas leaves directly via thî medioventral seconda^ b™!. ' ^ e vi den e*!0t n,eChQnl3m for this functional valving is unknown. There is no fioarf06 °r anatoinlcal valves; aerodynamic valving appears to play a signi¬ er it r° 6’ T6 fUn0tlonal siSnificance of unidirectional flow, in particu" ts importance for gas exchange will be considered below. GAS EXCHANGE IN THE PARABRONCHUS Sxchh° G3Sentlal 8tructural elements of the parabronchus in respect of gas Change are the following (see Pig. 3): P S&3 thus'anoewsacoanti0nChUS C°n9tltUte3 * long tUbe that is °Pen ^ *°th ends and lows continuous air flow from one to the other end. ^ass " irradiai direct! llarl63 °rlginate the Parabronchial lumen to al . ectlon into the periparabronchial tissue. Gas exchange ^ong the air capillaries is by diffusion. 959 Inspiration Expiration P i g. 2. Direction of air flow in the bronchial Bystem during inspiration (left) and expiration (right). The dashed arrow of expiratory flow in the main bronchus corresponds to an unknown, but probably small fraction of ex¬ piratory flow exiting caudal air sacs directly via main bronchus. Abbreviat ion for air sacs: Clav., clavicular; Th. A., cranial thoracic; Th. P. , caudal thoracic: Abd., abdominal Secondary Parabronchus bronchus / Secondary bronchus Pf — — — _ /?*= -zT w — — P| . _____ . * lH bH b/H — Blood capillary Barrier Air capillary H g. 3, s * -w - w OJOUCIU A ftdil exchange in the avian parabronchus. P02 in gas entering (P ) and leaving ( p_ ) parabro^^^110 Q-nH a** «Uaj «—j- — -*-■» /*. « . . . . — Hi For details. and in mixed arterial see text (P&) and mixed venous blood (P“). 3. Blood capillaries contact the air capillaries all along the parabron¬ chus. 4. A thin tissue membrane separates air capillaries and blood capillaries Diffusion constitutes the mechanism of gas transfer across this membrane. Consider a volume of air entering the parabronchial lumen from the me- diodorsal secondary bronchus. Oxygen in this air enters blood of the first blood capillary. Thereby, the Pq2 in the gas volume drops as it passes- down the parabronchial lumen to the site of origin of the next capillary (Pig. 3, lower diagram). This results in a continuous decline of P0, in the air along the parabronchus. Likewise, blood perfusing the capillaries differs in the degree of artérialisation, there being a drop from the gas entrance end to the outflow end of the parabronchus. Gas leaving the parabronchus contains the lowest P02 CPB), while arterial blood, resulting as a mixture from all capillaries, may well be higher in Fq2 than P . This is depicted in the lower part of Pig. ^ where the p m in Parabronchial gas and in capillaiy blood are shown. The crossilg-o^r oî pai lal pressures in the gas and (mixed) blood phases, which is particularly prominent for C02, reflects the efficient performance of this seri^Îu ofP ie7entilated8SZirenttSyStr’ •"1*°ar °f Whioh is hiSher ^an ttot 1975). ted P°01 8yatem °f “alian alveolar lungs (Piiper, Scheid, SIGNIFICANCE OP UNIDIRECTIONAL PLOW It is apparent from Pig. j that reversal of the flow , rabronchus does not affect +>,- , , ow dlre°tion in the pa- :z ina small (as compared to mammalian alveolar space), a rapid dror, p 11 iCrthe™ riSe f PC°2 Sre expeCted when Parabronchial flow' drops to zero.2 pendit 6 f°re’ the reversal of flow W necessitate additional energy ex deceieration air aow* remarkably smo th • &Ve revealed air H°w in dorsobronchi to be kably smooth during, breathing at elevated frequencies (panting). ly connect tl 7” “ additional of parabronchi which mein¬ st nne=ts the ™am bronchus and dorsobronchi to the caudal air sacs This .ystem, termed "neopulmo" by Duncker (1971), is particularly well dev^lopel dors 77 In th63e MrdS’ the “ bronchus> Cfiudal to the origins of nectedl0! Ï T mUCh redU06d S° thSt thS abdominal air sacs are con- I 2 d°r7r0nCM by neopulmonary parabronchi only. Therefore, air in these parabronchi must be in opposite directions during inspiration ^t expiration, respectively. Since their microscopic structure suggests is e •„ °r033‘current system applies to neopulmonic parabronchi as well it 1 IxcZlsT* Unidirecti0nal air fl0W iS naadat0Iy parabronchial BIRDS VS. MAMMALS: ADVANTAGES OF THE AVIAN RESPIRATORY SYSTEM ““ *"• Ion of long. prop„ ana ‘ V “"P1” ««■ pottom and th. cro«- P«^ ^ ^ perfualng the hlood ca- °iuIriTv',”«ÎIto^ tie. through the open-ended p.r.bronohlel tube, ae- su.ee the" same direction both dur^ “od^ ge 1« i-e p.r.bronohn. can ade,„ately b d ■ „bed by a the effioiency ol »hioh is superior to * „»idirecti- parabronchial ga. .«hange is independent of «ir flo» direction, onal air flow appears to be advantageous. References Duncker H.-R. - Ergebn. Anat. Sntwckl.-Gesch. , 1971, 4£, N 6, Duncker H.-R. - Respir. Physiol., 1972, 14, p. 44-63- Piiper J. , Scheid P. - Respir. Physiol., 1975, P- 209-221. Powell P.L. et al. -Respir. Physiol., 1981, 44, P- 195-213- Scheid P. - Rev. Physiol. Biochem. Pharmacol., 1979, §6, p. 138-186. Scheid P. - In: Avian Biology. Vol. VI / Eds. D.S.Famer, J.R.King. Academic Press, 1982. 962 INERT GAS TRANSFER AND FUNCTIONAL INHOMOG ENEITIES IN AVIAN LUNGS Frank L. Powell Department of Medicine, M-023 University of California, San Diego La Jolla, CA 92023, USA S The evolution of the respiratory system of terrestrial vertebrates is haracterized by an increase in gas exchange surface area This - to allow the increased oxygen uptake required by endotheray and more energe^ o'“ (aSSUminS a fiXSd comPoaLtion and minimal thickness ore 1 ° “d S ««« tension driving the diffusive trZT T n°reaSed 3Urfa°e area was achieved bN Partitioning the lung into many finer subunits resulting in a larger surface: volume ratio. The Zhrdfwhich thlG Strat6Sy 1S nlCely Sh°TO WUhin the reptiles- Varanid li- zards which are very active predators with high aerobic scopes hl^T^ulti- c^eral lung with many more subdivisions than the paucicameral lung Oâ lizards which have a more limited aerobic scope (Mitchell et al., Perry, Duncker, 1978). yal ’ At some point in the early evolution of the reptiles, the way in which lungs were partitioned diverged. The end results of this divergence are the ^als with ymogeneoug partitioning and the birds with heterogeneous parti- ng (Duncker, 1978). Although structural differences between avian and Scheid1^^8/37,160'1 tQ dlffGrences in the efficacy of gas exchange (cf. ' ’ 13 V°lume)’ common factor which can reduce the efficacy of gas ange in either type of lung is functional inhomogeneity. That is, venti- lon and blood flow (perfusion) may not be optimally matched with one a hi °r Wlth the diffusive Properties in the individual subdivisions of inc y partltloned lunS‘ Thls reduced efficacy is one of the "costs" of J*™** SUrface area by partitioning and it is reasonable to ask the gens-îr1’ /IS thl3 redu0ed efficacy of gas exchange from functional inhomo- m* 63 "partitioninS cost") «ore or less in avian lungs compared to ^™alian lungs?". INERT GAS TRANSFER aisln!rt.8a3ea Sre USeful in studyine the effects of ventilation-perfusion seama!°hinß ln 1UngS f°r several reasons. Firstly, inert gases are those ga- ^ which do not enter into chemical reactions with the blood (like 0 , CO ihd C°2 d0)* Hence’ one can study the gas exchange properties of the lungs of blood chemistry and not be confounded by differences in hemo- ai Q3’ f°r example* Secondly , because inert gases are only carried in phy- iisa S°lution by the blood they obey Henry's law and show linear blood-gas Part°0iatiOn curves. This constant realtionship between blood contents and f6r fal Pressures allows one to write analytical descriptions of their trans- Üff °r VQrioua lung models. Thirdly, because inert gases come rapidly to feci;U0lOn e<3Uillhrium across the blood-gas barrier, they are virtually unaf- 1 9q0) ^ diTlusive/perfusi ve functional inhomogeneities (Fiiper, Scheid, ^hga” • ^ faot’ the efficacy of an inert gas' transfer in avian and mammalian t3 Primarily a function of ventilation/perfusion (V/Q) equality. 963 Pig. 1. Excretions and retentions of inert gases, not present in the inspi- rate, being eliminated from venous blood as a function of their blood-gas partition coefficient. For homogeneous alveolar lungs, E=R for all gases while E 2 R in cross-current lungs, indicat¬ ing greater efficacy of cross-current gas exchange. A more familiar example of superior efficacy iD cross-current compared to alveolar exchangers is PE- Pao2> J0g and PEcof PaCo ifi birds while expired gas and arterial blood are in equilibrium in mammals Consider first the elimination of an inert gas from venous blood in a single subunit of a mammalian lung (i.e. alveolus) or an avian lung (i.e. parabronchus) . Gas exchange can be described in terms of excretions (E) and retentions (R) by normalizing expired and arterial to mixed venous partial pressures as: E = PE/Pv and R = Pa/Pv Because elimination of a gas is directly proportional to E, or PE, for fixed V/Q and Pv (i.e. VPE^) , greater E for the same gas and ventilation in one compared with the other lung indicates greater efficacy. Similar arguments hold for R and Q (Parhi, Plewes, 1980). Figure 1 shows that the efficacy of the cross-current exchange (for the avian lung) is greater than alveolar. If birds do not eliminate inert gases better than mammals, then (a) V/Q inequa¬ lity may depress inert gas elimination more in avian lungs or (b) birds may have more V/Q inequality. The effects of V/Q inequality on inert gas elimination were examined with a computer model of cross-current gas exchange first. Equations predicting expired gas and arterialized blood concentrations of inert gases were solved for 50 ga3 exchange units (representing parabronchi) , each of which could have different values of ventilation, perfusion and V/Q. Thus, parallel V/Q inequality between parabronchi was studied. Serial inequality of blood flow along a parabronchus will not affect inert gases (Powell, Wagner, 1982a) s° blood flow was assumed to be uniformly distributed within a given exchange unit for simplicity. Ventilation and perfusion were distributed between the individual units as logarithmic normal distributions because (a) this method has been previously employed to study the effects of inhomogeneity in al¬ veolar lungs (West, 1969), (b) many biological variables are described by log-normal distributions and (c) most importantly, the inhomogeneity can be described by a single parameter - the log-standard deviation of the distri¬ bution. Furthermore, a given log-standard deviation of either blood flow or ventilation distributions has an equal effect on depressing the efficacy of gas exchange. Computing flow weighted means of inert gas partial pressures in blood and gas leaving the individual exchange units gives whole lung re¬ tentions and excretions. 964 .001 .01 .1 I 10 too. y Partition coe-Fficient blood-gas partition coe^ icienle'ir for gases wi™ different cross-current (lower) gas exchangers IT”' = log standard deviation of Ÿ or q vs V/o ln z/Q~ ‘ /Q Quality creased (R-2) increases indicating red^d effi 00»««rt»«ta) is in- *‘ *"**"• Mth amount or incquÙÛTi, T"' ‘h' cross-current exchangers. Partition coeftM < * “ alveolar compared to most physiologic interest beole 1 °* ' ' “d 10 «1».. «...OIM* ,lth 0j „„ C02 exohaii” ™W> «•« various ar.,"^ï:rd”C™i‘“ “"r::« r-; *re - Jungs with various amounts of ~Q inequality to ““ Cr°S3-CU™ (o) °f the distributions is Zero this lifr l°S-standard deviation than in alveolar lungs t0l M ’ ^«erence is less in cross -current case m Figure 1). With in f PartiW°n °°efficlent (as was the dl-ops in both models as th/ret T lnequallty Sas exchange efficacy sitive. This is si' i! + ratention-excretion difference becomes more po- creasing'the arter^ impairment reducing efficacy by il iuequaïitv th! c XPlr note that for any degree of lun g w / fl*CUrrent 1Uûe alWayS better than thTalv^lL lungs m0r.e than 6q ty Sh°Uld depreSS lnert Sas elimination in bird S3 more than xn mammalian lungs unless there is more of it. MEASUREMENT of v/q inequality in birds oup^i fSSeSS *h' <=r ventilation and blood flow mon. „a.. ,14*U»°^«îat,d ’PPlle< ti' ln'r* *" «“»l»*«»» technique to lac, Z I rllJlZ ITT' T"' 158a)- “* «a Î1» blood are a 1 1 “\h °f ^ ««".ted from I«. T . bl„„d-ga, partition coaffioie», „„ th, verai^r--iiEiâ By simultaneously measuring retention and excretion of «-Î ,ToZTYla m*- -».T.;:«": 'Vest, 1980). qUe" ° ln GT a V/Q ately Predict arterial Pq2 and Pgo2 in resting mammals at sea level and indicate a larger diffusion resistance for 02 in avian lungs (Powsli, 967 1982). Recall that the model assumes diffusion equilibrium, which is valid lor inert gases but may not be for Og. Also, inhomogeneous blood flow along a parabronchus can affect Og exchange, unlike inert gases, but the effect is very small (Holle et al., 1978; Powell, 1982). These two factors may be involved in depressing arterial P_ in birds. u2 PHYSIOLOGICAL SIGNIFICANCE In answer to our original question, it appears that gas exchange efficacy is reduced from ideal levels more in avian lungs that it is in mammalian lungs. Thin is because there is more inequality, not because cross-current gas exchange is more susceptible to effects of V/Q inequality per se. Howe¬ ver, the avian lungs start out with an advantage - efficacy of ideal cross¬ current lungs is greater than ideal alveolar lungs - so the end result is similar gas exchange efficacy in birds and mammals. The net efiect at rest and sea level is similar arterial PQ„ in birds and mammals but lower arterial PC02 in birds. Lowered arterial Pco has been shown to be important for maintaining arterial Pq2 in mammals at high alti¬ tude (West, Wagner, 1931). The abilities of birds at high altitude are well documented (ot*. Black, thi3 volume) but evolutionary pressures for high al¬ titude flight were probably small so other consequences of the low cross¬ current arterial PC02 may be more important (e.g. acid-base regulation). Al¬ ternatively, PCO 2 differences may be only incidental. Mammals could easily lower their arterial Pqo2 to avian levels by mild hyperventilation (Scheid, personal communication) . If ono considers a minimum arterial Pq2 ia necessary for survival then more efficient gas exchange, like that provided by the cross-current model, may be required for heterogeneous lungs. The larger amount of V/Q inequality in avian compared to mammalian lungs may be a direct consequence of heteroge¬ neous partitioning. Flow through ventilation of the avian lung by air sacs acting as bellows might be inherently less uniform than tidal ventilation ih alveolar lungs. The advantages of cross-current exchange may offset such P°3' sibly uns, vo i dsble functional inliomogönoitios* Once the structural and functional basis for the measured V/Q inequality m avian lungs is better understood, there may be further insights. For ex- 968 31be: “//VneqUality 13 Uad0r 30me SOrt °f Physiological control then it T +be HredU°ed -Citions like exercise or hish altitude. A full lung s "awai t s °no t ^ ' f8““*6“00 °f the and function of avian ungs awaits not only complete descriptions of V/Q inequality but other ti0nal 1nh°m°geneities (e.g. diffusion-perfusion mismatches) as -well. SUMMARY crer°dUti°n °f end°therrny and associated high metabolic rates required in- of mllîT TT 3UrfaCe arSa‘ Thi3 °CCUrred by homogeneous partitioning mammalian alveolar lungs and heterogeneous partitioning of the avian res¬ pirator system. The "cost" of increased surface area by partitioning in „ ”°’T" Inert sec öfter . „Z ” proM»"- »«» *>« cross-current « .«hange in an lungs is not affected more than alveolar gas exchange by V/Q inequality «. Z Z t? lnTut’ sh°’ »Z t L ITJ1T re un 1 3UPeri0r effiC8Cy °f oross~ourrent gas exchange in birds * * " hißher efficacy or i^ert gas elimination in birds. Models show he e fects of V/Q inequalUy of and to ^ 3imiiar d ^ ; •ZlIZ It nhanSeS- H0W6Ver’ °2 6XChanSe ia impaired lore fact 7 Cr°SS-CUrrent models V/Q inequality, indicating other at 1 Vl8* aiffUS10n »»stance«) may impede gas exchange in birds. Thus I 6334 at rSSt “* sea «» inherently greater efficacy of avian gs is reduced to a level similar to alveolar lungs. Ref e r e n c e s Duncker H.R. pirat^ !*ChanSe &t higil altituâe- (This volume). *oäy:::: sr66* vo1* 11 7 - * Kelman a r’ f * ’ Scileid P- ' ^ J* Physiol., 197s, 234, p.r146-154 G r " d * APPl* PhySi01** 1966* P- 1 375-1 376. ^ Wilts' nlP* PhySi01-’ 1967> * P* 111-1 15* p P- R29-R37, * leeS°n T*T*’ BenneU A-P- * Physiol. , ,98,. 240, Pii!LS;P* - Respir- Physiol, , 1978, 34, P. 61-81.. Scheid P. - In! Pulmonary Gas Exchange. Vol. I / Ed. by J B West P ‘ - Acaderai0 P«3S, 1980, p. 131-171. 7 J-B.West. Po»ell P‘L' ~ Ped’ Proc‘> 1982. fowen I*L"’ Wagner P,D* - Respir. Physiol., 1982a. °*eli — ~ - «espir. ’ Wagner P.D. - Respir. Physiol., 1982b. B pi wa r’ See this volunie* J.B wll’ lVeSt J‘B* ~ In: Gas Exchange. 219-262. j ( ' • aw; ruxmonary uas at" ,We°t. K*y-: Academic Press, 1980, p. Vol. X / Ed* by Weat A,#A#Î *««*ueinic Frees, 1980, p. 219-262 West J*B‘ ‘ Re3pir* Physiol. , 1969/70, 8, p. 66-85. •B-, Wagner P.D. - in: Bioengineering Aspects of the Lung / Ed. “•West. T\L V- . Mr* - -, _ ^ -Dio engine er mg Aspect ^stYJ63*- N*Y*: tercel Dekker, 1977, p. 361-457. •» Wagner P.D^ - Respir. Physiol., 1980, 42, p. 1-16. hy 969 AVIAN RESPIRATION IN Tp SERVICE OP BODY TEMPERATURE REGULATION Claus Bech, Kjell Johansen Department of Zoology, University of Trondheim, N-7055 Dragvoll, Norway; Department of Zoophysiology, University of Aarhus, DK-8000 Aarhus C. , Denmark INTRODUCTION Ventilation in birds and mammals serves primarly in gas exchange, but the passage of air through the airways will inevitably also results in loss of water and heat to the surrounding air. These exchanges will increase with increased temperature difference between the deep body and the ambient air. Heat loss from the respiratoiy tract is the most important avenue for evapo¬ rative heat loss at high ambient temperatures in birds and mammals practic¬ ing panting. The present review attempts to evaluate our present knowledge of some of the ways in which changes -in ventilatory pattern serves the body temperature regulation in birds. See Dawson (1982) for a more extensive review of the evaporative water loss in birds. EXPOSURE TO HIGH AMBIENT TEMPERATURES Exposed to high ambient temperatures, birds typically increase the venti¬ lation of the upper respiratory tract as the only regulated response for in¬ creasing the rate of evaporative cooling. This increase may be due to gular fluttering and/or panting. Gular fluttering consists of rapid movements of the buccal floor, often at frequencies synchronous with the panting frequency (Lasiewski, 1972). Weathers and Schoenbaechler (1976) reported that evaporative cooling contri¬ buted by gular fluttering accounted for 20% of the total evaporative water loss in the Japanese quail (Coturnix cotumlx). In the Domestic fowl (Gallus gallus) 35% of the total water loss during panting could be attributed the gular pump (Brackenbury et al., 1981b). Although gular fluttering is of com¬ mon occurrence in many non-passerine species, the studies on the Japanese quail and Domestic fowl appears to be the only ones offering quantitative data on the importance of gular fluttering for the total evaporative heat loss. Similar studies in species of the Caprimulgids, Cormorants, and Peli¬ cans, for which gular fluttering by observations seems to be conspicuous, would likely prove rewarding. An attempt has been made by Lasiewski (1969). who found that the gular fluttering in the Poorwill (Phalaenptilus nuttalljj/ probably contribute more than half of the total evaporative water loss at ambient temperatures above 39.5°C. Panting as a source of evaporative cooling have been observed in nearly all species of birds studied (Salt, 1964; Richards, 1970; Calder, King, 1 974/ ' Panting results in several-fold increases in total ventilation, but very few studies have involved direct measurement of tidal volume (Bech et al. > 1979). Pig. 1 illustrates changes in breathing frequency and tidal volume and the resultant effect on total ventilation. Typically ventilation in¬ creases 2.5 to 6 times the non-panting value, the result of a 10- to 30-f°ltl increase in breathing frequency and a simultaneous decrease in tidal voluroe to between 15 and 40% of the non-panting value. 970 6 Times increase m breathing Treçaencg Ln * * * * 6‘ « Rela^l0n8hlp between respiratory frequency (as a multiple of the non-panting value) and the tidal volume (expressed as a percentage of the non-panting value) during panting in birds. The lines show isopleths for 1982! VantlJati0n-increasea panting. ! - gulica atra (Brent et al., " 4«as platyrhynchos (Bretz, Schmidt-Nieloen. 1971) q (Calder, Schmidt-Nielsen, 1967), 4 - liviaTcald )‘A~4^r,1UB g8llUS (Brackenbury et al*. WD, 6 - Columba 1*974) 8 Tv °° 1t"N!el8en’ 1966)’ 7 * * ' Anas platyrti.vnchos (Bouverot et fnlV97^ r~-S ° Bech’ Johansen’ 198°). 5 - Phoenicooterus 6 a *’ 10 - Columba livja (Remirez, Bernstein, 1976) the ^rkad ^crease in ventilation volume associated with panting subjects su* f! rlSk °f a reaplratory alkalosis. To avoid this it has been ggested that birds are able to shunt portions of the ventilated air away om the parabronchial gas-exchange surfaces during hyperventilation (Zeu- en, 1942; Marder et al., 1974; Marder, Arad, 1975; Krausz, 1977). However 0 anatomical evidence for such a shunt mechanism have been presented. In- a ead, recent experiments have suggested three afferent panting patterns ich may offer protection against overventilation of the gas exchange sur¬ faces of the lung. These different patterns .re schematically illustrated lh Pig. 2. F 1 1 g. 2. Schematic illustration of 6 three different patterns of pat>ting found in birds A IMute swan ( nach & Johansen 1980) Flamingo (Bech et al. 1373) JJomestic fowl (BracKen burg el al. 1981) Normal l/v Parting Pigeon (P ami rex & Bernstein 1976) necK ed raaen (Hudson & Bernstein 197B) 971 In the simplest form (Pig. 2, A' , which have been described in the Mute swan (Cygnus olor) (Bech, Johansen, 1980), the hyperthermic breathing is characterized by a high breathing frequency and a constant low tidal volume. Each tidal volume typically is only slightly larger than the anatomical dead space. Calculations show that the parabronchial ventllatiorf during this pant¬ ing pattern is held at the pre-panting level despite a 5.4-fold increase in total ventilation (Bech, Johansen, 1980). Another pattern (Pig. 2, B), termed the "flush-out" panting, consists of a high frequency, low tidal volume pattern, with tidal volume equal to or smaller than the anatomical dead space. At' regular intervals a few very deep breathing movements occur. These regularly occurring "flush-outs" serve to maintain parabronchial gas exchange, while the high frequency breathing pri- marly subserves the need for convective air flow to promote evaporative cool¬ ing. Plush-out panting was first described in the Greater flamingo (Phoeni- copterus ruber) by Bech et al. (1979) and have recently also been reported for the Domestic fowl by Brackenbury et al. (1981a). A third panting pattern (Pig. 2, C) involves a stable and very high breathing frequency with tidal volumes smaller than the dead space. Parabron¬ chial ventilation is produced by alternating imbalances between the inspira¬ tory sind expiratory volumes such that the parabronchial surfaces become ven¬ tilated at a lower frequency than the actual panting rate. This pattern has been termed "compound" panting and has been reported to occur in the Pigeon (Columba livia) (Ramirez, Bernstein, 1976; Bernstein, Samaniego, 1981) and the White-necked raven (Corvus cryptoleucus) (Hudson. Bernstein, 1978). All the described patterns of hyperthermic panting have been demonstrated to be associated with small or no respiratory alkalosis as evidenced by near¬ ly stable arterial pH (Bech et al., 1979; Bech, Johansen, 1980; Bernstein, Samaniego, 1981). Recent data (Brent et al., 1982) on ventilation in the European coot (Pu- lica atra) have shown that lung oxygen extraction decrease markedly when birds are exposed to an ambient temperature of 35°C (Table 1). In spite of a more than doubling of the parabronchial ventilation at 35°C, the Og-uptake increase only slightly. This situation correlates with a reduction in the parabronchial oxygen extraction to only 1 3- 9%, compared to 27.0% at an am¬ bient temperature of 30°C. Bucher (1981) also reported lung oxygen extrac¬ tion in the Linneated parakeet (Bulborhynchus iineola) to decrease during panting. A regulated alteration of parabronchial Oj-extraction offers obvious ad¬ vantages for body temperature regulation. It enables birds to iocrease lung ventilation during panting without a resulting respiratory alkalosis, because the reduced O^-extraction balances the elevated ventilation with respect to overall respiratory gas exchange. The mechanism behind the changes in oxygen extraction remain unknown. Based on anatomical evidence a ventilât ion- shunt seems unlikely. Changes in para- bronchial perfusion, either in the form of discrete shunts or an alterated regional blood perfusion are probably participating factors. Parry and ïates (1979) indeed found a change in regional blood perfusion of the parabroncbi during panting in the Domestic fowl but not in the pigeon. In the fowl the 972 !"“*t T““ th' PT.to.ichl were relatively leas „„ rrrrr.:^ ~t nv° “• — -p«.è: “r;, ai ,q7R p P tne Parab*>nchi in non-panting birds (Holle et 19795 ’ the PerfUSi-C^a ^ound during panting H!n^978T rr tend t0 deCreaSe = r:=~ — :;rep~ to^T"' ”° ?* 1”01”4-' “™* "»«■T»»».. T tidal ,„i™, « ' thc“',èî °e“ÎL«c“^‘LâUrI”e P“t1”8 S' *°° “Ual”S “* ■«“”"«■‘1» or cv a* !■ 3entilaUon t0 be proportional to the increased breathing freouen quency sU^furth^ (4°°C) increased the breathing fre- therJ, nt ’ but when this happened the birds became severely Lper- few hours At^oc’Lbi^J T™ t0lmte exP0Sure t0 4°°C for more than a reached , 3 ambient temperature the lung oxygen extraction may have «to c f ”* ’°"ale r‘d“o«“- *»- «W further l„cre„e !» ■■»ill«/’1 lB ^fPoo.P"1* “a alkaloeie, because th, par.bronchl.1 ».«to* r r:? ia par*iiei wi,h «» *» *o.«i .«.ii.««. £ ter, ! habit.t of the coot, .ugg.sts a leaser depends»« on respira- (b«::“; ,ta' 01 conveouve h*‘' i°- f™ «» *•«« ( SrS^i”**11“ (,974! '*» epeoiee or Hawaii« hon.pcreepers ° a inemcient evaPorative cooling capacity. At about so rP,nfUreS 38'390C th6Se 8peCleS W6re °nl* able t0 dissipate an ambi t0tal ^ Production- and for one of the species ^ ambient temperature of 40°C was found to belethal. The marked reduction in mal haMtir'T I “ th6Se Spe°ieS is Probably related to their nor- ProbabÎ ’ 13 hißh f0reSt reSi°n’ Where the “bi6«‘ temperature ly never exceeds themal neutrality for honeycreepers (MacMillen, 1974) rocï° ,S !" R0Mn 09775 reP°rted that thS desert-living sandgrouse, Pte- ’ ^----a-ohata. did not use panting during incubation in the open sun, where Used gu^Snr!+reaChed ValU6S eXOeedlnS 5°°C- Instead thesa birds apparently snalig 1 fluttering and "beak gaping". However, the authors did only vi- neede^ °bserve the birds from a distance, and a more detailed study is 0 confirm the absence pf panting in the sandgrouses. •SjLgQSURE TO T.nw AMBIENT TEMPERATURES dreaseT3161111 temperaturea below the thermoneutral zone birds have to in- deep h ,he h6at Production and/or to reduce heat loss in order to keep -the ^ °dy temperature stable. Sir t 1 Sr t0 What haa been found for many mammals, a decrease in exhaled emperature relative to body temperature has been recorded for several 973 avian species exposed to decreasing ambient temperatures (Schmidt-Nielsen et al., 1970; Murrish, 1973; Brent et al., 1982). The amount of heat and water recovered by decreasing the exhaled air temperature may exceed 85%. So far, there seems to be no clear relationship between either body size, habitat or general behaviour and the capacity to decrease exhaled air tempe¬ rature. In addition to the obvious advantage of a reduced expired air temperature for heat conservation, further prevention of heat loss could be obtained if the total volume of air ventilated could be reduced in relation to the aero¬ bic oxygen requirement of the species (i.e. a reduction in the ventilatory requirement). This form of heat conservation is clearly operating in the coot, expressed by a marked increase in parabronchial Og-extraction. Table 1 shows that the oxygen extraction in the coot changes from 28.4% at thermoneu¬ trality to 62.0% at an ambient temperature of -25°C (Brent et al., 1982). The benefit of this change is striking. At -25°C the aerobic Og requirement can be maintained by only 50% of the parabronchial ventilation which would have been necessary if the Og-extraction had remained unchanged. In addition to the change in oxygen extraction, the coots lower the exhaled air tempera¬ ture, at -25°C to about 0°C. Calculations show that this brings total heat conservation at -25°C to about 90% of the heat added to the air at inspirat¬ ion. About 79% can be accounted for by the lowered exhaled air temperature and 11% by the increased oxygen extraction. At -25°C the amount of heat re¬ covered by the increased oxygen extraction is 2.6% of the total heat pro¬ duction. Although this appear of limited importance, it actually implies a reduction of the respiratory heat loss by more than 50%. An additional bonus concerns water conservation since the increased Og-extraction also reduced the respiratory water loss by more than 50% (Brent et al., 1982). Bucher (1981) found the oxygen extraction in the Linneated parakeet to increase from 29% at thermoneutrality to about 37% at 5°C, at which temperature the change in oxygen extraction accounted for a reduction in the heat and water loss of 21%. Bernstein and Schmidt-Nielsen (1974) did not find any significant changes in oxygen extraction in the Pish crow (Corvus 03sifragus) at ambient tempera¬ tures between 5°C and 25°C, although their data suggest a small increase at the lowest ambient temperature. In the Pigeon, the oxygen extraction re¬ mained unchanged between 2°C and 22°C (Bouverot et al., 1976). The study on the European coot (Brent et al., 1982) is the first which T a b 1 el. Oxygen uptake (2 - ml Og kg-1 min-1 ), parabronchial ventilation (3 - ml kg min ),an» « > »«=««1» summary surffp 18 oharaoterlzed bY Io» environmental oxygen partial pres- (alti .. °A’ QWhil6 °nly f6W human 8UbJect3 bave been able to climb Mt. Everest tQJtxtude, 8848 m; P02 * 42 Torr) without additional 0,, several bird species ly of H 9^6n hlgher alWtudes‘ The effect of lung structure, and particular¬ ity. +, 6 hlSher gas ««hange efficiency of the avian parabronchial compared ai e mammalian alveolar lung, has been estimated by calculating to what aame U ® 111011 could climb when equipped with a parabronchial lung. For the Torr» arterlal P°2> man equipped with parabronchial lungs could afford a 5 ?S0 iareduotlon in ambient P02, corresponding to a gain in height of about for ThUS,.the higher £as exchange efficiency of the avian lung can account aoCou °ignificant increase in high altitude tolerance; however, this cannot 26-3aK^ entirely for the apparent high altitude tolerance of birds. 977 RECENT ADVANCES IN UNDERSTANDING THE CONTROL OP BREATHING IN BIRDS M.R.Fedde, J.P.Kiley, F.M.Faraci Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA INTRODUCTION The respiratory control system adjusts ventilation of the gas exchange re¬ gions of the lung so as to eliminate excess carbon dioxide produced by in¬ creased metabolism, or to conserve carbon dioxide at 3ome present level when metabolic rate is low. There are at least three categories of factors that influence the central respiratory controller to produce a neural output to respiratory muscles in accordance with metabolic or heat exchange require¬ ments. These include: 1) chemogeDic factors, which involve chemical changes in the body; 2) thermogenic factors, which result from changes in the exter¬ nal and internal thermal environment; and 3) neurogenic factors, which arise from activation of higher brain centers and/or from stimulation of receptors in muscles, tendons and other regions of the body. This review discusses the current state of knowledge about the influence of each of these factors on the control of breathing in birds during rest and exercise. CHEMOGENIC FACTORS IN THE CONTROL OF BREATHING 1. Chemical stimuli. Three principal chemical stimuli known to change the magnitude and pattern of ventilation are: 1) Changes in the partial pressure of 02 in the arterial blood (Pa02) ; 2) Changes in the partial pressure of C02 in the arterial blood (PaC02) and in the intrapulmonary gas; and 3) Changes in the hydrogen ion concentration in the arterial blood, /H+/a. In addition, other chemicals may be produced by increasing metabolic activity in muscle or other regions of the body. These stimuli appear to reflexly activate ne¬ gative feedback mechanisms that attempt to prevent marked changes in arte¬ rial PC>2, PCOg, and pH despite changes in the activity patterns of the birds. 2. Chemo receptors. The chemical stimuli are detected by chemoreceptors whose afferent neurons project to the central nervous system. These chemo¬ receptors are located in several regions of the body and appear specialized to detect specific stimuli. One of the most studied organs containing chemoreceptors is the carotid body. A carotid body is situated on each side of the bird caudal to the thyroid gland in the thoracic cavity, on or near the carotid or caudal thy¬ roid artery (de Kock, 1958; Dreyer et al., 1977) from which it receives its blood supply. Innervation is supplied by small nerves leaving the nodose ganglion of the vagus nerve. Cells within the carotid body possess afferent, efferent, and reciprocal synapses. Two or three cell types (Type I, II, and III) are present (Kobayashi, 1969; Kobayaahi, 1971; Hodges et al., 1975; Kin£ et al., 1975; Dreyer et al., 1978) but it is still not known if one of these cell types is the receptor cell or exactly how the afferent neurons are acti' vated. Current evidence suggests that the carotid body is the only receptor system in the bird which senses low partial pressure of 02 (Bouverot et al* * 1974b; Bouverot, 1978; Bouverot et al., 1979). The afferent discharge from this organ increases when arterial P02 is lowered and is suppressed by elevst* ing Pa02 by inhaling high concentrations of 02 (Bouverot, Leitner, 1972)*®1® 978 receptor may also have some sensitivity to PaCO but - *•">* «"»» I- ). forInZXerCiSlnS dUCkS’ 6levations in Pa02 al3° reduce the ventilatory ef- Pig. la). That reduction is even more prominent if the duck is made boIZZ prl0r t0 elevatinS ?*°2 (»8. Id). It thus appears that the carotid i* la9 a 3ignifioant influence on the central respiratory controller dur- 18 various metabolic states. the1*1 the reStins state* when PC02 is elevated in the arterial blood or in inI 8ES Withln the lunS> ventilation is markedly stimulated, usually by an rease in tidal volume (Pedde, 1976). That response has been obtained when 979 Normoxia 2 ru 0, 100°/. 0, AwMVvVMWi B Hypoxia. 1. 2% a , toov. 0. ! sec \ml - 0 50 ml 0 mill’d Pattern’°r a Pe^n duck aiming on a tread- * a a 3 incline) when allowed to breath 100# 0p. A, in- tally breathing air (minute ventilation, 2058 ml- min"1) followed by 100% 2 ventilati°n. 2077 ml- min'1); B , initially breathing hypoxic gas containing 12% o2 (minute ventilation, 4438 ml- min"1) followed by 100% 0, minute ventilation, 2992 ml-min^). Inspiration is from the center of tL tracings down and the calibrations indicate inspi^toïy tidal volume CO is inhaled or PC02 elevated in the mixed venous blood (Boon et al., 1980). hi response can result from altered activity of IPC alone (Pedde et al., 1982, , but receptors in the carotid body and brain also may be involved. During exercise, birds hyperventilate, as indicated by a reduction in PaC02 and in the C02 concentration in the clavicular and abdominal air sac (Butier et al., 1977; Torre-Bueno, 1978; Kiley et al., 1979; Brackenbuiy et al., 1981; Bech, lïonoto, 1982). Such a response should reduce the ventilatoiy drive from carotid body and central chemoreceptors, and increase the central inhibition from increased discharge of the IPC. Therefore, these receptors are not likely to be responsible for the hyperpnea of exercise. The IPC and perhaps also carotid body and central chemoreceptors, may be acting to limit the degree of hyperventilation during exercise, thereby preventing severe respiratory alkalosis. THERMOGENIC FACTORS IN THE CONTROL OF BREATHING I- Thermal stimuli. Although most studies have concentrated on the ef¬ fects of elevated environmental temperature on the respiratory control sys¬ tem, both heating and cooling of the brain and spinal cord have been used to identify regions of the central nervous system important in thermal regulation. 2. Thermoreceptors. Receptors sensitive to thennal changes are present in the skin, spinal cord, and brain of birds. Current evidence suggests that stimulating peripheral thermoreceptors will not elicite panting unless cent¬ ral receptors are also activated (Richards, 1970). However, peripheral ther¬ moreceptors may provide a facilitating or inhibiting influence on the thennal response. Available evidence indicates that a pacemaker in the midbrain or rostral pons is the dominant frequency controller in panting (Richards, Aveiy, 1978), but thermoreceptors in the spinal cord and hypothalamus may act to initiate or inhibit panting (Rautenberg et al., 1978). „ 3’ responses to stimulation of thermoreceptor«- Polypnea is the result of increases in environmental temperature. It may occur without causing hypocapnia in some birds (Schmidt-Nielsen et al., 1969; Bouverot et al., 1974a), but usually produces a reduction in PaC02 in the chicken (Lina- 980 ley» Burger , 1 964; El Hadi, Sykes, 1982) Tho-ro to + ** ■“*- *— « the : llnlZZ ~T in receptor drive (Mather et al., i980; Bamas et 11 îs “ î a lower intrapulmonary and arterial PCO t’ ’ polyPnea causes r :iiowed * — -- s heat loaded but hypocapnia and alkalosis are not allowed to occur, the“ degree of polypnea is significantly reduced. Thus, at least in the chicken — rrïï™:: L-~ri *>; *“u - — *° ’”™“ "'«• hypocapnia .hlf. «1«.^ *' “ re “ir io" * ~ »' . erre« -r? i”"“,ea- *h» a“*- ~ « jncnce . l“.’— poo “!L a“P,r0f ”"1°' 5°* «1 i-te- P00s may drop by .. 5_e If ducke an, ,««la,d does8not rise ^he patt COld envir°™t (-5°C) so that body temperature not decL Ippr c I L6IId r fS ^ “"“«*• Tidal *». 60 breaths-min^ Th respiratory frequency increases to only about 3 Tor; ft “ flan ” rrr ‘’“‘T“1*1 * “ *■">“»»*■ « ■»* about tiiatorv n»tt n yperthermic drive to breathing alters the ven- cause Z the eXer°iSe ** Wel1 33 durln* rest but is not the sole of the exercise hyperpnea in birds. N3UR0G3NIC FACTORS IK THE CONTROL OF BREATHING Pari; SflLCatVtlmi1fltiT MeChani0al Sti“Uli -e P-sented to most body exerci8e Su^h r *Btort9A “d are -P-ially prominent during movement ' of o Z ^ oontinuously present or present only during ihvo £ Z*T , TCtB °f n'eChBniCal 3timUli °n apeCifiC -ce p^rs the control of breathing have not been extensively studied. b) • -^anoreceptors. Recent experiments in chickens (Ballam et al.,i98ia vol * emonstrated that mechanoreceptors, stimulated by changes in body rent f1ÎSVe “ lnfluenoe 011 the ventilatory pattern. 'It is known that atte¬ st al 7*7 AZ°m mechanoreoePtors course ceritrally in the vagus nerve (Fedde et al*’ ’ Ut* Wlth excePti0« mechanoreceptors in the gizzard (Duke recent ' ^ (EataviUo- BurSer. 1973), the location of these demons,™ ! ?0t Pulmonal^ mechanoreceptors have not been conclusively ai30 r beca««e previous attempts to distort the pulmonary tissue have nty. 6SUltedlD distortion of other organs in the thoracic and abdominal ca- ^^Most muscles in birds contain muscle spindles or tendon organs (Dorward f erent Eldr6d’ 1971 ' de Wet et al* ’ 1971)* but “ is not if af¬ in* „ “Pulses from these receptors are involved in driving ventilation dur- “Uscle movement. (i>orwth°Ugh meobanorecePtors are present in the skin and around feathers ard, 1970b), there is no evidence that they are involved in the control 981 of breathing. Receptors located in the laiynx or within the upper respiratory passages can produce apnea when stimulated by water (Jones, Johansen, 1972) or by noxious substances (Eaton et al., 1971). These receptors may have a protective role in preventing material from entering the respiratory tract. 3* Ventilatory responses to neural stimuli. As indicated earlier, during exercise birds overventilate in proportion to the increased rate of metabo- Lism. In recent experiments, we studied the changes in ventilation in ducks that were exercised on a treadmill while holding arterial blood gases nearly constant (PaC02 increased less than 2 Torr). Ducks were unidirectionally ven¬ tilated with a constant flow of gas, thereby uncoupling their respiratory effort from the gas exchange function of the lung. The ventilatory effort in these ducks markedly increased during exercise (400% over rest), with only a small fraction of that increase (5%) accounted for by the slight increase in PaC02. These data suggest that nonchemical, nonthermal factors are of great importance in the control of breathing, expecially during activity. Use of exercise as an experimental tool may provide insight into the multiple in¬ terrelationships of the factors that influence the respiratory controller. ACKNOWLEDGEMENTS This work was supported, in part, by a grant-in-aid from the American Heart Association, Kansas Affiliate, Inc. and the Kansas Lung Association. Special thanks are extended to W.D.Kuhlmann and T.Fosha for their technical assistance. Contribution No. 82-41 5-A, Department of Anatomy and Physiology, KAES, Kansas State University, Manhattan, Kansas, U.S.A. Ref erences 169-181. 177-186. Ballam G.O., Kunz A.L. , Clanton T.L. , Michal E.K. - Fed. Proc., 1981a, 40. Ballam G.O. , Clanton T.L. , Kunz A.L. - Physiologist, 1981b, 24, p. 132. Barnas G.M. , Estavillo J.A. , Mather P.B., Burger R.E. - Respir. Physiol., 1981, 42, p. 315-325. Bech C., Nomoto S. - J. exp. Biol. ,1982, 97, p. 345-358. Boon J.K. , Kuhlmann W.D. , Pedde M.R. - Respir. Physiol., 1980, 39. Bouverot P. - Physiol. Rev., 1978, 58, p. 604-655. Bouverot P. , Douguet 0., Sébert P. - J. Comp. Physiol., 1979, J_22, . . . Bouverot P. , Hildwein G. , Le Goff D. - Respir. Physiol., 1974b, 22, p.137-1 56* Bouverot P. , Lextner L.-M. - Respir. Physiol., 1972, J_5, p. 310-320 Brackenbury J.H., Gleeson M. , Avery P. - Comp. Biochem. Physiol., 1981 §2£, P. 449-453. Butler P.J., West N.H., Jones D.R. - J. exp. Biol., 1977, 71, p. Crank W.D., Kuhlmann W.D., Fedde M.R. - Respir. Physiol. ~ De. Kock L.L. - Açta anat., 1958, p. 161-178. De Wet P.D., Farrell P.R., Fedde M.R. - Poultiy’sci. , 1 971 50 Dorward P.K. - J. Physiol. (L.), 1970a, 2n, p. 1-17. — ’ Dorward P.K. - Comp. Biochem. Physiol., 197B, 35, p, 729-735 Dreyer M.V. , De Boom H.P.A. , De Wet P n e+ „1 ... * *•' wet et al. - Acta anat., 1978, 102, P« C.\ ' Dreyer M.V. , De Boom H.P.A. De Wo+ ^ , Eaton J.A. Jr., Fedde M.R., Burger R.E. - Respir, Physiol. 1 971 , H,p.i67- l7?‘ 7-26. 1980, £1_, p. 71-85- P- 1349-1357- 982 El Ha dl H., Sykes A. H. - Brit. Poultiy Sei., 1982, 2^, p. 49-57. Estavillo J., Burger R.E. - Am. J. Physiol., 1973, 225, p. 1063-1066. Fedde M.R. - In: Avian Physiology / Ed. by P.D.Sturkie. 3rd ed. N.Y.: Sprin¬ ger, 1976, p. 122-145. Fedde M.R. , Gatz R.N. , Slama H. , Scheid P. - Respir. Physiol., 1974a, 22, p. 99-114. — Fedde M.R., Gatz R.N. , Slama H. , Scheid P. - Respir. Physiol., 1974b, 22, p. 115-121. ’ ’ Fedde M.R., Kiley J.P., Powell F.L. , Scheid P. - Respir. Physiol., 1982, 47, p. 121-140. Fedde M.R. , Peterson D.F. - J. Physiol. (L. ) , 1970, 20^, p. 609-625. Fedde M.R. , Scheid P. - Respir. Physiol., 1976, 26, p. 223-227. Fedde M.R., Kuhlmann W.D. - In: Respiratory Function in Birds, Adult and Em¬ bryonic / Ed. by J.Piiper. N.Y.: Springer, 1978, p. 33-50. Hodges R.D. , King A.S., King D.Z. , French E.I. - Cell Tiss. Res., 1975, 162. p. 483-497. Jones D.R. , Johansen K. - In: Avian Biology. Vol. 2 / Eds. D.S.Famer, J.R.King. N.Y.: Academic Press, 1972, p. 157-285. Kiley J.P. , Kuhlmann W.D. , Fedde M.R. - J. Appl. Physiol: Respirât. Environ. Exercise. Physiol., 1979, 47, p. 827-833. King A.S., King D.Z., Hodges R.D., Henry J. - Cell Tiss. Res., 1975, 162. p. 459-473. Kobayashi S. - Arch.histol. jap. , 1969, 21» P* 9-19. Kobayashi S. - Arch, histol. jap., 1971, P- 397-420. Unsley J.G. , Burger R.E. - Poultry Sei., 1964, £3, p. 291-305. Mater A., Eidred E. - J. Comp. Neurol., 1971, J£2» P* 25-37. Mather F.B. , Barnas G.M. , , Burger R.E. - Comp. Biochem. Physiol., 1980, 67A, p. 265-268. Milsom W.K. , Jones D. R. , Gabbott G.R.J. - J. Appl. Physiol.: Respirât. En¬ viron. Exercise Physiol., 1981, 50, p. 1121-1128. %e P.C.G., Burger R.E. - Respir. Physiol., 1978, £2» P» 299-322. Howell F.L., Gratz R.K. , Scheid P. - Respir. Physiol. , 1978, £5, p. 65-77. Rautenberg VV. , I,1ay B. , Necker R. , Hosner 0* - In: Respiratory Function in Birds, Adult and Embryonic / Eds. J.Piiper. N. Y. : Springer, 1978, p. 204- PI 0. Richards S.A. - Biol. Rev., 1970, £2, p. 223-264. Richards S.A. , Avery P. - In: Respiratory Function in Birds, Adult and Em¬ bryonic / Eds. J.Piiper. N.Y. : Springer, 1978, p. 196-203. Scheid P. , Gratz R.K., Powell F.L. , Fedde M.R. - Respir. Physiol., 1978, .35, P» 361-372. Scheid P. , Slama H. , Gatz R.N. , Fedde M.R. - Respir. Physiol., 1974, 22, P» 123-136. Schmidt-Nielsen K. , Kanwisher J. , Lasiewski R. C. et al. - Condor, 1969, 7£, P» 341-352. Sebert P. - IRCS Medical Science, 1978, 6, p. 444. Sebert p. - j. Physiol. (P.), 1979, 7jj, p. 901-909. iorre-Bueno J.R. - In: Respiratory Function in Birds, Adult and Embryonic / Sd. by J.Piiper. N.Y.: Springer, 1978, p. 89-94. 98? respiratory adaptations to high ALTITUDE IN BIRDS Craig Patrick Black Department of Biology, University of Toledo, Toledo, Ohio 43606, USA INTRODUCTION Existence at high altitude presents one of the most rigorous physiologic challenges to living organisms on the surface of the earth. In spite of this, species from all four classes of terrestrial vertebrates do occur at altitudes in excess on 3500 meters. Members of the class Aves have clearly been the most successful of the terrestrial vertebrates at invading the high altitude environment, both in the air and on the ground. The record altitude for any vertebrate was recorded when an aircraft stimck a soaring Ruppell's Griffon (Gyps rueppellli) at 11,300 meters and observations of flight at high altitudes have been made on several other species in the Himalayas and North America (Laybome, 1974). How representative of normal flying altitude these records are, however, is uncertain, although at least one species, the Bar-headed Goose Unser 'indiens) , has been repeatedly observed flying at al¬ titudes up to 9200 meters during its twice-annual migration over the Hima¬ layas (Swan, 1961). In addition. Rahn (1977) has assembled nesting records for 11 bird species at altitudes over 4900 meters, with ? of these above 5000 meters including the Alpine Chough (pyrrhocorax graciai at 6550 me¬ ters. An examination of the literature suggests that reptiles occur no higher than 5400 meters (Swan, Leviton, 1962) and mammals exist continuous¬ ly no higher than 5500 meters (Schaller, 1977). HIGH ALTITUDE RESPIRATION AND GAS EXCHANGE Although a number of bird species clearly function very successfully at high altitude, the physiologic basis for this ability has not been thorough¬ ly investigated. The primary problem for any animal at high altitude is maintaining adequate 02 transport to the tissues in order to sustain aero¬ bic respiration; thus investigations have primarily addressed various aspects of 02 transport under hypoxia. Although numerous studies exist des¬ cribing responses of the avian respiratory system to hypoxia, they add lit¬ tle insight to the question of existence at extreme altitude, since they either have been perfomed on unconscious or chemodenervated animals (e.g., Ray, Pedde, 1969; Bouverot et al., 1979) or have failed to expose the birds to hypoxiq as severe as that encountered at extreme altitude (Bouverot et al., 1976; Jones, Holton, 1972). Tolerance to Extreme Hypoxln 0»1, three «tadle, ha,, examined bird. near their ll.lt. of hypoxic to- „ance. Thicker (,968) found th.t Bud8.,lg„. (,.lo„i,t.e„. flj In • hyp, baric chunter up te .bout 3700 .etere, »hlle House Sperre.« (P^e; o-estlousi could fly up t, 6.00 »eters end «.intnlned con.cloushe.s up to 9140 ..ter,. Coleelne et .1. (1977) fou„a Duckl, (Ana3 ol„_ Hr^hos forme dc.e.tlc.) »all, tolerated 9000 „.tore and eho..d no d.J rease n their ability to extract 02 from the air up to 6000 meters. Black and Tenney (.980) found th.t Pekin Duck, and Canada G«..e Cr.„t. 984 £is, showed none of the behavioral reactions typical of severe cerebral — T SS Mgh SS 7600 metereS’ While Bar-headed Gees^ showed no reactions below 10, 670, meters. After 15 minutes at 12, 190 ne.ers II» T G6eSe C°Uld 3tand 811(1 h°ld th6ir headS ere0t- tolerance' thus varies among avian taxa, but of the groups examined, waterfowl, espe¬ cially Bar-headed Geese, are most tolerant. Ventilatory Response to Hvnnrln Birds show a pattern of augmented ventilation (V ) with both acute and Z 7 OTT" t0 117150X18 8imil8r t0 that ~ 1-. although the P rn of change in tidal volume and breathing frequency producing the in- rease Vg differs (Ray, Fedde, 1969; Jones, Purves, 1970). Further in apecies which have evolved at high altitude, the increase in V, fir^t ap¬ pears at much more severe levels of hypoxia than when it first appears in a- evel species. Pekin Ducks show a noticeable increase in Vr at Pan 50 orr, w lie Bar-headed Geese do not show a comparable increase until Pa0,O5 t rr (Black, Tenney, ,980). As in other vertebrates, the hypoxic ventila^ sponse is mediated by the carotid body, although Van Nice et al. (i960) a;e suggested that in birds the carotid body may sense arterial C>2 content ^ao 1 rather than Pa„ . J u2 02 gas Exchange During Hypoxic Exposure Once inspired gas has been moved convectively to the vicinity of the ex- ange surface, 02 movement from the gas phase into blood occurs via diffus¬ ai. At this point two factors will profoundly influence Pa0, and thus the vllZl0! 7ria WhlCh Can be t0lerated! 15 the P02 Of gas in the cinity of the exchange surface, and 2) the magnitude of the' partial pres- bov e^adlent re<îuired t0 m°ve sufficient 02 into the blood to support meta- ic demands (a reflection of air-blood diffusion resistance). In the al- ^eo ar lung, which is found in all terrestrial vertebrate classes except irds, pAo^ (alveolar Pq2) must be less than Pl0 (inspired P0p). Although e increased V£ which occurs with hypoxia will raise PA closer to Pt ^ the alveolar lung, the Pi^ to PAq gradient will alwayl be relatively2 ',-***, SlnCe the alve0lar lung aots as a ventilated pool type of gas exchan- coId(PilPer’ Scheidf 1975)* The inspired-arterial Pq2 gradient present under itions of extreme hypoxia has been found to be much smaller in birds li7 |nmammals (Table 1) probably due to the more efficient parabronchial S piiper,Scheid , 1975). Even without any other adaptation to high al- 1 udo> this ability alone potentially gives birds a great advantage. Up0The ability °f the avlan lung-t0 raise Pa02 to near PlQ depends not only aig11 brinßing inspired gas intfo the parabronchi, but upon having minimal re- c 01106 to diffusion between the parabronchial lumen and pulmonary blood. 7 llarieS" Soheid has proposed a comprehensive model for gas ex- ^ange in the avian lung which suggests that at rest diffusion resistance is ■theSed rainima1’ but that during exercise it increases substantially. Thus, pen- nUmberS in Tat|ie 1 which seem to explain at least in part the bird’s su- are° hypoxic tolerance may not pertain, since under natural conditions, birds exposed to the most severe levels of hypoxia only during exercise. 985 Table 1. Inspired (PiQ BTPS) and arterial(Pao2) oxygen partial pressures for man (Dejours, 1981), Pekin Duck and Bar-headed Goose (Black, Tenney, 1980) at sea level, near summit of Mt. Everest, and near record altitude for bird (Bar-headed Goose only). Values for man were calculated, values for birds were determined after exposure to hypoxic hypoxia for 15 minutes Pekin Duck Bar-headed Goose Altitude (meters) PT (torr) s SL 149 8848 42 SI 146 9150 37 SL 146 9150 37 11,580 23 Pa (torr) u2 91 22 93.5 30 92.5 28.5 22 Blood 02 Transport During Hypoxia Although the avian respiratory system functions very effectively under conditions of hypoxia, those species which have evolved at high altitude have adaptive adjustments in the oxygen-carrying characteristics of the blood which further improve hypoxic performance. Only two bird species na¬ tive to high altitude have been examined, but in both, the Huallata (Chloe- phaga melanoptera) from the South American Andes (Hall et al., 1936) and the Bar-headed Goose (Black et al., 1978) hemoglobin-0 affinity is higher than in sea-level waterfowl. The effect which this adjustment in hemoglobin-02 affinity has upon 0 transport by the blood is demonstrated in Figure 1 , which shows the relatr Fig. 1. IS_vlvo 02 transport in the Pekin Duck (top panels) and Bar¬ headed Goose (bottom panels) exposed progressively to gas mixture corres¬ ponding to sea level and three altitudes. ax = arterial points, v , venous points, left panels: middle dissociation curves, a., and v, - sea level • left dissociation curves, a2 and v? - 9i50 meters; right dissociation curved, a3 and v., - 10,668 meters; right dissociation curves, a, and v, - 11,580 me¬ ters (Goose only). Right panels: area in boxes proportional to'blood 0, transport (numbers = Vo2, ml/min); horizontal side, cardiac output; vertical s e, a v 02 content difference. (Data from Black and Tenney, 1980) 986 ion ship between 0 consumption, cardiac output, and 0 delivery to :rrr * ,ie “ ■«. .»«»< i\zz le,.'“ „g' ““ E«.« at tj l.v.l. ,l„»latlag 1, 9150 meters (near summit for Mt. Everest), 10,668 meters and 11 son ”‘r *1«*"de f°r * h±rd). Sea-level a«.«.l to“ “r tt.T ,^°W *hat ”*,lne Peki” “"°k 10 touting „» th, upp„ toll ot toedieeoclatlor. ce roe, .Ml, t*e go... 1, „„„g or.ly ,he n0„ ZU toek"Plta SPl1' °r th“ “d ,h8 th‘* ”»*n compared to ,h. zi r z.\tt rio° output’ “ •tm ■“ • -■* ftnUy°2' Prl“rl!ï a“* *° *»• higher h.„oSloMn-oWge„ al¬ io Bkp°’"” °' botl apaolo. to hypoxia almulatlng 9150 meter, re.ult. 1„ the i!L™ dissociation ourv. ,uru„g „ ,h, i,ft. ArtM >n(J ve»““ [Il " ^ t?" *hi" ““ 8°°" 1S “tora.dhg on the .teepe.t of Itoer endlr^ T“1* d“Ck " ■*•">«»* » th. much more .hallo., (1R curve. At this point the goose has a higher mixed venous Pr, ney, °980r lower^^ ^ ^ *“*’ & l0W6r minUtS ventilation (Black, Ten- that it is'able oonsu®Ption, and a lower cardiac output, indicating at this .Iff 0 “attain relatively good oxygen transport to the tissues than altltude whlle sti11 ha^ng reserve capacity for exercise. The less tha« nonnoxxc cardiac Qutput levei suggesta that the lncreased Qxygen ie_ess s imposed by exercise can potentially be met without significantly lower- 7T !°r ThiS iS °f °0UrSe CrttiCal Since ^ Poin/at fli^t I,!! 80036 Wm en°0Unter 011011 extreme hypoxia is during is Î ^ the metabolio cost of High-altitude flight is unkown, it tern,- 1683 th8J1 the 9-10 times atandard metabolic rate de- «tition ff V VSriety °f 8Pe0i63 fl0TO in Wlnd tUnnels ™der aea-level con¬ ditions (Hart, Berger, 1972). Increased C02 production by muscle during exercise also could potentially ice oxygen transport efficiency. Under the resting conditions employed m s study, arterial and mixed venous pH were nearly the same at all simu- IenLal^«n?e ^ “d arterial PC02 were very low (Black, Se y, 1980); thus, the full potential impact of the Bohr effect cannot be tuet1* DUrin® 3trenuous exercise higher venous PCo2 levels due to increased a olism would presumably result in considerably greater a-v pH differences, cum ^ the ~'VlV9 dissociation curve even steeper than thè one plotted. As- ebea?6 ^ 3Sme arterlal point- a steeper dissociation curve would allow a the +6r a"V 0Xygen content difference and therefore increased 0o delivery to issue for the same mixed venous Pq2. ve il 3d7lated alWtudea of 10-668 “d 1 1.580 meters, the dissociation cur¬ acy Shli-ted t0 the right for b°th species, presumably due to metabolic Porti (Blaolc'TeDDey. 19S0). Arterial and venous points drop from the steep tent It 01 the °UrVe d0»• ,„2, j°«es b.’r!’ ■ j- e*p- «»i-. 1972, P. «7-666. £*•"“ Lo- * ÄÄ"* «.S" '„T f- - H,*pi- >«5, a. ;. 209.221. .1«_, C toATr1"“' *“>»»» «9 z - ' **- University of Chicago Press, 1977. ‘ Himalayas. sZ'll' ' !eSPir* PhySi01*’ 1978’ P- «7-49. L.W. - Sei. Am. , 1961, 205, p. 68-78. C L,w* ■ Nat* Hist'* 1970> 22. P- 68-75. L‘ ST A0‘4' 501 1%2’ ^ p- 103-147. Van w io1, ’ 196S* 4§* P* 55-66. D. 347-350P1SCk C'P*’ Temey S*M’ " C°mP’ Biochem- Physiol. , 1980, 66A, 989 PHYSIOLOGY AND METABOLISM IN BREATH-HOLD DIVING David R. Jones The University of British Columbia, Department of Zoology, 6270 University Blvd. , Vancouver, B.C. V6T 2A9, Canada INTRODUCTION Diving birds can be forced to remain submerged for periods of time which would kill their more strictly terrestrial relatives. The single physiolo¬ gical variable most often recorded as an indicator of this capacity for un¬ derwater endurance is the heart rate. However, in a single species. Anas pla- tyrhynchoa , heart rate data have been amplified by recording blood pressures (Butler, Jones, 1971), cardiac output and its distribution (Polkow et al., 1967; Jones et al., 1979) and even redox balance of cerebral tissues (Biyan, Jones, 1980a, b). Nevertheless, even if only heart rate is recorded, it now seems possible to identify three different types of diving response depend¬ ing on whether the animal is diving voluntarily or is forcibly submerged. TYPES OP DIVING RESPONSE U Porced dive response; exemplified by laboratoiy studies, in which the head of an animal is submerged in a beaker of water. Heart rate falls more rapidly in diving than dabbling ducks but after 40 s or so of the dive it stabilises at a rate which may be one-tenth of the pre-dive value. Heart rate stays at this level for several minutes and then it usually doubles, but it is still only one-fifth the surface value, remaining at this level for the rest of the dive. The fall in heart rate is taken to indicate a like decline in cardiac out¬ put which is offset by a sufficient increase in total peripheral resistance to keep mean arterial blood pressure constant. Most tissues don't receive any measurable vascular supply while others, such as the heart and brain, have their blood supply maintained or increased (Jones et al. ,1979). Consequently, we assume that oxygen, stored in the body at the start of the dive, is saved for the heart and brain while the other tissues metabolise anaerobically. At the end of the dive, cardiac output increases dramatically and flow is res¬ tored to all regions of the body. Products of anaerobic metabolism are flus¬ hed from the tissues and minute ventilation is elevated for a period which varies directly with the duration of the preceding dive (Lillo, Jones, 1982). 2. Conditioned dives: these are short forced dives (40 s duration), which are performed repetitively during several days until the animal no longer displays a fall in heart rate. At the start of a series of trials, heart rate in naive ducks falls to about 20% of the pre-dive value in 40 s of diving. Repeating the diving protocol, over several days, results in less and less heart rate change during a dive until, in fully conditioned animals, heart rate remains at the surface rate throughout the dive. Since there appear to be no cardiovascular adjustments in the conditioned animals it seems reason¬ able to assume that metabolism remains at the surface level yet, surpri singly . arterial oxygen tension after 35-40 a submergence is the same in naive as i» conditioned ducks. Giving naive ducks 100% oxygen to breath pre-dive pre¬ vents bradycardia, while if conditioned ducks are pre-treated with slightly reduced oxygen (15% 02 in Nj) bradycardia always develops in the 40 s dive. The period of hyperventilation at the end of conditioned dive is short and there is no post-dive tachycardia. — luntary dlye3! these are 'short dives (10-40 s' in wh-i „», llZTTsToTu *1' presumed that ffietabolisra is eievated ^ ™ Wn ! J‘5 reSting level (Praß«e« Schmidt-Nielsen, 1970- , h8’ U 6r’ 1982)* Nevertheless cardiovascular adjustments are made which are quite distinct from those which are associated with exercise on land. Just before a dive, ducks hyperventilate and heart rate incre^es On au mergence heart rate falls rapidly to its lowest value and then in cr les h 2 nrlYTy '.T1 after 6-8 8 (BUtler’ W°a*e8’ 1979>‘ ™3 steaT d r u re3ting level in pochards (^a * ucks QLLuligula), cormorants (.Phalacrocorax annitn.l penguins (Pygos- 8 6llae) 311(1 ^ — be aTIigh as when the animals he surface at the same speed (Millard et al., 1973; Butler, Woakes 1979- hi h Y al” 1981 ‘ BUtler> 1982)* lightening ducks to dive results in v W rat6r rat6S* PreVentinfi tUfted duck3 Trom surf acing^af t er PeiwTi? °areS 0 marked faU ln rate* ^ a ^ recovery “ WS rCh dlVe bef°re the animal' ia again ready for the next un- around th^Y MVe3 USUaUy °C°Ur ln 8 8erle3 “d heart rate remains round three times the resting rate in the periods between dives. MAXIMUM DIVE TIMES IN FORCED, CONDITIONED AND VOLUNTARY DIVES stored TV*, dlVe h1“6 that Can be 6ndUred de*end8 on the amount of oxygen of thi ln y at the 3tart °f the dlVe’ the caPability for mobilisation sue t f“ 8t°re’ “ld the rate at Whl0h 0Xysen 13 a«lised hy the tis- ral LZ & V diV6’ bl°°d aUPP3y 13 Prefereßtially directed to the cent¬ al oT Y ^ h6“' alth0Ugh* as the Circulation is divided, blood drainl 8h the 1UnS3’ A38U,ning that 0ßly these three tissues will be store T Y OJ5y8en reSerV°ir ln the dive *»», Ü the size of the oxygen s known, by estimating the oxygen consumption by these tissues we ob- in Y IalUe f°r maxlffluœ undensater endurance. The amount of oxygen stored for “ 1UngS at the 3tart (that in °ther b0dy tissues is not available he heart, lung or brain), and that remaining at the end of a maximum e has been measured. For a 1 kg domestic duck (Anas platvrhvnchns', the ! . I °f 0Xygen U3ed from the store is 20.76 ml (Hudson, Jones, 1983). In a ab 8 Y the braln Welghs 5 g (Hudson’ Jones, 1983) and the spinal cord half hSlf thl3‘ The weight 3Peoific metabolic rate of the cord is about He ?St °f the braln (Mlnk 6t a1*’ 1981 1 ‘ üsing Usures for brain metabo- •mi estimated for chicken by Mink et al. , 1981 (about 0.06 ml.g"1. Tjj 11 then the brain ^ spinal cord use oxygen at a rate of 0.5 ml* min"1, tab 1,1338 °f a 1 ** dUCk 18 about 12 g (lasiewaki, Calder, 1971) and me- (K ° 10 rata °f 103111111311311 lungs is anywhere from 0.004 to 0.02 ml.g-1. min"1 0 b3’ 195^j Wallace et al. ,1974). Henoe the lungs could use from 0.05 to for ral‘min ’ However. since brachial blood supply is greatly reduced in a cardid dlVe (J°neS 6t a1*’ 1979' then perhaps we should take the lower value. 80 0Jtygen consumption can be calculated from the external work done by W' rlfht 811(1 left ventricles if the efficiency of cardiac contraction is (Jones, Johansen, 1972). The external work done is the product of 991 cardiac output and arterial blood pressure. The rather complex relation between heart rate and dive time must be taken into account but if stroke volume remains fixed at 1.5 ml then the heart will use. on average, 0.9 ml* min" if it works at 10% efficiency. Hence the total oxygen utilisat¬ ion rate is 1.45 ml* min and maximum dive time will be 14.2 minutes. This compares well with experimentally derived values for two ducks of 1.3 kg mass which dived for 9 and 11.0 minutes (Hudson, Jones, 1983), particularly in view of the fact that we have not taken account of the oxygen demand of tissues such as the eyes and adrenals in this calculation. For conditioned dives the calculation is greatly simplified. Since there are no cardiovascular changes then it seems reasonable to suggest that meta¬ bolic changes from rest are unlikely. What then is the resting metabolic rate likely to be under laboratory conditions? Calculations from the relation ship between body weight and metabolic rate predict a resting oxygen uptake for a 1 kg duck of 11.3 ml*min-1 (Lasiewski, Dawson, 1967). However, our own and data of others suggest that, in the laboratoîy, resting metabolic rate is at least twice this value (Prange, Schmidt-Nielsen, 1970; Jones, Holeton, 1972) so, if the maximum available store of oxygen is 20.76 ml then it will last for 55 s, which is slightly longer than we are usually able to condit¬ ion ducks to maintain their heart rates at resting levels. What sort of metabolic profile should we assume for a voluntary dive? It is possible to measure the speed at which the animal swims underwater and relate this to what its oxygen consumption is when it is swimming at the same velocity on the surface (Woakes, Butler, 1982). Nevertheless, the fact that some cardiovascular changes occur implies that there may be some prefe¬ rential redistribution of blood flow (i.e. to active muscles). Woakes and Butler (1982) report the oxygen usage in voluntary dives is approximately 3.5 times resting which, for a 1 kg tufted duck (A. fuligula) . is about 32.5 ml* min . At this rate of oxygen utilisation then the duck could dive, without recourse to anaerobic metabolism, for 38 s if its oxygen store was no bigger than that in the domestic duck (A. platyrhynchos) . The longest re¬ ported natural dive in this species is about 40 s (Dewar, 1924). RELATION BETWEEN BODY MASS AND DIVE TIME Given that the animals in conditioned or voluntaiy dives have the same ability to withdraw oxygen from the store as in forced dives then it is pos¬ sible for both these dives to be made without recourse to anaerobic energy production. However, aerobic diving places definitive limits on the animal’s underwater abilities. These abilities can be stretched by using combinations of aerobic and anaerobic diving or by increasing the size of the oxygen store. Since the size of the oxygen store increases slightly more proportion¬ ately than body mass increases, while metabolism increases somewhat less, then one might predict a selection pressure for large body size in diving birds. If we assume that in conditioned or voluntary dives there are no circulat¬ ory adaptations which will affect the relation between metabolic rate and mass (Lawiewski, Dawson, 1967) then for these dives Metabolism oc Mass0’^"^ 992 H»™.,*, „„ of lie >tor6 ^ 'J'"“' Jones, ,983), «preee.d In the «Done trie foan, i. Oxygen Store o c Mass1*'31 Therefore in aerobic diving, maximum underwater endurance (dive time) is related to mass as follows Maximum aerobic dive time oc Maaa 1.131 cC Mass ,0.4 Mass®" 723 "r;:::: * ,o «- “*» — - ■*- «- r::.— — i- - * *>* Proportion to body mass while th ... ncreaoes in almost strict combined «“ “ “ “ - Heart and Brain Mas oc Mass0, 65 However, the actual rate of metabolism of heart and brain will not « in strict proportion to their increase in mass but rather t ^crease n -, .. ™8a Dnt rather to mass raieeri +„ ^ relaterr^Tthe 8U^al ^ Maximum forced dive time QC Ma33 1.131 cC Mass ,0.65 (Mass0,65)0,73 aeroMHiver forirbodTeater adVant&Se °n Survival 1» forced rather than *U1 -P nearly 5 times in ZZliZ ^1«" T] ’»«•»«ter endurance Perimentally that for for«. «,,• ’ f 0 ’ we have established ex- time is oc Mass0,64, ** 1VSS ^ relatlon betwaen body mass and dive CONCLUSIONS d*veHu^ iTîoLTd^rThflLnmeS ir\TCea’ °0nditi0ned “d voluntary ^r£l£v~“ nr;—« When it i ° 10 dlVe* The foroed dlva response can oxily be of value Words a ! WMle mUCh °f the atore remains unused, m other °*ygen mUSt be k6Pt °n 11011(1 lH b°th °°nditioned and vo- lh Col.t : fiB appears t0 be the caae. for bradycardia rapidly ensues their calcuuLdUOkSianer ^ ° SUbmergence which ia ab°at two-thirds of are verv h + ^ aer°blC tolerance‘ ^thermore, most voluntaxy dives 0alcuw I ° J °Ut 10-20 S (Butler’ Woakes, 1979), which is only half the plated maximum aerobic tolerance. „rnferv advanta«ea °n the animal in terms of the total from ° V? thSt Can be spent ^derwater in a given time period. Recovery lete r„ 6 ,S 13 3 l0ng prooeaa ^ the length of time required for comp- Butler °°Very Vari6S directly with the length of the dive (Lillo, Jones, 1982; - Recovexy from diving may have two components with vexy en time courses, one, a short 'time course component representing ■3aK,98l 993 replenishment of the body oxygen stores and two, a long time course compo¬ nent representing breakdown or elimination of the products of anaerobic me¬ tabolism. After aerobic diving only the first component is observed. Thus, in a one-hour diving period, the animal could opt for a strategy of one ma¬ ximal dive of 10 minutes duration which would require at least 50 minutes for recovery (Butler, Jones, 1982) or a series of 30 s dives with about 20 s for recovery from each dive. The latter strategy allows the duck to be un¬ derwater for 36 min of the one-hour period. On the other hand, any disadvantages of diving aerobically for short pe¬ riods have not been clarified. The major constraint on this kind of activity is that the animal must be equipped with a mechanism which either causes it to surface or go into the forced dive response before its oxygen stores are exhausted. Certainly, there seems to be no advantage to the forced dive res¬ ponse in short dives, even in terms of oxygen conservation. In naive and conditioned ducks the same amount of oxygen is removed from the blood in the first 40 s of the dive despite bradycardia in naive ducks. ACKNOWLEDGMENTS Supported by operating and travel grants from N. S.E.R. C. of Canada and the British Columbia Heart Foundation. I am grateful to Drs. W.K.Milsom and N.H.West for reviewing this manuscript. References Bryan R.M. , Jones D.R. - J. Physiol., 1980a, 299. p. 323-336. Bryan R.M. , Jones D.R. - Am. J. Physiol., 1980b, 239, p. R352-R357. Butler P.J., Jones D.R. - J. Physiol., 1971, 214. p. 457-479. Butler P.J., Jones D.R. - Ins Advances in Physiology and Biochemistry. Vol. 8 / Eds. by 0. E.Lowenstein. N.Y. : Academic Press, 1982. Butler P. J., Woakes A.J. - J. exp. Biol., 1979, 79, p. 283-300. Dewar J.M. The Bird as a Diver. L. s H.F. and G.Witherby, 1924. Folkow B. , Nilsson N.J., Yonce L.R. - Acta physiol, scand. , 1967, 70. p. '347-361. Jones D.R. , Bryan R.M. , West N.H. et al. - Can. J. Zool. , 1979, 57, p. 995-1002« Jones D.R. , Holeton G. F. - J. Exp. Biol., 1972, 56, p. 657-666. Jones D.R. , Johansen K. - In: Avian Biology / Ed. by D. J • Famer , J . R. King. N.Y.: Academic Press, 1972, p. 157-285. Kanwisher J.W. , Gabrielsen G. , Kanwisher N. - Science, 1981, 21 1 . p. 717-719« Krebs M.A. - Biochem. Biophys. Acta, 1950, 4, p. 249-269. Lasiewski R.C., Calder W.A. - Resp. Physiol., 1971, JJ., p. 152-166. Lasiewski R.C., Dawson W.R. - Condor, 1967, 6£, p. 13-23. Lillo R.S. , Jones D.R. - J. appl. Physiol., 1982, 52, p. 206-215. Millard R.W. , Johansen K. , Milsom W.K. - Comp. Biochem. Physiol., 1973, 46a, p. 227-260. Mink J.W. , Blumenschine R.J., Adams D.B. - Am. J. Physiol., 1981, 241 . p. R203-R212. Prange H.D. , Schmidt-Nielsen K. - J. exp. Biol., 1970, 32, p. 763-777. Wallace H.W. , Stein T.P. , Liquori E.M. - J. Thor. Cardiovasc. Surg. , 1974, 68, p. 810-814. 994 ”™“rs ™ sm raspmTi°" “ Patrick J. Butler Department of Zoology and Comparative Physioloirv tt -i Birmingham, Birmingtham B15 2TT, England ’ niVersity of INTRODUCTION .vCS m.TlT °” "0lU4*° «“ »•“« P-nguins, - or vuzzz " :iisht"- io aaai«™ remarkable. Non atop flights of 2 7nn i™ S grato;or niSht are quite aune» »«ni, ££ L7J” » ££ £? ,T *°- Pluvial! a dominica fin™ (Johnston, McParlane 1967) T . S°lden plover. while a flock of bar headed geese (a ind-ir ’ 3 7) have been «ported, summit of Mt Everest (Swan, 1961)- ^ alff3] ^ °bSerVed flyin£ °«r the this altitude, environment ^ 5 9’°°° *' At uptake in man is close to his h t mmH6 maximum oxygen ing, thenefora, ,L° om “ TT requirra.at,. It lm aot ^ or 01« flight, particular* oSÏ.tÎL” IT r"C‘“l,a W »■POO*. lon. It is doubtful if d ergy requirements of migrât- «1 », th. LTfoT.'rrnTai.t8oi“i,u* ”oia »«IMt, of fllTit TM« „ouia “T“8 ,h' 0“»rS.*1'" and metabolic .«sumption and ,„^u; Zl Z.I T "0* ”■■“«“»*■ or °w» «0.1 oo„a , I T TuT thS Mra “d 01 r”™1“»* meteorolo- ** «»■ .to! T«! Tr"“7 *° k”°’ ,he ,,r“eth “a ai~=«» °r *»««T^rJTTT°La'MT“*1“‘‘ 01 ”,,ba11“ a“« -*»— ». ■Iquea that alio, the d‘ t night behaviour have -to be assumed, Tech- »h.t«™ :.T ; “**"““* °f ■“«•» “P*»h. and ef other rea- »or, = ,. '"der oontroll.d condition., but long flight. *lhla. ïh, recTT St‘h* S“al““s °f “‘“»1 ■«»«.». are no, po.f ' « «... proh":;.“" °f m imprinted gee.. mar overcome some measurement op metabolism during migration a' height loss « t°LlT:“TT TUe‘ 01 "*t*bolis r«*o a“rt"S rilght .ere e.timat- •»at rat conatiL " T T “rlW * l0”® ,llsh* '*'* ‘he assumption *1., 196, i f, 7 fai* the mQj°r Part °f thl3 wei^t loss (Nisbet et Elated tt® Caloriflc value of fat (9.5 kcal g"1), these authors 12°C ha * S 19 g blackPo11 warbler, Dendroica strintn. flying at 6- °2 min-^a !°Wer conauinPtlon of approximately 1 kcal h"1 (1 . 1 6 War, 3.5 mi ®ore rece ri" la 40% of that Predicted by allometric formulae based on the method (BUtler’ 1981 ’ 19825 * Berger 311(1 Hart (1974) have criticised that weim.ht measurin8 weight loss to determine power input as they believe loss may exceed the production of metabolic water. b) qq — 2 Production using doubly labelled water îhe cent ral factor of this method is that the oxygen in respiratory C02 995 is in isotopic equilibrium with the oxygen in body water (Lifson et al., 1949). Thus, the hydrogen of body water is lost primarily as water whereas the oxygen is lost both as water and as C02. The turnover rate for the oxy¬ gen in body water is greater than that for the hydrogen and the difference is proportional to the C02 produced. The two turnover rates can be obtained by labelling the two components of body water with stable isotopes of hydro¬ gen and water, viz deuterium and 1S0. Validation of this method by comparing the calculated C02 production with that measured directly from birds in a respirometer shows that there is an average overestimation of 3-4% for pi¬ geons, Columba livia, (LeFebvre, 1964) and house martins, Delichon urbica, (Hails, 1979). In the former study the mean percentage error was 8%. Although there are certain assumptions associated with this method (lifson, McClin¬ tock, 1966), errors in field measurements fo C02 production can be reduced to 10% (Nagy, 1980). The use of this method by LeFebvre (1964) with pi¬ geons flying a distance of at least 480 km, demonstrated that the value of power imput obtained (22 kcal h_1) is similar to that calculated from esti¬ mated fat loss (i.e. the difference between estimated fat content at the be¬ ginning of flight, baaed on measurements from other birds, and actual fat content at the end of the flight). It also happens to be within 2% of the value calculated for similar sized birds using the allometric formulae of Butler (1981, 1982). Thus measurement of fat loss and C02 production using the D2018method seem to give reasonable values of power input during long flights, and the technique has been used more recently on smaller birds (Ut¬ ter, LeFebvre, 1970; Hails, 1979). Actual measurements of oxygen uptake and respiratory performance require more direct recording techniques. DIRECT MEASUREMENTS USING WIND TUNNELS The first direct measurement of oxygen uptake of a bird during forward flapping flight was that of Tucker (1966) working with and budgerigars, Me- lopsittacus undulatus, flying in a closed wind tunnel. The birds had to be trained to fly in the tunnel. Oxygen content of the air in the wind tunnel was measured continuously as a bird flew with no leads or cannulae attached to it. In subsequent papers, Tucker attached a loose fitting mask to the face of budgerigars (Tucker, 1968) and laughing gulls, Larus atricilla (Tucker, 1972). Air was drawn through the mask at a known rate and oxygen measured in the effluent gas (see Fig. 1). These historic papers heralded the begin¬ ning of an era when respiratory variables could be recorded from birds flyihS at controlled velocities and angles. However, only a handful of publications have been forthcoming and a number of them have merely repeated Tucker's measurements on other species (Bernstein et al., 1973; Torre Bueno, Larochel' le, 1978). The word "merely" is not meant in any derogatory sense; the author is only too well aware of the difficulties involved in training birds to fly in a wind tunnel. It was possible to get only 5 out of 12 pigeons to fly under such conditions, but we did succeed in obtaining samples of arterial and venous blood during the flights for measurement of blood gases and lact» te (Butler et al., 1977). Only Bernstein and his coworkers have managed to record tidal volume ( vjy as well as respiratory frequency and oxygen uptake from birds flying in a wind tunnel. A small, hard wired, air flow transducer (hot-thermistor or hot 996 Pi K* .A pigeon flying in a wind tunnel while wearing a loose fitting ®ask for measuring 02 uptake and C02 production. Note the sample tube and thermocouple lead from the mask positioned above the head and along the back of the bird (Butler et al., 1977) Perature (T ) of 22°C V * “ Mlbient tem~ vus OBBit A ’ T °S d0ubles durinS flight in the fish crow, Cor- and is independent of flight velocity (Bernstein, 1976), iRg valued 6 W ^te'ne°ked raVeû’ - 'Clypt0leucu3 VT is sin>ilar to the rest- nature (T ^ (HUdS°n’ Bemsteln’ 1981). Above T 22*C, body tempe- specie, V increases during flight in the white necked raven, and in both are Sim-1 T lncreases as TA rises* At the lower ambient temperatures, there above ln0reaSe3 in dilation volume (fy and oxygen uptake, (V0„) the r' e.reStlng leveIs’ during flight in the fish crow, but above T ^22°C decret®1?/1 13 accompanied ^ increase in Ÿ0z, so oxygen extraction Pears emstein, 1976). Even at lower ambient temperatures, there ap- lings « be a 3li8ht increase in effective ventilation, at least in star- (Torrè r^113 vulgaria’ as Pq2 in the air sacs increases and VCq2 decreases high Uen°’ 1978a)* The extra increase in ventilation during flight at l°sisamÏlent temperaturea would tend to cause further hypocapnia and alka- Sort ‘ U haS been demonstrated, however, that the white-necked raven re- rature ° S° Called "coraPound ventilation" when flying at high ambient tempe- tilato^ ThlS °C0Urs when TB risea above 43°C- A high frequency, shallow ven- ajid ma comP°nent is superimposed upon a deeper, lower frequency component, 1978) 3erve to reduce hypocapnia during thermal panting (Hudson, Bernstein, fly at 4 has been su«sested. that during long flights (e.g. migration)birds siVe rean.altltude »here is low enough to prevent hyperthermia and exces- ThuSSPirat0Iy Water loas (Torre-3ueno, 1978b; Hudson, Bernstein, 1981). ®ade b ' WlDd tunnels have given us a glimpse of the respiratory adjustments ^ hinds during flight. However, the technique does have its problems °f Whirl. _ _ . . _ . . . . ’ Some bati°nalW 1Ch W6re outlined by Rothe and Nachtigall (1980) at the XVII Inter¬ est tQl °rnithological Congress. The bird has to fly in a restricted space, er&te the noise of the fan motor and is in an optically motionless 997 P i g. 2. Pigeon with transmitter and mask for telemetry of respiration rate and heart rate. Leads from thermistor in the mask and from the ECG electrode enter front end of transmitter. Power supply is by three Nicad batteries shown above transmitter. Antenna is shown projecting from back end of unit (Drawn from photograph in Hart and Roy, 1966, by permission of the publisher University of Chicago Press) and monotonous environment. In addition, it may also have to carry an exter¬ nally fitting face mask and trailing wires and cannulae, all of which will affect its flight performance. No doubt related to some of these factors is the observation that the flight pattern of a pigeon is different In a wind tunnel than it is during free flight (Butler et al., 1977). Depsite the prob¬ lems, Rothe and Nachtigall (1980) could see no alternative to the wind tun¬ nel method for the investigation of the physiology of bird flight. DIRECT MEASUREMENTS USING RADIO TELEMETRY As a possible alternative to the wind tunnel, radiotelemetry and had not shown much promise in its early usage. Hart and Roy (1966) published the first comprehensive set of respiratory data from flying birds (pigeons) using radiotelemetry. Everything, i.e. face-mask and transmitter, was mounted ex¬ ternally (Pig. 2) which must have affected the energy requirements of flight (Hart, Roy, 1966). To prevent loss of the transmitter, and presumably to keep the receiver within range of the transmitter, the birds were restrained by a nylon line tied to the harness, so that the flights were, on average, of only 9 s duration. Thus, the birds had barely taken off and were nowhere near a steady state, so that all the measured values were considerably highs1" than they would have been after several minutes of flight. Similar criticism® can be levelled at subsequent papers by these authors (Berger et al., 1970a, b) . A long range (80 km) transmitter was attached externally to herring gulls and used to monitor heart rate during flights of up to 20 km in distan' ce (Kanwisher et al., 1978). This is clearly a great advance over the earli®*" systems as far as the duration of the flights is concerned, but the external- mounting and the possible lack of information on the bird's behaviour during such long flights are still defects of the technique. Although not measuring any respiratory variables, Torre-Bueno (19765 com¬ bined the use of radiotelemetiy and a wind tunnel. He implanted a small teffl- perature sensing transmitter into starlings and was able to record core and skin temperature during flights of 0.5—2 h duration. Thus during this work, 998 I 1 s" 3* Imprinted barnacle geese chicks being taken for a walk by their "oster parent (Woakes, 1980) trL!!rf+WaS n0t burdened by “y externally mounted hardware or leads, the the n • Jr WaS maln1:ained cloae t0 the receiver throughout the flight and Ses of S °°ndltions were taowl1 «t a^ times. Unfortunately the disadvanta- centi! ! tUmiel (R°the’ Nachtigall’ 1980) still remained. It has re- can Z eeil dem0Dstrated however’ that implantable, short range transmitters 1980). USe Wlth freely flying birds engaged in long flights (Butler, Woakes , b0rraC!e S6eSe’ — mta leuC0Psis’ were raised from eggs hatched in a la- 8ave tZ lnoubator 311(1 they were imprinted (Lorenz, 1970) on a human, who They w Sm 03 mU°h attention as Possible during the first week after hatching. after are kSPt With thls foster parent for 16 h Per day during the first week the n atChin€> 311(1 for several hours of that period they were handled. the . __ - ^ «exe xiohUu j.eu« j?’or a-9 h SlX W6ekS thSy WeFe kePt indoors 311(1 close to the foster parent for ly i hPSr day- ^ring this period they were taken for walks for approximate- (Brown eVel^vday (Pig- 3) in order to reinforce the "following" response Weeka + 19755 0110 the fo3ter Parent frequently called "come on". At seven tains t Sy W6re l6ft outside 311 day in 311 0Pen-topped compound which con- 1hdooraW° P00ls' They were still taken for 1 h walks each day and were kept CoUrag3dat nieht’ The geese became flighted at 10 weeks of age and were en- ics t t0 fly by the foster parent who ran along the University’s athlet- but 3 SCk While calling "come on" to the birds. Six geese reached this stage, aCcU8tWere l0St during their early exploratory flights before they became anq fle 6 to the local geography. The remaining 3 became proficient flyers 511(1 Pool ar0Und the University campus as they desired, using the compound Wepg 8 as a home base. When they were 4 months old, these three geese bsl*ind en t0 3 disused airfield where their willingness Was tested to fly Pick-up truck containing their foster parent. 999 P i _ 4. (a) Barnacle goose flying beside truck containing its foster parent and companions (b) Baraacle goose slope-soaring on the airstream rising over the front of the cab of the truck One bird at a time was free, the others were caged in the back of the open-topped pick-up truck, and they, together with the foster parent who was also in the truck, were fully visible to the free bird. This goose was pla¬ ced on the ground and as the truck accelerated away, the bird flew after Üs foster parent and companions. At the first attempt, two of the geese follo¬ wed the truck artjund the airfield (Pig. 4) and allowed themselves to be caught at the end of the flight. The other bird began to follow the truck but soon flew too far away and' lost contact with the foster parent; it was never recovered. A two channel, PM radio transmitter (Pig. 5; V/oakes, But¬ ler, 1975) was completely implanted into these geese and measurements of heart rate and respiratory frequency were obtained during flights of an average duration of 14.4 min aod at a mean air velocity of 18.7 m s ^Butl®1-' 1 980; Butler, Woakes, 1980). A perfectly clean e.c.g. signal was obtained (Pig. 6) and by taking a cine film of the geese during flight, respiratory activity (i.e. lung ventilation) could be related to wing beating. Several interesting features emerged from this preliminary study. Resting values of heart rate and respiratory frequency were approximately 50$ lowef than the values predicted from allometric formulae. This could have been 1000 î1 i g. 5. Encapsulated, two channel PM radiotransmitter used for transmit¬ ting respiratory frequency and heart rate from free flying barnacle geese. The bipolar ECG electrode was placed next to the heart underneath the ster¬ num, the transmitter was placed in the abdominal cavity and the thermistor was placed in the lumen of the trachea. The leads between the thermistor and ■transmitter were run un^er the skin la) ECG ^ d £• 6. Traces from a cj barnacle goose, mass 1.7 kg, showing heart rate and respiratory frequency obtained from an implanted 2 channel radiotrans— mltter before, during and after a flight of 11 min 52 s duration (a) Take 0ff! (b) steady flapping flight at 22 ms-1, 5 min after take off; (c) 3 min after landing. The vertical dashed lines in (a) indicate when (i) the truck atarts to move; (ii) the bird begins to run and flaps its wings; (iii) the bird is airborne (Butler, Woakes, 1980) be °ause °ur geese were physically fitter than other birds that had been stu- ^d/or that they were far less stressed when the data were obtained. aled, ®°he of cne measured variables viz heart rate, respiratory frequency, wing fï'equency varied with flight velocity, except when the birds slope 1001 P i g. 7. Diagram of an implantable air flow transducer, shown partially sectioned. The acrylic collar is split into two sections which fit round the trachea. The two sections are held together with 1 mm diameter screws which also retain the mounting studs. These studs project into the lumen of the trachea and carry the piezoelectric transducers (Woakes, Butler, 1979) soared on the airstream rising over the front of the truck (Pig. 4b). Heart rate was then 50$ of the value during flapping flight and respiratory fre¬ quency was 70%. This is in accordance with a lower metabolic rate when glid¬ ing than during forward flapping flight (Baudinette, Schmidt-Nielsen, 1974). There was a 3:1 correspondence between wing beat frequency and respiratory frequency together with a tight phase locking between the two, which probably persisted throughout the flight (Berger et al., 1970a). The phase relation¬ ship was maintained even during transient changes in one of the activities. Perhaps the most important feature of the study is the demonstration that it is possible to obtain physiological data from free flying birds, that are unstressed by the restrictions of a wind tunnel or externally mounted leads or equipment, and yet are close enough to obtain accurate measurements of their air speed and behaviour. We are now embarking on a programme involving Canada geese, an implantable multichannel transmitter and transducers for measuring tidal volume (Pig. 7) and tracheal oxygen tension (Jansen et al., 1978). This will allow the di¬ rect measurement of oxygen uptake and extraction of oxygen in free flying birds during flights of long duration. There will be no externally mounted equipment and the birds will be flying in as near natural conditions as pos¬ sible. This could be a realistic alternative method to the wind tunnel (Rothe, Nachtigall, 1980) in the study of avian flight. However, a combination of a number of the newer techniques, used with one species of bird, is likely to give the most comprehensive and useful insight into that most pervasive of activities of our feathered friends; flight. SUMMARY Metabolism during free flight has been estimated from fat loss and from C02 production, using the D2018 method, during flights of several hours duration. However, behaviour of the bird during flight is not always known. Short range radio transmitters have been used to record oxygen uptake and respiratory variables in flying birds, but the flights were only of a few seconds duration. 1002 It has been demonstrated that short range radio transmitters can be used durxng relatively long flights by keeping the bird close to the receiver, is was achieved by raising bemacle geese from eggs and imprinting them on human. The "following response" was re-inf orced daily so that they would follow the "foster parent". Having established that a particular bird would fly behind a truck with the "foster parent" in the back, a 2 channel radio ransmitter was then implanted into it. Thus it was possible to record respi¬ ratory frequency and heart rate from birds that were flying at known air velocities for known durations although they were completely unrestrained. th the necessary transducers and transmitters it should be possible to re¬ cord oxygen uptake and respiratory tidal volume under similar conditions. acknowledgements The author’ s work was financed by the Science Council. and Engineering Research R e f e r e n c e s Ini ““ / M. by Cambridge lass. Nuttal Ornithological Club, 1974, p. 330. !-V;,TS:hmidt’NielSen K* - NatUre’ 1974’ ^ P- *3-84. Hart J.S. - In: Avian Biology. Vol. IV / Eds. D.S.Famer, Be ,K,Kine* Academic Press, 1974, p. 415-477. Berg^ ÎÎ* ’ H0^ °‘Zm' Hart J*S* ' Z* ver&‘ toyalol., 1970a, 66, p. 190-200. Beast ’ R°y °‘2' " Z’ VSrSl* Physio1” 1970b, 66, p. 201-214. Bg stein M.H. - Respir. Physiol., 1976, 26, p. 371-382. ^nstein M.H. , Thomas S.P. , Schmidt-Nielsen K. - J. exp. Biol., 1973, 58, B^own J.L. The Evolution of Behaviour. N.Y.: W.W. Norton, 1975, p. 628. çSr P,J’ " In: A Handbook on Biotelemetxy and Radio Tracking / Eds. Butl" J*Amlaller’ D,W-Maodonald* Oxford: Pergamon Pre33, 1980, p. 569-577. P.J. _ in- Advances in Physiological Sciences. Vol. 10 / Eds. L. A.Debi’eozeni. Oxford; Pergamon Press, 1981, p. 155-164. er ~ Exogenous and Endogenous Influences on Metabolic and Neural Buti°ntr01 ^ Ed8‘ A* D.F. Addink, N.Spronk. Oxford: Pergamon Press, 1982, p. 105. Butl61" P'J*’ Woalces A. J. - J. exp. Biol., 1980, 85, p. 213-226. Rail61" P’J'’ West R*H. .Jones D.R. - J. exp. Biol., 1977, 71, p. 7-26. Hpj,,3 C'J‘ ~ Comp. Biochem. Physiol., 1979, 6J3A, p. 581-585. Hud Hud -v - - ' — . - 7 - •s-, Roy O.Z. -Physiol. Zool.., 1966, ^39, P- 291-306. Sori D.M., Bernstein M.H. - Fed. Proc. , 1978, p. 472. D.M. , Bernstein M.H. - J. exp. Biol., 1981, 90, p. 267-281. S ©ft rp p “ ■ " Lafeher N.H. , Visser H.K.A. et al. - Med. and Biol. Eng. and John0?*’ 1978,.!6, P- 274-277. ^ston n.w. Kan 'st on Wisher D*W. , McFarlane R.W. - Condor, 1967, 69, p. 156-168. J.W. , Williams T.C., Teal J.M. , Lawson K.O Auk, 1978, 95, p. 288- 1005 LeFebvre B. A. - Auk, 1964, 8^, p. 403-416. Lifson N., McClintock R. - J. Theoret. Biol., 1966, _12, p. 46-74. Lifson K., Gordon G. B. , Vis3cher M.B. , Nier A.O. - J. Biol. Chem., 1949, 180, p. 803-811. Lorenz K. Studies in Animal and Human Behaviour. Vol. 1. Translated by R. Martin. L. , 1970. Nagy K. A. - Am. J. Physiol., 1980, 238, p. 466-473* Nisbet I.C.T., Drury W.H. , Baird J. - Bird Banding, 1963, 24, P- 107-159. Ogilvie M. A. Wild geese / Eds. T., A.D.Ppyser. Berkhampsted , Herts, 1978. Pennycuick C.J. - Ibis, 1969, III . p. 525-556. Rothe H. -J., Nachtigall W. - In: Proc. I7th International Ornithological Congress. Berlin: Deutsche Ornithologen-Gesellschaf t , 1980, p. 400-405. Swan L.W. - Sei. Ara., 1961, 205, p. 68-78. Torre-Bueno J. R. - J. exp. Biol», 1976,65, p. 471-482. Torre-Bueno J. R. - In: Respiratory Function in Birds, Adult and Embryonic/Ed. by J.Piiper. Berlin: Springer-Verlag, 1978a, p. 89-94. Torre-Bueno J.H. - J. exp; Biol., 1978b, 75., P* 231-236. Torre-Bueno J.R., Larochelle. - J. exp. 3iol. , 1978, 75, p. 223-229. Tucker V.A. - Science, 1966, 154, p. 150-151. Tucker V.A. - J. exp. Biol., 1968, 48, p. 67-87. Tucker V.A. - Am. J. Physiol., 1972, 222, p. 237-245. Utter J.M. , LePebvre E. A. - Comp. Biochem. Physiol., 1970, 25» P* 713-719. Woakes A.J. Biotelemetry and its Application to the Study of Avian Physiolo¬ gy. Ph. D. thesis, University of Birmingham, 1980. Woakes A.J. , Butler P.J. - Biotelemetr-y , 1975, 2, p. 153-160. V/oakes A.J. , Butler P.J. - In: A Handbook on Biotelemetry and Radio Track¬ ing / Eds. C.J.Amlaner, D.W. Macdonald. Oxford: Pergamon Press, 1979, p. 287-292. 1004 ABSTRACTS OF AFTERNOON SYMPOSIA FORAGING PATTERNS, RESOURCES UTILIZATION AND THE TROPHIC ROLE OF BIRDS BIRDS, PESTICIDES AND OTHER POLLUTION % ECOLOGICAL MORPHOLOGY ORIGIN AND EVOLUTION OF BIRD SONG POPULATIONS OF GAME BIRDS AVIAN PARASITES PAIR BONDING OCEANOGRAPHIC DETERMINATION OF PELAGIC BIRD DISTRIBUTION LEK BEHAVIOUR INTRASPECIFIC VARIATIONS LOSS OF AVIAN HABITAT THE ORIGIN AND EVOLUTION OF COOPERATIVE BREEDING IN BIRDS hole-nesting birds SPECIATION and evolution OF social birds STRUCTURE OF FEATHERS STRUCTURE and evolution of avian chromosomes STATUS of THE WORLD’S CRANE SPECIES physiology and ecology of incubation moult SONG DEVELOPMENT AND SPECIES EVOLUTION ADAPTATION TO DESERT CONDITIONS seabrids AND NUTRIENT CYCLES biophysics of bird flight GULLS, TERNS AND SKUAS SYMPOSIUM FORAGING PATTERNS, RESOURCES UTILIZATION AMD THE TROPHTC ROLE OF BIRDS Convener: R.T. Holmes (USA), co-convener: A. A.Kistchinsky (USSR) FEEDING PATTERNS OF WOODLAND BIRDS AND THEIR BIOCENOTIC ROLE D. V. Vladishevsky Institute of Forest and Wood, Siberian Branch of the USSR Academy of Sciences, Krasnoyarsk, USSR Composition and quantity of food used by birds are determined by its quality, accessibility and correlation of birds' food needs and the abundan¬ ce of food. When there is no enough food, the whole of its accessible portion is used. Determining the value of the accessible portion is a complicated ecological problem. This portion has been showo to in¬ crease in direct proportion to the increase in probability of finding food, its accessibility and. its density. It also depends on the spatial distribut¬ ion of food, as different substrates (leaves, branches, etc.) are convenient to different degrees for searching by birds. The methods of evaluation of convenience of different substrate searching and the results of the corres¬ ponding studies are presented. The suggested approach allows the predication of the removal value of different food groups - seeds, fleshy fruits, insect, etc. To evaluate the trophic role of birds in ecosystems, two basic characte¬ ristics are used - the quantity of the eaten food and the probability of sur¬ vival of potential prey in the absence of birds feeding on them. The second characteristic is rarely used in biocenotic studies, therefore it seems im¬ possible to obtain the true idea of the role of birds and other animals in ecosystems. Oi a particularly great Importance is the correct evaluation of the effect caused by the seed dispersion by birds. While studying the after¬ effect of predation, an important ability of birds to switch over to mass prey species is considered. This shortens the delay period and leads to the effective control of prey abundance. On the whole, birds contribute to higher resistance of both undisturbed forest ecosystems and those changed by the man. The role of birds is most appreciable on plant succession. IMPACT OF INSECTIVOROUS BIRDS ON THE POPULATION PROCESSES OF THEIR PREY, WITH SPECIAL REFERENCE TO THE CODLING MOTH David McKellar Glen Long Ashton Research Station, University of Bristol, Bristol, BS1 8 9AF, UK In most studies of the effects of insectivorous birds on their prey num¬ bers, lack of information on other mortalities means that the effects of birds on the population dynamics of their prey are unknown. Studies on the population dynamics of codling moth (Cydia pomonella) show that predation by birds is of great importance when larvae are exposed to predation for seve¬ ral months. Codling moth larvae are exposed to predation by birds when they mature and build cocoons beneath the bark of apple trees. This predation has littl® 1006 e feet on larvae that develop without delay to give a second or third gene¬ ration in warm supers. However, larvae overwintering in diapause are exposed to bird predation for about eight months, woodpeckers (Di^obatesspp) in Ca¬ nada, silvereyes (Zosterops lateralis) in New Zealand, and tits (Parus soul in Europe take 50-95% of such larvae. The intensity of predation in any one year is spatially density dependent, but from year to year it depends on fluctuations in the numbers of birds, as well as larval density. THE IMPACT OP BIRD PREDATION ON THE PATTERNS OP LEAP CONSUMPTION BY FOREST INSECTS John C. Schultz and Richard T. Holmes Department of Biological Sciences, Dartmouth College, Haoover.New Hampshire, USA Even though birds exhibit both numerical and functional responses to in¬ creasing prey densities, they seem to be generally ineffective in control¬ ling outbreaks of herbivorous insects (especially Lepidoptera larval. Re¬ cent evidence, however, suggests that birds do exert significant predation Pressure on endemic populations of their prey. Although this pressure may help to further suppress insect populations and to extend the periods bet¬ ween outbreaks, we propose that the more important influence of such heavy Predation on low density prey is to exert natural selection for prey adaptat¬ ions, many of which result in restrictions or modifications on the patterns insect feeding. Adaptations such as crypsis, aposematism, restricted choice of feeding substrates, rigid feeding schedules, tissue (food) prefe¬ rences, and even the organization of some life cycle features may be favored y natural selection due to predation; these in turn determine or affect the Patterns and amounts of leaf consumption by these herbivorous insects. In thls Paper, we review the evidence for this hypothesis, using data primarily Irom our studies of bird/insect interactions in a northern hardwoods forest ^n New Hampshire, USA. Prom this analysis of the adaptive syndromes of her- v°rous insects and of bird foraging behavior and pressure, we suggest fur- ther observations and experiments that will test the hypothesis that bird Predation has been a major organizing force on the trophic-dynamics of her- Ivorous forest insects. Symposium £1RPS. PBSTTHTnra AND OTHER POLLUTION Conveners R.W.Risebrough, USA USE OP MANAGEMENT TECHNIQUES TO PROMOTE THE RECOVERY 0P AN ENDANGERED POPULATION OP PALCO PEREGRINUS Brian j. Walton Predatory Bird Research Group, 231 Clark Kerr Hall, University o$ California, Santa Cruz, California 95064, USA tli^Fere8rine Falcons have experienced severe declines in populationnize °ughout most of their cosmopolitan range since the late 1940's. Is ce; BIBI. iMUSEl lPARI central 1007 Dim irvrutrs! ic t coastal California the decline has mainly been due to DDE-induced eggshell thinning, resulting in lower productivity and in recruitment failures. By 1970, only one known territory was occupied (by a lone male) along the 400- mile coastline which includes 25 historical nesting territories. By 1981, as a result of reduced environmental levels of DDE and of management of the ex¬ isting population since 1977., six coastal eyries were occupied. The manage¬ ment techniques, first developed by the Pergrine Fund for endangered pereg¬ rine populations but suitable for other raptors, enabled maintenance o' ex¬ isting territories and expansion of the remnat. •• .pu-.'t'.ion in .o arm.. for¬ mer range and historical nesting territories. This management includes: 1) captive incubation of thinshelled wild eggs; 2) fostering of the young from captive-incubated wild eggs; 3) introduction of young from captive breed¬ ing falcons into wild nests; 4) hacking of young at currently unoccupied his¬ torical nesting territories; and 5) supplemental feeding of 'wild falcons by providing a clean food source (domestic pigeons'. However, unless DDE levels in peregrines and in the environment are permanently reduced, this populat¬ ion, like all peregrine populations, continues to face extinction, or reliance upon management on a permanent basis. IMPACT ON THE AVIFAUNA OF PESTICIDE USE IN THE STATE OF RIO GRANDE DO SUL, BRAZIL Robert W. Risebrough, Alan M. Springer, Jorge L.B. Albuquerque, Martin Sander The Bodega Bay Institute, 2711 Piedmont Avenue, Berkeley, California 94705, USA Caixa Postal 10323. 90.000 Porto Alegre, Rio Grande do Sul, Brasil Centro de Ciencias Biologicas, UNISINOS, Caixa Postal 275, 93.000, Sao Leopoldo, Rio Grande do Sul, 3razil * The use of insecticides, including chlorinated hydrocarbons that are no longer applied in many northern hemisphere countries, is generally believed to be increasing in South America. The effects on the avifauna are as yet largely undocumented. In the state of Rio Grande do Sul, Brazil, there is widespread pesticide use, but there is also increasing public concern over the effects of the indiscriminate use of many of these pesticides. Data are presented in this paper on the levels of the organo chlorine pesticides in rep¬ resentative species of the avifauna. Nothura maculosa, a common inhabitant of the principal land use types in the state (soya cultivation, rice cultivation, pastureland, and uninhabited grasslands) , was used as an indicator of the re¬ lative levels of contamination in these areas. Data on organo chlorine levels in raptors and aquatic birds with close relatives in the northern hemisphere permit an assessment both of general contamination levels, and the effects of these compounds on local species. 1008 POLLUTANT EFFECTS ON OSPREY P. Spitzer Section of Ecology and Systematica, Cornell Univ. Ithaca, N.Y. 14850, USA Many factors were considered as contributing causes to the initial decli¬ ne of Osprey population in the north-eastern United Statesr encroachment by man, loss of habitat, reduction of the food supply, as well as a varity of pollutant chemicals. The work of Dr. Spitzer and his colleagues has conclusi¬ vely demonstrated that only one pollutant, was responsible, DDE, the environ¬ mentally stable derivative of the ineecticide DDT. The DDE effects were as¬ sociated with shell thinning; Dr. Spitzer' s studies have further demonstrated that productivity was significantly lowered when the degree of shell thinning wa3 not su? ficient to cause breakage. Thus there i3 not necessarily a "thre- shold-of-effect" level of DDE upon productivity, indicating that factors other than egg breakage are involved. . . Other case histories were reviewed, including the Bald Eagle, Haliaeetus jeucocephalus, in northwestern Ontario, the White-tailed Eagle, H.albicilla. in Scandinavia, Finland, and the German Democratic Republic, the Brown Pe- lioan’ Pelecanus occidentals, in southern California, and the Peregrine Fal- Con’ Falco peregrinus. in Great Britain and arctic North America. In each case reproductive failures, usually with regional population declined, had been associated with eggshell thinning; in the majority, an inverse relat¬ ionship had been demonstrated between shell thickness and DDE levels. In each case either a partial or a complete recovery occurred with a decline of environmental levels of DDE. The influence of other environmental factors, including pollutants such as PCBs, other synthetic organics, and trace ele- ments, had either been minimal and not demonstrable, or had been discounted. The conclusions of these field studies have been supported by an extensive Senies of laboratory investigations which have shown that DDE causes shell Winning in many bird species, particularly raptorial and fish-eating spe- °ies, but including doves and ducks, at levels frequently found in the en- Vir°nment. Other organochlorines, including the common pesticides and the C3, were found not to cause the effect. We can therefore conclude with reasonable certainty that the shell thin- which has been documented in many populations, and the associated popu¬ lation declines of some of these, have been caused only by DDE. . Allowing the ending of DDT use, environmental levels of DDE are falling northem countries. In one area, the central coastal region of California, vels have remained too high in recent years to permit the sucessful repro- °tion of Peregrine Falcons. Comparison of the relative amounts of DDE, ’P -DDT, mirex, dieldrin and heptachlor epoxide in unhatched eggs of this P°Pulation with those in comparable samples from Greenland and from arctic j ■‘•hterior Alaska, have lead to the conclusion that the majority of the currently accumulated by this population originated from DDE originally PPlied in California rather than from DDT recently used in Latin America. 28- 3aK. 98i 1009 SYMPOSIUM ECOLOGICAL MORPHOLOGY Convener: B. Leisler ( PRG } , co-convener: F.Ya. Dzerzhinsky (USSR) Comparative studies in eco-morphology try to understand the relationship between morphological variation in animals and their ecology. As almost all features of an organism are interdependent and are results of compromises such studies require a good knowledge of the life history of the species in¬ vestigated and information about phylogenetic relationships among the spe¬ cies. One objective of the symposium was to concentrate on some historioal- evolutionary aspects in eco-morphological studies. DRINKING BEHAVIOR AND FEEDING ADAPTATIONS IN PARROTS Dominique G. Hornberger Zoology and Physiology, Louisiana State University, Baton Rouge, Louisiana 70803, USA Within Parrots, at least four different drinking methods can be distin¬ guished, each of them characteristic for an entire subfamily, irrespective of the feeding specializations of the particular species. Each subfamily is also characterized by a specific basic morphology of the tongue, bill, and mouth cavity. The various basic morphological types of the feeding apparatus have been evolved as feeding adaptations from that in ein ancestor adapted to seed-eating. During this first stage of adaptive radiation, not only were the feeding apparatus and feeding method fundamentally transformed, but with it also the drinking method. The following stages of adaptive radiation, taking place within the subfamilies, did not affect the drinking methods. The vari¬ ous drinking methods evolved as a by-product of the adaptive changes con¬ nected with feeding specializations and were not under the control of Selec¬ tion forces associated with drinking. Although there are uo clear eco— morpho¬ logical correlations to be found for the drinking methods, the distribution of certain species may be affected by their drinking method. The drinking be¬ havior in Parrots illustrates the need in eco-morphological studies to dis¬ tinguish between those structures and behaviors that evolved under the cont" rol of a selective force not related to the environment to which they are presently adapted. * THE FORAGING OF INSECTIVOROUS AND FRUGIVOROUS BIRDS AND THE IMPORTANCE OF MORPHOLOGY TO BEHAVIOR Roger Joseph Lederer Department of Biological Sciences, California State University, Chico Chico, California 95926, USA The diminution of competition among animals is frequently attributed to the differences in foraging behaviors of the potentially competing species« Field studies are frequently done which demonstrate that, for example , birds feed on different foods, at different heights, or on different parts of the vegetation. However, the trophic apparatus, and those parts of the bird ths^ assist the trophic apparatus in obtaining or minipulating food, is limited its ability. Thus the behaviors we observe may not be a result or competLt^015 1010 There exist possible conflicts between behaviors induced by ecological constraints and those allowed by morphology. The foraging behaviors observed n the field are most often attributed to environmental causes-competition, weather, and food supply, for instance. Morphological aspects are typically considered in only the broadest sense (hummingbirds east nectar and insects but cannot eat berries), yet they may be at least as important as the ecolo- gical factors which are measured in more detail. This study looks at an example of an insectivorous species and a frugivo- rous species and weighs their ecological and morphological constraints. SONG ASPECTS OE THE ADAPTATION OE THE DEEDING APPARATUS in ROLLERS (g ORACII) L.P. Korzun Biological Faculty, Moscow State University, USSR Some new aspects of feeding adaptations in rollers were discovered with be help of morphofunctional analysis of their feeding apparatus. The origi- bal adaptations that developed in this group (Coraclldae. Brachypteraciidae !“d bep*°gomatidae) were for catching relatively large insects in flight. is key adaptation included automatic mechanisms insuring an effective grip °h the prey and protecting the eyes against contact with the prey. The super¬ ficial orbital oponeurosis has a basic role in the eye protection mechanism; e iS tensed automatically by the protracted upper jaw as the bill opens. The ^yes are covered by the raised lower eyelid which contains cartilage. Vibris- s like feathers form an elastic screen providing passive protection. The t^ngtheoed palate is crucial for catching flying insects. It assimilates ^ impact energy of the prey and uses it for an automatic sharp closing of St® mandible. The ossified postorbital ligament is essential for this action. e r0ngl3r developed maxillopalatines and prefrontals seem to damp surplus ^bergy. The main features of thiS key adaptation are retained in all species °IIers. They are most specialized in Eurystumus, Leptosomus discolor of a agascar catches relatively large sluggish animals on branches. The jaw Paratus of Uratelomis shows adaptations to pecking (e.g. , to obtain ter- eSj‘ Coracias has the most generalized jaw apparatus. SÏMPOSIUM AND EVOLUTION OF BIRD SORG Convener: L. Baptiste (USA), co-convener: G.N.Simkin^ USSR bIRD SONG AND AVIAN SYSTEMATICS Robert B. Payne Seum of Zoology and Division of Biological Sciences, The University of Michigan, Ann Arbor, Michigan 48109, USA Sop Song is useful in avian systematics primarily at the level of the Pt-o • * 01rds use song in mate selection and in species recognition. Song ^ides an experimental method of determining species limits in some birds. ^mental bests of mate choice in females finches (Vi dua) and grebes 1011 (Aechmophorus) have shown that females are attracted to consplcific sexual song and not to the song of closely related species. A less critical test of species distinctiveness is playback to males which sometimes respond to other species (especially if they are interspecif ically territorial) and so¬ metimes do not respond as strongly to songs of various population dialects as to their own local population. Song is learned in most passerines, so by itself it is no indicator of genetic distinctiveness at the species level. Moreover, song differences among populations do not necessarily indicate ge¬ netic or systematic differences, for many freely dispersing birds have song dialects (learned). It is necessary to associate song differences with mor¬ phological or other genetically-determined differences among populations to determine species limits. In systematica above the species level, song is useful as one among many characters, and has not the significance that we find at the species level. Members of a species group, genus or subfamily often have similar song, but even here exceptions occur with some species having songs unlike their clo¬ sest genetic relatives. At- higher levels song is even less reliable as an in¬ dicator of evolutionary relationship; flamingos and geese both honk, but bio¬ chemical and paleontological studies point to other groups (storks or waders) as the possible sister group of the flamingos. Song appears t6 be increasing¬ ly less useful in reconstructing cladistic or evolutionary relationships at the higher levels of systematics. The complex of morphological features under more direct genetic control reflect lineages with Hennigian or other logical phyletic techniques that deduce evolutionary history. In contrast, song (at least in £asseriformes) is learned in block, either from one parent or from several neighboring conspecifics. The processes of cultural tradition differ from those of genetic or biological evolution in several ways (lack of suc¬ cessive meiotic genome sampling of the preceding generation(s) , lack of ad¬ ditive genetic dif ferentiation over time) that render questionable any higher- order biosystematics based primarily on song. CENTRAL NERVOUS PROCESSING 0? BIRD SONG Hans-Joachim Leppelsack Lehrstuhl für Allgemeine Zoologie, Ruhr— Uni versi tat Bochum, 463 Bochum, ERG ‘The contribution of neurophysiology to our understanding of evolution of bird song may be its explanation of the central nervous mechanisms of song analysis. The principles discovered can elucidate the functioning of intra- specific communication and of species recognition. The only information that nerve cells within the ear of a bird receive about a song are the frequency and intensity components that it contains. All the other information about conspecifity and individual recognition, has to be worked out by central nervous mechanisms. These mechanisms occur at diffe' rent levels of the auditoiy pathway as the acoustic signal proceeds through it. The higher the station in the auditoiy pathway, the more detailed is the information about an acoustic signal within single neurons. Although it is not likely that one will find single cells responsible for the recognition oi singie song phrases, we can find neurons whose responses represent important parts of these phrases like the dynamics of frequency modulation in trills, and bandwidth of frequency in aggressive calls and song parts. Another important neurophysiological aspects is the neural plasticity during song learning. It can be shown that learning different types of song influences the response behavior of central neurons and thus determines central mechanisms of song recognition. VOCAL LEARNING STRATEGIES IN BIRDS Donald E. Kroodsma Department of Zoology, University of Massachusetts, Amherst, MA 01003, USA Birds are highly vocal creatures and males (sometimes females) of many species learn to sing just as humans learn to speak. This phenomenon has received v/ide-spread attention and study, yet the functions of vocal learn¬ ing and the selective forces favoring this learning continue to be debated. These functions and forces may not be unitary, however, for the consequences of vocal learning vary remarkably among different bird species. Insights into the vocal learning strategies of birds will be discussed by examining: 1) different vocal development and population consequences in closely re¬ lated songbird species (Troglody tidae) ; 2) the marked difference in micro-geographical variation with functional¬ ly different song types within a species (Parulidae) : 3) differences in song development among the imitative oscines (e.g. , -LSgglqdy tidae, Emberizidae) and the non-imitative (?) non-oscines (e.g., Ty- ïâhhidae) ; 4/ disparity in both size of song repertoire and volume of neural song control areas between two populations of the same songbird species (Marsh ^reh, Cistothorus palustris). SYSTEMATIC 3 AND CARDUSLINAS SONGS M.M. Zablotskaya Irioksko-Terrasny State Biosphere Reserve, Serpukhov, USSR Detailed studies of the systems of acoustical communication in Cardueli- (13 species from the genera Acanthis. Spinus. Carduelis. Chloris, Pyr- ^ii§> Serlnus) let assess the applicability of different categories of ac0U3tical signals for systematic purposes and make apparent some trends in "heir evolution. Our results suggest, that one should use polythetic approach 0 the bioacoustic criteria to make them into suitable tools for investigati- 0hs in systeraatics on different levels of taxonomic scale. Songs, because of complex structure and high degree of variability, are of little' use ■f°1’ systematic studies above the species level. The study of calls which are - biogene tically more ancient, of simple structure, less liable to geographi- aT and individual variations permit to reveal both species-specific and 8r°up characters with more ease. In order to determinate whether the forms ^der discussion may be considered specifically distinct, it is convenient study "call-söngs", males' courtship calls, females' calls preceding co¬ nation. For definition of the taxa at the generic and familial levels it 1013 is expedient to apply the signals of such functional categories which are of little or no connection with reproduction and retain ancestral, common for the group features: nonspecialized aggressive and alarm calls, mobbing calls, flight calls, signals for flock integration. Strict distinction bet¬ ween main categories of vocalization, i.e. calls and songs, does not exist. On the ground of our data and in consideration of the principles developed by G.N.Simkin (1982) we come to conclusion that song is. the product of phy¬ logenesis of the complex multifunctional demonstration which forms as a rule on the basis of species-specific call system as a result of rituallzat- lon. The most simple form of Carduelinae songs i3 "call-song", genetically preformed unsophisticated vocalization with sexual motivation, characteristic only for males. The main song type is "advertising song" which serves first of all as a means of attraction and stimulation of females. During phyloge¬ nesis it develops on the basis of several categories of the calls: flock calls, call notes, males' calls accompanying courtship and territorial de¬ monstrations. Calls, which turned into song elements, retain their structure unaltered or have certain modifications of physical patterns. Song becomes complicated also by developing specific song elements. Complex structure of Carduelinae "advertising song" serves principally to secure individual mark¬ ing of the male and to characterize his physiological state and social status. SYMPOSIUM POPULATIONS OF GAME BIRDS Convener: S.G.Priklonsky (USSR), co-convener: P.Rajala (Finland) COMMON EIDER NEAR COASTS OF EAST EUROPE V.V.Bianki Kandalaksha State Nature Reserve, USSR Thanks to a system of protection measures, fulfilled in the USSR, and to careful attitude towards this species in the northern countries of West Europe there is an abundance of common eider in Estonia, on the White, Ba¬ rents and Pechora Seas in 1970-ies there was 50-70 thou, adult birds, of •which 10-17 thou, inhabited Estonia, the rest-Arctic ocean seas. Their abun¬ dance seems to be close to the optimum level in the north, the increase in number on the Baltic Sea continued. They began nesting off the north-west coast of the Black Sea. It is suggested, that 3 geographic populations - one of the White Sea and two of the Barents Sea - inhabit the north. Geographical features of seasonal distribution, morphometric differences and variants of male dress and other features of common eider define them as belonging to a certain population. Despite a small annual mortality and com¬ paratively small number of eggs in a clutch, yearly variance in a number of common eider nesting on different archipelagoes often reach 50-60% and so¬ metimes more. This is due to changes in bird distribution on aquatic area, which is inhabited by a population in a year cycle. The weather conditions and sometimes other ecological reasons are usually the reasons for these changes. Mostly young birds seem to perfora migrations since females, which nested earlier, show significant nest site fidelity. The abundance of common eider is negatively influenced by predation of big sea gulls and hooded crows, in some regions by helminthosis and by other factors. EUROPEAN WOODCOCK POPULATIONS, ABUNDANCE MIGRATION AND UTILIZATION Heribert Kalchreuter Bundesforschungsanstalt für Naturschutz, 7823 Bonndorf-Glashütte, PRG The main breeding areas of the European Woodcock (Scolopax rusticola) extent through Northern and especially Eastern Europe and Asia, the main wintering areas lay in Western Europe, roughly bordered by the Januaiy iso¬ therm of J.5°C. Due to a considerable variation in the direction of migrat¬ ion the winter quarters of the breeding populations are not sharp to define. Breeding records and especially hunting statistics point to shifting abundances in different parts of the woodcocks range during this and the last century, for which climatic changes might have played an important foie. The woodcock is a valuable game bird throughout its range. The hunting Pressure is highest in the wintering areas of western Europe. According to tand recoveries an overall average of a fifth of the European population may e taken by huDters annually. The main harvest is done during fall and win- 'ter, some countries traditionally harvest courting males in spring and sum- mer> as in other polygamous game birds. Recent research projects, coordinated by the "International Waterfowl Re¬ search Bureau", deal mainly with habitat preferences, breeding biology, band- fdg calculations and kill-statistics. The latter two providing aspects of the size of the European populations. THE POPULATION ASPECTS OE THE COOT'S ECOLOGY IN WEST SIBERIA K-T.Yurlov, A. I. Koshelev Biological Institute, Siberian Branch of the USSR Academy of Science, Novosibirsk, USSR ^he numerous Coot's population is distributed in the steppe and woo'd- steppe zones of We st Siberia. The main body of Siberian Coots stay for win- erihg on the Caspian Sea and on the inner lakes of the Middle Asia. In ®Pfing the first Coots reach West Siberia in the second half of April. enesting period is very short. The first egg is laid not more than 2-5 after arriving. Mass laying of eggs takes place in the first decade of J- Mass patching was observed on the average in the last decade of May ^ at the beginning of the first decade of June. The young Coots begin to ^ Y at the end of July. The yearly production of the local Coots population 8 high. The average clutch size during the 1970-1980 years was 8.8+0.11 eggs °h size - 6.8+0.09 nestlings, the surviving of nestlings - 77.3%. During ~ August the population is represented by adult nesting birds by young ^ one year old birds (who do not reproduce this year) in correlation 1:2:4. ^°ods, local and migrate one year old birds and moulting birds (adult and Year old) are isolated in space. The migration takes place during the IO15 end of August - the middle of October. The migration of bir/is of different ages is isolated and takes place at different dates. During the autumn hunt¬ ing season hunters shot about 90-95$ birds of one year old. It is connected with their approachability and long stay in the nest area. Altogether 0.4- 0.5 million Coots were shot in West Siberia during th^ hunting season. This constitutes an average of 10% of the total amount of the Coots population (3-3 -4.3 millions birds). GENERAL FEATURES OF FINNISH TETRAONID POPULATIONS DURING RECENT DECADES Paavo Raj ala, Harto Linden Finnish Game and Fisheries Research Institute, Game Division, Helsinki, Finland Since 1964 large-scale route censuses of tetraonids have been carried out annually in Finland in order to monitor the population densities as well as the structures of populations. The route census results have indicated a marked decline in tetraonid populations. Capercaillie populations especially have clearly decreased; the Black Grouse and Hazel Grouse populations also show significant decline. These negative trends have been most marked in central Finland, which still has the best populations. Northern Finland has not suffered any significant decrease. By combining the results of route censuses with game questionnaires it is possible to backdate the tetraonid population estimates to 1946. During the 35-year period the Capercaillie populations have decreased by about 45%. The highest populations were recorded in 1953 and 1962. The Finnish Capercaillie populations cam be divided into three asynchro¬ nously fluctuating regions, which fit well with the presumed areas of dif¬ ferent subspecies. The Black Grouse populations reveal the existence of four fluctuation regions, while the Hazel Grouse and the Willow Grouse populati¬ ons show no such regions. Percentages of juveniles, brood sizes, adult sex ratios and proportions of hens with broods are compared at different phases of the fluctuation. SYMPOSIUM AVIAN PARASITES Convener: V.Barus^ (CSSR,) , co-convener: |K.Ryzhikov,'] (USSR) THEORETICAL AND PRACTICAL ASPECTS OF RESEARCH ON BIRD PARASITES Vlastimil Barus Institute of Vertebrate Zoology, Czechoslovak Academy of Sciences, Brno, ÏSSR The accumulation of data on the parasites (in the widest sense) of various taxa and whole systematic groups of avian hosts in various geographic regio113 has lead to their confrontation and synthesis in subsequent stages of deve¬ lopment of ornithology and parasitology. The synthesis on the level of the 1016 host-parasite relationships has made it possible to formulate, enlarge, sup¬ plement, or precise certain regularities of general importance (such as a larger number of parasitophyletic ' rules or laws; the specificity or hostality phenomenon; reservoir or parathenic parasitism; zoogeographic classification, and others). The study and evaluation of the parasite-host-environment re¬ lationships in which the hosts are avian taxa (populations) yields new data which enrich not only ornithology but which often clarify complex epidemiolo¬ gical and epizootological problems, the maintenance and circulation of such pathoergonts as viruses, bacteria, mycotic organisms, protozoans, helminths and arthropods. The many-sided applicability of such knowledge is documented by the solution of problems concerning diseases of man and domestic animals which show marked natural focality (both transmissive). Quite a new angle to view the dynamic evaluation of the relationships between birds and their pa¬ rasites is provided by the complex study of the process of their synanthro- plzation and synurbanization. Due to the variability of external factors and the differential adaptability of both components these processes, taking place quite recently, are considerably diversified. It is a matter of lear¬ ning the general laws that govern a short period of evolution of the inter¬ action between the human population and those of birds and their parasites, involving valuable practical aspects. REGULARITIES OP ANSERIFORM HELMINTH FAUNA [K.M. Ryzhiko'vf, P.G.Oshmarin Helminthological Laboratory of the USSR Academy of Sciences, Yaroslavl State University, USSR Among the helminth fauna of Anseriform birds are trematodes belonging to ibe family Echinostomatidae which will be used to establish generalities in the development of helminth species composition in the Anseriforme3. Ecological factors are most important with hydrotopical species being Predominant in the helminth fauna of these birds. Similar helminths in dif¬ ferent hosts result from similar ecologies, especially feeding. Phylogenetic relationships is also of some importance in the helminth parasites of Anseri- f°rro species. Helminths having an ecology different from that being typical for this family usually acquire new hosts although this is not characteristic for this Eroup. changes in host ecology enlarge the species composition of its hel- minth parasites. Host specialization results in the evolution of new higher taXonomic groups of helminths. Abrupt changes in the morphology and biology of echinostomatids occurred in non-intestlnal (liver, kidney, bursa Fabricii, 6tc*' species which is not typical for the family. Different modes of feeding, e.g. , in mallards, increases the number of pa- rasites. Among the Anseriform helminths, are found certain groups in the Process of active spéciation. Members of' these groups are found in hosts ei°nging to different avian orders and vertebrate classes which favors the Process of spéciation. IO17 PARASITIC ARTHROPODS IN BIRDS Vladimir Cemy Institute of Parasitology, Czechoslovak: Academy of Sciences, Prague , CSSR The role of birds as hosts of various arthropods (except extrasomntic ni- dicoles) is discussed. Temporary parasites, alternately staying on hosts and in free nature, are represented by exophilic Diptera and exo- and endophilic Acarina. Periodical parasites showing permanent parasitism of certain developmental stage, both mites and flies, are less frequent. Permanent parasites with constant parasitism of all developmental stages constitute the biggest group. Within the parasitocenosis of a host, the pa¬ rasitic arthropods from a pterocenosis which, together with protozoans and helminths, is an important part of the bird somatocenosis. According to the localization of the parasites, an exo- end endosomatocenosis may be distin¬ guished. The main components of the pterocenosis are the plumicolous end syringicolous Acarina and plumicolous Mallophaga. The exosomatocenosis comp¬ rises various mites and biting lice which live on the 3kin surface. The louse- flies form a transient category. The representatives of cutaneous, subcuta¬ neous, nasocavital, pulmonar and tissue parasitic mites are components of an endosomatocenosis. The possibilities are discussed of using arthropods parasitic on birds to determine the phylogenetic relationships of their hosts. The knowledge of the parasitic arthropods as vectors of arboviruses is of great practical import¬ ance. PARASITOPHYLETIC ASPECTS OP ANATID BIRD LIFE W. Eichler Museum of Natural History, Berlin, GDR The paper includes an analysis of species composition of Mallophaga in Anatinae. Studied the host specificity. A fairly strict predestination of certain species and groups of Mallophaga towards their host' was shown. On the basis of this regularity, the phylogenetic relationships between groups of Anatinae , as well as their relations to other birds, were analysed. ROLE OP SEASONAL BIRDS’. MIGRATIONS IN THE HELMINTH FAUNA FORMATION M.D. Sonin, A.,N.Pelgunov Helminthological Laboratory of the USSR Academy of Sciences, Moscow, USSR • A migration effect on the formation of helminthofaunistic complex in birds has been studied for nematodes of Calidris species with the application of matrix analysis. The nematode fauna of Calidris has been shown to be dependent on the site of location of these birds and the season of year and to a lesser extent on the species. This enabled us to use for the analysis the general lists of nematodes parasitic in all Calidris species in 11 regions of the USSR. 1018 Intersections measure matrix has been made, inclusions measure matrix has been constructed on its basis. For the analysis of the latter directed graph with "67% of banality"has been applied. It has been shown that the nematode fauna of Calidris birds of Baltic region and Turkmenia is more "exotic" and "original" than that of Calidrls birds of the mouth of Yenisei i^Lver, region of Lake Baikal and Yakutia is most "banal". On the basis of the intersections measure matrix a similarity measure matrix analyzed by means of graph "similarity 53%" has been made. It can be assumed judging from the composition of the nematode fauna that Calidris birds nesting at the Ob inlet migrate along the Caspian-Iranian route; those nesting at the mouth of Lena River along Khinganian route and the birds nest¬ ing at the mouth of Yenisei River - along both routes. The nematode fauna of .Calidris nesting on Chucotka is similar to that of this group nesting in Pri- morye Territory and on the island of the Bering Sea. This is indicative of a fact that Calidris birds migrate for wintering along these two routes. Therefore the helminth fauna composition of Calidris birds is dependent on their routes of migration. The analysis of Calidris nematode fauna also demonstrates that the helminthofaunistic data may supplement and sometimes develop our knowledge about the routes of bird migrations. WILD WATERFOWL AS HELMINTH RESERVOIRS TO DOMESTIC FOWL B.Rysavy The Chair of Hydrobiology and Parasitology of the Charles' University, Praha, Czechoslovakia The paper includes the results of investigations on the helminth fauna in domestic ducks and geese and in wild waterfowl that was investigated in the same water reservoir where also domestic fowl was reared. The total number of helminth species in domestic and wild birds was the same (59 species) when the majority of species (40 species) was found in both groups of birds. Examined the dynamics of infestation by helminths in domestic ducks. The infestation starts during the first 24 hours after the young bird is released °n the water reservoir. Cestodes (Hymenolepididae) are the first ascertained Parasites. The infestation is realized by eating up crustaceans, the inter¬ mediate hosts of these helminths. Crustaceans are infected by eating up ces- i°de eggs, excreted by wild waterfowl living on the reservoir. It was found idat a young duck eats up a fairly high number of crustaceans and of other invertebrates being intermediate hosts of helminths. With respect to that, tïle infestation cannot be avoided even at a low percentage of infestation of temporary hosts by helminth larvae. Molluscs have a greater epizootological I'°^e in helminth exchange between wild and domestic waterfowl. They are in- ermediate hosts of all trematodes parasitizing these birds, and they are Reservoir hosts of hymenolepidid cestodes. 11-19% examined Mollusca were in- 6a'ted by cysticercoids of Hymenolepididae. 1019 L OH THE APPLICATION OP HELMINTHOLOGICAL DATA IN ELUCIDATING THE PECULIARITIES OP BIRD DISTRIBUTION V.I.Zinovjev Kalinin State University, USSR While studying the characteristics of the helminth fauna of different ecological groups of Charadri i f orme s birds we have made an attempt to as¬ sociate them with the pattern of distribution of these birds. The material has been collected in the territory oT central regions of the European part of the USSR. Of 23 Charadri 1 formes species from the forest zone 18 species (182 specimens) belonging to 3 ecological groups (waterside, meadow and forest) have been studied. In waterside birds 9 parasite species were found, mean number of species per bird is 1.5; mean number of helminths- 26.3 individuals; 9 3% of all studied birds were infected. The figures for meadow birds are respectively 42.0; 1.2; 40.0; 90%; those for forest species are 14.6; 0.9; 19.0 and 100%. 6 helminth species are found only in waterside, 34 only in meadow and 6 only in forest species. 3 helminth species are found in all ecological groups, 7 in waterside and meadow, 7 in meadow and forest, and 3 in waterside and forest groups. The individual parasite groups having marine invertebrates as the inter¬ mediate hosts disappeared from birds of the forest zone and were replaced by the species freshwater and terrestrial invertebrates as intermediate hosts. The helminth fauna of modem ecological groups of Charadri if ormes birds was ultimately formed in several definite foci under the control of biocenotic factors. Differences in the parasite faunas of different ecolo¬ gical groups of Charadriiform birds allow the assumption that the distribut¬ ion of these birds occur by the colonization of waterside biotopes of fresh¬ water reservoirs, meadow and lastly forests from marine coasts. SYMPOSIUM PAIR BONDING Convener: G.Orians (USA), co-convener: W. Wickler (PRG) CHOICE OP BONDING PARTNER William A. Searcy Rockfeller University Field Research Center, Millbrook, New York 12545, USA Since the choice of the individual with which to mate can have a large ef- feet on the reproductive success of the chooser, we can expect selection to have produced strategies for optimizing mate choice. In birds, as in most animals, females usually have primary responsibility for mate choice. Female® should be influenced in mate choice by any male characteristic that (a) ha® an important effect on female fitness, (b) is variable from male to male, ^ (c) is accurately assessable prior to mating. Females might base thoir choice on the genetic quality of males, in order to secure good genes for their off' spring. However, because fitness has low heritability and is difficult to assess, choice on genetic quality is unlikely to be favored if alternative strategies are available. Choice on parental care quality is likely to be 1020 adaptive in those species in which males furnish parental care, provided that there is some basis for assessing future male parental care quality prior to anting. Choice on the quality of resources provided by males is clearly adap¬ tive whenever males provide resources; in birds, such resources may include nests, nuptial gifts of food, and access to feeding and nesting territories. Mixed strategies, in which more than one male characteristic influences choice, are highly probable. In the Red-winged Blackbird (Agelaius phoeniceus) males defend territories in which harems of females nest and gather part of the ■food resources for breeding. Data from several studies indicates that terri¬ tory quality is much more important for female choice than is the quality of the male. Harem sizes in successive years on arbitrary territories are strong¬ ly correlated, whether or not the same male is holding the space. In addition, there is no correlation between harem sizes and such measures of male guard¬ ing ability as the attack rates of males on potential predators nor any cor- relation between the attack strength of the male and the rate of predation °h nests within his territory. Harem sizes increase with the age of the male as well. In some Redwing populations age is also correlated with the amount of feeding of nestlings by the male but in others it is not, so that the reasons for the preference shown by females for older males are not yet clear, is it clear how much genetic variance in male quality is present in this other species of birds. CHOOSING AND KEEPING A PARTNER C.M. Perrins Edward Grey Institute, Department of Zoology, South Parks Road, Oxford. UK Great Tita males defend territories that contain both nest sites and all of the food resources used by the pair and its offspring during the breed- season. Extensive data from a population of individually marked birds 3how that older birds breed 3ooner in the spring, have larger clutch sizes, higher fledging success and post-fledging survival than do younger ^fds. Therefore it is advantageous for all birds to mate with older in- aividuals. Pairs are not formed randomly with respect to age of partner. &ther, most older birds are mated to other older birds and young birds are t®d to young birds. The experience of the mate is much more important to tetialgg than lt ls tQ males; pairs consisting of an old male and a young male are as successful as pairs consisting of two old birds, whereas Paira consisting of a young male and an old female do nearly as poorly as Pairs insisting of two young birds. b Great Tits do not move far between breeding seasons so that if both mem- ^ s °f a breeding pair are alive the following year they are likely to be aie one another's presence. Nonetheless between 30 and 40% of pairs in D°th partners survived divorce between years. The breeding success of o^lrs which breed together in successive years is compared with the success bii’ds which change partners. Birds which fail to raise a brood (the mam for which is usually predation) are more likely to change than birds lcil a;be successful. Part of the reason for this is that birds which lose 1021 a brood tend to nest further away from the nest site of the previous year than do birds which are successful. The breeding success of birds in relat¬ ion to moving and changing partner is compared and selective value of such behaviour is discussed. PAIR BONDS AND DIVORCE AMONG CORVIDS Gert Baeyens Vogelenzangseweg, The Netherlands . Most West-European Corvid species (Corvus corone, Corvus frugllegus, Corvus monedula, Pica pica) maintain a continued monogamous pair-bond, i.e. they do not switch mates between successive breeding seasons. When divorces do occur they usually include a switch of territory as well as of mate. The readiness to accept a new mate seema#to be facilitated by sex-specific to¬ lerance. Males are likely to tolerate female intruders in their territory and territorial females also do not always expel intruding males. In this way extra-marital courtship is sometimes induced. Pair members which seldom attack intruders of the opposite sex also often fail to assist their- mate in chasing. The proportion of individuals showing sex-specific aggression and weak or absent co-operation in attack vary within and between species. Even within an individual's lifetime the ten¬ dency to favour a certain mate by chasing potential rivals can change. If prior knowledge of the territory is particularly important for the success of a nev/ly settled bird, then individuals would benefit by deserting their mates to pair with a widowed territorial resident. However, if an es¬ tablished pair does better in unfamiliar terrain than a newly formed pair, even if one partner knows the area, then divorce should be rare. Among the family Corvidae some species move into new breeding sites as pairs and sel¬ dom divorce their spouses, while in others individuals readily divorce their mates to form bonds with widowed birds on better territories. Connecting the character of the pair-bond to reproductive output and co-operation in repro¬ ductive activities are important first steps to a functional explanation of intra- and interspecific differences in co-operation and persistence of mate choice. CONFLICT IN REPRODUCTIVE EFFORT WITHIN AND BETWEEN PAIR BONDS Gordon H. Orians Department of Zoology, University of Washington, Seattle, Washington 98195, USA Time expended in courtship feeding, nest building, incubating, advertize11® for more mates, seeking outside copulations, feeding young and defending teJ"' ritory compete for the limited time available to a mated bird. Because of their lower energy commitment to gametes males find themselves in situation® where reduced expenditures within an existing bond may lead to enhanced rep" roductive success more often than do females. In this family of about 95 species there is no reported case of courtship feeding, feeding of the in" cubating female by the male, or of incubation by males. In only two specie® are males known to participate in nest building. In contrast, males of evet? 1022 monogamous species so far studied help feed nestlings and fledglings. Among polygynous species , males feed nestlings and fledglings in some species, but do not do so in other species. Males that do feed, usually favor nestlings in their primary nests, but can be induced to feed at secondary nests if the young are growing more poorly there or if there are more young in the secon¬ dary nest than in the primary nest. Thus, male investment in nestling care is highly variable and apparently well-adjusted to immediate conditions. This is in striking contrast to the patterns that are invariate, or nearly so, in the entire family. These patterns could be explained in one of severalways. First, it is Possible that it is not advantageous to either males or females for males to incubate, feed the incubating female or build nests in any of the species. Second, it could be advantageous to males not to perform those activities but females would benefit if they did. Females could be in a "cruel bind" because they are unable, at the time of pair formation, to assess the probability that their mates will perform such parental behavior. By the time it is evident that they will not, it is too late to desert. Moreover, they would face the same assessment problem with any new mate. Third, it could be advan¬ tageous to both males and females for males to incubate and feed incubating females but the requisite components of the behavior have not yet arisen in those species. It is, as present, impossible to distinguish between these possibilities because the lack of variability in male behavior prevents us from making the »°st useful comparisons. However, assembling additional comparative informat¬ ion may reveal new patterns that are more informative and may suggest expe¬ riments not currently evident. SYMPOSIUM PCEANOflRAPHTC DETERMINATION OF PELAGIC BIRD DISTRIBUTION Convener: G.Hunt (USA), co-convener: R.G.B. Brown (Canada) SEABIRD DISTRIBUTION AT SEA IN RELATION TO WEATHER and WATER MASS CHARACTERISTICS R.W. Abrams Percy Fitzpatrick Institute of African Ornithology , Cape Town, South Africa ?he distribution of birds at sea in the Southern Ocean south of Africa delates poorly with each of the- following environmental parameters: baro- ”l6tric pressure; salinity; air temperature; water temperature; wind strength; ^ wave height. However, principal component analysis applied to the en- vil'onmental parameters defines two potentially useful factors (weather and *ater mass), but the birds' distribution still does not appear to be corre- ated strongly with abiotic environmental .features. A variety of possible ^inationa of cause-effect interactions among the physical parameters (baro !“et^ Pressure, temperature and wind) revealed.no highly significant linear ïelationships between seabird distribution and weather. Linear models ex- 1023 plain a very small proportion of the spatial variation in seabird community structure. Thus, the U3e of abiotic environmental features as predictors of seabird distribution seems limited, which suggests that pelagic seabirds are distributed randomly at sea or their distribution is non-random as a conse¬ quence of a combination of biogeographical history, food requirements, breed¬ ing period and locale, and physical environmental features. This hypothesis may only be testable with a complex stochastic model, and we lack sufficient data for a number of important variables necessary for the construction of such a model. At present, the only meaningful patterns discernible in the distribution of Southern Ocean seabirds relate to spatio-temporal separation by diet and feeding method. THE DISTRIBUTION OP SEA-BIRDS DURING AN YEAR AND THE CAUSES OP ITS CONCENTRATION OP THE GEORGE'S BANK L.Belopol' skii , V.Babaryka Kaliningrad State University, USS^i Analysis of the results of investigations undertaken by the authors permit the following conclusions: 1. Large nesting and feeding concentrations of sea-birds are formed in re¬ gions or in separate local sea areas having high biological productivity. Birds contribute to this productivity directly by fertilization with their excrements which speed up development of the feeding base. 2. Analysis of changes of the biomass in phyto-zooplankton, ichthyofauna and cephalopods revealed its annual development and reproduction on the Ge¬ orge's Bank and its attraction for a large number of sea-birds in this region- 3. The 140.000 recorded individual sea-birds on the George's Bank belon¬ ged to 40 species, of which 36 nest in the northern and 4 in the southern Hemisphere. Thus, the sea-birds of the area belong to two quite different avifaunas - northerns and southerns. 4. The species-composition of migrating sea-birds changes year by year. The quantitative ratio of individuals of each species changes also and leads to a considerable modification of the avifauna most years. 5. The composition of the sea-birds on the George s Bank depends not only on trophic factors, but also on periods of wandering and migration which are governed by endogenous rhythms of each species. 6. In ecological investigation of marine avifaunas, special attention should be given to the change of quantitative rations between "northerns" and "southerns" because the phenomenon of replacement of one fauna by the other typical to the region of the George's Bank must be found in other oceanic areas. This suggestion is supported by the presence of transequato- rial migrants in both the southern and northern hemispheres. 1024 SEABIRDS DISTRIBUTION IN THE NORTH SEA AND ADJACENT NORTH ATLANTIC OCEAN: OCEANOGRAPHIC AND ECOLOGICAL INTERPRETATION Claude R.E. Joiris Laboratorium voor Ekologie, Vrije Universiteit Brussel, Pleinlaan 2 - 1050 Brussel, Belgium Seabirds were counted for one-hour-periods, from both moving and stationa¬ ry oceanographic ships: R.V. Meteor and R.V.Anton Dohm.FRG, and R.V. Mechelen, Belgium. The distribution of pelagic seabirds is clearly related to the different water masses, determined by their oceanographic characteristics: salinity and temperature. A group of 'species which are almost absent in the North Sea water and are bound to Atlantic water: Gannet (Sula bassana) 1.4 individual per station; Great Skua (Stercorarius skua). 4 ind. ; alcids ( Pratercula arctia. Uria aalge and Alca torda) 20 to 60 ind. per station. Two species are present in both Atlantic and North Sea water: Fulmar (Pulmarus glacialis) , respectively 40 to 70 and less than 20 ind. per station; Kittiwake (Rissa tri- dactyla, . resp. 15 to 60 and less than 10. The main difference between Atlantic and North Sea waters is attributed to their ecological structure. A complete food web is developed in Atlantic water, with high densities of zooplankton, fishes and pelagic seabirds, and low density of bacteria. In North Sea water, however, for comparable levels °f primary production, a high density of bacteria reflects that the organic Matter is mainly recycled by bacteria, and the higher levels of the food web, zooplankton, fishes and pelagic seabirds, are present at low densities. It is concluded that, in zones presenting a good oceanographic homogeneity. Pelagic seabirds can be used as bioindicator for the ecological structure of manine ecosystems, combined with a simple measurement of phytoplankton den- aHy, such as chlorophyll. THE SIGNIFICANCE OF OCEANOGRAPHIC DOMAINS AND FRONTS FOR SEABIRD DISTRIBUTION IN THE BERING SEA George L. Hunt, Jr. Department of Ecology and Evolutionaiy Biology, University California, Irvine, California 92717, USA The shelf waters of the southeastern Bering Sea are separated by fronts Ihto three distinct oceanographic domains; the inner or coastal domain, the *i!idle domain, and the outer domain at approximately the 50, 100 and 200 m ^obaths. The inner domain is characterized by a uniformly mixed water °°lumn, the middle domain by a two-layer water column separated by a sharp i^onmocline , and the outer domain by a multilayer system. The density and community structure of seabirds differs between domains, ^0l"them Fulmars (Fulmaris glacialis), Fork-tailed Storm-Petrels (Oceanodro- ^-gbrcata) , Black-legged Kittiwakes (Rissa tridactyla) and Red-legged Kit- i Wakes (R. brevirostri s) are most common at the shelf— edge and outer domain, 29-3a*. 981 1025 while murres (Uria sp.,) and auklets are more plentiful over the middle do¬ main. Shearwaters (Puffinus sp. , mostly ?. tenuirostris) are most abundant in the inner domain. In general, the outer domain is dominated by surface fora¬ gers taking pelagic fish and invertebrates, the middle domain is dominated by alcids, and in the inner domain, birds dependent on epibenthic fish and euphausiids predominate. While there are major differences in bird populati¬ ons between domains, there are also differences in bird densities between fronts and interfrontal areas, due to occasional high concentrations of birds over fronts. Species composition of such aggregations vary, although murres and shear-waters are frequently conspicuous. SYMPOSIUM LEK BEHAVIOUR Convener: J.Kruijt (The Netherlands), co-convener: A.Lill (Australia) POSSIBLE SELECTION PRESSURES INVOLVED IN THE EVOLUTION OP LEK BEHAVIOUR A.Lill Psychology and Zoology Departments Monash University, Clayton Victoria, Australia , Most attempts to identify the likely selection pressures which influen¬ ced the initial stages of the evolution of display clustering in promiscuous male birds have been speculative, a posteriori adjuncts to investigations, often of high quality, but with different objectives. The recent modest trend towards the derivation and field testing of predictions about such selection pressures stemming from various theories of lek evolution should be continued and expanded. Any comprehensive theory of the evolution of display clustering must ex¬ plain the continuum of male spatial dispersions ranging from uniform fields to leks observed in promiscuous birds. A useful starting point is to consi¬ der the possible costs and benefits of male display clustering to both sexes, the -underlying premises involved and the main predictions which follow if these costs and benefits are real. This application of current sociobiologi" cal ideas and knowledge to the problem of the evolution of spacing in promis" ouous male birds should elucidate the kinds of data needed to understand that process. .To illustrate the approach, we can consider just one of the many example9 of possible costs and benefits of male clustering to both sexes which were examined. This was the idea that clustering involves a greater time and energy investment in inter-male aggression. The main premises underlying tlliS supposed cost of clustering to males are (I) that clustering increases the frequency and/or duration and/or intensity of inter-male aggressive inter¬ actions and (II) that the resultant greater time/energy expenditure on agS' ression reduces male fitness. Therefore if thi3 is a real cost for males,1*1® time/energy investment on aggression per male should increase with cluster size within species and should result in relatively lower courtship and/or self-maintenance investment levels. If unbalanced by sexual benefits of clustering, this should be reflected in decreasing mean male lifetime rep¬ roductive success with increasing cluster size. 1026 These predicted trends in aggression and courtship levels occur in Gol¬ den-headed manakins but do not always lead to reduced male mating success (Li 11, 1976). In bowerbirds, bower construction and maintenance are ex¬ pensive activities and bower destruction and decoration theft by neighbours ls common. the uniform dispersion of males may be adaptive in reducing these behaviours (Donaghey, 1981; Pruett-Jones and Pruett-Jones, 1982). The tooth¬ billed bowerbird which does not build a vulnerable bower is the only, or one of the few bowerbird species in which male display clustering probably oc¬ curs (D. Frith, pers. comm.). Although display clustering may often involve benefits for both sexes, it »ay sometimes evolve as a default phenomenon i.e. there are not necessarily any socially determined advantages for either sex, although there may be so¬ cially mediated costs. Thus males may be forced to cluster because females cluster to exploit heterogenous resources or males may cluster in a few, rest¬ ricted, predator-proof sites. Many of the predictions about possible costs and benefits of male display clustering which were developed are testable, but the relevant data remain to be gathered. The most fruitful testing ground for these predictions lies in intra-specific comparisons in promiscuous species with locally variable male dispersion patterns. SEXUAL SELECTION IN BIRD LEKS Robert B. Payne Museum of Zoology and Division of Biological Sciences, The University °f Michigan, Ann Arbor, Michigan 48109, USA The intensity of sexual selection in birds that display on leks is higher nn in monogamous species and than in most polygynous species where the tnale provides resources or a nesting site. A theoretical population genetics ®°bel of Wade and Arnold (1980) indicates the potential for sexual selection a Population as the variance in breeding success/ mean success . The model used to test whether the potential for sexual selection differed in spe- s with different mating systems. Especially in lekking species, a few mal © q Q account for most of the success, and most males have no success. The eaults showed the greatest relative variance in success, and thus the great- th Potentiab genetic sexual selection, in males of the lekking species, and e lowest in the monogamous species. ion The implied variation among bird species in the intensity of sexual select- generally parallels the observed evolutionary results of sexual selection mo S6XUa^ dimorphism in body size, male ornamentation, or both. Sexual di- 0f sm is greater on average in the lekking species in several families irds, though not in all. avioral mechanisms that underlie evolutionary sexual selection in- Veral ma'''e~maie competition and the choice of a mate by the female. In se- for ^eklting birds, female mate choice appears to be directly or indirectly ev„-,tile more aggressive males. Intrasexual competition may explain most solved * at lnstances of sexual selection in lekking birds. Alternative sexual iug egies auch, as noncourtship rape and sociosexual parasitism by deceiv- aPParently noncompetitive males generally are uncommon in birds. 1027 ECOLOGICAL DETERMINANTS OP ALTERNATIVE MATING STRATEGIES IN RUPPS (PHILOMACHUS PUGNAX) Johan G. van Rhijn Zoological Laboratory, University of Groningen, Box 14, 9750 AA Haren, the Netherlands Sex ratio of Ruffs in the Dutch breeding areas seems to be subject to considerable changes every season. In early spring, when females copulate, sex ratio is biased towards females; in late spring, when females nest, it is biased towards males. I concluded that females copulate on migration, which would be adaptive since conditions for male competition seem to be best in the south of the breeding area, whereas food conditions for chicks seem to be most favourable in the extreme north. This hypothesis implies a temporal and spatial segregation between copulation and egg fertilization (Van Rhijn, 1983). In the present paper the evolution of this presumed seg¬ regation is discussed. On the basis of the diversity of mating systems within the family Scolonacidae (Pitelka et al., 1974), and a number of other features like sexual size- dimorphism and sperm morphology (McFarlane, 1963;, females of ancestral species were supposed to lay two clutches of eggs, the first being incubated by their former mates, and the second by themselves. At present similar mating systems are known in Calidris alba (Parmelee, 1970) and C.temminckii (Hilden, 1975). In this presumed ancestral mating system females may be expected to exert two different kinds of choices for mates. For their first clutches they were supposed to prefer males with good parent¬ al qualities, for their second clutches males with good genes. Thus, females may select disruptively in the male population, which could be a cause in the evolution of role differentiation in male Ruffe (Hogan-Warburg, 1966; Van Rhijn, 1973). SEXUAL SELECTION AND MATE CHOICE IN BLACK GROUSE (TETRAO TETRIX L. ) J.P.Kruijt, G.J. de Vos, I.Bossema and O.Bruinsma Zoological Laboratory University of Groningen, P.O.Box 14, 9750 AA Haren (Gn), the Netherlands On leks or arenas, Black Grouse males can neither monopolize females, nor do they provide resourcea for them. Yet, mating is clearly non-random and ^ thus appears to be due to female choice. The main aspect of female preferer^ is that they mate much more often with males whose territories are dustere« on the center of the arena than with males defending marginal territorie Ultimate and proximate factors, underlying female choice, are discussed. With regard to ultimate factors, we argue that males whose territories are small, and clustered on the center of the arena, are in a better posit ion than marginal males, to exploit the heterogeneously distributed resour ces of very large home ranges, because they tend to synchronize activitieS and leave their territories outside periods of display. Furthermore, maleS in a cluster are usually several years old, and have to be in good physlC 1028 condition in order to face the severe competition between males for terri¬ tories on the center of the arena. These properties may reflect high quality of central males and, if heritable, females should be expected to choose a mating partner from the center rather than one of the marginal males. We showed experimentally that females were actually more attracted to a group of 6 stuffed males, than one of 3, which suggests that a cluster as such is attractive to females. However, other differences 'between clustered males must also be involved, because copulations are often very unequally divided over the males of a cluster. Copulation success is positively correlated with the time during which males have defended a territory on the arena. This suggests that suc¬ cessful males possess behavioural and/or morphological characteristics which are attractive to females. In this paper we draw attention to one possible behavioural factor: va¬ riability of rookooing, the vocalization of males which is produced almost continuously during display, especially when females are present on the arena. Rookooing consists of strings of phrases which may be produced for minutes on end. Each phrase of 2.5 to 3 sec. can be subdivided in an inflat¬ ion section during which the oesophagal pouch is filled with air, and a convulsive section during which the pouch is partially deflated and rein- elated in rapid succession. Convulsive sections are highly stereotyped(about •25 sec.), but the duration of inflation sections varies among males from ab°ut 1.1 to 1.4 sec. As a result, males with short inflation sections pro- °e a higher rate of rookooing phrases, which is further accentuated because anch males seldom interrupt rookooing when females are nearby. In two seas- oris> the male with the highest copulation success was also the male which Produced short inflation sections and high rates of rookooing phrases. Thus, although proof is lacking, females possibly discriminate between males on e basis of such differences in rookooing. functionally, this discriminat- ohr W0U''t* become understandable if differences between males in rate of se Production reflect heritable quality differences between males. symposium lijYRASPECIFTC V APT A IT OKS Convener: F.C. James (USA), co-convener: V.M.Loskot (USSR) TIJE GEOGRAPHY OP ALLELIC FREQUENCIES IN THE WESTERN pbYCATCHER (SMPIDONAX DIFFICILIS) K. Johnson, Jill A. Märten dseum of Vertebrate Zoology, University of California, Sorkeley , California, 94720, USA ■fcely leg. StQrch gel electrophoresis was used to survey genetic loci in approxima- 200 Western Flycatchers from 10 populations in the western United Sta- Phi* Tradibional biosystematic treatment had demonstrated significant geogra- Variation in the Empld ooax difficilis complex that approaches the species 1029 level. Of 39 scorable loci surveyed, 12 were polymorphic. Seven other sys¬ tems could not be scored. The data permit the calculation of genetic distan¬ ces and the construction of dendrograms which depict relationships among populations. The allelic frequency data for certain loci correlate closely with patterns of geographic variation in size, color, and structure of song syllables. Similar data for other loci appear to be geographically random. The new genic information will be integrated with a previously proposed hypothesis on the mode of sibling spéciation in Ehipidonax flycatchers. TRANSPLANT EXPERIMENTS AND MORPHOLOGICAL VARIATION IN BLACKBIRDS (ICTBRIDAE) Prances C. James Department of Biological Science, Florida State University, Tallahassee, Florida, 32306, USA Many species of birds breeding in the eastern and central United States have the same pattern of intraapecif ic size variation. Body size is smallest in the warm humid southeast. Larger birds occur northward and westward where the climate is cooler and/or drier. In the Red-winged Blackbird (Agelaius phoenlceus) there is also allometric bill shape variation. The extremes are the small slender-billed population in southeastern Florida and the large conical-billed population in central Colorado. We transplanted eggs during incubation between nests in northern and southern Florida and the phenotypic development of these nestlings was modified toward that of the foster populat¬ ion. In a second experiment eggs were transplanted from Colorado to Minnesota. The extent of the nongenetic component of intraspecific morphological variat¬ ion in birds will be discussed. TEMPORAL AND GEOGRAPHIC CHANGES IN THE BREEDING RANGE OF THE BLUE MORPH OF ANS ER CAERULESCENS F. Graham Cooch Canadian Wildlife Service, Ottawa, Ontario, K1A 0E7, Canada Cooch (1962) traced the expansion of the blue morph of Anser caerulescens from 1929 to 1961 and made predictions as to the continued expansion of this morph. In the 20 years since then the numbers of A.c. caerulescens have doub¬ led. Most of the increase has occurred in Hudson Bay, Canada, south of 64°N* latitude. Although the blue morph is spreading westward as predicted, the rate of increase in the proportion of blue morphs in colonies where it was previously established has slowed or reversed. A hypothesis has been devel°" ped to explain these changes. 1030 MORPHISM AHR HYBRIDIZATION OP WHEATEARS OEHAHTHB HISPAHICA AHD OE. PLESCHAMA Vladimir Loskot Zoological Institute of the USSR Academy of Sciences, Leningrad, USSR Field studies conducted in 1965-1979 and the study of collections (over 900 specimens) resulted in new data on intraspecific variability of Oenanthe Si3£anica and Oe^leschanka. A combination of discrete colour characters of Plumage allowed discrimination of local populations and groups of populati¬ ons with distinct proportions of morphs. A hybridization zone of these wheatears was the subject of a special study. Contraiy to Northern Iran where purapatric hybridization was described (Haffer, 1 977) ,. situation in Trans¬ caucasia and Mangyshlak Peninsula is an example of sympatric hybridization (or zone overlap and hybridization). No data were found supporting either the role of the Mangyshlak population in maintaining the proportion of white- throated morph over the remaining area of Oe. pleschanka or a gradual reduc¬ tion of the frequency of this moiph outside Mangyshlak Peninsula (Panov, vanitzky, 1975). No evidence was obtained of any significant westward gene low from a narrow hybridization zone into the area of Oe. hispanica. Hence e leading role of hybridization in the origin of morphism in these species wheatears (Haffer, 1977) is not supported. A hypothesis of ancestral Oe. -i5£anioa being primarily polymorphic in plumage coloration and origin of Qgj-jjleschanka from a most pigmentated eastern form of this ancestral species aeems more plausible. GEOGRAPHICAL VARIATION IN SOME AMASON FOREST BIRDS Jürgen Haffer, John W. Fitzpatrick Tommesweg 60, 4300 Essen-1 , FRG* Field Museum Natural History, Chicago, Illinois, 60605, USA Geographical variation in several widespread and common species of Amazon f°rest birds is studied through computer analyses of various mensural and °°lor characters. The resulting contour maps for individual characters and' f°r character complexes illustrate regional gradients in geographical cha¬ racter variation within Amazonia. In some cases these patterns permit mean- l£ful application of the taxonomic subspecies concept. Broad rivers are riers to dispersal for species inhabiting the forest interior. These bar- to gene flow introduce steps or breaks in -the regional gradients of Se°graphically variable characters. The extent of these breaks varies con- th 6ral3'^ between species. The breaks disappear in the headwater regions of e Amazon tribultaties, where rivers are smaller and channel meandering ^Wnits easy gene flow across them. The results are interpreted in light of ei,ent ecological habits of species studied, differing ecological condit¬ io^ two across Amazonia, and the changes in vegetation cover during the last Willi on years. 1031 SYMPOSIUM LOSS OF AVIAN HABITAT Convener: R. A. McCabe (USA), co-convener: I. Ahlen (Sweden) LOSS OP OPEN PEATLAND AND SOME OTHER OPEN HABITATS IN SWEDEN AND THE EFFECT ON THE BIRD FAUNA U.Bostrëm, I, Ahlén Department of Wildlife Ecology, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden Draining of wetlands has taken place in Sweden since the 19th century. Until 1970 about 1 million, out of a total area of 7 million, hectares of peatland have been drained for different purposes. During the last decade the demands for wetland drainage has increased rapidly. It has been proposed that more than T5% of the peatlands in South and Central Sweden and in the coastal parts of North Sweden should be drained for forestry or fuel peat production. The effects on the bird fauna of these activities have often shown to be drastic. Peatlands which are wet and treeless lose most of the waterfowls and wader-species within a year after draining. Twenty years later all the original species have been found to be replaced by other species on fertile peatlands. On less productive sites the process is slower. The den¬ sity of wetland birds varies markedly between different areas according to many different habitat factors. The major part of all wetland birds is found on a limited proportion of the peatland area. This emphasizes the urgent need of a conservation programme. Other open habitats such as heathland, shrubland and wetland pastures are also lost as important avian habitats due to afforestation, cultivation and free successional growth, with effects on various groups of birds as a consequence. EFFECTS OF HABITAT FRAGMENTATION ON SOUTH FINNISH FOREST BIRDS Yrjö Hai la Department of Zoology, University of Helsinki, P. Rautatiekatu 13, SF-00100 Helsinki 10, Finland Formerly continuous forest habitats have been increasingly fragmented owing to human economic activities during the past decades. In this paper quantitative data, mainly based on extensive censuses of land birds on the Aland Islands (60°N, 20°E) in 1926-27 and in 1975-80, are used to specify aI,d quantify effects of fragmentation on forest bird populations. Two major topics will be addressed: 1. Edge effect increases the numbers of a large and heterogeneous group of forest passerines that are favoured by bushes and saplings in the forest- increasing fragmentation has a negative effect on species demanding large 0Ild continuous forest tracts. Several nonpasserinea belong to this group. 2. Studies of insular habitats indicate minimum area requirements of di*' ferent species. Prevalence functions based on census data are an effectif method for this purpose; these functions express relative densities in are00 1032 Of different size and show whether the area of a habitat fragment has an ef¬ fect on densities or not. The significance of forest fragmentation as a cause of population decrease will be discussed. The importance of quantitative data for identifying ecolo¬ gical factors leading to declines of bird populations is stressed. HABITAT CHANGES IN BRITISH SCRUBLANDS AND THEIR INFLUENCE OF BREEDING BIRD COMMUNITIES Robert J. Fuller British Trust for Ornithology, Beech Grove, Tring, Hertfordshire, UK In Britain, scrub is a localised type of vegetation yet many species of rds depend 011 it as a breeding habitat. Not only is the habitat an ephe- meral one, as a serai stage in various successions, but also it is frequently controlled or totally destroyed in order to improve grazing lands and to rec¬ laim land for a wide range of developments. The aim of this paper will be as follows: 1* To illustrate for several types of scrub the rate of change of bird species composition and specificity of species to stages of the scrub succession. 2. To outline the impact of scrub removal on bird communities from various quantitative case studies. 3. To predict the ornithological impact of selective srub removal. f The paper will be based on a wide set of quantitative data drawn from the d 6S of the British Trust for Ornithology's Common Birds Census and from a e ailed study of the dynamics of scrub bird communities on the chalk es- s-hpment of the Chiltem Hills, England. THE DECLINE OF MEADOW-BIRDS IN THE AGRICULTURAL land in Holland Albert J. Beintema Research Institute for Nature Management, the Netherlands . tfle Netherlands, densely populated for centuries, practically all lana are man_raade• Thus, agricultural activities in the typical polder- S have created ideal conditions for 'meadow-birds'. In the low, moist aids some wader species breed in numbers not known elsewhere. As a ty¬ pical atnaii lhi£ example, about 80% of all Europe's Blacktailed Godwits breed in this country. Water shown SUffj 5 s situation is now gradually destroyed again, by means of lowering of tables, and intensifying of dairy farming in all its facets. It can be 1 Vl _ a mathematical model that a reduction of hatching success alone is ^Cient to explain the present decline. The model, which has been tested by sPecies, works with daily survival rates of nests, basically determined tinr eda^don' but heavily modified by cattle densities, grazing periods, and ail ^ and frequency of mechanical management, such as mowing. The model PoPui -0r rela*inS after nestloss within certain limits, depending on the in dynamics of the species. Thus, it can be shown that species differ r vulnerability towards agricultural pressure. Vulnerability increases 1033 in the order: Oystercatcher, Lapwing, Godwit, Redshank, Ruff. The first 13 still increasing, benefited by increased biological production, the last has already practically disappeared from this country, apart from nature reserves. When in a certain area the management is known in detail, the model can predict which species will be able to maintain their populations. Finally, the model predicts that when the ultimate agricultural intensity, as propa¬ gated by official bodies, will be reached nationwide, there will be no meadow— bird habitat left in the Netherlands, outside reserves. THE LOSS OF A LARGE COLONY OF YELLOW HEADED BLACKBIRDS (XANTHOCEPHALUS XANTHOCEPHALUS) FROM SOUTHERN WISCONSIN Robert A. McCabe Dept. Wildlife Ecology, University of Wisconsin, Madison, WI, USA The yellow headed blackbird is a marsh nesting species that builds its nests in vegetation primarily cattail (Typha latlfolia). Such marshes were scattered throughout this state but agriculture, urbanization, landfills and other forms of development have caused such wetlands to disappear. Bet¬ ween 1947 and 1951 a yellow headed blackbird colony was studied on a wetland 15 miles north of Madison, Wisconsin. During that period (5 years) 243 nests were located; those nests produced 444 fledglings with a nest success overall of 71%. Only about 2/3 of the entire wetland was in the study block. The es¬ timated population in this block in 1948 was 400 birds including a small nonbreeding cohort. This area of wetland including a shallow lake had gone dry several times in recorded history. On this basis the owner was able to take legal action to drain the entire area. In spite of detailed testimony on its value as a wetland the court upheld the owner and he drained the marsh. In 3 years after drainage 99% of the marsh land birds disappeared including the yellow headed blackbird colony. Also lost were populations of coot (Fulica ameri- çana) , Florida gallinule (Gallinula chloropus) , black tern (Chlldonias nlger)< ruddy duck (Oxyura .lamaicensis) , red-winged blackbird (Agelaius phoeiceus) and long billed marsh wren (Cistothorus palustris) and numberous other birds and mammals including a thriving population of muskrats (Ondrata zibethicus)» RAPTOR POPULATIONS DECIMATED BY FARMING IN SEMI ARID KALAHARI Richard Liversidge McGregor Museum, Kimberley, South Africa Strip counts along dry "riverine" habitat in the southern Kalahari in¬ dicates that the raptor population is drastically reduced where no protect¬ ion is afforded. Farming activities prompted by traditional anti-raptor sentiment with consequent shooting of raptors and deterioration of the habitat due to ex¬ tensive stock farming have resulted ins h) reduction of the commonest vulture to more than one- tenth normal numbers; 1034 b) reduction of eagle population from one tenth to nearly 1/200 normal levels; reduction of the commonest 'hawk to one third of normal numbers; d) no reduction in the smallest shrike-sized hawk. habitat loss and its role in the decline op the PUERTO RICAN PARROT (AMAZONA VITTATA) James W. Wiley « U.S. Pish, Wildlife Service, USA Smce 1968 we have been measuring habitat needs of the endangered Puerto p °an Parro*«ïn this research we have traced the history of habitat loss in uerto Rico through the substantial records maintained by individuals and the s and agencies (primarily Commonwealth and Spanish agriculture departments the U.S. Forest Service) and by interviewing "old-timers" familiar with e parrot and its former status. Major causes of habitat loss have been ebtifie(j as have their relationship to the parrot's decline. In the Luquillo Forest habitat utilization by the remnant parrot populat- °n has been extensively investigated. The- forest has been sampled for avaiiabiilty of nesting sites: 1216 trees- in 27-3 ha of the Luquillo Forest e climbed to determine presence and suitability of cavities for parrot th S* revealed that there were very few adequate sites available. Fur- r Investigations have revealed several management (e.g. timber stand im¬ provement) policies and selective cutting of potential and actual nest trees for parrot chicks or honey) that substantially reduced available nest¬ ing habitat. symposium ^SILORIGTN awn OP COOPERATIVE teDINC TTO TtTPriQ Convener: R.P. Baida, USA pQ^0Dperative breeding refers to situations where adult birds regularly take in helping to rear offsprings which are not their own. Helping behavior occurs -iv, Va 0Ver 200 species of birds, which inhabit ecological conditions 0ll 1118 fr°m forests through savannahs to desert. Helping thus poses questi- for ecdogists concerned with the role of the environment in shaping p6Qi_ features of avian social organizations. Cooperative behavior also ap- to contradict the theory of natural selection, since helpers behave in r6cl . at Incurs a cost to themselves while providing a benefit to the c6llPieata (the breeders). Coqperatively' breeding species thus provide ex- W.6at Samples for testing various sociobiologioal hypotheses for the evo- j°n of "altruism". be thla symposium, five very different examples of helping behavior will aimii&inlned in detail- The comparative approach will serve to clarify the m^Hes, and the differences, in the selective forces that have deter- °°Perative breeding strategies. 1035 GROWTH OP TERRITORIES IN THE FLORIDA SCRUB JAY Glen E. Woolf enden, John W. Fitzpatrick Department of Biology, University of South Florida, Tampa, Florida, USA; Field Museum of Natural History, Chicago, Illinois, USA The Florida Scrub Jay (Aphelocoma c. coerulescens) is a cooperative breeder in which many pairs receive assistance from non-breeding helpers, and pairs with helpers raise more young. Preliminary analysis showed that territory size and family size are positively correlated (Woolfenden and Fi tzpatrick, 1 978) . A positive correlation does not demonstrate a causal re¬ lationship; howerver, because large territories could harbor individuals or resources capable of producing more young than do smaller territories. A critical test for our territorial hypothesis is to measure territory size within families that have varied in size over several years. We now have 25 families that meet these criteria, and 22 of the 25 (88%) showed territorial growth between family sizes of 2 and 3, and 17 of 23 (74%) between family sizes of 3 and 4. The possibility exists that territories simply have increas¬ ed in size from one year to the next because of stability of the pair, and that additions to the family are coincidental. Testing it we compared changes in territory size between consecutive seasons within families whose size and breeding pair remained unchanged. Of 43 such cases, 19 showed slight increase, 17 slight decrease, and 7 no appreciable change in territory size. Territorial budding, in which a helper becomes a breeder in a segment of its natal territory, is an opportunity restricted to males. Because it seems that male helpers can gain more from territorial growth than female helpers, we examined territorial growth and sex of helpers. For pairs with only one, older helper territory 3ize was significantly larger if the helper was a male (mean = 11.5, n = 14) than if a female (mean = 7.9, n = 11). These data strengthen the hypothesis that Florida Scrub Jay helpers gain directly from helping breeders raise more young. COOPERATIVE BREEDING IN THE MEXICAN JAY Jerram L. Brown Department of Biological Sciences, State University of New York Albany, New York, USA Social organization in the Mexican Jay (Aphelocoma ultramarina) was studied in 1958 and 1969-82. Social units of 5-25 Jays defend group territories in pine-oak woodland from Arizona and Texas south through central Mexico. One to four pairs breed separately within each territory (plural breeding). Nestling8 are fed communally by parents and non-breeding helpers, which may constitute 50% of a unit. Fledglings are fed communally by all parents "reciprocally"* Within units jays compete for food in winter, and their relationships can be expressed as a linear dominance hierarchy with few reversals. When breeding» pairs in a unit rob each other' s nest lining and eggs. Mutual benefit from sharing tasks augmented by indirect fitness due to close relatedness, help3 to maintain the social system. 1036 PINON JAY FLOCKS AND PATCHY PINON PINES Russell P. Baida Department of Biological Sciences, Northern Arizona University Flagstaff, Arizona, USA Pinon Jays (Gymnorhinus cyanocephalus) live year-round in large (70-150 birds) tightly knit flocks. Flocks are composed mainly of extended family hhits. The timing of most events in the yearly cycle is set by the size of the Pinon Pine cone crop of the previous fall. The high energy pine seeds serve as the major food in the winter and spring. Seeds are retrieved from subterranean caches made on a communal area. Pairs breed in colonies where mutual ne3t .defense and helping behavior occurs.' During October and November some yearlings switch flocks. Those that remain in their home flock have se¬ veral options open to them during the breeding season. (1) Most yearlings Porm pair bonds and court but do not oest. (2) Some yearling females nest with older males. (3) Some yearling males help raise their siblings. (4) Some Psirs nest wilh varying degrees of success (5) Some Yearling males ne3t with older females. The relative merits of each of these options will be discussed with an emphasis on those young males that help. the adaptive significance of cooperative breeding in the pied kingfisher (ceryle RUDIS) Heinz-Ulrich Reyer Max-Planck-Institut fuer Verhaltensphysiologie D-8131 Seewiesen, FRG Pied Kingfishers in breeding colonies can adopt a number of different strategies. They can be helpers or breeders (1); as helpers they can raise siblings or strangers (2); and as breeders they can accept or reject helpers (3). 1. The decision whether to breed or to help depends mainly on the avail¬ ability of females since the sex ratio is 1.8 males: 1 female. 2« The helpers prefer, to feed close kin ("primaiy helpers") but if none are around they try to feed the young of non-relatives ("secondary helpers"). Primary helpers tend to invest more, and consequently have a lower survival ra'te, than secondary helpers, who frequently breed in the same place they ^elped the year before, sometimes with the female they helped. 3. If the breeders' time and energy are sufficient to rear most of their y°bhg alone, they tend to reject potential secondary helpers. If not, they wiH accept them. This can be shown by comparing birds living under different 6°°logical conditions and by manipulating clutch sizes and food supply. Primary helpers are tolerated under all conditions. The adaptive significance of the helpers' and breeders' behavior will be discussed by comparing the inclusive fitness of birds following these dif- Perent strategies. 1037 COOPERATIVE COURTSHIP: ANOTHER TYPE OP HELPING BEHAVIOR Mercedes S. Poster Museum Seet+*t>. U.S. Pish and Wildlife Service National Museum of Natural History, Washington, D.C. , USA Cooperative courtship behavior haa beeD reported for at least six species °L^S\.th0Ugh preliminarV evidence indicates that it probably occurs in 77 77’ 83 Wel1* SUCh b6haVi0r genera11^ ^e performance11 of advertising vocalizations and precopulatoxy displays, and the defense of the copulating pair from rivals. In all instances so far reported, the hel- 717 7ea f ^ek-breedln« 8Peoies- For several, reasons, social systems in which the pair bond is short and courting males are closely spaced are preadapted for this type of behavior. Its evolution, however, will depend upon associated increases in fitnesses of the individuals involved. Possible benefits «owing to thn donor of the help are an increase in inclusive fit- ness through kin selection, increase in his own probability of mating, in¬ creased probability of inheriting the mating site, and improvement of sub¬ sequent reproductive performance through leading. Benefits to a recipient of the help may include attraction of greater numbers of females, increased copulatory success, and in some instances, a decrease in disruption of copulation. SYMPOSIUM HOLE-NESTING BIRDS Convener: C.M. Perrins (UK), co-convener: H. Löhrl (PRG) DIMENSIONS OP NEST-HOLES OCCUPIED BY GREAT TITS AND EVALUATION OP THEIR FUNCTIONAL SIGNIFICANCE H. Löhrl* Bei den Eichen 5, D-7271 Egenhausen, PRG thelel silil 73 nS8tS in S V6ly Wide of holes. Never- heless, significant preferences (particular hole depth, wide internal dimeter) are shown to exist. The preferences were examined by putting up pairs of boxes of different dimensions, close together and examining the wit“:7 WTh eSCh tyPS °f b°X WaS °°CUpled* Presented with boxes Z 7 11*5’ U-° ^ 20*° «• Great tits preferred ones 7 b -7 preferred deep (H cm: 19 cm) boxes to shallow ones and built deeper nests in the deep boxes. It is thought that the birds 7ub7° h Ulati°n *r°m thS d6ePer aeSt Whlch — them energy during ncuba ion. However, they also need to keep their nest at a considfrable dis- IZZlT 7 neSt entran°e if thSy Sre t0 be *«*ond the reach of predators, especially those such as the Marten (Martes martes) which may reach in and Sk buildi°7th bhetnSSt 18 t0° 01036 t0 the entran0e* Hence a bird caM10t risk building the best size of nest (for , . cavity is too small. incubation purposes) if the nest The Great Tit shows little preference for the size of nest entrance (provided the hole is reasonably small), offered choices of holes of 30, 32 1038 811(1 38 mm. diameter, the Great Tit showed no significant preference for any °ne of them. This was not the case for the smaller species all of which when offered the choice between holes of 32 and 26 mm. diameter, showed strong Preference for the latter. This again may be related to predation since very few predators can get through a hole of 26 mm. ' diameter; even the Weasel Mustelw nivaliB is usually excluded. The Weasel can however, easily get trough a hole of 30 mm. diameter. This is the smallest hole through which a Great Tit can easily get. Hence there is little advantage to the Great Tit ln choosing nest-sites with small holes since the Weasel, which can be a 8erious predator, can get through any hole that the Tit can. The smaller species may, in addition, get some advantage from the use of sites with small entrances in that the Great Tit is excluded; at times it may be a consider- able nuisance to them if it can enter their nest. Hence presumably the smal- ler species can reduce the risk of competition with the Great Tit by choosing the smaller holes when they are available. Some hole-nesting species such as the Pied Flycatcher, Ficedula hypoleuca. defend a very small area around the nest-site rather than a "normal" ter¬ ritory. The Great Tit however, defends a normal territory, often of about °* 5-1.0 ha. With a very high production of young, there seem to be, at least ih some years in some areas, a number of birds which are unable to obtain su°h a territory. Reproductive success of the great tit parus major IN RELATION TO ITS TERRITORIAL STATUS André A.Dhondt department Biologie, Universitaire Instelling, Antwerpen, B-2610 Wilrijk, Belgium Ihe Great Tit is a territorial species, although in some years pairs are observed that breed without having defended a territory around the breeding ho:Le* Some of these 'intruders' defend a territory adjacent to the study p!ot where no nestboxes are available, and are called territorial intruders. °thers have not been observed to defend a territory anywhere, and typically Ulld their nest very rapidly. These are called real intruders. I will argue *hat these birds are floaters that attempt to breed after the territorial rRs have started. 1980 was a year with numerous intruders. In a study plot 11 ta in a wood near Antwerpen 46 first clutches were found; 27 delonged q° birds territorial on the study plot, 7 to territorial intruders, and the ^er 12 to real intruders. AH intruders were yearlings. Territorial intruders laid later than ter- rit°rial birds, but were equally succesfull. Real intruders were less suc- ^efuU than both other groups, and I will discuss what factors- inf luenced reproductive success. Owing to the large number of intruders it was possible to analyse the "fect intruders have on the reproductive success of the host pair. Territo- lal birds with intruders lay a smallfer clutch, have a lower nesting success ^ hence fledge fewer young compared to birds without intruders. Some ®°ns herefore will be suggested. ltJtPiüally I will discuss why Great Tits should defend a territory, taking a°counf data from years without intruders. IO39 REPRODUCTIVE STRATEGIES OP TITS IN MEDITERRANEAN CONTINENTAL AND INSULAR HABITATS J.Blondell, P.Isenmann 24, Chemin de Truchet, P-13200 Arles, Prance On the mainland there are live species of Parus Blue Tit, Great Tit, Coal Tit, Marsh Tit, f. palustris, and Crested Tit, P.cri status. The last two of these nest at the lowest densities and are absent from Corsica. Corsica has 14.7 pairs of Blue Tits per 10 ha. as opposed to 4.7 on the mainland. It may be that one of the explanations for the higher densities on the island is that there is a lowered' inter - specific competition (a number of insectivorous species are absent),. but that, as a result intra¬ specific competition may be more intense. The average date of 1st egg on Corsica is 2-3 weeks later than on the mainland ( 1 3 May and 25 April) and the clutch size is also much lower (6.0 eggs and 8.8 eggs). Breeding success is also poorer, on average 20 pairs in the mainland raise 130 young compared with 56 raised by the same number of pairs on Corsica. Such .variation is compensated for by the fact that adult birds live longer on Corsica; 60% of the breeding birds are older than one year old compared with only 36% on the mainland. Differences of the same order of magnitude were also found for the Great Tit and the Coal Tit. SYMPOSIUM SPECIATION AND EVOLUTION OP SOCIAL BIRDS Convener: L.L. Short (USA), co-convener: J.F.M.Home (Kenya) DUETTING, SOCIALITY AND SPECIATION, WITH REFERENCE TO BARBETS (CAPITONIDAE) Lester L. Short, Jennifer P.M. Home Ornithology Dept., American Museum of Natural Histoiy, New York, New York '10024, USA Research Associate, National Museums of Kenya, P.0. Box 24622, Karen, Nairobi, Kenya The studies have focused on the patterns of sociality and group-or pair- duetting in the hole-nesting and roosting African Capitonidae, particularly the genera Trachyphonus and Lybius. These are sedentary species defending territories in pairs or groups year-round in areas where the breeding season is unpredictable. Intricate polyphonic duets with fitted sets of duet songs by the partners in Trachyphonus are correlated with patterns of morphological geographic variation, and with sympatry and allopathy of duetting relatives- Antiphonally duetting species of Lybius show duets to be most different where there is sympathy, and broad sympatry occurs mainly between precisely duetting species and species that either do not duet or have simple simultaneous duet "songs" or calls. Fpur- teen of 36 African barbets duet; duettera are largely allopatric and seem t° differentiate more strongly and perhaps more rapidly speciate than do non- duetters. Duettera are more social, with some cooperative breeding, than are some non-duetting barbets (e.g. Pogoniulus). but less so than o-fher non-duet- ters such as Gymnobucco sp. , lybius melanoptam«. and others. A problem exi^e 1040 m how different the duet roles may be to preclude interbreeding of duetters. Duetters often have "helpers", which are usually prevented from participating in the duet of the primary pair. At least in Iybius leucocephalus and probab- ^ in Trachyphonus damaudii there can be differences in details of duets among conspecific populations, whereas major differences in timing and struc¬ ture of duets (e.g. between Trachyphonus erythrocephalus and T. damaudii .and between Lybius torquatus and L. rubrifacies) seem required for sympatry and the culmination of spéciation. allospeciation and social evolution IN MEROPS (MEROPIDAE) WITH A SYNOPSIS OF CORACIIFORMES Q.P. Crick, C.H.Fry Aberdeen University, Zoology Department, Tillydrone Avenue, Aberdeen AB9 2TN, Scotland, UK Merops bullockl and M. bullockoides comprise a classic superspecies, with its two allospecies nearly in contact in the Albertine Rift. Each has been studied demographically ; they breed colonially and co-operatively, and there are some minor differences in their social Organizations (Nigeria cf. Kenya). These differences are explored but cannot yet be related with any ecological dissimilarities. Natural selection is discussed in relation to body size, sex hatio and survival. Other Merops species which have been investigated range in social orga- hization from solitary, monogamous forms without helpers (M.pusillus, M. ^2®hmi) through more or less densety aggregated forms with a low (M.apiaster. Mfhubicus) or high incidence of helpers (M. bullocki supersp., M. oraatus) . i° the loosely colonial M. albicollis with up to six helpers at all nests. °uch a spectrum in a genus which is otherwise rather uniform both etho- ec°l°Sioally and morphologically ought to disclose character correlates and hence indicate evolutionary causation. The most promising indication seems to he survival curve shape; but these birds are long-lived, so that demonst- rating a relation between helping behaviour and survivorship will necessitate manY years further study. ^he genus, with 50 taxa in 18 species (3 superspecies and several species- 619 ups are readily identifiable), well exemplifies the process of allospe- Cj-ation. Its evolution into temperate latitudes has probably promoted sexual dimorphism of plumage but not affected mating systems. In other respects al- °sPeciation within Merops does not differ identifiably from that of les s°cial species. 3S3 SPECIATION AND EVOLUTION OF BEHAVIOR IN WEAVERBIRDS (PLOCEIDAE) N*E.Collias Department of Biology, University of California, Dos Angeles, California, USA 1 Three populations of Ploceus cucullatus. representing different subspecies U West. Central and South Africa, differed in degree of polygyny and numbers Uests woven by the males, depending on whether or not the male fed the estUngs. There were also differences in protective behavior related to ^dation pressure. In this species, the male weaves the nest and displays it 30 3aK. 98, -lOqq to unmated females, who select a mate. Color differences between males of different species are associated with differences in the nest-displays and details of habitat. Young males, who are ignored by the females, spend much of their first two years in the practice of nest-building. There are many more species of true weavers (Ploceinae) .with marked sex dichromatism, than there are species in other subfamilies of Ploceidae which often lack sex dichromatism, suggesting that a greater intensity of sexual selection in the Ploceinae may have led to a higher degree of spéciation. . In the Plocepasserinae, Plocepasser mahali, which finds all its food in a small group territory, has small colonies, while Pseudonigrita amaudi often has larger colonies which share extensive feeding grounds. Multiple factors, operating together, have probably led to the evolution of the huge, compound and communal nest characteristic of Philetairus soclus. THE CORRELATION OP AND POSSIBLE RELATIONSHIP BETWEEN ■DEGRES OP SOCIALITY AND SPECIATION IN NEW WORLD JAYS John William Hardy,- Ralph J. Raitt Florida State Museum, University of Florida, Gainesville, Department of Biology, New Mexico State University, Las Cruces, USA It now seems likely, based on much new but still incomplete information, that a great majority of New World jays, especially Neotropical ones, are to varying degrees communally social breeders. Of the 19 species of the Ornate Line (Cyanocorax, Calocitta, and Cyanocitta) there is some evidence that 12 of these are communal at least in part of their range. Both species of Cyano¬ citta are considered non-communal. Cyanocorax yncas is communal in parts of South America, at least, but apparently non-communal 'in Middle and North America, For 6 species, all South America Cyanocorax. there are no satis¬ factory data. In the Inornate Line (Cyanolyca, Aphelocoma, Gymnorhinus) , the 12 species include 5 that are communal breeders, one (A. coerulescens) seem¬ ingly being so only in Florida (USA), Of the 8 species of Cyanolyca 6 are es¬ sentially unknown in their breeding biology. C. nana is non-communal, breed¬ ing in pairs. C. viridicyana is communal at least at one locality in Peru. The recognized subspecies of various species suggest a slow evolutionary rate. But when one regards the various species now recognized as allopatric forms of a few mega- and superspecies, it can be seen that rapid evolution has occurred, resulting in many distinctive but clearly closed related spe¬ cies of distinctive phenotype. Clannishness and sedentary habit associated with communal breeding probably contribute strongly to this effect. Evidence will be presented from studies of the San Bias jay, Cyanocorax aanblaslanug* THE SIGNIFICANCE OF IMPRINTING AND TRADITION IN THE EVOLUTION OF BIRDS Jurgen Nicolai Institut für Vogelforschung, "Vogelwarte Helgoland", 2940 Wilhelmshaven 15, FRG Hand-reared European Bullfinches, isolated from conspecifics for the fir®* 6 months of life, can be trained to whistle short folk songs (up to 80 note® 1042 result of sexual imprinting to the human keeper. Females, reared under entical conditions, show sexual excitement and copulation responses if he particular folk song is whistled to them after they have reached sexual gica^ T’ 111 the SenSitiVS period of ^venile life, not only morpholo- ons ' 7 the 8PeCieS (°r f08ter 3Pe°ies) but also lts *ocali«ti- bTh and have a crucial influence on the later sexual preferences. Birder/1"?1" lmprinting Presses, the males of the African Widow Exp . ~;Ul^ae) mlndc the son«3 “«* calls of their particular host species. tur WhlCh y0Ung widow birds were reared by another (than the na-I al, host species have shown, that the young males adopt the vocalizations * the experimental host and that the females prefer males which sing this erent type of song. This preprogrammed behaviour has resulted in a paral¬ lel evolution of hosts and parasites. Early stages of this historical development are reflected ih the adaptat— n of the Paradise Widow Bird (Steganura paradisaea) to the subspecies for- lon of lts host, the Melba Finch (Pytilia melbal. EVOLUTION of group life with special reference to the ARABIAN BABBLER (TURDOIDES SOUAMICEPS) Amotz Zahavi Institute for Nature Conservation Research, Tel-Aviv University , George S. Wise Faculty of Life Sciences, Israel j Babblers are group territory birds. Groups number 2-15 individuals. Usual- neat116 PaiP breeds 811(5 the rest of tbe group, young and adults, help at the t ” Soraetimes up to 3 males and 3 females share in reproduction. Staying the- 6 Sr°Up is the beat °Ptio11 for non-breeders to survive and wait for tbenjr tUrn t0 breed- Tlle breeders benefit from the large group which help ti m to defend the territory. Group life select for apparent altruistic ac- rif1 leS SUCh aS allofeeding> sentinel activity, common defence of the ter- as 0ry and the help at the nest. Individuals compete with one another to act altruists. Dominants tend to interfer especially with the altruistic ac- a les °T individuals, which follow them in the dominance hierarchy, but a tolerant tQ altruiain of lower members in the hierarchy. Neither kin -LOtl nor any form of reciprocal altruism may explain the social adap- °ns of babblers. The argument that e helper benefits by increasing the ^ J- ane group, on which its future breeding success is dependant, is tta^argumenb based on group selection. The apparent altruistic adaptations be interpreted as an investment in the quality of the altruist, ana ° be:r seb °f social adaptations includes contact behavior allopreening too Pe°uliar morning dance. It is suggested that the bond among group “embers ~ f0 strengthened indirectly from these activities by providing in- on rather than directly from the activities themselves. It will be the tllat 5:116 Problems of group life are not qualitatively different from Problems involved in the evolution of all other social adaptations. 1043 Symposium STRUCTURE OF FEATHERS' Convener: J.Ijyck (Denmark), co-convener: P. Stettesheim (USA) MOLECULAR MORPHOLOGY OP FEATHERS: AN EXPERIMENTAL APPROACH Alan H. Brush University of Connecticut, Storrs, Connecticut, 06268, USA Understanding the molecular organization of morphologically diverse struc¬ tures presents one of the most challenging aspects of contemporain comparat¬ ive and analytical biology. We have undertaken investigations of the molecular structure and supramolecular organization of avian epidermal U -) keratin structures (feathers, down, scale, claw and beak). All structures consist of fibers organized from filamets constructed from a closely related family of proteins. A minimum of structural differences occur among the gC -polypeptides. Yet there are vast morphological and functional differences at the phenotypic level. Our work has encompossed the biochemical basis of polypeptide hetero¬ geneity and the process (in vivo and in vitro) of filament formation. Protein production involves a set of repetitive instructions. Fabrication of filamets is an epigenetic process based on physical recognition and precise interac¬ tions of polypeptides. This information can illustrate constraints of design, and the relation¬ ships of supramolecular organization to the structure and function of the features involved. In an evolutionary sense, the major structures probably arose rapidly and perhaps included the "invention" of a unique set of prot¬ eins. Parallel changes in the genetic programming produced morphological variation with little change in the structural genes. Overall constraints on shape and functional limitations are a result of the nature of the molecules and the ways in which they can interact. IMPLICATIONS OF STRUCTURAL DIFFERENCES AMONG DIFFERENTLY COLORED FEATHERS Edward H. Burtt, Jr. Department of Zoology, Ohio Wesleyan University, Delaware, Ohio 43015, USA Anecdotal evidence (Averill, Condor 25: 57-59, 1923; Barrowclough and Sibley, Auk 97: 881-883, 1980) and recent experimental evidence (Burtt, The behavioral significance of color, Garland STPM Press, 1979) show that melanic feathers are significantly less abraded by airborne particles than non-mela' nie feathers whereas abrasion-resistance is unaffected by moderate concent¬ rations of carotenoids. In addition to destruction of feathers by particular abrasion, feathers are scraped and abraded when they rub against one another or against other objects (e.g. , bark, stones, leaf litter). Is resistance to scraping across a rough, unyielding surface different from resistance to col' lision with airborne particles? What of repeated bending? Feathers at the joints and in the wings and tail are subject to frequent flexing. Is resü' iance correlated with the presence or absence of certain biochromes? How does the microstructure of differently colored feathers affect resistance t0 1044 the mechanical stresses outlined above? How is the microstructure affected ty these same mechanical stresses? These questions are addressed by a com¬ bination of electron microscopy and stress analysis developed by mechanical ngmeers. The results are discussed in light of the pattern of color of wood warblers (Parulidae). feather structure and maintenance in relation to bathing, swimming, and diving Johan G. van Rhijn Department of Zoology, University of Groningen, P.O.Box 14, 9750 AA Haren, the Netherlands The evolution of feathers in birds may be related to the development of omoiothermy, or flying ability, or both. Feathers provide an efficient in¬ flating covering with a very light weight. In addition, they are essential 0r excellent aerodynamic properties of wings and tail. To maintain these insulating and aerodynamic properties bathing in water 3eems to be indispensable for a large number of bird species. The most im¬ portant features of this maintenance behaviour will be described. This will e related to the effects of water on the bird's plumage as deduced from ex¬ periments with single feathers subjected to controlled water contacts. Some birds spend a considerable part of their life on or in water. This Requires a number of special adaptations in order to maintain insulation and Provide sufficient buoyancy in swimming birds, or to overcome buoyancy in lv'ing birds. In this context attention will be paid to the structural nro- P®Î'"t"î Q -P f ^ ^ es °* feathers, the role of the oilgland, and the soaking of some feat- 8 in a number of diving birds, as cormorants. ARCHAEOPTERYX AND THE EVOLUTION OF FEATHERS: SOME CONSIDERATIONS %ck J. institut of Comparative Anatomy, Universitetsparken 15, DK-2100, Knibenhavn 0, Denmark The last ten years have witnessed a renewed interest in the reptile-to- evolution and the related question of the evolution from scales to X 0A + y, ner. We found it improbable that feathers first evolved to aid reptiles/ 8 glide between trees. Because if selection had been for gliding, feathers UW be horizontally expanded structures, which they are not when studied the microscopical level. Neither did we find the other existing theories dew SCale-t o-feather evolution logical and convincing, and he proposed a theory, namely that feathers evolved in order to increase the water-re- len°y of the surface of the reptile/bird. sÏMP0SIUM ^SDÇTURE and EVOLUTION OF AVIAN CHROMOSOMES c°nvener: Gerald F. Shields, (USA) , co-convener: Nina Bulatova (USSR) lti Hlst°rically the study of bird chromosomes has lagged far behind studies °ther vertebrate groups. Bird chromosomes are inherently difficult to 1045 study because of the presence of microchromosomes which are difficult to count and identify. Only about 5% of the 8,900 extant bird species have been studied and most of these have not been done well. Recently, however, there has been an increase in the number of cromosome studies in birds and this symposium is a first attempt to 'characterize some of these. We are in a transition period wherein recent studies are beginning’ to employ techni¬ ques which result in a more diagnostic description of the karyotype. Such techniques include the use of more reliable tissue culture media, larger sample sizes, and a variety of procedures used to differentially character¬ ize individual chromosomes. KARY0L0GY AS A TOOL FOR SOLVING TAXONOMIC PROBLEMS IN BIRDS I^eobert E.M. de Boer Biological Research Department, Royal Rotterdam Zoological and Botanical Gardens, Rotterdam, the Netherlands Three main problems are hampering the use of karyological data in taxono¬ my: (1) the rate of karyotypic change during evolution in birds, as in other vertebrate groups, is not. constant, so that degrees of karyotypic similarity or dissimilarity do not necessarily reflect degrees of phylogenetic relation¬ ships; (2) most, if not all, of the nossible karyotypic changes (rearrange¬ ments) can occur in both directions, so that it is often difficult or even impossible to distinguish between plesiomorphic and apopmorphic characteris¬ tics; (3) the degree of resolution with which avian chromosomes can be stu¬ died at this moment is too low. The few large chromosomes of the average bird karyotype generally do not provide enough information, while the smal¬ ler elements and the microchromosomes are too small to allow detailed com¬ parisons. Recent increase of the karyological data available on birds has shown that avian karyotypes are not as uniform as was formerly believed. Although some groups do display uniform karyotypes, others exhibit wide karyotypic variability. In the latter groups in particular karyological data may cont¬ ribute to the solution of taxonomic problems. Examples are given from Cico— niiformes, Galliforme3, Falconiformes and Psittacif ormes. In conclusion it may be stated that promising results are to be expected if methods are im¬ proved and the karyological inventory of the various avian orders is regour- ously increased. KARYOSYS.TSMATICS IN SOME PALAEARCTIC PASSERINES (PARIDAE, PLOCEIDAE. CORVIDAE) N. Bulatova, A.Graphodatsky, S.Smirensky Institute of Evolutionary Morphology and Ecology of Animals, Moscow, Institute of Cytology and Genetics, Novosibirsk, and Moscow State University, USSR Karyotypes and differential staining of chromosomes were studied in 5 species of Parus, 2 of Passer and four of the Corvidae. Birds of these three families share a common karyotype structure, the so-called "basic karyotype"* It designates a large group of families which are not distinguished karyolo- gically and which are systematically close to other relatively less represah" 1046 tative groups within the Oacines. This complex of families could he asso¬ ciated with the extensive radiation (spéciation) during the evolution of passerine birds. Karyological differentiation of these species occurred by both structural chromosomal reanangements and by interchromosomal variat¬ ions of a presumably regulation character. Karyotype data contributes sig¬ nificantly to the study of the systematics and hybridization of those well- toown examples of Parus ma.jor major and P^m.minor and Corvus corone and C- comix. TRENDS IN THE EVOLUTION OP BIRD CHROMOSOMES Gerald P. Shields Division of Life Sciences and Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska, USA Avian cytogenetic research has, until recently, lagged far behind efforts ih other vertebrate groups. Avian chromosomes are inherently difficult to study because moat exist as minute microchromosomes whose morphology and number are obscure. Since 1966, improvements in methods of culturing avian sells have resulted in an increasing number of comparative chromosome studies whose quality parallels those for mammals. This recent synthesis in comparative avian cytogenetics now allows us to assess such factors as the overall karyotypic variability in birds and to c°nsider the role that chromosomal change plays in avian spéciation. In the Present study, chromosomal variability was assessed within and between spe- cies of the same genus and within orders of birds. Chromosomal differences am°hg local populations appear to be associated either with mechanisms that ^Pport balanced polymorphism or frequency dependent selection and not wlth spéciation. The data are discussed in light of current models of CItp» omosome evolution proposed for vertebrates other than birds. CHROMOSOMAL EVOLUTION OP SOUTH AMERICAN COLUMBIPORMES* Edmundo José de Lucca Eepartmento de Genética, Instituto Basico de Biologia Médica e Agricola, Universidate Estadual Paulista "Julio de Mesquita Pilho", Botucatu, Sao Paulo, Brazil Köryotypes of 13 species of Brazilian Columbi formes were compared by conventional homogeneous as well as Giemsa (G) and (C) constitutive hetero- ^ oinatin staining of chromosomes. Chromosomal rearrangements as evidenced measurements of arm ratios, relative chromosome lengths and banding pat- appeared more freouent in some pairs. Chromosomes 3, 4, and 5 appeared 8table. The'I’he ^es of chromosomal rearrangements appeared to vary among the genera. Cl genus Columba was characterized by paracentric inversions, Uropelia and ^ävls by chromosomal fusions and translocations and Geotrygon by centric WefSl0n‘ Finally. the genera Columbina, Leptotila, Zenaida and Scardafella tr 6 Characterized by several rearrangement, types including: chromosomal yj^locations as well as paracentric and pericentric inversions. .j has been supported by a grant from CNPq(SIP 04/015, PROC. 222. 5/77 and PROC. 40.0499/80) which is greatly appreciated. 1047 All species of Columbi formes thus far studied share a large positive G- band on the first chromosome. The W chromosome is largely heterochromatic while slight heterochromatin exists at centromeric regions on the other chromosomes. The distribution of this heterochromatin was, however, hetero¬ geneous. Decreases in the size of heterochromatin blocks appeared to be accompanied by increases in G band number in some chromosomes. This suggests a disper¬ sion of heterochromatin into intersticial portions of the chromosomes and this may be based upon rearrangements in internal chromosome regions. Some modifications and additions of the Columbiform phylogenetic tree are suggested. SYMPOSIUM STATUS OP THE WORLD' 3 CRANE SPECIES Convener: J.C. Lewis (USA), co-convener: I.A.Neufeldt (USSR) The symposium began with introductory remarks by J.C. Lewis. Ornithologists recognize 15 crane species in the world. The cranes' affinity for wetland habitats, and their preference for isolation from human activities, are dis¬ advantages in a world where wetlands are rapidly being drained or filled and where human populations continue to increase. Several of the crane species and subspecies are rare or endangered. Examples are the Cuban aaedhlll crane (Grus canadensis nesiotes) of which there are perhaps s 200 birds in western Cuba and the Isle of Pines; the Mississippi sandhill crane (G. c.pulla) of 40-50 individuals in Jackson Country, Mississippi , USA: the v/hooping crane (G. americana) with about 85 wild and 30 captive birds in North America, and the Siberian crane (G. leucogeranus) of 250-310 birds nesting in the USSR. The distribution and population sizes of all crane species are sharply re¬ duced from those of a century ago. This symposium discussed populations of most crane species; the excepti¬ ons were those of Africa and western Europe. The symposium was followed by an evening round table discussion chaired by George Archibald of Internation¬ al Crane Foundation (USA) and Vladimir Flint of the Nature Conservation Re¬ search Institute (USSR). The discussion focused on ways to help the endan¬ gered Siberian crane. STATUS OF HOODED AND SIBERIAN WHITE CRANES OF THEIR WINTERING GROUNDS AND OF BLACK-NECKED CRANES THROUGHOUT THEIR RANGE Yi-Ching Ma Institute of Natural Resources, Hapin Road, Harbin, China The black-necked crane is the world's only alpine crane species; its nest¬ ing areas are 3,500 to 5,000 ra above sea level; Even in winter it is unusual for this crane to migrate to warm lowland areas. They have nested in Qinghai and northwestern Sichuan Provinces and southern Xizang Autonomous Region. They used to nest (1930' s) in northwestern Kansu Province, but there are no records in recent years. The density of a population nesting at Lonbaotan, p southern Qinghai Province, in 1978-79 was 0.16-038 cranes/km in June. Dur¬ ing fall migration this crane is sometimes seen in large flocks. A flock of 1048 300-400 was seen in September 1973 at Tangra Range pass flying southward and in mid-October 1979 a flock of at least 600 was seen in the Tsaidam Basin. Black-necked cranes spend the winter in southwestern Sichuan, southern Xizang, western Guizhou, and Yunnan Provinces. In early December 1979 a wint¬ ering flock of 70-80 cranes was found at Caohai in western Guizhou, Province where they roosted with G.grus lilfordi. Total populations are unknown but are probably declining due to habitat changes. The Siberian crane is a migrant and winters in China. In the past, they were recorded nesting around Dalainor and Qiqihar lakes and in Liaotung of northeastern China. However, there are no recent nesting records in China. In late May 1981, 24 subadult Siberian cranes stopped near Qiqihar of Hei¬ longjiang Province during migration. Siberian cranes migrate in spring and fall along the Nenjiang River in central Heilongjiang Province and southward along the coastal province to their wintering grounds on the Lower Yangtze River. In January 1981 a wintering flock of more than 100 Siberian cranes was west of Poyang Lake, northwest Jiangxi Province. A winter flock was also reported from the Anquing district of Anhui Province. THE STATUS OP RED-CROWNED AND WHITE-NAPED CRANE Hiroyuki Masatomi Hokkaido College of Senshu University, Bibai, Hokkaido, Japan There are two populations of red-crowned crane, a sedentary one in Japan a migratory one breeding along the middle Amur River and its branches. — hYi£io mainly nests in northeastern China and winters in Korea, Japan, and Astern China. Populations of both species in Japan decreased until the end °f the 19th Century, and populations on the mainland apparently also greatly diminished during and after World War II, Crane populations have gradually recovered in Japan since the 1950’s due to protection and winter feeding Programs. In Japan there are now about 250 G. japonensis and over 1,000 SiYi£io. Based on recent surveys of .iaponensis in the USSR and China, popu¬ lations in the mainland are estimated at 1,000. Two thousand G. vipio have wintered in South Korea recently, consequently the total population may be ^■000-5,000 including those flocks that migrate to eastern China. The red- crowned and white-naped cranes are legally protected, but their nesting habitats are threatened by land development for agriculture and industry, and hy construction of roads and railways. On the wintering grounds in Japan tilere are excess concentrations of these cranes that have led to crop damage nearby farmlands. status op broiga and sarus cranes 1. Gole W°rld Wildlife Fund representative, India The western sarus (G. antigone antigone) is restricted to north and Gent¬ il'1' India. Occasionally it has appeared in Kashmir in the foothills of the malayaa up tQ 1800 ^ in slnd in Pakistan. The eastern sarus (G.a.shar- occurs in India from Assam east to Kamrup and Manipur. Outside India a 'la Sported from Burma, Cambodia, Laos, South Viet Nam, north Malaysia, nd the Philippines. But most of the reports are from the 1930’s and 1940’s. 1049 Since then the reports indicate the eastern sarus has severely declined over most of its range. In the 1960's it appeared in north Australia. The brolga (G.jpibicundus) is restricted to Australia. A population estimate is unavail¬ able for any of these three species. The population of western sarus, according to knowledgeable Indian orni¬ thologists, is either stable or has slightly declined over much of its range, The western sans has lost nesting and wintering habitat due to human sutt- lement and cultivation. The eastern sarus, the most threatened of the three, appears to have disappeared from the Philippines, Malaysia, and Thailand, and its existence in South Viet Nam, Cambodia, and Laos is doubtful. Its status in eastern India and Burma needs to be thoroughly investigated. In Australia the species appears to be stable or possibly increasing. In main¬ land Asia the decline seems due to hunting and loss of habitat. In Burma and the Philippines, the destruction of tall grass habitat probably caused its decline. The main threat- to the brolga appears to be destruction of habitat. STATE OP BREEDING POPULATIONS OP COMMON, ASIATIC WHITE, HOODED AND DEMOISELLE CRANES IN THE USSR I. A.Neif eldt , V.E. Flint Zoological Institutej Academy of Sciences of the USSR Nature Conservation Research Institute, Ministry of Agriculture, USSR Siberian Crane (Grus leucogeranus) . In the USSR there are two separate populations. West-Siberian and Yakutian. West-Siberian population nests along the right tributaries of the Ob River to the north of Beryozovo town (in 1981 8 nests were found in the Kunovat River Valley). Overall numbers don't exceed' 50-60 birds and are likely to reduce. Yakutian population breeds on a stretch of flat marshy tundra between the Yana and the Kolyma Rivers (the bulk of population nests between the Indigirka and the Khroma rivers). The numbers are 200-250 individuals (about 60 breeding pairs) and remain com¬ paratively stable. Common Crane (G-grus). Overall numbers are unknown, but according to in¬ direct data they comprise 60-100 thousand individuals. The numbers reduce over the whole territory of the European part of the USSR (except some boreal forest regions) , because of bog degradation. In Western Siberia the numbers are relatively stable (in Baraba Steppe the density is 0.5-9. 2 individuals per- 100 km 5. In Kazakhstan and eastwards the numbers reduce. Hooded Crane ( 0, monacha) . Overall numbers within the breeding range are unknown (according to count data obtained at wintering places in Japan in 1981 the population was more than 4000 individuals and even increased). The condition of nesting habitat (almost inaccessible moss-larch bogs of middle and southern taiga situated in the south of the Middle-Siberian Plateau, in the lower and probably middle Amur basin) is satisfactoiy. The largest of all known colonies is situated in the lower Bikin River (about 50 pairs, two thirds of which do breed; nesting density is about 1 pair per 20-25 km2). Demoisalle Crane (Anthropoides vlrgo). According to the indirect data overall numbers comprise 45-50 thousand individuals. High density was obser¬ ved m some regions of Pricaspian Lowland (up to 42 individuals per 100 km 3' in Western and Central Kazakhstan, the Altai, the Tuva and in the southern 1050 regions beyond' Lake Baikal. Over the remaining portions of the breeding range the numbers considerably reduced in seventies .although during several rlast years certain stabilization is being observed. It is the consequence of changing the nesting habitat by breeding pairs by shifting their breeding territories from ploughed steppes southwards to the zone of arid semi-de¬ serts (changes in range outlines) and use of man-made landscapes to some ex¬ tent (nesting on sowing areas). STATUS AND DISTRIBUTION OP CRANES IN NORTH AMERICA James C. Lewis, Rod C. Drewien US Pish and Wildlife Service, Port Collins, Colorado, USA, Univ. of Idaho, Moscow, Idaho USA The whooping crane reached a population low of 21 in 1941 but now numbers about 85 wild and 30 in captivity. This bird is symbolic of United States of America efforts to conserve endangered species. The only self-sustaining Population winters at Aransas National Wildlife Refuge and vicinity on the Texas Gulf Coast and nests in Wood Buffalo National Park, in northern Canada. A unique restoration experiment is underway to establish a second wild po¬ pulation that will nest at Grays Lake in Idaho and winter in New Mexico. There are six sandhill crane subspecies (G. canadensis) : three are migrat- oyy« Nonmigratory subspecies are the Cuban (O.c. nesiotes) which is believed to number about 200 living in western Cuba and on the Isle of Pines, the estimated 6.000 Florida sandhill ( G. c. pratensis) of Florida and southern Georgia, and the 40 Mississippi sandhills (G. c. pulla) of Jackson County, Mississippi. An estimated 40.000 to 45.000 greater sandhill cranes (G. c. ta- ^îââ) nest in the northern United States and winter in the southern states. Canadian sandhill crane (G. c. rowani) nests in central Canada, winters Texas, and totals about 55.000 birds. The lesser sandhill (G. c. canadensis) Crane which nests in Siberia, Alaska, and northern Canada, winters in Texas, New Mexico, California, and Mexico, and totals over 500.000 birds. The les- Ser and Canadian races are hunted in parts of North America and the annual harvest is close to 20.000 birds. Four Russian scientists (A. A. Vasilchenko of Sohonda Reserve, Yu.V.Shi- k&ev and N.M. Litvinenko of the Institute of Biology and Soil Sciences in ^Tadivostok, and S.M. Smireosky of Moscow State University) presented brief uhscheduled reports on the status of rare cranes in specific parts of the USSR. SYMPOSIUM ££YSlOLOCy ANn F.noLQGY OF INCUBATION Uonvener: S.Haftorn (Norway), co-convener: H.Biebach (PRG) tue assessment op the energy requirements for incubation J°seph A.L. Mertens Institute for Ecological Research, Kemperbergerweg 67 Amhenythe Netherlaods • “'^Yorts made during the past decade to assess the energy requirements of J‘°r’ incubation hu/e produced conflicting results* 10^1 Computations based on heat-budget modeling predicted that a bird might accomplish the incubation without increasing its heat production about the level of the resting metabolic rate. However, recent direct measurements on incubating Great Tits showed a considerable increase of the nocturnal heat production during the transit¬ ion phase from egg-laying to incubation and the birds continued this high i\el.°rjheat Pr°du0ti0n throuS*out the whole incubation period. The question will be discussed of why birds obviously spend more energy for incubation that should be sufficient on the basis of computations. TYPES OP HATCHING AND HETEROGENEITY OP BIRDS EMBRYOS DEVELOPMENT A.I.Shurakov, A.M. Bolotnikov Perm Pedagogical Institute, USSR In the process of evolution of birds 3 types of hatching arised during oviposition (relatively uninterrupted, interrupted and combined) - A.M.Bo- otnikov, A.I.Shurakov,. 1970, - which in a compound complex of behaviour reactions are nothing but taking care of posterity, directed to the full realization of primary fecundity. The combination of heatings of eggs in periods of visiting a nest by a brood-hen with hindering the development of embryos, while she is absent, unng graduate increasing of density of hatching (the 2-nd and 3-rd types) and graduate raising inside nest temperature under the influence of a stage of a hatching spot’s development (all types) conditions the difference in the speed of development of every oviposition from the very beginning (es¬ tablished on 88 speices of birds, 13 orders and 31 families). . Heterogenety of the development arising during ovioposition is preserved in the embryo and post-natal onthogenesis, it is the common regularity for the class of birds and is considered to be one of the mechanisms of the ap¬ pearance of phenotypical heterogeneity individuals of each brood, and the¬ refore population on the whole (heterogeneity of broods in population in¬ creases at the expense of stetching out of nesting). THE PHYSIOLOGY OP INCUBATION AND ITS IMPLICATIONS ON CHICK SURVIVAL Johan B. Steen Institute of Zoophysiology, University of Oslo, Box 1051 Blindem, Oslo 3» Norway Aspects of incubation have been studied in the domestic hen and in the willow p armigan Lagopus lagopus) both in the laboratory and in the field. The lemale incubates alone and leaves the nest one to three times a day to forage. During her absence the escea coni off „ .. v. , , egg3 0001 ofT* The degree of cooling depends on the ambient weather conditions nnri no ^ . xlons and °n the duration of her absence. Upon rstum the i smale increases hpf , , . ner metabolism and heart rate to rewarm her eggs# The degree of metabolic increasp depends on the temperature of the eggs* 5-0 egg temperature, the female «11 lucrease the metabolism three to five times the metabolism Mp.rlog off as the egg. beet,», „a»er. I» a pta»««“ hen the caloric cost of rewn-mH«,-. , n „ - warming 10 eggs from 10-40°C requires an 0„ co asunP IO52 2 tion of 1500 ml 02/hr compared to a resting metabolism of 375 ml 02/hr. The energy required for re-warming must be secured during the f oraging intervals. Field studies indicate that poor weather conditions may lead to negative energy balance thus rendering the hen in poor condition at hatching. Accurate control of water loss from the eggs during incubation affects the vitality of the chick. Preliminary data on ptarmigan chicks indicate that this may be a factor in annual chick production. THE ENERGETICS OP INCUBATION IN STARLINGS (STURNU3 VULGARIS' AND POSSIBLE ECOLOGICAL CONSEQUENCES Herbert Blebach Max-Planck-Insti tut fuer Verhaltensphysiologie, Vogelwarte Radolfzell, D-7760 Radolfzell, Am Obstberg, PRG During incubation by female European Starlings the potential time for foraging is greatly reduced because they spend most of the time on the eggs, together with the added energetic cost of incubation this phase of the breed- ing cycle might be the energetic bottleneck for reproduction. Direct measur- sments of energy expenditure during steady state incubation at night and in the day, and during rewarming of the eggs after an inattentive period allow Predictions of the total energy budget. An earlier than normal onset of in- cubation should result in a negative energy balance, and this effect is in- creased by an increase in clutch size. The length and amount of inattentive Periods are important for energy balance because of the great amount of energy needed for rewarming the eggs. . symposium Moult Convener: E.Sutter (Switzerland), co-convener: C.Edelstam (Sweden) moult in large raptors Carl Edelstam Swedish Museum of Natural History, 8-10405 Stockholm, Sweden Traditionally, the study of moult rests on the examination of actively aouiti; few hg birds. Large raptors in active moult are rare in collections, and are trapped and examined alive. Moreover, analysis becomes complicated f tilis case by the fact that individual wing quills may serve their owner two years or more, and three or four generations of flight feathers may Present at any one time. % recording carefully the state of wear and fading of every quill in large number of postjuvenile specimens, whether actively moulting or not, a it Pr0 of f°Und ls Possible to reconstruct the details and time schedule of this moult Cess* In the course of the present study, notes were taken of the status °ver so ooo quills in more than twenty species. The moult pattern was ^ b be aerially continuous. A key to the determination of age of the ape!tUre bird is provided by the regular generation (once a year, in the iti Cles so far examined) of a new moult wave among the inner primaries. This turn offerg ^ opportunity to study the temporal development of plumage, 1053 and thus to obtain more reliable age criteria than have hitherto been avail¬ able for most large raptors. The use of such criteria will be demonstrated by a series of slides of eagles photographed in the field. In serial moult (Staffelmauser) in Falconi formes the flight-feathers, primaries and secondaries, are replaced in regular sequence, starting from several centres. The primaries have a single centre at the carpal joint. The innermost primary (nr 1) is the first one to be replaced in every single moult-wave. However, in contrast to the situation in smaller species (e.g. Accipiter nisus) the replacement of a set of primaries is not completed in the course of one season in larger species (e.g. Pandlon. Haliaeetus. Segit- tarius , Vultur) . So in first— year birds of these species the juvenile outer primaries are retained. In the next moulting season the moult is resumed where it was suspended, but also a new moult wave is started at primary 1. As the birds grow older, three or more series may be active at the same time. This slow type of moult assures that the wings always retain a rather closed surface without big gaps. established It was sup- PRIMARY MOULT STRATEGIES IN TERNS ST3RNIDAJJ C. S.Roselaar Instituât voor Taxonomische Zoologie, Postbox 20125, 1000 HC Amsterdam, the Netherlands In 1966, Stresemann and Stresemann (J. Orn. 106, Sonderheft) the existence of what they called Staffelmauser or serial moult t+ cal and temperate regions. Most of these speciea^TTT^ially s 0”£ ant and in recent years such a serial descendant moult is widel^"^ dnmited time for n^t ing'Lso'TrimXTu^sMrts ^ ^ this series is about half-way a ?nH . ” h h innermost; when the innermost, while in smaller teLs^do" 'XT'?*** "itb bifrons and relatives) even a 3rd serieiT^f - T* J?5*5’ ^ : idonias> - At the end of this season, feather replacement Tit ^ 381,16 m°Ult SeaS°n' Staffelmauser, is not resumed in the next sea \ ries are replaced once a year and innerst LTl ‘ r63Ult’ °Ut6r Prin,S' latter wear much less quickly. That not eh lmeS & yeBr’ although the replacement mw Pe .J and anaethetus with relatives which wi th -^erna paradisaea, fuscat§, series per season only. ’ * Slmllar way of life ^ow a sing** It seems a vaste of enersv tn -„„-i during the course of a single year atT * lnner primarles three times planations, Mr. Roselaar concluded' ’that' 'it' S0V6ral P0S8lWe eX' , in spring freshly moulted white inner win Î! lmP°rtant for terns t0 during sexual display. When the feath “ Ä0TO t0 the ^ to dark grey. Repeated renewal would 613 W°m’ **** qUi°kly become 1054 prevent the wing from becoming dark. black-winged terns, such as Sterna fuscata. no serial moult is present, whereas in Chlidonias niger it is much reduced in comparison with C. hybrida. Sterna paradisaea also lacks the serial moult, but this is related to its extensive migrations and short moulting season in the southern oceans. In the discussion the point was raised the serial moult might not be present in all populations of a species, as students of Sterna antillarum had not found it in birds of the American west coast. SHEDDING INTERVALS OP THE PRIMARIES DURING POSTJUVENAL MOULT OP THE TREE SPARROW PASSER MONTANUS E. Sutter Museum of Natural History, Basel, Switzerland The Tree Sparrow has a complete moult of the Juvenal plumage in autumn. As three broods are raised during the breeding season, there are three Groups of young with different fledging dates, different dates of the begin- nihg of moult and even differently scheduled moult. Young of first broods started moulting at the age of 45 days, whereas young of later broods start- e its songs are subject to cultural evolution. Two lines of 981 1057 evidence were used to assess the effects and importance of cultural evolution on geographic variation in avian song patterns. An In— depth Analysis of One Species. In 1940 a small population of wild- caught House Pinches (Carpodacus mexicanus) native to western North America were introduced onto western Long Island, New York. That introduction initiated an ideal evolutionary experiments it was recent; it occurred only once and in one, restricted, extra-limital location; and the history of subsequent colonization and spread in eastern U.S.A. is well documented. Song variation was determined by sampling modern populations that now in¬ habit the entire extent of Long Island.' Geographic variation was analyzed graphically with isoglosses, a technique borrowed from human dialect geog¬ raphy. An isogloss is a line that maps the geographic distribution of a given vocal variant. Several isoglosses may run along in parallel forming bundles which mark the boundaries between vocal traditions. Two types of House Pinch boundaries were identified: 1) song dialect boundaries, and 2) song institution boundaries. Song dialects are local pronunciation va¬ riants, i.e. , different local populations pronounce the same basic set of syllable types differently. The song institution in a new concept. It is regional rather than local in extent, and is based on differences in song syllable vocabularies. Different song institutions are characterized by qualitatively different lexicons (syllable repertoires) just as different human languages are. There are over two dozen modem House Pinch song in¬ stitutions on Long Island as compared to only three or four likely for the original founder colonies. The evolution of over twenty new sets of song syllables in less than 30 years is too rapid for biological evolution alone, but it is readily accounted for by cultural evolution. Overall, the House Pinch is a songbird in which different regional populations are characteri¬ zed by qualitatively different syllable repertoires, and the striking dif¬ ferences among these syllable sets are primarily the result of cultural evolution. Inter-8pecif ic Comparisons. A comparison of 27 passerines whose song variation was sampled regionally suggested that each species has its own species- typical song development program, and that the importance of cul¬ tural evolution on song variation varies significantly among species. The majority of species in this sample (18 species) had qualitatively different song syllable repertoires in different regions. Like the House Pinch, cul¬ tural evolution may play an important rule in the song variation of such species. À sizable minority (8 speciesj were characterized by vocal imii£l^4,, ion and by each having only one basic syllable repertoire throughout it® regional sample. Song variation in f.uch species was interpreted as the product of both a constrained cultural evolution and to strong species-ty- pical constraints on song development. Finally, one species exhibited spe¬ cies-typical constraints too but also very little evidence of vocal irnit®1'”’ ion. Cultural evolution may havf little or no effect on song variation i11 species with such a song development program. 1058 GEOGRAPHIC song variation, interspecific response TO SONG AND SONG DEVELOPMENT IN REGULUS Teter H. Becker Institut für Vogelforschung "Vogelwarte Helgoland", FRG According to various authors, the genus Regulus consists of at least 4 ®Pecies. Above all, vocalizations and behaviour of the two European species, oldcrest (R.regulu3) and Firecrest (R.ignicapillus) . are well known by stu- ^les of THALER, LÖHRL & THALER, LEISLER & THALER, BECKER and others. regard of behaviour, Goldcrest and Firecrest show greatest interspecific Hf erentiation in vocalizations. tw In Paper’ referihK mainly to my studies of vocalizations of these 0 Eur°Pean sibling species, some aspects are picked out contributing to e eubject of this symposium. Vocalizations and their discrimination. In Goldcrest and Firecrest, vo- alizations are significant of interspecific behaviour and serve as isolat¬ es mechanisms. éiic variation in song. We find uniformity in the continuous area Central Europe but great interpopulatfonal differences in western and ouIhern Europe, mainly Spain, inhabited by isolated populations. Thus de~ belt*5111611'! of dialects accompanies the separation of populations which is eved to be one of the main preconditions for spéciation. Responsiveness to other dialects declines with decreasing structural aimii, dual. arity of test song to that of the local population. Therefore, indivi- s from populations characterized by different dialects can experience ems in communication, though these apparently can be overcome through » common and widespread song parts and through learning as mixed-di- s~singers show. From these findings it remains questionable if in Gold¬ in 8 dia:l-eot3 can build up a barrier against interpopulational exchange to birds- yet they appear to represent first steps toward song in its funct- as 011 isolating mechanism. 1^~~â£âgter displacement. It is not found in sympatric populations. As al- the ri° I’irecreat3 react stronger to Goldcrest songs than sympatric ones, ontrast between species' song partly has to be learned by Firecrests n sympatry. ^ £Sagg_and co-existennp. Individual experience, being significant for in- ana ,ecifIc response, can also be seen in specimens singing mixed songs Spec^n interspecific territoriality. Both occur only exceptionally in the "iïic1SS Wlth much lower population density .locally , presumably caused by le °:rrect" Imprinting. Thus the’ isolating mechanism song, built up through oft ;a*Ung, “Hit th® border of 3 species' area. Loss of isolating mechanisms fa- 'uide>, ^*6S hybridization which can occur successfully in the two species can become lost secondarily by learning in special conditions, aer Son, consideration. f^75s^gvslopaant in tt. ^enns Regulus. According to our knowledge derived song °0inPari3on of songs of all species and many, subspecies and populations, S ln consist ot tWG part3l the main part and a variable ending, . 1059 with the exception of R. ignicapillus and presumably populations of R.regulus jagonensis living in the Ussuiy region in East Siberia. In both cases, the song ending was obviously lost during evolution. SYMPOSIUM ADAPTATION TO DESERT COHDTTTfWK Convener: I.C.R. Rowlev ( -î o' ^ y Australia, , co-convener: N.N.Drozdov (USSR) NOMADISM AS A RESPONSE TO DESERT CONDITIONS S. J. J# F# Davies CSIRO, Division of Wildlife Research, Clayton Road, Helena Valley, Western Australia , Australia from1L!1td3,haVe the Pr°blem °f find±nS resOUroes which to sustain life from day to day. In arid lands those needed by some species may occur in“ once t f °ne Slte 80 thSt the Mrd °ften haS t0 move distances met. Usually theST3ttd bef°re “ flndS “°ther ^ ltS ta are to move ifi ! f movement must differ every time the bird has tha" . ' * n0t °lear how a bird f^s these resources, but it is clear arid îld6Pth f°r SUrViVal °n findlng "" 1SaSt SdeqUate f00d and ^ arid lands the occurrence of this year by year is less predictable than in igher rainfall areas. Every such episode has three elements, initiation i ~ izi\T, ,e"f:Uon th“ c“ ”* •» zz* individual in a population undertaking a movement. The movement pattem shown by the population as a whole is the result of the v, h , dividuals within it. A characteristic of If behaviour of the in- all individuel « • 1 • V T of some arid zone species is that not an individuals initiate at the same time, orientnte = or terminate at the same place Some oft 16ntate in the same direction vive but eo i ’ ten many* individuals will not sur¬ vive, but so long as some do the population rin >. tboeo • population Will be preserved. Provided that those which survive are not alwavs thooo + . . ^ always tüose that move at the same time in the same direction to the same place the mo,.»™ 4. • species can nnon»m k ’ 6 m0Vement la not a migration and the species can properly be called nomadic. A proportion of birds living in and areas exhibit nomadic behaviour and the» +v, + . S . . . * and ohose that do depend upon resour¬ ces whose distribution is unpredictable Men, +v P resour . , ^ , aiiiJxeaictaDie. Many other species are successful residents because their needs are met regularlv in the T successful arid areas. regularly in the same place, even in “ 1“? 1MPMI°>S OP BIRDS DUE TO THE AHHROPOOEMIO EFFECTS ON THE KARA-KUM DESERT 0. Sopyiev Turkmen Agricultural Institute, Ashkhabad, USSR Some ecological and ethologies! erien+ = +- 1» typical aria »a lutr.conal bird 1.!,. “* ““U",d v.lbp.en, ol the desert. Bu“o **" quiets, P...„ ,Ia„i,x "üg*. ~ * «aablter. gootoc.ro. 1»- a TH j - - s °uan8e the positions and heights of ne9tfl in areas with degraded woody-shrub vegatett ~ neignts oi ne Passer simplex, that is closelv n i * ! anthropogenic effect on ecologically , «. b, both advÎL J““ *° “*cla <«-.oa.ndrbb “»iHg1 . , . , e ^nesting sites decrease due to anihilat1011 of sand acacia) and favourable fnQc+a . ^ to 301,1 106Q sting sites increase due to extension of areas with sand acacia). Not only Buteo rufinua. Cerchneis tinnunculus and • - gfte noctua, but also such species as Burhinus oedicnemus, Passer simplex. £°doces pander! and Corvus ruficollis which are narrowly specialized in nest respect, change their nest stereotype and place their nests on components of ■the anthropogenic landscape that arose in the desert, with some of them be- 1Q® observed to have increased fecundity (e.g. .Athene noctua has up to 12 eggs here instead of 5 to 7, Buteo rufinua has 6 instead of 3 to 5, etc.). Be¬ cause of the scarcity of sites for nesting, birds are forced to nestle in unusual conditions, e.g., Upupa epops. Passer ammodendri and Passer indicus - ih the casing and pipes of an unused water-raiser, and Scotocerca inquiéta - in a tin. Ecologically pliable birds, such as Streptopelia senegalensis. ^crtdotheres triatlB, Pica pica and others, penetrate far into the desert Allowing man, often as far as 150 to 200 km from the nearest oases. The facts described cannot be attributed to some anomalies of the ecology and behaviour, but should be regarded as manifestations of the adaptation a med at conservation of the species under the extreme conditions of the deaert. energetics, thermoregulation, and water balance °E DESERT BIRDS William Ryan Dawson Division of Biological Sciences, University of Michigan, Ann Arbor, MI 48109, USA Deserts are areas of intermittent and generally low productivity. Birds 0 Spying or passing through them must content with potentially severe prob- ms of energy balance, as well as with the better publicized challenges of e®Perature regulation and maintenance of water balance under heat and arid- y‘ Avian adaptations involving basal metabolic level or torpor will be hsidered in relation to these energetic problems. Thermoregulation in heat can produce substantial loss of water in evapor- ative °olling. This process will be reviewed in combination with a conside- the importance for the water balance in desert birds of their being Pat8 t0 maintain a controlled hyperthermia in the heat and utilize behavioral e*hs that reduce heat stress. t , Llke birds generally, desert species gain water from their oxidative me- thr°liSm 0110 fr°m inSestin« in their food or by drinkin«* They lose water e °Ueh evaporation and by voiding urine and feces via the cloaca. The water 6COnomies of certain desert birds will be examined and mechanisms that curtail ^Poration or cloacal water loss, or facilitate rehydration described. In- ^ ln this discussion will be consideration of a few exceptional birds cah subsist under certain conditions on a dry seed diet without drink- hE ecological-physiological adaptations op water 'tabolism in desert birds ¥-B- Amanova ^®eh State University, Ashkhabad, USSR A comparative physiological analysis was carried out with twelve bird spe- 8 °f the Southeastern Kara-Kum Desert. Special features of water metabolism were investigated in birds living under different ecological conditions of the arid zone. Some tissues of the birds under investigation consume more water than others depending on the physiological state of organism. Ecologi¬ cally different groups of birds responded non-uniformly to moisture decrease in food in the experiments with dry feeding. The results of research into electrolyte contents in tissues and organs show that the specific features of their distribution are of great importance to retaining and redistribution of water in bird organisms. In particular, it was established that the desert species are characterized by high concent¬ rations of sodium and potassium in internals and caudal parts of intestines. The level of absorbtion is also intensified by increasing electrolyte concent¬ rations in the walls of caudal sections of intestines, manifested especially clearly with overheating. The content of electrolytes (with relatively lesser amount of water in internals) seems to reflect adaptational responses of the desert species to arid conditions. Kidneys play an important part in the regulation of water-saline homeos¬ tasis. Renal losses of water in desert bird species can be reduced to limits ultimately permissible for the organism. The process of intensive reabsorb- tion of water in kidney tubules is predetermined largely by structural feat¬ ures of the excretory system. With adaptations to arid conditions, the abili- ty for osmotic concentration of urine in birds, as distinct from mammals, originates due to the development of a complex of structures of kidney medul¬ la, rather than to lengthening of Henle's loops. THE SANDGROUSE (PTEROCLIDAE) : ADAPTATIONS TO THE DESERT ENVIRONMENT David H. Thomas Department of Zoology, University College (University of Wales), Cardiff, UK Sandgrouse (Syrrhaptes, 2 spp. ; Pterocles, 13spp.) live in Afro-Asian deserts where they may experience high temperatures and heat loads or low temperatures and heat losses, depending on locality and season. Being small (150-450 g) and ground-living, they have an adverse (surface/volume) ratio, but live in the habitat zone of thermal extremes. In Pterocles spp. , insul0*' ion is increased at both high and low ambient temperatures, by raising feat¬ hers and huddling together with other inidividuals. Radiant heat exchange is regulated by seeking sun or shade, as appropriate. Resting metabolic rates are apparently low, and metabolic heat production is minimised under hot cob ditions by reducing activity; this effect is more marked in dehydrated the11 hydrated birds, and very marked in incubating birds which normally sit in full sunlight. Convective heat loss may be exploited under hot conditions, but is not always appropriate, and some species use forced evaporation f°r heat dispersal only as a last resort. Water turnover is low (3-4% body wt.day-1), and individuals may drink only every 3-5d, saving energy by in' frequent flights to distant drinking places, and reducing exposure to Pred8 ors which congregate there. Birds feed selectively on seeds high in protei1^ and energy, but differential feeding techniques in sympatric species sugße that interspecific competition for food is avoided. 1062 the levels and aspects op convergent adaptations in desert birds N. N. Drozdov Faculty of Geography, Moscow State University, Moscow, USSR Adaptations of organisms to analogous environmental conditions in the process of evolution lead to convergence (approximation of features). This is manifested especially vividly under extreme conditions, and under arid conditions in particular, as many factors of the environment here are within tbe sphere of a minimum or a maximum and require of living organisms intri- cate adaptations, often on the verge of their biological possibilities. The Phenomenon of convergence is traced clearly in a comparative analysis of or¬ ganisms of isolated arid regions with fauna differing in composition and scar- cely related, but with analogous ecological conditions. Such an analysis of individual bird species and communities in separate aridity centres of the Earth gives ample material to reveal convergent adaptations at different ievelg and in different aspects. Two levels of adaptations are singled out in the process of evolutionary convergence, viz. adaptations at a level of sPecies and at a level of communities. Pour main aspects of convergent adap¬ tations are distinguished at a level of species, namely, morphological, phy- aiological, ecological and ethological aspects. The degree of convergence at a level of species is determined by a collection of aspects in the pair of species under research and by the extent of their taxonomic chyatus (apper¬ taining to various species, genera or families). The degree of convergence at a level of communities can be established by a general similarity of struc- tai'al-funotional models of the biocoenoses under comparison and by a number analogous blocks formed by the non-related components. The study of con- Vergent adaptations allows distinguishing the trends and evaluating the li- mits of adaptation evolution of both the birds themselves as a whole and the “Unities they are part of. symposium ■^SIRDS AND NUTRIENT CYCLES c°hvener: J.R.Croxall (UK), co-convener: A. M. Golovkin (USSR) SEABIRD METABOLITES: A SPECIAL FORM OF THE RELATIONSHIP Between birds and marine ecosystems A*N. Golovkin Al 1-Union Research Institute of Nature Conservation and ^serves, USSR Ministry of Agriculture, Sadki-Znamenskoye, -79° E.O. VILAR, Moscow Region, USSR Ttl6 necessity to consider the role played by seabirds in marine biocenos- ta b! ,lS due to their consumption rate and also to the importance of bird me- °lltes as seawater fertilizers. The latter is insufficiently studied, ho coeffioienta of metabolism (food/wet weight/: excrement s/dry weight/) ter I* to be the same for different fisheating seabirds (8. 2-9.0). In seawa- ,161 n*g at phosphate phosphorus, 0.549 organic phosphorus, 0.036 nitrate 1063 nitrogen and 1.856 organic nitrogen dissolve from 1 mg of bird excrements. Bird droppings add a little to nitrogen and phosphorus concentrations in areas with mean densities of birds. However the excrements do influence the biogenic substances regime in the vicinity of nesting grounds with high bird density. In the North only 8.0-25.7% of excrements are deposited on shore during breeding season. All the rest fertilize the water mass. Analysis shows that enriched water areas exist near nesting grounds in the Barents, Chuk¬ chi, Okhotsk, Caspian and Scotia Seas. They were confirmed mathematicaly as hydrochemical anomalies. The size of the areas (2-240 km2) depends on the number of breeding birds. The seabirds involved in circulation of organic matter near seashore account for thé rate of circulation, redistribution of substances, local phyto- and zooplankton productivity and stability. These areas are typical of marine ecosystems. They were discovered not only near bird colonies but in the vicinity of coral reefs, mussel grounds, etc. The relationship between seabirds and marine ecosystems, through metabolites is of great importance. It confirms a seabird being a genuine marine organism. TROPHIC DEMANDS OF SEABIRDS IN ALASKAN WATERS John Wiens, George' Hunt, David Schneider Department of Biology, University of New Mexico, Albuquerque, New Mexico 87123,* USA, Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92717, USA Trophic demands of seabirds were estimated for the shelf waters of the southeastern Bering Sea distant from colonies, for waters adjacent to the Pribilof Islands in the Bering Sea, and in the vicinity of Kodiak Island, m the western Gulf of Alaska. In the open southeastern Bering Sea, trophic demand varied between oceanographic domains, as defined by water column structure. For depths of less than 50 m, the uniformly mixed waters of the- inner domain supported heavy trophic demands by shearwaters. The middle do¬ main, of 50-100 m depth characterized by a two-layer water column, supported relatively few birds. The outer and shelf edge domains (100-200 m depth) sup¬ ported large numbers of birds, with 1-2% of the prima^ productivity cycling through seabirds. In the Gulf of Alaska as a whole, trophic demands varied seasonally, largely due to the movements of shearwaters, which accounted for as much as 92% of the total energy f low through the bird community. Nearer to breeding colonies, trophic demands were more concentrated spa¬ tially and were generally of greater magnitude. In the vicinity of the Pri¬ bilof Islands, seabird populations were large, with mean densities of up to 53° birds per km . Trophic demand there showed a strong seasonality associat¬ ed with breeding activités. Murres (Uria) account¬ ed for roughly 80% of the aggregate avian community trophic demand, and theif foraging activities were concentrated in areas within 40 km of the breeding colonies, mcluding the additional demands of chicks, the trophic demand tbe+ rl .. ° 3 and colonies was more than an order of magnitude greater” than that in the outer domain, and showed quite different seasonal patted Estimates of trophic demands of the dominant breeding seabirds in colonies on Kodiak Island suggest a much lower value than that obtained for the Pri' bilo slands. This estimate is complicated, however, by the overlapping ^raging zones of different colonies and the greater incidence of transien*3’ 1064 such as shearwaters. These and other problems that beset attempts to generate valid estimates of seabird trophic demands are addressed. RELATIONSHIPS BETWEEN SCOTTISH SEABIRDS AND PISH STOCKS Robert W. Furness Zoology Department, Glasgow University, Glasgow G12 8QQ, Scotland, UK Applying a bioenergetics model to seabird communities in north Britain in¬ dicates that seabirds annually consume the energy equivalent of 20-305Î of the &ruvual production of zooplankton-consuming fish within a 50 km radius of iheir colony. This implies that seabirds, predatory demersal fish and indust¬ rial fisheries are in direct competition, such that an increased energy flow to one would be at the expense of another. Problems and uncertainties in the modelling will be discussed. The links between recent increases in Scottish 8®abird populations and changes in- fish stocks resulting from overfishing W111 he explored and the possible influences of current trends in the pat- terns °Y North Sea fisheries on seabird populations will be outlined. DYNAMICS OF PAST AND PRESENT SEABIRD COMMUNITIES AND FOOD RESOURCES IN THE BENGUELA 'CURRENT REGION Walter Roy Siegfried, John Cooper, Graham Avery Percy FitzPatrick Institute of African Ornithology, University of ^ape Town, Rondebosch 7700, South Africa; South African Museum, 6l , Cape Town 8000, South Africa PRe fossil record and information on abiotic changes (e.g. sea level, tem- Perature) in the Benguela Current region off the southwestern Cape, South Af- ri0a* the late Miocene/early Pliocene to the present day is used to dis- °°Ver ^d explain changes in seabird communities and their food resources that nave occurred over a period of seven million years. The breeding seabird 11110 of the late Miocene/early Pliocene included penguins (Spheniscif ormes) »at P6trels (Rrocellariif ormes) ♦ These penguins are allied to modern cold e;r species and are suggestive of a colder climate at that time. Petrels no n8er breed in the region. The present assemblage of breeding seabirds has Ç - r - - theSted Sinoe at least 100 000 years B.P. during the Pleistocene, although Jac r6lative Proportions of species have altered. There were apparently more 0e° ass Penguins than Cape Cormorants during the last Glacial. Since the Holo- j 6 CaPe Cormorants have been more numerous than penguins. The Cape Cormorant le ilOW eyen more relatively abundant, probably due to a reduction in availab- haaPrSy Slze by commercial overfishing affecting penguins. However, no species tiV‘beC°me extinct in the Benguela Current region in modem times; man's ac- Ulea have "only" reduced numbers and affected relative proportions. g ACT °P SEABIRDS ON MARINE RESOURCES, j PeciALLY KRILL, OF SOUTH GEORGIA WATERS B°h0 P-Droxall, Peter A. Prince, Christopher Ricketts ritl?h Antarctic Survey, NERC, High Cross, Madingley ttOad n ’ Abridge, UK 6 fo°d composition of the breeding population of South Geogia seabirds 1065 during their breeding season is estimated using data, from studies conducted there, on breeding population size, timing and duration of breeding activi¬ ties, energy costs of incubation in petrels, energy costs of incubation, moult and swimming in penguins and detailed information on the composition of the diet of all the eighteen main breeding species. Existence and flight costs are estimated using standard equations and relationships. Chick energy budgets are calculated using data on meal size and the frequency with which chicks are fed. Costs of accumulating and res¬ toring fat reserves are assessed for the albatrosses and penguins, from information on weight changes throughout the breeding season. Demographic and ecological information are combined to estimate the consumption by failed and non-breeding birds. Krill forms about 88% of the 2.7 million tonnes of food consumed, 80% of which is taken by camaroni penguins. Seasonal variation in krill consumption is analysed in relation to changes in the chemical composition of krill and preliminary information is presented on geographical variations in the im¬ pact of the seabirds on krill around South Georgia in relation to what is known of its distribution from acoustic surveys. TROPHIC RELATIONSHIPS OP HAWAIIAN SEABIRDS AND THEIR IMPACT OP MARINE RESOURCES Craig S. Harrison, Thomas S. Hida, Michael P.Seki U.S. Pish and Wildlife Service, P.0. Box 50167, Honolulu, Hawaii 96850, USA; National Marine Fisheries Service, Noaa, P.0. Box 3830, Honolulu, Hawaii 96812, USA Ten million seabirds of 18 species breed in the sub-tropical Northwestern Hawaiian Islands. The seabirds in this community weigh between 0.05 and 2.8 kg and utilize a variety of strategies to partition available food re¬ sources. In addition to size and anatomical differences, they breed in dif¬ ferent seasons, feed in different locations, and forage at different times of the day. All feeding occurs near the ocean surface, often in association with predatory fish such as tunas. A wide variety of marine organisms are eaten, but the most important are commastrephid squid and fish (often juve¬ nile) in the families Exocoetidae. Carangidae. Mullidae. Synodontidae, Clu- peidae, and Myctophidae. Most seabirds vary their diets by season and locat¬ ion, implying that they are opportunists and can exploit most any prey of suitable size in surface waters. This community therefore possesses a me»**« of resilience since many species can switch from one food source to another during times of food stress. On Laysan Island, an estimated 350.000 kg/ day of marine resources are consumed by birds. The refinement of such an estimate of the daily impact of colonial seabirds on surrounding waters is conting«3* upon improved estimates of both daily food consumption and populations of seabirds. Complete assessment of the impacts of seabirds on local marine resources additionally requires a detailed knowledge of feeding areas. 1066 Symposium BIOPHYSICS of bird flight Convener: W. Nachtigall (FRG), co-convener H. Oehme (GDR) SURVEY OP THE BIRD PLIGHT RESEARCH IN THE USSR N.V.Kok shay sky Severtzov Institute of Evolutionary Morphology and: Ecology of Animals, USSR Academy of Sciences, Moscow, USSR After a short review of attempts to elucidate the physical principles of bird flight in Russia a more detailed account was given of studies of bird flight mechanics by N. E. Joukowsky , one of the founders of modem aerodynamics almost 100 years ago. Problems of energetics in animal flight were already interest for aerodynamicists and engineers in the early stages of aero- hautics. Statics and dynamics of the locomotor apparatus were investigated. °ubstantial contributions to the investigation of bird flight were created by Soviet ornithologists during the last five decades in the field of com¬ parative morphology and ecology. Prominent representatives of these branches ware N. A. Gladkov and B.K. Stegmann. Extensive investigations of the bird's flying equipment and its evolution, alterations of proportions with respect to fbe function of the flying apparatus, connections of these interdepen¬ dences with habits and environment brought up a lot of highly valuable faults, in the last twenty years the analysis of mathematical and physical * Pr°bleins of bird flight grew more and more important. The publications of •A. Judin, G.S. Shestakova and N.V.Kokshaysky are documents of the advances atiained in this field by means of efficient methods of recording and ex¬ perimenting. Finally very important contributions to the physiology of bird flight, especially to its energetics, emerged from investigations on bird Migration, represented by prominent biologists as V.R.Dolnik and T.I.Blyumen- a1, An enlarged version of this paper with appropriate bibliography entit- " ^klad otechestveonoy oauki v izuchenie poleta ptlts" is published in D°logichesky Journal 61, 971-987 (1982) aerodynamic aspects op formation plight in birds ^•Hummel Ihstitut für Strömungsmechanik, Technische Universität, Bpaunschweig, FRG Ia formation flight each bird flies in an upwash field generated by all fl 6r “embers of the formation. This leads to a remarkable reduction in sh 8ht Power demand. Plight power reduction was calculated for arbitrarily ^ peP"1* »“"««». r.O. Box 56l , S 751 22 Uppsala, Sweden In central Sweden, most pied flycatcher „ . female, leave their first mate temporarily to III Sf!er a°quired * 15% of the males are successful. All Zll + aBoth•p feniale' Up t0 feed her young. Although bigamous met ^ ^ t0 thelr first female and female, many of her young starve. Diff3 S0Iïetlmea feed the y°ung of the second appear far too slight to make i/advan^"063 ^ territ°iy quality mated males instead of unmated males •feraalea t0 choose already presence of other females of a aale. ’«JV! n0t aware of the against their direct benefit Mai ^ ^ thUS ^ pair Up with bigamous males «h. „„ .uLT,: rm to hid* ,h'ir *• ritories of other males. 8 S Sre usuaHy separated by several ter- 1072 The benefit of becoming polygamous may be counteracted by an increased risk for polyterritorial males of being cuckolded. We found that tarsus length of nestlings was more closely correlated with that of the female than with that of the male at the nest. About 28% of the young are gathered hy cuckolders in pied and collared flycatchers. In most cases the cuckolder is the male breeding in the nearest next box. CHANGES IN REPRODUCTIVE BEHAVIOUR OP BIRDS UNDER ANTHROPOGENIC INFLUENCES (EFFECTS) V. N. Amelichev, A. L. Podolsky , O.F.Sadykov, V.L.Kharin Institute of Ecology, Sverdlovsk, USSR Birds’ adaptation to antropogenic factors is often displayed in the chan- Ses of their reproductive behaviour. Unusual behaviour of black grouses and capercaillies is noticed at their mating places in the South Urals, in the traditional game-shooting regions. Groups of black grouses change their mat- lr>g places daily moving on territories of thousands of hectares thus evading shooting from the ambush. The capercaillie involved in reproduction fly from one place to another svery 5_io minutes without apparent cause, and many of their songs lack the "stone-deaf" phase. 18 cases of blackcaps nesting on the tree at the height of 2-3,5 metres Were observed on the cattle pastures in the Volga region. Low-set nests are widely destroyed by the cattle. Iß the city the incubation period of the magpie is being prolonged to 6- ^ days, (n = 30) nestings of the lesser whitethroat stay in nest 15 days = 15), lesser whitethroat (n = 23) barred warbler (n * 9) and crested lark (n = 27), Nests are located higher: not lower than 7-8 m in the spot- ted flycatcher (n = 100), about 6-13 m in greenfinch (n = 200), more than 0 m In the fieldfare (n = 36). Urban white wagtails and wheatears nest k°ve the earth in technical structures and buildings. In Magnitogorsk and Sverdlovsk rooks nest on the transmission lines' sup- Ports (n = 34). In Sverdlovsk in the nest of the Blyth' s reed-warbler and the marsh warb- ler (n = 11). Sylvia borin (n = 5), the Great Rose Finch (n = 6) covering tpay fully consists of snatches of thin copper wire. A lot of other behav- changes in reproduction have also been "recorded. effect of spring waterfloods on nesting birds in The valley of the mid-ob river A* Ananin, T.L.Ananina ^nguslnsky Reserve, Davsha, USSR f Peculiar features of apace distribution, periods and results of nesting f°r the basic bird species in the Mid-ob valley were studied for two dif- Q®rent years: the year of 1978-79 with high spring water floods and the year 1980 - with low spring waterfloods. Observation was made along the estab- t^hed study routes (15 km long) and" over the testing grounds (24.6 ha), by method of individual bird's markings. 32- 3aK. 98 J 1073 It was found that high and prolonged floods resulted in shrinking ter¬ ritory for small Passeriformes nests (by 1.7-1. 9 times) , shorter distances between nests within the birds’ colony (by 18-34%), greater density of nests (hy 35-45%), lower reproduction rate (from 46.2% to 38.8% for Motacilla flava and from 51.1% to 42.8% for Emberlza aureola), the growing number of "reservist" non-breeding individuals. The following year due to the increas¬ ed dispersal value of the young some changes in the sex and age composition in some resident Passeriformes were observed. Low spring floods and the ensuing low summer level resulted in lower density, smaller bird productivity for the nesting Sandpipers (by 1.2-2 times) , partial dislocation or disappearance of the Tern and Seagull colo¬ nies, decline in the number of breeders. ARBEITSREGIMES DES SCHALLSTRAHLENDEN SYSTEMS DES MITTELOHRES DER VÖGEL W. Anisimow Severzow-Institut für Evolutionsmorphologie und Ökologie der Tiere, AdW der UdSSR, Moskau, UdSSR. Ein einheitlicher Mechanismus der Arbeit des schallstrahlenden Systems mit zwei aneinandergebundenen Regimes ist ermittelt. Die Durchführung des Schallsignals im ersten Regime wird ohne funktionelle Teilnahme des Mitte - lohrmuskels verwirklicht. Der physische Faktor der Bewegung des Trommelfells und des Stapes ist die Energie der Schallwelle. Im ersten Regime vollzieht sich die Verstärkung oder die Abschwächung des Schalls nur dank der struk¬ turellen Anpassung des äusseren und mittleren Ohres an die akustischen Be¬ dingungen der Umwelt. Die Arbeit des Mittelohres im zweiten Regime ist mit der Punktion des Mittelohrrausckels verbunden. Die Adaptationen des Gehör¬ systems, die die Empfindlichkeit des Gehörs bei den echolotenden Arten und den Arten mit entwickelter akustischer Kommunikation und Signalisierung erhöhen, charakterisieren sich durch das Vorherrschen des zweiten Regimes. Die regulierenden und Schutzprozesse in der Mechanik der Schall Strahlung werden in diesem Pall durch reflektore Zusammenziehungen des Mittelohimus- kels gewährleistet. Die Zusammenziehungen des Muskels werden vom zentralen Anteil des Gehörsystems nach dem Prinzip der Rückkopplung kontrollliert. FIRST PHOLOGRAPHS OF MEMBERS OF THE MESITORNITHIFORMES (MADAGASCAR) Otto Appert EKAR, Manja, Madagascar The order Mesitomithif ormes consisting of three species in two genera is found only in Madagascar. The author was able to observe all members the order in life. For the first time photographs were taken of living Monias benschi Oust Grandid and of living Mesitornis varlegatus (Geof-fr. )• representatives of the two genera of the order. Apparently no artist drawing illustrations of the Mesitomlthlformeg had seen living birds of this order so their representations, especially the body shape and posture, are unsatisfactory. 1074 AH Mesitornithiformes are inhabitants of the primeval forests where they search for their food among the leaf litter on the ground. Monias is found in the southwestern part of the island, Mesitornis variegatus in the north- west and Mesitornis unicolor in the east. At least some of the species are supposed to be flightless, but the author was able to observe that all species can fly, even when they do so rarely. The systematic position of the group is still uncertain. In any case, they should not be placed in the Rallif ormes (as is sometimes done), but they possess the status of a independent order, next to the Rallif ormes, ^jjypygl formes. Heliomithi formes, Gruif ormes and others. BRUTNACHWEISE der ANATIDAE UND CHARADRIIFOHMES AUF INSELN TENDROWSKY MEERBUSEN SCHWARZMEER NATURSCHUTZGEBIET T. B. Ardamazkay a Schwarzmeer Naturschutzgebiet, USSR _Charadrilformes 3ind die zahlreichsten und verschiedenartigsten Brutarten auf Inseln Naturschutzgebiet. Hier brüten 8 Arten Möwen und Seeschwalben: sHbermöwe, Schwarzkopfmöwe, DÜnnschnabel-MÖwe, Lachseeschwalbe, Raubseesch- walbe, Flu^seeschwalbe, Zwergseeschwalbe. Die Anzahl der Schwärt zkopfmöwe- Population ist die höchste. Seit 1935 nahm die Anzahl der Brutpaaren mehr als um 12 Mal zu. Im Jahre 1981 beobachteten wir 275 530 Paaren. Die zahlreichste Art unter Seeschwalben ist die Brandseeschwalbe. Aber lhr Bestand schwankt von Jahr zu Jahr, die höchste Zahl (30 806 Paaren) bo- bachteten wir 1981. In den 70 Jahren ist die Raubseeschwalbe zur gewöhn¬ liche Brutart geworden. Früher brütete diese Art sporadisch. Hier finden wir 4 Brutarten Haematopodidae : Austemf ischer, Seeregenpfeifer, Rotschen— kel> Säbelschnäbler. Im letzten Jahrzehnt vermehrte sich die Anzahl der In- 3elpopulation dank der Übersiedlung aus der salzhaltigen Steppe. Anatidae: sind die zahlreichen Brutarten, Brandgans, Stockente, Schnat¬ terente, Mittelsäger. In den letzten 25 Jahren vergrößerte sich die Anzahl dieser Arten um 9 bzw. 24 Mal. Bedeutend weniger brüten Spiessente, LÖffe- letlte und Knäkente. Eine neue Brutart-(Kolbenente)-erschien. Die Brandgans baut ihre Nester auf den Inseln nicht in Höhlen. wie gewöhnlich, sondern auf ber Oberfläche auf verschieden Pflanzen. The INFLUENCE OF FEEDING THRESHOLD LEVELS OF p,p'-DDE 0n PHYSICAL AND PHYSIOLOGICAL PROPERTIES OF EGGS OF THE Ringed turtle dove (streptqpelia risoria) An>os Ar, Ziona Maslaton (Malachi) bept. of Zoology, Tel Aviv University, Tel Aviv, Israel t Ri»ged turtle dove (Streptopeliajdsoria) eggs and reproduction are known ° be affected by pesticides. We tested the influence of threshold doses of ^'P'-DDE (Dp 0. 1-6.3 mg. kg-1 BW- day-1) on DDE concentrations in eggs (DE, egg mass (W) eg -face area (A), shell mass (Wsh) eggshell Z^SS • prepipping 02 and 002 . V r»C0V ■ ana iem.1. productivity. 20 p.lr. «ere muntmned Ul1 c„ tt 25+2°C . 16 Hours li8h. .»d = Hours dsrH.es,, «d fed enriched sorghum ad lib. Females were daily administered DDE orally in 1 ml soybean oil for 60 days. Eggs were collected to initiate a new egg laying cycle and some were artificially incubated at 38°C +0.5 and 51% RH +3. DE as a function of DF was: DE = 0.89+0.23 log DF +0.26 SEE (r^ = 0.919)* W, A and Wsh dropped significantly (p .<£. 0.01) at DF = 0.6 mg* kg 1 by 1% +2 SD, 3% +1 SD, and 4% +1 SD, respectively. No significant change in L could be detected up to DF = 3.0 mg* kg-1 BW* day-1 . Yield point dropped con¬ tinuously from an average control value of P « 218 g +7 SD at a rate of 1 9 g per mg DF, to a plateau at 79% +5 SD. Gh2o* ?Ao2 and FAco2 Were normal and not affected by DF in the range tested. Clutch size dropped from 1.9 to 1.2 eggs at DF = 6. 3 mg*kg-,BW*day-1 and total productivity dropped from 4.3 to 1.5 eggs per month. It is concluded that the amounts of DDE transfer¬ red to eggs increase relatively little with augmented parental contamination levels. Practical indicators for low DDE levels in this species are egg mass and yield point reduction. BONY -TOOTHED BIRDS • (ODONTOPTERYGIFORMES HOWARD, 1975). SYSTEMATICS. DISTRIBUTION. CA3PIODONTORNIS KOBYSTANICUS SP. FIRST BONY-TOOTHED BIRD FROM USSR S.M. Aslanova , N. I.Burchak-Abramovitch Institute of Geology of the Azerbaijan SSR Academy of Sciences, Baku; Institute of Paleobiology of the Georgian SSR Academy of Sciences, Tbilisi, USSR Bony-toothed Birds ( Odont op terygif ormes) are a separate order which have four families (Harrison and Walker, 1976). But Bony-toother Birds are one suborder of the Pelecaniformes according to other taxonomists. Most ancient records of the Bony-toothed Birds date by Lower Eocene (Odontopteryx and Pseudodontomis longidentata from London Clay). The records of the Bony- toothed Birds were restricted to England, Prance and to North America bef°re 1977. Position of Gigantomis eaglesomei from the Nigerian Middle Eocene between Bony-toothed birds are doubtful. The sternum of this genus is found* but cranial structures are unknown. The cranium and the mandible of Bony- toothed Bird were in the sea deposits of the Middle Oligocène near the Be** rikishkul Village (East Azerbaijan) in 1977. This bird was described as Ça3' pidontomis kobystanicus by Aslanova and Burchak, 1982 (Pseudodonoraithid&ê C asp i dont omis was the water bird the size of the pelican. The Caspidont££~ nis's teeth of the mandible and maxilla are situated vertically in front oi the beak, but behind it are inclined on. The teeth alternation are large* small, middle, small, large, etc. STRUCTURE OF BILL TIP ORGAN IN ANSERIFORM BIRDS K. V. Avilova Moscow State University, USSR Structure of mechano-receptor complexes forming cara papillas in the ^ lower jaw and com cups in the upper jaw are dealt with herein. Data on Anseriform species of the USSR fauna are discussed and a number of trite3 such as Anserini , Tadomini , Anatini , Somaterini , Aythini , Mergini are compared. 1076 The lower jaw apparatus is found to be more developed in dubbling ducks M-d other strainers who are food-searching in water or mud, often at night. The upper jaw apparatus is found 'to be more developed in grass-eating spe¬ cies searching for ground food. Receptor complexes in mollusk-eating species are big and rough while in invertebrate-eating species they are thiu and T°ng. Sometimes these complexes within the same species diverge in size and shape. Birds feeding on water vegetation, such as the mute swan, possess the peculiarities of both the dubbling duck and those of the grass-eating species. x V efficiency of food utilization during migratory FATTENING in THE GARDEN WARBLER (SYLVIA BORIN) Franz Bairlein Zoologisches Institut, 5000 Köln, 41, FRG The efficiency of food utilization during migratory fattening in the Garden Warbler was examined under constant conditions. The main goal of the experiment was to test whether body weight increase in a passerine bird dur- xnS migratory fat disposition is only due to hyperphagia or whether other Mechanisms such as changes in the efficiency of food utilization are invol- V6d* It wa3 found that the efficiency of food utilization defined by "daily cody weight gain (g)/daily food intake (g)" increases during migratoiy fat¬ tening. nhe results are discussed ir. relation to the underlaying mechanisms and in relation to an optimal feeding strategy of a migratory bird. homing performances in the sand martin (riparia riparia) Hatale Emilio Baldaccinit Sergio Frugis, Bmanuele Mongini Zooj.ogy Department, Farma Univ., lama Italy; Italian Center 0rnith. Studies, Parma 'Jr.iv. , Parma rtaly THe homing performances of Sand Martins (Hirundo riparia) breeding in , h^ee Clonies located along two tributaries of the Po River (Northern Ita- J' have been tested with the classical method of registering both the va- }‘l8hing points at the release site and the recoveries at the colony. Sand “®nins Were caught at the colony by mistnets and by "funnel traps" puaced "^ctly at the entrance of the’ nest hole. Within three hours of the capture bird3 Were released at two opposite sites, NW and SE with respect to 8 colony, at distances of 28 and 67 kms respectively, p A total of 102 individuals have been singly released and 81 vanishing ai: 7ts WQa obtained. In the release tests performed we found a nonrandom and ribution vanishing points in five oases out of six (Rayleigh test) J 511 Reward orientation in four out of six (V test). Furthermore at 20 ^ 40 seconds after release, some birds were already homeward oriented (3 m, °Ut 01’ 6 respectively). the',6 return was measured in two tests, with results of *0.7% irom heareat release-site and of 4455 from the farthest one. Bx°mstricßl data were Glg0 taken to characterize the population studied. 1O77 PHYLOGENY 0? THE RATITES AND COMMENTS ON THEIR ORIGIN J.C.Balouet, P.V.Rich, G.F.Van Tets Museum National Histoire Naturelle, Institut de Paléontologie, Paris, France A study of the gross structure and ultraatructure of ratite feathers, based on biometrical and morphological data confirms some of the postulated relationships among the ratites. Supporting evidence is provided by the osteology , structure of the egg shell and other features of fossil and liv¬ ing ratites. Some trends can be shown in ratite feather structure. Our study permits further comments on the origin of this group. DISTRIBUTION AND POPULATION OF HERONRIES IN ITALY Francesco Barbiéri, Mauro Fasola, Claudio Prigioni Istituto di Zoologia, Université di Pavia, Pz. Botta 9, 27100 PAVIA, Italy In the first national census of Italian heronries (1981) we checked 57 colonies, out of a total number of about 60, plus some small groups of Purp- le Herons. Most heronries were in Northern Italy, 2 in Central Italy, 1 in southern Italy, 1 in Sardinia, 30 colonies were concentrated in the small, North-Western zone of intensive rice cultivation, 6 were along the Po River, and 10 on the coastal lagoons of the northern Adriatic Sea. Counts of the nests were difficult to make because many heronries were large, inaccessible, and mixed species, but in 35 colonies nests counts were correct within a 5/o range of error. The total number of censused nests was (most likely estimate and probable range) : Night Heron N.nycti corax 17. 300 (15800 / 20.200) Little Egret Egretta garzetta 6. 600 ( 5600 / 8. 300) Grey Heron Ardea cinerea 690 ( 640 / 740) Purple Heron Ardea purpurea 450 ( 350 / 660) Squacco Heron Ardeola ralloides 150 ( 100 / 200) In the main range in the Po plain the Grey Heron breeds only in the west and the Purple in the east; the other species are widely distributed, but the Night Heron is more abundant in the rice fields zone and the Egret in the coastal lagoons. These differences in distribution may be related to the preferences in feeding habitats of each species. lhe very high density of Night Herons (about 1.5 times the censused po¬ pulation for all. the rest of Europe) may be explained by the presence of large areas of rice fields, used by these birds as feeding zones. STRUCTURE OF MIXED-SPECIES FLOCKS OF TITS A. V. Bardin Institute of Zoology, Academy of Science, Leningrad, USSR Tits and related bird 3pecies were examined at Pechoras, the Pskov regi°n in 1368-190;). Various species were observed in the mixed-species flocks (n=762; wi th the following frequency! Parus montanus - 74.9)5, P. oristatus 68.J%; Regulus regulus - 56.5%; P. ma.jor 33-7%, Certhia famillarls - Sitta europaea - 17.1%; P. ater - 13.9%; P. palustris - 12.6%; Aecithalog cauda tu s - 8. 0% ; P. caeruleus - 3*9%. Floks made up basically of P. montan]i5 1078 J - - — s-nà P. cristatus were most common. Their main features are: 1) adult pairs are established and keep within the same territory of 10 ha; 2) the young after postfledging dispersal become resident and settle on the adults' territory. The newly-formed social groupings are established all through autumn and summer; 3) the territories of groups P. montanus, P. criatatus. P. palustris coincide. The territories of S. europeaa pairs include 2-4 territories of Tits communities; 4) P. montanus, P. cristatus, P. palustris. P, ater. europeae store large amounts of food, which is later used collectively. The non-storing birds sponge on the other species; 5) because of the adult bird's attachment to particular dwelling sites, mixed-species flocks of Tits tend to occupy the same territory year after year. Mixed-species flocks formed of A. caudatus or P. major groups have a dif¬ ferent structure. M0RPH0-ÖK0L0G ISCHE ADAPTATIONEN VON ZENTRALEN ABSCHNITTEN DES HÖRSYSTEMS DER VÖGEL D. Barsowa Moskauer Staatliche Universität, UdSSR Die morpho-ökologische Analyse des zytoarchitektonischen und Neuronen- baues der akustischen Zentren der Medulla oblongata und des Mittelhirns ist bei den Vertretern von 6 Ordnungen (14 Arten) Bodenvögel mit verschiedener stufe der Spezialisierung des Hörsystems und bei den Vertretern von 4 Ordnun- ®eh (10 Arten) Wasservögel durchgeführt worden. Bei den Bodenvögeln, deren Gehör verschiedene Rolle bei der Nahrungssuche ^ in der akustischen Kommunikation spielt, kennzeichnet sich die Veränder- iahkeit der zytoarchitektonischen Charakteristiken durch die Veriationen Anzahl von Neuronen mit langen Axonen und durch die räumlich-funktionel- e Verbreitung. Die Veränderlichkeit der Neuronenformen kennzeichnet sich àUl,°b den Ausmass, Verästelung und Fläche der Dendriten, wodurch die Verän- ^8 des afferenten Feldes von Neuronen bestimmt wird. Die Angaben über ^le Neuronenzahl in Horkemen der Medulla oblongata und des Mittelhirns al- ®r Versuchten Vogelarten sind angefüht, sowohl die Schemen der Neuronen- ®bruktur von kochlearen Kernen, des laminaren und vorderen olivaren Kernes 611 Mgjulla oblongata und dorsalen mesenzephalischen Kernes. v Bei den Vertretern von Wasservögeln sind keine bedeutende Schwankungen f°n ^Charakteristiken der akustischen Zentren nachgewiesen. Die Neuronen- Jn the Braunschweig district (from 1954-1981) the results are based on checks of an annual average of 400 nestboxes. In spite of frequent and sizeable fluctuations in the populations of the . - _ % +V.O TJntVintnVi fmfly. . iïl spite of frequent and sizeable fluctuations in the populations oi the ^U6 Tit (ln6u. 120> 31 pairs/i 000 nestboxes) and the Nuthatch (max. 30, „j1* 12 Pairs/1000 nestboxes), both species show neither a long term m- J6aaihS nor decreasing trend. The striking fluctuations from one year to !*°ther are more easily explicable in terms of the species-specific behav- bf1 ^toire (e.g. irregular migratory movements, considerable suscep- ^lity in winter) than by the relatively slight differences in annual rep- tive efficiency. 1081 Red3tart (at least from 1955-1981) and Wryneck (since 1927) populations showed a significant decrease. In the period under investigation no changes in the reproductive efficiency, measurable as a trend, could be discerned. The authors believe it possible that influences during migration and/or in the winter quarters are responsible for the declines. AKUSTISCHE SIGNALISIERUNG STRUTHIONIFORMES , RHEIFORMES UND CASURIIFORMES IN FRÜHER ONTOGENESE M. Bewolskaja, A. Tikhonov Moskauer Staatliche Universität, UdSSR Im Naturschutzgebiet "Askania-Nowa" wurde die Entwicklung der akustischen Signalisierung Struthio camelus, Rhea amerlcana. Dromiceus novae-hollaodlae untersucht. Nach funktionellen Merkmalen und struktureller Anordnung sind die ermittelten Laute den Lauten anderer nestflüchtender Vögel in der Pe¬ riode der frühen Ontogenese ähnlich. Die Analyse der akustischen Signale und der Morphologie des unteren Kehlkopfes ermöglicht das Vorhandensein gemein¬ samer "primitiver" Mechanisme der Schallstrahlung in pranataler und früher postnataler Ontogenese der Vögel anzunehmen. Diese Art der Schall Strahlung charakterisiert sich durch die glockige Form der Frequenzmodulation und ver¬ wirklicht sich ohne Nervenkontrolle über Spannung membrana tympani. Die "pri¬ mitive» Art der Schallstrahlung in frühen Stadien der Entwicklung der akus¬ tischen Signalisierung ist für Vögel im allgemeinen eigen. Eine stabile Span¬ nung der inneren membrani tympani wird in dieser Periode wahrscheinlich mit¬ tels m. tracheolateralis errungen. Die Formänderung der Frequenzmodulation wird sowohl durch die Spannungänderung membrani tympani, als auch durch die Geschwindigkeit des Luf tdurchflusses bestimmt. MIGRATIONS DE TRAQUET ISABELLE (OENANTHE ISABELLINA) EN L'URSS ET SON PROBABLE RÔLE DANS LE TRANSPORT DE L'AGENT DE LA PESTE D.I. Bibikov Institut de Morphologie Évolutionniste et d' Ecologie des Animaux de nom A.Severtsov, Académie des Sciences de l'URSS Comme espèce de fond des déserts et steppes de l'Europe et de l'Asie, Ie TRAQUET ISABELLE est étroitement lié aux rongeurs dans les naturels foyers <*e la peste. Ses migrations saisonnières et déplacements locaux contribuent à la diffusion des puces (plus de 25 espèces) et des ixodes dans le terrain et donnent la possibilité de transport du microbe de la peste (Sergueev, 1 93^5 Bibikov, Bibikova, 1956; Kalaboukhov, 1969, etc.). Les Traquets non seulement transportent mais aussi diffusent les ectoparasites en vastes espaces de 1« région de leur nidification et leur hivernage. Les observations des voie8 et de la vitesse (en moyenne, 200-300 km en vingt-quatre heures) des migration saisonnières de millions d'individus de Traquet isabelle permettent de eup' poser la possibilité de transport du microbe de la peste par les'oisaux ma' lades à grandes distances. D'après 1' expériment, on a constaté la perte quart de population de Traquet isabelle le 10-e - 1 9-e jours après la con¬ tagion (Peyçakhix et d'autres, 1969, 1970). Malgré l'absense d'étude sy8t^' mat î que on connaît déjà des cas d'isolement de microbe de la peste du Tra9«e 1082 isabelle et de ses parasites en Altaï, dans les régions entre les fleuves Volga-Oural et Oural -Kouchum, à Daghestan et en Mongolie (Chevtchenko et d'autres, 1980). ADAPTIVE STRATEGIES OP BIRD BEHAVIOUR IB A BIG CITY 1 K.N.Blagosklonov] Department of Vertebrate Zoology, Moscow State University, USSR In the Moscow area (about 900 km2) there nest 110 bird species, the city Deing a survival habitat for many of them. Urbophobous birds (i.e. the ma¬ jority of birds) are retained where their natural habitats are preserved. Ihe urban avian fauna is composed of urbophiles (synantropes including) and Predominantly of species with labile behaviour (Corvidae. Stumidae) since behaviour is the main pathway of adaptation to urban conditions, which are fairly complex and varied. In many cities the number of Corvidae increases rapidly, each city with a dominant species: the hooded crow in Moscow, the raven in Riga, the rook in Lublin, the magpie in West Berlin and Gorky, the in Kharkov, the jackdaw in Tartu, etc. Selection has given rise to populations with a considerably weakened man- fright reaction. This is primary adaptation. Just like the tamest cage birds, as was observed by D.K. Belyaev, quiet and fearless urban crows develop changes in timing and periodicity of breeding. Drastically changed are the P°Pulation demographic structure and nesting behaviour such as "balcony" atarlings and tits, crow nests ostentatiously open in crowded places, their ïles't ranges being reduced by dozens of times. In food behaviour, stable in¬ dividual habits are due to imitation. Thereby, the number of trained birds is ever increasing, involving, in certain cases, the entire population. At a certain urbanization stage, migratory birds such as rooks, starlings, ®aHards (the three latter species from 1 960ies-1 970ies) settle down by re¬ ining populations wintering in cities. differentiation of ecological features in urban and non-urban populations 3Ult3 in ecological isolation. AGE-RELATED ASPECTS OP DIVING BUCK REPRODUCTION d-Blums, A.Mednis, A. Petrins ■institute of Biology, Latvian 3SR Academy of Sciences, Riga, USSR w ^ intensive long term banding program at the Engure Marsh, Latvia(north- ®8t Part of the USSR) has established a marked population of female Pochard ^ted Duck of known age. Physical condition of females (body weight and length), clutch size and egg volume as well as duckling weight and sur- clVSl varied with age of parent female. Yearlings nested later, and their oiu!°h Slze- e88 volume and one-day-old duckling weight were lower. The mean sin h 8iZ6 ^creased as seasoA progressed. This relationship held when i ^Sle aea classes were examined. Survival of offsprings produced by year* K 88 significant^ lower than that produced by older breeders (measured Random recovery rate and recruitment rate of females to the native marsh), can, femalea nesting in habitats of different quality exibited signifi¬ ed, in their morphological and reproductive characters; female ition. egg volume and one-day-old duckling weight of the same age cohort were higher in the optimal nesting habitats. Pochard yearlings were found to nest predominantly in sub-optimal habitats. Age-related différencies of parent females play an important role in the self -regulatory process of po¬ pulation numbers (see Mihelson et al., this issue). NESTING OP COMMON AND LITTLE TERNS (STERNA HIRUNDO AND STERNA ALBIPRONS) ALONG THE PO RIVER Giuseppe BogliaDi, Prancesco Barbiéri Istituto di Zoologia, Université di Pavia, Pz. Botta 9, 27100 PAVIA, Italy The inland population of Common and Little Terns nesting along the Po, the chief river in Italy, was cansused in 1981. Over a 536 km stretch of the river, from Turin to the Adriatic Sea, we found 35 colonies, with a total population of 353 pairs of Common and 405 of Little Terns. In many of the colonies the Little Ringed Plover (Charadrius dubius) was also found to be nesting. There were more colonies in the higher reaches of the river than in the lower, where the river is partially canalized. The mean number of nests, with a maximum of 10 per km, was positively correlated in the various sections of the river, to the amount of low and/or stagnant water and with the number of islets. The nesting population is stable, as may be seen from the partial counts made from 1977 to 1980. Nests were placed mainly on sandy or pebbly islets without any vegetation or on open banks. Both species use little or no material to line the nest, which are very scattered, having a mean nearest neighbour distance of 10.3+5.6 m in the Common and 4. 3+3. 6 m in the little Tern. SECONDARY SUCCESSION OP BREEDING BIRD COMMUNITIES IN DRY PINE-PORESTS IN POLAND Zdzislaw Bogucki, Jan Bednorz Institute of General Zoology, Adam Mickiewicz University, Poznan, Poland This study was made in a large area of uniform pine forests on poor sandy soils in northern Poland in 1978-80. The field studies were done with two methods: the mapping technique (at least 5 repeated censuses on 14 plots; sampled area - 165 ha) and the "taxation method" (censusing once but on ^ dispersed plots representing 9 age-classes of forest; sampled area - 678 ha)‘ The first one giyes an accurate number of birds inhabiting particular plot but the second provides a list of potential inhabitants of particular type of vegetation. Results differ slightly but biocentic indices are comparably The crucial stages of succession of bird 'communities according to the a®8 classes of trees are: (1) the open clearing (up to 7 years), only birds °f open country; (2) the brush (8-20), birds of coniferous bushes, increasihß density of pairs, absolute dominance (more than 50%) of Phylloscopus _lus_; (3) the thicket (20-30), poor breeding avifauna, formation of a fores* bird fauna, increasing species diversity, decreasing density; (4) the P°le' tree stand (30-60), formation of the pine-forest avifauna, density and di^' sity relatively low and stable; (5) the young forest (60-80), rapid i^e&3 1084 in diversity and in density, absolute dominance of Fringilla coelebs; (6) the matured forest (80-100), increasing portion of holenesters, absolute dominance of F. coelebs. further increase in diversity but stability in den- Sltyi (7) the old pine-forest (more than 100 years), greatest diversity and richness of bird community, stability in species diversity but further in¬ crease in density. RECORDING OF BIRD VOICE AT THE BRITISH LIBRARY OF WILDLIFE SOUNDS Jeffery Bo3wall, Ron Kettle British Library of Wildlife Sounds, The British Institute of Recorded Sound, 29 Exhibition Road, London SW7 2AS, UK The British Library of Wildlife Sounds contains about 8 000 separate tapé recordings of some 2 000 animal species, the majority of them of birds. B-l.O.W.S. also holds copies of all the natural history recordings in the ß-B.C. 's sound archive, comprising 6 000 recordings of about 1 500 species, ’"ell over half being of birds. It also houses over one, thousand gramophone ^Phonograph) records and cassettes of wildlife sounds, published between 1910 and 1982, again mostly presenting avian sound production. Co-founded in 1969 by Patrick Sellar and Jeffery Boswall as a new department of the British Institute for Recorded Sound, B.L.O.W.S. was inaugurated by David Attenborough and its full-time curator is Ron Kettle. The recordings come fr°ra all the zoogeographical regions of the globe, but particular emphasis Placed on the western Palearctic and Antarctica. The B.I.r.s, provides a free listening service. The opening hours are 10* 30-1. oo and 2.30-5.30, Monday-Friday. It is advisable to make an appoint- meht beforehand. Copies of most tape recordings and B.B.C. Sound Archives Wordings in B.L.O.W.S. can be supplied for scientific study on payment of a service fee and the completion of an agreement limiting their future use, and Protecting copyright. Offers of recordings are welcomed, and the Curator WU1 be pleased to supply details of how to contribute. If original record- XnSs are deposited, copies can be supplied to the contributor without char- expositors have the satisfaction of knowing that their work will be ^served for posterity and, provided they give agreement, made available °r research. In all cases the recordist's copyright is protected, and there BS Tno restriction on putting the recordings to any further use whatever.The win supply blank tape for use on approved projects, subject to a S^d agreement that copies of all recordings will be deposited in ‘7°-W-3. under the usual terms. B.L.O.W.S. includes a collection of books Zl °th*r Printed material relating to bio-acoustics. Discographies and Nicies about wildlife sound are published from time to time in the "8Utute's journal., Recorded Sound'! and further scholarly contributions W "horned. Three 'special issues, nos. 34, 54 and 74-75, marking the open- ««1. •». tenth ™iv.re«rl.. o' B.L.O.W.S. respective!, , .ere Ce- . ?; *»«>-,1, t0 „uallfe sound. Le.net. .« B.L.O.W.S. ere .v.U.hl. tile on. 1te of the poster. 1085 SOCIAL RELATIONSHIP AS A VARIABLE IN REACTIONS TO ALERT , ALARM, AND ASSEMBLY CALLS AMONG COMMON CROWS (CORVTJS BRACHYRHYNCHOS) Ellie D. Brown Dept, of Zoology, University of Maryland, College Park, Maryland, USA The Common Crow (Cor vu a brachyrhynchos) of North. America is a social species in which groups of individuals often harass a predator. I have in¬ vestigated the effect of the social relationship between sender and receiver in determining responses to various calls given in contexts involving poten¬ tial danger. Pour types of calls were tape recorded from each of 6 individual crows and played back to 7 captive Common Crows. The taped senders were eit¬ her well-known (e.g. , cageraates) , somewhat familiar, or unfamiliar to the receivers. Responses of each receiving bird were monitored by tape record¬ ing, and direct observation in some oases. Results were analyzed to deter¬ mine differences in response with respect to sender-receiver relationship; responses to playbacks pre also being compared with responses to naturally- occurring vocalizations of different senders. Results are discussed in relation to crow social organization. THE INFLUENCE OF MOUNTAINOUS AREAS ON BIRD MIGRATION Bruno Bruderer Swiss Ornithological Station, Ch-6204 Sempach, Switzerland There is ample evidence that mountainous areas have an influence on bird migration. However, detailed studies on the degree and nature of these in¬ fluences on the general course of migration, on different bird species, po¬ pulations and age-groups are largely lacking. It is the aim of a new nation¬ al research program to concentrate bird migration research in Switzerland on the study of migration in the area of influence of the Alps, in order to develop models on migratory strategies related to mountainous areas. This presentation aims at a stimulation of discussion on observed or sup¬ posed influences of mountain ranges (and other barriers) in different parts of the world. .Mountainous areas may have (actually or through selection) different meanings for migrating birds, such as: areas with limited food resources °r with improved food-resources (owing to later vegetation period or migratiuS insects); unfamiliar habitat; limited range of visibility; turbulent, ir¬ regular and unpredictable airflow; protection against unfavourable v/inds; updrafts; retarded movements of weather systems, followed by sudden weather changes; optical or physical barriers causing vertical or horizontal devis* ions in flight paths (and thus impeding orientation) ; lower temperatures sh^ decreased oxygen pressure at higher flight levels; leading-lines; releasers of innate shifts in the primary direction; and other factors. CLASSIFICATION OF BIRD POPULATIONS OF THE USSR V.V. Brunov Department of Geography, Moscow State University, Moscow, USSR of The subject of classification and mapping is the territorial groupie8 1086 Sumer and winter populations of birds of basic habitats. The populations are classified according to two parameters: the similarity in the ecology and storey structure, and the share of different geographical-genetic groups in bird populations. At the first stage of classification of populations ac¬ cording to the ecology and storey structure, groupings are singled out with Predominance of birds most differing in ecology (with predominance of forest birds, birds of open habitats,' water-bog birds, etc.). At the next two sta¬ ges, the populations are classified according to participation in them of birds of different storey groups. At the first stage of classification ac¬ cording to the share of different geographical -genetic groups in bird popu¬ lations, groupings are distinguished with predominance of birds of major in¬ dependent geographical-genetic groups; at the second stage the populations era classified according to participation in them of birds of subgroups dis¬ tinguished within these groups. When preparing maps of summer and winter populations of birds of the USSR, tbe legend is planned to be of three parts, viz., matrix-legend, textual legend and supplementary designations. Classification of populations accord- to ecology and storey structure is given in vertical columns of the mat¬ rix-legend, and classification according to participation of different geo- Sraphical-genetic groups and subgroups in bird populations - in horizontal c°lumns. The textual legend shows the dominant and co-dominant species in ibe populations, and also which types of habitat these populations are cha- acterized by. The total summer density of bird populations in one or another yPe °f habitat is shown by hatching of different closenesses in the supp- mehtary designations of the map of summer populations, and in those of the °f winter populations - by how many times the density varies from summer to winter. STUDY op SOME ASPECTS OF THE MOBBING-BEHAVIOUR OP THE STARLING (STURNUS VULGARIS VULGARIS L. ) Cristina de Bruyn, Rudolf Verheyen department of Biology, Universitaire Instelling Antwerpen, Belgium a fobbing in the starling occurs during the reproduction period. Upon seeing lvlnS little owl (Athene noctua (SCOP.)) a nestovmer reacts with calls ar,®Creaa>ing alarm’, ’spet’ call), a wing- and tail-flick, - Daanj e • -flight the owl and sometimes even pouncing on the predator. In a breeding °bber starlings generally join the first one. Ur observations (1980-1981-1982) allow a detailed description of the action (kind, intensity, latency, course, after-discharge, habituation the course of the mobbing-behaviour during the reproduction pe- With Mobbing by starlings shows important fluctuations during the year, a Peak during the breeding-season. te 6 Pleasing factors causing this behaviour include both external .and in¬ ti^*1 °0InP°nents. We report on experiments carried out in 1982 both m cap- , * *** in the field: U * ^mal factors. The mobbing reaction resulting from a) visual stimu- a dittle owl ( Athene noctua (SCOP.)), a squirrel (Sciunas vulgaris L . ) 1087 and a domestic cat (Felis catus L. ) , and b) acoustic stimuli of sounds ut¬ tered by the other starlings while mobbing. This will examine the possible communication function of these sounds. 2. Internal factors. The relations between the testosterone level in the starlings and its reaction to owls. TROPHIC EFFECT OF BIRDS IN STEPPE FORESTS OF THE UKRAINE V. L. Bulakhov, A. A. Gubkin, N. S.Romaneev Dnepropetrovsk University, Dnepropetrovsk, USSR There are more than 230 species, of birds of various phenological and trophic groups in steppe forests of the Ukraine. The annual consumption of the biomass by all birds in different types of forests totals 3.5-23.3 t/km2, where phytomass constitute 32.5-41.3% and zoomass 58.7-67.5%. Consumed bio¬ mass by phytophages constitutes 41.2-47.6%, zoomass of entomophages - 10.2- 13.0, that of predators - 0.004-0.05%. Birds affect about 400 invertebrate phy tophageous species and 10 species of rodents. In July the birds reduce phy tophageous biomass by 4.8% in damp ash-oak forest, by 8.7% in 'dry pine forests and by 2.9% in ash-oak plantings in placor plain. In the forest biogeocenoses, the biomass of Lepl dopt era is re¬ duced respectively by 7.6%, 14.1%, 4.2%, the biomass of Coleoptera - by 5.7%, 13-7%, 3.3%, the mass of Hemiptera - by 2.6%, 3-5%, 2.2%, that of Tenthredi- nidae by 5.0%, 8.7%, 0%, the biomass of Orthoptera - by 0.18%, 6.6%, 2.1%, that of Homoptera - by 0.9%, 2.3%, 0.6%, the biomass of terrestrial mollusks is reduced by 16%, 2. 5%,0«6%. The birds also reduce the biomass of rodents (by 13.6-37.0%). As shown the phytophagan consumption by birds in azonal forest ecosystems is more than in zonal ones (inosemtsev, 1978). By isolation of sample trees from birds, it was shown that in oak woods and floodplain oak forests, birds can reduce green mass losses, caused by phytophages, by 25-26% and stem - growth losses by 16-18%, in pine forest - by 17*5% and 6.8% respectively. In areas with dense bird population (oak forests) the reduction of losses can be 3-3.5 times higher. ON PHENOTYPIC VARIABILITY OF CLUTCH SIZE IN A POPULATION OF THE MEDDOW PIPIT (ANTHUS PRATENSIS) R. G. Chemyakin Kandalaksha State Nature Reserve, USSR 120 clutches of 5 and 6 eggs each (seven clutches of 4 and 7 eggs were left out; and the weight of nestlings of 104 broods were observed on the Aynovy Isles of the Barenz Sea in 1972-1980. Proportion of 5-egg clutches varied from 18.2% to 64.7% (M+m « 39.4+8.4%! n = 6 years). The mean number of nestlings from 6-egg nests varied from 4*9 to 5.6 (M+m = 5.24+0.13; n = 5 years), from 5-egg clutches - from 4.0 to 5»® (M+m » 4.52+0.26; n = 5 years). The weight of nestlings before leaving the nest in 6-nestling broods (n = 31) made up 17.8+0.16 g, in 5-nestling broods (n = 43) - 17.28+0.21, in 4-nestling broods (n = 30) - 17.43+0.22. If the clutch size is hereditable, the more fecund genotype should out tb® lesser the fecund one. In the present case the 6-egg elutoh is more productif' 1088 though on the average more than one third of clutches are less viable; 2) seasonal conditions which make the smaller clutch more productive are re¬ peatedly by more frequeot; 3) rearing of a larger brood adversely affects the parent's breeding success; 4) influx of less fecund immigrants is high; 5) part of genetically "6-egg" breeders lay a smaller clutch. Hence, it might be concluded that: l) weight, if considered a viability index, is higher in nestlings from larger broods; 2) the large clutch was found more productive in each of the observed seasons; 3) variation in ex¬ penditure energy spent by parents on rearing 5-nestling broods or 6 ones is almost negligible as is indirectly indicated by a greater weight of nest¬ lings from larger broods; 4) immigration of less fecund genotype is not to 136 fully excluded but it can hardly be intensive enough since the areas with ihe dominating 5-egg clutch are remote in distribution. All the data afford a conclusion that a considerable part of 5-egg clut- °he8 in the area are phenotypic modifications of various kinds. ASSORTATIVE MATING IN COMMON TERNS, STERNA HIRUNDO Malcolm C. Coulter hept. of Ornithology, The American Museum of Natural History, New York, 10024, USA I studied Common Terns on Great Gull Island, Long Island Sound, New York, Tjo » 1 • Although male and female Common Terns are almost identical, males tended 11876 larger bills than females. In 99$ of pairs examined the males had anger Hills than their mates. Furthermore, they mated assortatively : large- 1 Isd males mated with large-billed females çnd small-billed mated with ^all-billed females. This may be important genetically because bill size is Highly heritable. NOOD NICHE SEGREGATION IN THE GREAT REED WARBLER, ^££OgEPHALUS ARITWPINACEUS AND THE REED WARBLER, ^~§£IRPAC RUF, Bf HUNGARIAN RSEDBEDS fibor Csorgo department of Systematic Zoology and Ecology of the ®°ivös University, Budapest, Hungary w The prey composition, prey size distribution, and feeding microhabitats led6 analysed in Acrocephalus arundinaceus and A. solrpaceus at three reed- sites in Middle Hungary, by observation of the adult searching for food heck-ooliaring the young. by h6 Great Reed Warbler carried more variable food items to the young both mio^Pe°lea composition and size distribution and searched for food in more two Zitats than the Reed Warbler. There was a small overlap between the „ d6°ies in all aspects and sites studied. tjje 6 ^°°d of the Reed Warbler was more similar at the three sites while t0 reat Warbler had very different food items and microhabitat distribüt- 00 ‘ There "as a clear segregation between the two species at the sites of e*istence. 33'3a*98l 1089 CORRELATION BETWEEN FREQUENCY OF WING FLAPS AND FLIGHT VELOCITY IN THE GREY HERON (ARDEA CINEREA T.. 1 A.N. Cvelych, O.A.Mikhalevich, I. V. Zagorodnyuk Kiev State University, USSR Most attemps to establish correlation between wing flaps' frequency and flight velocity for various bird species have not proved successful so far (Sohnell,l974). Correlation between flaps' frequency and flight velocity in the grey heron (-?dea oinerea L. ) was studied. Inside the breeding colony during clam, wind-dead weather flight velocities were measured with the help of a trian¬ gular device (Cvelych, 1978). Number of bird's flaps on flight within the ob¬ servation strip were counted. Since it was found that the flight velocity of birds en route away from the colony to feed was statistically different from that of a bird flying back home after feeding, the obtained data were treated separately. The graph showing the heron's flying velocity in relatiori to its wing flaps' frequency is "V"-like, with a saturation point at the greatest speeds (correlative ratio r = 0.92; P> 0.001). The flaps' frequency was the minimal (2, 3 cycles p/s) whenHhe velocity was 39.7 km/h en route away from the co¬ lony, and 40.3 km/h in the opposite direction. Hence a conclusion can be drawn that for the heron there might exist a flying regime with the minimal energy expenditure (i.e. when the flaps' fre¬ quency is minimal) but the optimal flying velocity. This seems to agree with the data obtained by other researchers (Ryden, Kallaoder, 19645Kuzmin,SurbaDOV, 1978). ACOUSTIC DIFFERENTIATION IN THE YELLOW WAGTAIL- COMPLEX (MOTACILLA FLAVA SSP.) Harald Czikeli Inst. f. Med. Chemie, Veterinärmed. Univ. , Vienna, Austria Acoustic signals from various study-areas (South France, South Spain, North Italy, Yugoslavia, Bulgaria, Rumania, North Greece, Austria, Switzer¬ land, FRG, GDR) are compared (sqnagrams). There is a clear cut call-note dis- similarity: southern subspecies (feldegg, cinereocapilla and iberiae) have •thrill-call-note-types, whereas central and northern palearctic subspecies (flava, beema and thunbergi) have homologous non-thrill-call-note-types. Southern subspecies have song-types, which are missing in flava, having only one song-type. Sonagrams of song-elements were measured. Though partly sig¬ nificant there is wide overlap. Yet it can be shown by a discriminant-analy¬ sis, that there are two differentiated groups: flava on one hand and the southern subspecies including hybrid-populations on the other. Subspecies¬ grouping by acoustic data makes much more sense in this case than the prev¬ ious museum-studies. There is less inter-group hybridization than within these two subspecies-groups. Moreover there is no more patchy distribution of subspecies-groups, like there has been in former taxonomic revisions. Juveniles of flava utter a thrill-call-note type, which might suggest, thrU1' call-notes being the elder. In those intergradation-zones where few hybrids (20-30%) occur (flava x cinereocapilla x feldegg in the Alps and in Dalm^*®1 1090 £lava x feldegg in East Yugoslavia and Rumania) there is bilingualism in regard to thrill- and non-thrill-call-notes, no intermediary types exist. This bilingualism is restricted to southern phenotypes and hybrids with flava, but is lacking in pure f lava-phenotypes. In the Camargue (South Pran¬ ce) where flava and cinereocapilla hybridize ( 73 % hybrids) there -is an in¬ termediary call-note-type. This intermediate pattern is regarded as a pro¬ duct of hybridization. Considering that there is influence of learning, it is auggested, that the fixation of used call-note-types within the respecti- Ve Populations is a question of phenotype frequency (ratio parentalss hyb- rids) or the social or sexual position of potential tutors. TERRITORIAL BIRD GROUPINGS AND COMPONENTS OP anthropogenic landscape A.K.Danilenko, E. A. Danilenko Moscow State University, USSR Formation of territorial bord group-populations (TGP) is affected with some regularity, by anthropogenic landscape components (CAL). Among the CAL, railway and motorcars are most common. Because of it, and also because of all sorts of linear extensions (such as power transmission lines, gas Pipelines, etc.) that go along the rail and motor ways, they pley ar. im¬ portant part in forming birds' TGP all over the USSR. Thus, rail and motor Ways ®ay serve a suitable model for establishing any regular effects that CAL may have on birds' TGP. B°th the qualitative and the quantative compositions of natural birds' are affected by CAL. The greater is the saturation of CAL, the more atrikingf as compared to natural conditions, is the contrast they create, tlle greater are their effects in either expanding the existing ecological asibiiities or creating the new ones. ^or instance, in the steppe zone jackdaws, rooks, magpies and some other aP®cies nest in forest strips and on power bearings. In the forest zone the aa®e CAL are insignificant; if there are no forests, the jackdaw nests in ridges, roof recesses in stone building, etc. Thus CAL affect the format- °h of birds' TGP in many various ways depending on the nature of the zone °Bserved. TROPHIC RELATIONS AND BIOCENOTIC ROLE OR BIRDS IN TUNDRA B»N. Danilov institute of Plant and Animal Ecology, Sverdlovsk, USSR °*t of 64 bird species populating Yamal, seven species are plahteaters, apVe eat vegetative parts of plants, though not very regularly yet, five ! 6 l3erry -pickers, ten eat seeds. Speaking of comivores as birds' feed, byTnSa are eaten by nine species, microtines - by seven, willow grouses b ive> ducks - by five, shorebirds by six, passerines by eight and fish - eight. Speaking of insects as birds' feed, longlegs are eaten by 35 Z °ies (With 16 out of 35 species consuming them in great numbers) flies - u 7 3Pe°ies (with 10 in great numbers), chiromids - by 23 species (with Wating them abundantly) ground beetles - by 23 species (with 3 - in great b6rs)' teathredines larvas - by 1 3 (with 5 in great numbers), anarchie- by 15 (with one speecies very actively), triphopters - by 17, staphilinids - by 1 6. Over 1 ha of water aurfaoe in the summer months of different years birds consumed from 5 040 to 15 330 kilocalories, while over 1 ha of tundra onground insectivorous consumed from 3 300 to 8 1Q0 kilocalories. In spring their intake of momentous insects' supply for the 24 hours wa3 0.5-0.695, in summer - 1.5-1. 7%, in early autumn - 0. 4-0.7%. The total decrease in birds' prey is slight, for longlegs it is 1.3% of the supply, for chirono- mids - 0.4%, for arachnes - 4.7%, for tenthredins larvas - 2.4%, for lepi- dopterous larvas - 6.3%. Consumption was not even over the whole territory, it was quite random, when in some parts prey was consumed by half or more. Birds' energy expenditure came up to 0.3-0. 6% of all animals' energy over tundra. The role of birds in tundra's ecosystems embrace the quantitative re¬ gulation of birds' population and the regulation of the energy role of un- dertrophic levels. Moreover, birds transfer from water to land 2.5 kg/ha (damp weight) of organic substances. SHORT MIGRATORY MOVEMENT OP ROBIN IN CAMPANIA, ITALY Raffaele D'Anselmo, Antonio Lubrano, Danila Mastronardi, Mario Milone Istituto e Museo di Zoologia, via Mezzocannone 8, 80134 Napoli, Italy Erithacus rubecula rubecula is found in Campania, where it is considered to be a permanent resident. However, it undertakes regular migrations re¬ lated to its annual cycle. It prefers to winter in open fields and along the shore and to breed in mesophilic areas. The short migrations, which usually terminate on the inland appenniDics (mountains) , follow routes that take advantage of rivers like the Sele and the Voltumo, of the Lattari or Aurunci mountain chains, or of narrow valleys between the, Picentini and Al¬ bum! mountains. The major breeding sites are localized in the Matese, Lat¬ tari, Picentini and Albumi mountains. The migratory routes were studied, through repeated capture of individuals, beginning from Vivara Island, through the Gulf of Naples and towards Partenio, Camposauro and the Matese mountains. A faunistic inversion was observed in the mountains near Naples due to the peculiar microclimate character of this area; the Robin breeds at the bottom of the Astroni Crater and usually passes the winter months along its top. We have tried to differentiate the migrator of heterogeneous populations through an omithometric analysis. BIRDS RESOURCES OP THE YOUKON-KUSKOKWIM DELTA, ALASKA Christian P. Dau Izembek National Wildlife Refuge, Pouch 2, Cold Bay, Alaska 99571, USA 2 The Yukon-Kuskokwim Delta comprises an area of approximately 691 60 km * 400 kilometers north to south and 320 kilometers east to west from 60° N t0 63° N latitude and 160° W to 163° W longitude. Low, wet sedge-gfass meado* supporting numerous waterfowl and shorebird species, in high densities, d°'t minate the coastal fringe habitats. Lichen— ericaceous tundra prédominât®8 interior and more elevated locations. The avifauna of the vegetated in*®1" tidal zone, the low coastal frin affected hy maximum storm surges, supP° 1092 the broadest composition of nesting species and higher overall densities than all other habitats on the delta. Approximately 49 species nest within the vegetated intertidal zone, 36 of which also occur in other delta habitat Twenty-four — >ecies are known to nest only in habitats other than the vege¬ tated interti *1 zone. Small tidal sloughs and tidal rivers numbering 1933 311(1 153, respectively occur within the 8942 km2 area of vegetated intertidal These water bodies in addition to 27 lagoons p ovide essential molting and feeding areas for 22 species of waterfowl and 21 species of shorebirds. A total of approximately 100 species of birds occur regularly as both spring 511(1 fall migrants on the Yukon-Kuskokwim Delta. GENTOO PENGUIN ECOLOGY Bernard Despin Bsspin B. , Dr. Laboratoire de Thermoregulation CNRS, 8 av. Rockfeller, 69373 Lyon Cedex 2, Prance The Gentoo Penguin breeding cycle has been studied in two breeding loca¬ lities: Crozet Islands (ile de la Possession) and South Orkney Islands (Sig- ^ Island). The Gentoo Penguin is to be seen everywhere on the Islands but it is never abundant. BSg and chick mortality is very high on Crozet and less important on Sig- ^ (1976-1977) but it is sometimes catastrophic (South Georgia 1978). Chick faring, bird size, food and call have been compared in both populations. At attempt is made to explain the wide geographic distribution of the Peoies in relation with the ecological data. A°TH AND BEHAVIOUR IN DOMESTIC PIGEONS Pierre Devi ehe, Juan Delius Ruhr-Universität Bochum, Experimentelle Tierpsychologie, Uni ver si tat ss tr. 150, 4630 Bochum, Postfach 2148, PRG Extensive studies performed on mammals have clearly demonstrated that in several species, various peptidic hormones, and namely adrenocorticotrophic Ormone or ACTH, exert an important modulatory influence on behaviour. UP to now, however, the possibility that ACTH directly influences the be- ,avl°ur of non-mammalian species, and especially of birds, has been poorly inve3tigatecU *e studied this problem in the domestic pigeon. cs ACTH was administered either peripherally (into the pectoral muscles) or rally (into the cerebral ventricles). Tlle influence of the hormone was researched on one hand on "displacement ^tivitiea-. auch as yawning, headshaking or preening, and on another hand on °hditioned behaviour. Positive data were obtained, showing that ACTH induces shortterm effects ^Bearing within minutes after an injection) on some behavioural patters. ln Montant qualitative differences between results obtained in mammals and Pigeons were also observed. T^ese differences will be discussed. They point out to the possibility that the endocrine regulation of some aspects of behaviour differs in birds and 111 mammals. IO93 DEVELOPMENTAL FACTORS IN BIRD BEHAVIOUR DURING EARLY POST-EMBRIONAL ONTOGENESIS L.P. Dmitrieva, S.N.Khayutin Institute of Higher Nervous Activity and Neurophysiology, USSR Academy of Sciences, Moscow, USSR Study has been made of the relationship between the complication in the organisation of natural behaviour of 4 birds’ species (Ficedula hypoleuca, Parus major, Phoenicurus phoenlcurus and Cuculus canorus) and the whole comp** lex of ecological factors underlying the steady environment in the early post-embrional ontogenesis. It has been shown that at an early nestling stage only feeding behaviour appears to be formed. Thus before nestling's eyes are open, it is governed by acoustic stimuli, i.e. by wide spectre sounds arran- ged in mechanical succession (the bird makes noise with its feet, disturbs the nest, produces a specific "feeding" call). The passive defensive respond® appearing at the beginning of the second half of the nestling period (the bird becomes apprehensive) is controlled by rhythmically arranged alarm calls with narrower spectre sounds compared with a "feeding" call. Finally the be¬ haviour directed by species song appears at a later nestling stage. The rhythmical and structural complication of the above signal is accompanied by the narrowing of the frequency spectre. In the post-blind period the mo¬ dality of starting af ferentation of feeding behaviour changes which is now induced by diffusive change in lightning, the latter being caused by the parental shape in the nest hole. At the end of the nestling period food-ob¬ taining response is induced and directed by the moving silhouette of the bird. The involvement of the organised visual environment in the ontogenesi3 of the goal-directed behayiour suggests the existence of the corresponding visual experience acquired during specific for each type periods of develop¬ ment. Thus the complication of the acoustically and visually directed behaviour is typical for all the investigated species of nestlings in early post-e®- brional ontogenesis. It is accompanied by parallel strengthening of control¬ ling signal patterns. The gradual steady complication of sensory mechanic®9 and forms of behaviour directed by them is connected with the growing requis ements for the perception of the environment which becomes more and more complicated. DYNAMICS IN THE VARIABILITY OF MORPHO-PHYSIOLOGICAL INDICES IN BIRD ONTOGENESIS L.N.Dobrinsky Institute of Plant and Animal Ecology of the Urals Scientific Center, USSR Academy of Sciences., Sverdlovsk, USSR Changes in the values of variation coefficients in the relative weight® of heart, liver, pancreas, brain, locomotory and stomachic muscles, adren6 glands, and relative bowel and caecum lengths during growth and develop31611 ' were studied on birds of 50 species. A distinct inverse correlation bet«®eI1 the functional importance of each organ and the amplitude of its relativ'e size variability was examined. Variation coefficients of the heart and the 1094 Relative weights of the flight musculature were significantly greater in the embryos than in the young and the adults. This indicates that during the ac¬ tive life span of the bird (i.e. genetical diversity is disguised by pheno¬ typic variability) gradually individual, genetically determined changes in ese organs were smoothed away. The reverse phenomenon was observed in index changes in liver with age: for the embryos as compared to the young (generi- 0&1 diversity is strengthened by phenotypic variability) variation coeffi¬ cients were much lower. differences in the fine neuronal structure OF CERTAIN BRAIN SECTIONS IN CROWS AND PIGEONS. D. P. Dobrokhotova Department of Physiology of Higher Nervous Activity, Moscow State University, USSR Study of fine neuronal structure of paleostriatum, neostriatum and hyper- strlatum ventrale in crow and pigeoo brain was carried out on histological Preparations by Golgy method. The differences manifested themselves in the ^ creased area of cellular-dendritic fields, the increased number of dendrit- endings and a denser cover of protoplasmic protrusions in neostriatum and Perstriatum ventrale as compared to paleostriatum. The complication of the heuronal structure might determine greater functional capacity of neostriat- ^d hyperstriatum ventrale as compared to that of paleostriatum, th Dlfferences in the fine neuronal morphology have been observed between analogous neuronal groups in crows, possessing a great capacity for ex- Pdation and in pigeons deprived of it. As compared to pigeons the crow e°atriatum, neostriatum and hyperstriatum ventrale neurones are morpholo- ®lcally finer. tJle dendrites are thinner, more sinuous and are provided with ^denser cover of extremely fine 'protoplasmic protrusions. A more ingenious ronal structure apparently sets up morphological prerequisites for es- dahing a greater number of contact junctures and, probably, for finer ^alysia and processing of information by these brain regions in crows than Pigeons, which may contribute to crows’ greater capacity for extrapolation. CORRELATION OF COPPER, LEAJD AND ZINC MAINTENANCE IN plumage op some birls • V. Dobrovolskaya Centre for Bird Ringing, Academy of Sciences, Moscow, USSR of Satlation of biosphere with metals is one of the most important problems hitennr0mnental Pollution. United Nations Interdepartmental Group on mo- °ring ^3 llated lead> merculy> cadmium, copper as pollutters to be given attention. h0 6 easential condition for pollution control is in establishing regional hi~.S °f natural content of theseVnetals since technogenic pollution is Bo*e^ tha* the natural content, the latter due to its geochemical origin ®es being locally anomolous. In n aearCh °f bioindicators sensitive to the concentration of heavy metals her,atUral e^ironment by spectroscopy we examined metal content in the feat- °f 3ome bird species over different areas of the USSR European part. 1095 Direct correlation between lead and copper content in the plumage (r=0. 30, p .d 0.05) was established, though no correlation was found for zinc and lead or zinc and copper. Knowing the copper content, which is easy to de¬ tect, one can predict the lead content in the plumage. THE GREAT BUSTARD (OTIS TARDA) POPULATION AND CONSERVATION Max Dornbusch Biological Station Steckby of the Institute for Landscape Research and Nature Conservation, Academy of Agricultural Sciences, Halle, GDR The Great Bustard (Otis tarda L. . 1758) is an endangered species. The western palaearctic subspecies (0. t. tarda) is estimated at about 17000 birds (i960), the east Asian subspecies (0. t. dybowskii) amount to more than 3000. The western distribution centres are in the USSR (7000), Hungary (3400), GDR (500) and also Spain (more than 4000 birds). The decrease in the whole breed¬ ing area i3 reflected in the population decline in the GDR from 4000 (1940) to 500 birds (1980). Conservation management is necessary. The Great Bustard is internationally protected by CITES. In the GDR there has been no shooting Since 1949, protection by law as an endangered species (1955) and establish¬ ment of a special conservation programme (1971). In 25 State Bustard Protec¬ tion Areas (80 000 ha), there are protection of display and nest sites, cul¬ tivation of Brassicaceae etc. Between 1968 and 1980, 240 young bustards fro® disturbed clutches were hatched, hand-reared to adult size, ringed and re¬ leased in the wild. Since 1978, released females have been bred successful¬ ly. Several times those ringed birds returned after migrating more than 500 km from wintering grounds in the Netherlands. DER SCHUTZ DER WEINBERGE UND AGRARROHRSTOPPE VON VÖGELN IN USBEKISTAN A. Dshabbarow Moskauer Staatliche Universität, UdSSR Innerhalb 3.5 Monaten schädigen die Vögel den Weinbergen in Usbekistan. Im Juli werden die frühreifenden Sorten der Weintrauben von turkestanischeh 'Staren, Mainen, indischen Sperlingen, Feld- und Weidensperlingen geschädigt Im August sammeln sich in den Weinbergen auch Dohlen und westasiatische Elstern. Im September-Oktober werden die spätreifenden Sorten der Weintrau¬ ben von turkestanischen Staren, Pel Sperlingen, Dohlen und Elstern geschädigt Der Schaden betragt 20-25%. Um 10—20% werden Kernfrüchte, Getreidekultur uh Feige geschädigt. Es wurden Vergrämungsmassnahmen ausgearbeitet: akustis0*1® Repellents und optische Reizmittel (Spiegelkugeln). Effektiv sind Alarmsi® nale von Mainen und Rufe des Baumfalkes. Die Spiegelkugeln werden auf 2.5 3.0 m hohen Stangen gestellt (6-8 Stück auf 1 Hektar). Das vermindert den Bestand der Vögel auf landwirtschaftlichem Gelände um 60-90%. 1096 Role op environmental stimuli in regulation op annual CYCLES OF PROLACTIN SECRETION IN MIGRATORY AND SEDENTARY BIRDS V. P. Hyachenko Biological Station of Zoological Institute of the USSR Academy °Y Sciences, Rybachy, USSR Amplitude of diurnal fluctuations of pituitary prolactin content indicat- g the intensity of prolactin secretion was studied in the migratory Chaf- mch and the sedentary House Sparrow during the year. In the Chaffinch in- reaae in diurnal fluctuations occurs from April to October and coincides Productive phases of the annual cycle. In winter and in pauses between easonal events, pituitary prolactin content decreases and its diurnal fluc- °ns disappear. In the House Sparrow seasonal variations of the amplitude th f’l’UC^Uat:i'ons are similar to those in the Chaffinch. Differences between e two species relate to the pattern of diurnal rhythm of pituitary prolac- n in migratory periods. Amplitude of diurnal fluctuations of pituitary prolactin in every seaso- state (with the exception of the pauses' correlates with daylength. Ex¬ periments with different photoperiodic regimes in winter and in summer also ^ hfirm that the amplitude is mainly conditioned by photoperiod. However ^^reaae °i the amplitude in. transitional periods between seasonal events cates that other factors (perhaps endogenous) may influence the inten- y °f prolaction fluctuations. Mother environmental stimulus affecting pituitary prolactin content is ^emperature. Low temperature in winter has been shown to cause an increase diurnal fluctuations of pituitary prolactin in Chaffinch. iNTERCHANGE OF HELMINTHS OF WILD BIRDS AND P°UuTRY IN KAZAKHSTAN ““ ^«Gvosdev institute of Zoology of the Kazakh SSR Academy of Sciences, Alma-Ata, USSR f finitely marked community of helminth fauna of wild and domectic Galli- ln^es Anserifomes was determined as a result of the studies carried out Kazakhstan. Undoubtedly it shows the interchange of helminths constantly PatJne PlaCe bet*een them. It is known that about 20 helminth species are ( Oogenic to domestic fowl and turkeies parasite in wild Gallifomes feo!U’ 6rey Pa«ridge, pheasant etc.). More than 50 helminth species in- a domestic ducks and geese were recorded for wild waterfowl. There is Pou,"!1111'6 ec°l°gical chain providing helminth interchange of wild birds and tic e and ariaing now and then of epizootics of helmithosis among domes- Poul °WlB. ducks and feeese. Helminth fauna interchange of wild birds and V» ia also conditioned by historic factors. Conditions of domesticating *e Period from the beginning of domesticating of birds were of consider- imPortance t, «*» «l.etio» of poult»...l.= «°» of thoir du. f J '*««• «g». la.rtt.MJ took pl.c » »»■•< app..».o. of ... hel.l.th C‘ ***»*« to ,h. host, und to the oo.dl.io», of .help keep.ag ch.ag.d 1« and abi cess °f domesticating. IO97 BIOLOGICAL INTERPRETATION OP AVIAN SKULL MORPHOLOGY P. Ya. Dzerzhinsky Moscow State University, USSR Method of functional analysis based on morphological description draws on the physical laws underlying the mutual matching between the bone-muscu¬ lar construction on the one hand and the ecological properties of the spe¬ cies on the other. The skull ip to be analysed as a complex bony system to¬ gether with the ligaments and muscles as part of the whole feeding apparatus (jaw and tongue apparatuses). Methods of fundamental mechanics allow one to establish the mechanical properties of the morphological system which clear¬ ly determine its functional potentialities, and in this way afford the re¬ cognition of the biological (e.g. ecological) aspects of skull structure. The examples we used as illustrations are related to the significance of various cranial features such as the "hyoid" horns, lower and false upper jugal archer, schizognathous and schizorhinal conditions of the upper jaw and the structure of some quadrate articulations. THE EFFECTS OP MILITARY JET OPERATIONS ON NESTING BIRDS 07 PREY David H. Ellis Pish and Wildlife Service, USA During the 1980 and 1981 field seasons, data were gathered at more than 40 breeding sites of 10 species of raptorial birds in an effort to record responses to low level jets and sonic booms (or simulations). Severe nega¬ tive responses were occasionally observed. Most often adults and large young were merely alerted or alarmed by the stimuli. Young falcons tended to flee deep into the eyrie in response to nearby jets. No eyrie abandonments or reproductive failures were attributed to the jets or booms during the study- Eyrie reoccupancy rates were considered normal for sites tested one year and checked for occupancy the next. FEEDING ECOLOGY OF THE NIGHT HERON NYC TIC OR AX NYCTICORAX IN RICE FIELDS Mauro Fasola Istituto di Zoologia, Università di Pavia, Pz. Botta 9, 27100 PAVIA, Italy A dense population of herons (especially Night Herons, about 12.500 nestB in 1981) breed in about 5.000 km2 of Northern Italy in an area with few Qfl' tural marshes but with intensive rice cultivations. Rice fields, more uni¬ form and more easily observable than most natural acquatic habitats, are very suitable for studies on the ecology of wading birds. In our study area (near Pavia) , the main prey of Night Heron during nest ling period are amphibians, 60.3% (in number), and fish, 69.4% (in diy weight). Herons capture their prey in rice fields 60-70% (no.) or 30-60# (d.w. >\ a major prey item is tadpoles which are abundant at the time when the nestlings are growing and have higher food requirements. Observations made during the full daily cycle (at night with light in¬ tensifiera) showed that in nestling period, the Night Heron has a unif01® 1098 Activity rhythm, with a higher daytime food intake, when more tadpoles are a en. Prom these data and from the energy content of prey and the expendi- ure of each activity I calculated the mean energy intake of an adult as 0 kcal/day, or 112% of its expenditure plus that of the nestlings. The dispersion of the Herons to feeding grounds was significantly clumped, ^ the degree of aggregation varied in relation to patchiness of the prey, supporting the view that herons use other individuals as indicators of good oraSing sites. During foraging flights, herons do not leave the heronry Randomly in time and in flight directions, which supports the hypothesis of 6 colony as an information centre. They alight near plastic models of 6 ing herons in poor feeding sites, so they also locate food sources by i^tue of seeing other birds feeding. morphophy siological mechanisms op certain complex FORMS op bird behaviour I. B. Fedotova, Z. A.Zorina department of Physiology of Higher Nervous Activity, Moscow State University, USSR The lesion of the archicortex and the Wulst (striatum section progressi- developing in the class of birds) was attempted to determine the secti- in 0 Dird brain responsible for the functions performed by the new cortex mammals. Influence on the following experimental models of elementary aaoning ability was studied: the ability to extrapolate the direction of a food irritant, withdrawn m 'the field of vision, - in birds with an average (chicken) and high (Cor- level of reasoning ability; j tlle ability to operate the dimensions of figures obtained empirically - tedtiï,<ÎS a high level of reasoning ability (Corvidae). It was demonstra- ’ that the removal of the Wulst brings about behavioural changes common botln crea species in performing extrapolation tasks; more specifically, it in- the 86S the tncidence of failures accompanied by disorderly movements about of °age* The fact confirms the involvement of the Wulst In the construction ala°°mi>lex eyesight-controlled motory acts programm (Morenkov, 1975). It was len f0Uild that after the operation chicks retain the characteristic preva- liigCS °f 00rrect solutions (turning round the screen at the right side) dur- CorvrerOUS task Presentations (Zinovieva, 1975). In contrast to chicken, thoid 06 l0St the ability to extrapolate. In case of experienced birds, the ihco eïlGe °f correct passages decreased, even though it exceeded that of the eve^rre0t otles- Experimentally naive birds lost their ability to extrapolate ihig ln s*mPli-fied experimental situation (shortened screen). In contrast to hot [ the abllity to operate empirically-obtained dimensions of figures was repaired, in spite of the lesion of the Wulst. abUit data S° far received suggest that the structural basis of reasoning a\ ^ in birds varies according to: 1SVel of development in different species (Corvidae, chick, the fonn of reasoning ability specific to birds of a particular cles. 1099 VARIABILITY OP PLUMAGES IN THE SLATY BLACK-BACKED GULL LARUS SCHISTISAGUS, STEJNEGER L. V. Firsova Zoological Institute of the USSR Academy of Sciences, Leningrad, USSR Analysis of a series of 120 specimens (of which 63 were collected by the author at Geka Bay, Olutorski District, Kamtschatka Region in 1976-77) of Slaty Black-backed Gulls of different ages showed that: (1) A clear boundary for plumages is not observed in all individuals. .For the third nuptial plu¬ mage, 1 bird (of 11) had pure white reotrices, and for the fourth nuptial plumage, 8.7% of the birds (of 57) had remnants of brown coloration on these feathers, (2) In the fourth nuptial plumage, decreasing brown coloration on the feathers of the tail and the wings is independent to a considerable ex¬ tent. Birds with brown coloration of the reotrices may have the definition coloration of the wings, and on the contrary, individuals with pure white tails may still have the brown coloration on the wings developed to a maxi¬ mum amount. Irrespective of the coloration of the reotrices, a gradual tran¬ sition exists from maximum to minimum development of brown coloration on the wings. (3) The definitive coloration of the reotrices appears as early as the fourth non-nuptial plumage in 92% of the individuals and the definitive coloration of the wings appears only in the fifth non-nuptial or fifth nup¬ tial plumager in 98.3% of the birds. Therefore, the principle criterion of differentiation of the fourth and fifth plumages should be the coloration of smaller feathers of the wing (rudimentary primary, distal major primary coverts, feathers of the alula and minor secondary coverts), not the colo¬ ration of the reotrices as was accepted earlier (Firsova, 1975). NESTLINGS' CONTROL OF LOCOMOTION REACTIONS BY ACOUSTIC SIGNALS S. Ju. Fokin Central Research Laboratory of Hunting Economy and Reservations of the RSFSR, Moscow, USSR Our purpose was to study control of locomotion of nestlings under con¬ ditions of game-breeding farms by using "acoustic traos". 9 species of maturonal birds (Anseriformes, G_alliforme3) were observed. During the ex¬ periments records of different acoustic signals of the nestlings, females and their monotonal imitators were produced to the experimental groups of the same nestlings. The results of experiments showed that: (l) It is PoS" sible to use the juvenile contentment sounds, call-sounds of the female and monotonal signals in the specific ranges of frequencies as the acousti0 attractants if these signals were first presented to the nestlings during the "critically- sensitive period. (2) The hatch of nestling may be attracted to an immobile "acoustic trap" only in a distress biological situation. ^ In comfortable situations it is possible to direct the nestling movement W using mobile loudspeakers, only. (4) The acoustic attractants retain their influence until the birds are one month old. (5) The acoustic attractants can be used in game-breeding and poulti^-breeding for getting the nestli^8 together and for transferring them in a given direction. 1100 COMPARATIVE FORAGING EFFICIENCIES OF SELECTED AVIAN FRUGIVORES Mercedes S. Foster Museum Section, U.S. Fish and Wildlife Service National Museum ' of Natural History Washington, D.C. 20560, USA While the different foraging methods of avian insectivores have been studied extensively, relatively little attention has been directed toward the foraging behavior of frugivores. In this ongoing study, I am examining the feeding methods of more than twenty species of birds that exploit fruits djji.Qphyllu3 guarani ticus (Sapindaceae) either' opportunistically, or as a Primary food source. This tree, a common component of the forests of eastern ^araguay , haa fruits ranging from 7 to 10 mm in diameter. Observations are being made of birds in the field and in captivity. Particular attention is beihg paid i0 the manner iß which the fruit is removed from the branch, the Way the bird manipulates it in its bill, and the method by which the pulp is Separated from the single, large seed. The way in which these tasks are per¬ formed is determined in large part by the size of the bird's gape relative fruit size. Efficiencies of pulp removal by birds using different methods b&s been measured, and allows for an evaluation of these methods in terms of Ptimal foraging strategy. Population analysis of Sardinian warbler in the vivara ISLAND (MEDITERRANEAN SCRUB) Mauri zio Fraissinet, Diletta Coppola, Gabriele de Filippo, Mari0 Mi lone -ktituto e Museo di Zoologia, via Mezzocannone 8, 80134 Napoli, Italy This work presents an analysis of certain ecological aspects of the Sar- lnian Warbler (Sylvia melanocephala) , which is particularly adapted to the dd °Ii®ate of Mediterranean islands. Preference of habitat and distribution of the species were studied ^Ihly by employing the index of diversity (H). An analysis of stomach con- of accidentally killed specimens and a study of other competing species ^R°bin, Blackcap, Hedgesparrow, Chaffinch) in the area enabled us to compre- p6nd better its niche and feeding habit. This species is mainly insectivorous. re°al material, song and courtship behaviour were also studied, always in celatioaship to the characteristics of the scrub ecosystem. Capture and re- *Pture of ringed individuals were used to study population dynamics. Brief ouf118 ml8raW movements were observed; in this period migratory individuals numbered the local population. on,:lnally study of the structure of local population was complemented with «Uthometrie tables. The life span of the of Sardinian Warbler is 3 years. URBAN and SUBURBAN AVIFAUNA IN HOKKAIDO, JAPAN ^Jimaki Obihiro University 080, Japan was * -tudy ot the œa avifauna during the »reeding ..«.on „rï04'1 «dation vegetation cove, in Obihiro, Hokkaido. The »u-ber bPeolea ob.erved increased a. the percentag. of vegetation cover ln- »nd the «mtionahlp between the nu«bar of bird sp.oiea Pasturage of cattle, recreation, etc. This site (about 120 sq km) in- ivUdes fhe area inside the V.R. and some 5 km outside it. 2. Site II - relat- V6ly natural tundra environment (about 60 sq km). ro 011 both sites micro-rodent population peak was observed in 1979 and dep- easi°n in 1981. ' 3oatraiy to what was to have been expected, Rough-Legs' population den- ^ 1971 and 1981 and the breeding success in 1979 appeared to be higher aite I, 1108 ( B1BU0WÎŒÆ 1979 1981 nesting density site I site II site I site II (pairs/100 sq km) breeding success (average 19.4 14.7 12.5 8.3 fledgelings/ successful nest) 4.5 3.2 1.8 2.8 The data suggest, that the man-made landscape is likely to possess cer¬ tain advantages for Rough-legs which, to some extent, make up for the disad¬ vantages of the man-cultivated site. There might be a) comparatively greater abundance of microtine rodents (mainly voles) within the V.R. and their greater vulnerability because of scarce tundral vegetation, especially shrub¬ bery, and its substitution for carex-cereal cover; b) greater abundance of food in early spring, e.g. migrating ptarmigan dashing against the TEL wires. The TEL poles may serve as additional attractions for those raptprs as they are suitable perch sites and even nesting sites (5 neats were found on them)* Along the TEL Rough-legs showed especially high nesting density of 33*5 (1979) and 18.8 (1981) pairs/100 sq km. THE BIRDS OP PORES T-PLANT AT IONS OP MOLDAVIA I.M.Ganja, T. N. Kurganova, L.S.Buchuchanu Institute of Zoology and Physiology of the Academy of Sciences of the Moldavian SSR, Kishinev, USSR The dependence of specific and quantitative composition of birds on the quality, structure and age of plantations was determined. No more than 12 species of birds nested in young plantations. The population density was p 370 pairs/km . Larks, Stooechats and Warblers were predominant. In broad, dense middle-age forest-plantations tne population density of birds is 970 pairs/km2; the number of species increases to 24. Warblers, Thrush Nigh" tingale. Shrikes, Golden Oriole Magpie, Turtle Dove, Greenfinch predominate* The largest population density of birds (1600 pairs/km2) and number of spe" cies (42) were found in old forest-plantations with well expressed tiers. Shrub and crown species predominate in this plantations. Hole-neBting birds appeared here. The narrow forest-plantations, with high population density of birds, are characterized by few species of birds. SEASONAL MIGRATIONS OP LARUS ICHTHAETUS PALL. IN KAZAKHSTAN E. I. Gavrilov, E.M.Auesov, A. M. Sema, E.N. Volkov Institute of Zoology, Kazakh Acadeny of Sciences, Kurgaldzhino reserve, Alma-Ata, USSR The seasonal migrations of Larus ichthyaetus Pall, were studied at Alako:L Lake, Aral Sea, Tengiz and Dzalauly Lake (Kazakhstan). During 1952-1980, we banded 30376 nestlings and received 921 returns. Analysis of the results &e" monstrated that the spring migration began by the end of February and earl/ March. Adults migrate in shortest time but elongated flight of immatures i® finished by the end of April or mid-May. After the fledglings have begun t0 fly (June-July) , the gulls disperse very widely and the areas of birds f*®1* different colonies overlap very much. Over the greater part of Kazakhstan the migration is finished by October and the birds reach winter quarters °r 1104 near them In November. The winter quarters are mainly situated in the southern Caspian Sea and inland reservoirs of Iran. Small numbers of Larus Achthaetii h stay on the coast of the Arabian Sea, at Tana Lake in Ethiopia, in the delta of Brahmaputra (India) and probably at the Black Sea also. The wide wandering of birds during non-breeding time is an adaptation which pro¬ vides successful reproduction of progeny under sharp changes of external conditions in the nesting area. The mortality of gulls form 80% during the first year and 50% per anpum during the remaining years. The maximum sur¬ vival is 16 years and 3*5 months. BIRD COMMUNITIES IN EXOTIC PINE PLANTATIONS IN AUSTRALIA Brian Charles Gepp Wildlife Management Office, Woods and Forests Department, Adelaide, South Australia, Australia In Australia, 860.000 hectares of exotic conifers have been planted on land that was originally native forest. Bird species composition and abun¬ dance in plantations has been found to be different from that in native fonest and also between silvicultural treatments. The avian community in Plantations is dominated by predominantly "opportunistic" insectivorous sPecies, with a paucity of species that feed upon nectar or require hollows in which to nest. These differences are discussed in terms of the: (1) structural uniformity of plantation systems; (2) differences in the availa¬ bly of food (invertebrates, nectar, pollen) and nesting hollows; and (3) differences between the growth form of exotic conifers and native eucalypts. The paper reviews the results of comparative studies of birds in pme Plantations and eucalypt forests and discusses the implications of forest Sagement options to promote avifauna. Similar options have been generated in moat countries establishing plantations, viz.: (1) verymg plantation layout to maximize interfaces and age differences; (2) retaining or regene¬ rativ,™ „ * (1) Droviding natura) or artificial ating corridors of native forest; and P nesting hollows. L' HIVER DE LEUCOSTIGTK ARCTOA À KAMTSCHATKA H« N. Gerassimo v L' administration de chasse, Petropavlovsk-Kamt chat sky, USSR f II y a 10 ans la plupart des LeuçostiçWrçtoa hi veinant à Kamchatka ^entaient la littoral. . . nt au février et quittaient la A Betropavlovsk les oiseaux apparaissai e au mois de mars-avril. „„„„«ti rte arctoa apparaissent Les dernières années des milliers de Leucosti - - dana les villes de Kamtchatka avant la neige. ni «rctoa font la partie du paysage D octobre jusqu'à mai les Leuoosticte_S^ - ^IhroPogene des chantiers de constructif de neige les oiseaux se nour- lendant les périodes de 1- années ^ se réunissent sur 1 ent des semences des mauvaises her e , ^ indique le processus de ^ chantiers de construction sans de ne g . a aynantropisation de Leunojsticte_arçtoa. 34 - 1105 1 3a*. 981 AGE AND SEX RATIOS OP SOME BIRDS ON THE AUTUMN MIGRATION IN- WESTERN TIEN SHAN A.P.Gistsov, E~I. Gavrilov Institute of Zoology, Kazakh Academy of Sciences, Alma-Ata, USSR In the foothills of Western Tien Shan (Chokpack pass) 153246 birds of 14 species were banded during 1970-1979. In the first year after banding, the mortality of adults and yearlings was different in some species (in Hirundo rustics 43.7 and 65.7% correspondingly, in Riparla riparia 91.6 and 63.6%, Çorvus_oomix 37.5 and 76.5%, C.monedula 39.6 and 56. 6%,' C. frugilegus and 62.6%). In the most species males predominate, and in Accipiter niBus they formed 52.0% on average, in Streptopelia orientalis 54.6%, Merops aplaster 57.2%, Pringilla coelebs 56.1%, F.montlfripgilla 60.0%). The highest productivity is recorded in A. ni sus, Columba cenas. M.apiaster. H. rustics, R. riparia, Emberiza leucocephala, E, cltrinella, C. comix (1.7-4. 2 yearlings: 1 adult). At the beginning of migration the females and yearlings predominate in A.ni- sus, C. oenas, C, eversmanni, H. rustics, R. riparia. In other species the ^ÏT~ milar findings were not recorded which can be explained by the different periods of migration of different populations. The species with similar feeding (H. rustics, R. riparia) have different migration times which can have adaptive significance for the reduction of trophic competition at the flight route. STABILITY AND SUCCESSION OF THE AVIAN COMMUNITIES IN WOODLAND Zbigniew Glowacinski Research Centre for the Protection of Nature and Natural Resources, Polish Academy of Sciences, 31-505 Krakow, Ariaiîska 1, Poland Stability (as constancy and as resistance) of the breeding avifauna was determined for the five phases of the secondary succession of a deciduous forest in Poland. The variability (the reverse of stability) of species ri¬ chness (S) , species diversity (H- ) and density (N) of the bird communities were mainly analysed. A total variability (directional var. of succession + + random var-) 0114 ^Parately random variability which are independent of successional trends were estimated. In the first 15 years of succession the directed variability of the features investigated prevailed. In the later stages random variability is of decisive significant. The evaluation of both total and random variability shows that the stability of the bird communities increases in general, with the development of succession yet it need not be the lowest in the initial phase and the highest in the climax phase. These results are consistent with the Odum (1969) general "model" of succession. Total variability. is closely and negatively correlated (r = -0.9) with S, H’ “d N* 111 °ther W°rda ffiore and more diverse bird communities are more stable. But no causal-effective dependence between these values was proved* 1106 CLUTCH AND EGG SIZE IN GREAT CRESTED GREBE (PODICEPS CRISTATUS L. ) ON DRUZNO LAKE (NORTHERN POLAND) Michal Goc Department of Animal Ecology, Institute of Biology, University of Gdansk, 81-378 Gdynia, ul Czolgistow 46, Poland The research material of this study consists of over 1500 clutches measured in the years 1976-1980. Significant changes were found in the two parameters of clutch size and egg size during the breeding season. Between- years differences in egg size are smaller and are significant only for years of extreme values. Egg size on Druzno Lake differs from the data reported from some other geographical regions. The other aspects analyzed are the relations of both parameters to the type of nesting (territorially , colonialy and in Black-Headed Gull colony) and the with'in-clutch variation of egg size. COMPETITION AMONG NORTH KAZAKHSTAN PODICEPS DURING REPRODUCTION PERIOD N.S.Gordienko Naursum. Reserve, USSR The four Podlceps species making their nests together on the big reed lakea (?odiceps cri status, Podiceps griBeigena. Podiceps higricollls, Podi- j-gjos auritus) are similar in a number of indications: marriage behaviour, breeding spectra, nesting biotopes and main indices of the reproductive cyc- le" Competition between these species is weakened because of differences in heating and breeding sites, phenology of reproduction (small species start baying their eggs one or two weeks later than big ones) and also due to the humerical domination of one of the species on every site. Some peculiarities °f behaviour such as interspecies' aggressiveness (especially of Podiceps ghiseigena) during nesting and hatohing periods and early roaming of Podiceps ^S^tatus and Podiceps caspicus broods from their nesting places also pro- m°te this. The density of relationship increases under the influence of unfavourable abiotic factors and first of all under the fluctuation of hydrological regime °-f the reservoirs. Their shallowing alongside with the artificial thinning 0:f brushwoods make the Podiceps griseigena a dominating species. The fil- blhg - 0f big lakes changes the correlation in favour of Podiceps cris- — Some reservoirs, favourable for the habitation of all the four Podi- °ePs species, nevertheless from year to year are populated by one of them malnly. most often by Podiceps griseigena - a species of great competative ability. INTERACTION BETWEEN TEMPERATURE REGULATION, SLEEP AND CIRCADIAN TIME IN THE PIGEON R.Graf, H. C. Heller, S.Sakaguchi, W. Rautenberg Inst. Tierphysiologie, Ruhr-Universität, D-463 Bochum, PRG; Dept. ®iol. Sciences, Stanford University, Stanford, CA 94305, USA PiSeon0 show daily fluctuations of body temperature (T^) and arousal state abnibution. In is known that: (1) in pigeons, the T^-cycle depends on 1107 diurnal changes in spinal thermosensitivity; (2) hypothalamic thermosensiti¬ vity in mammals and spinal thermo sensitivity in birds are Influenced by arousal state; and(3) in mammals, arousal state distribution is altered by altering hypothalamic temperature. To study the interaction of temperature regulation, sleep, and circadian time, pigeons were chronically implanted with thermodes and thermocouple reentrant tubes both in the vertebral canal and in the anterior hypothalamus. Arousal states were determined by EEG-, EOG-, and neck muscle EMG-electrodes. Respiratory rate was measured via impedance pneumography; metabolic rate was determined by measuring oxygen consumption. First, we examined the characteristics of spinal thermosensitivity. At any given time of the light-dark (LD) cycle, the thresholds for penting and shivering were lower during slow wave sleep (SWS) than during wakefulness. Furthermore, these thresholds in both awake and sleeping animals were lower during D than during L, thus supporting the idea that CNS mechanisms cont¬ rolling arousal states and circadian rhythmiclty have separate influences on temperature regulation in the pigeon. In a second -series of experiments we looked at the influence of spinal and hypothalamic temperature on the distribution of sleep states during Di slight warming of the hypothalamus to a level characteristic of L had little or no effect, '.'/arming the spinal cord, however, increased the amount of SWS, nearly abolished paradoxical sleep, and, moreover, produced a sharp decrease in body temperatures. Since birds exhibit high spinal thermosensitivity, but not the hypothalamic thermosensitivity characteristic of mammals, our results support the hypothesis that thermoregulatory conditions have a strong in¬ fluence on the distribution of sleep states. DISTRIBUTION OF BREEDING SITES AND THE NUMBER OF SOUTHERN DUNLIN (CALIDRIS ALPINA SCHINZII) ON THE SOUTHERN BALTIC COAST Jadwiga Gromadzka Polish Academy of Sciences, Institute of Zoology, Ornithological, 80-680 Gdansk 40, Poland Until the end of the last century, the dunlin was a common breeding bird along the southern Baltic coast. Because of the cultivation of the seashore meadows, its number has decreased very much. Now the dunlin breeds only in relatively few places. In the G DR there are five breeding sites along the coast and one inland site. The largest breeding place is found in the middle. coast - Darsser- Boddenkette, where about 45 pairs breed. In the countiy as a’whole about 90 pairs breed. ■ In Poland, along the coast, about 80-100 dunlin pairs breed on three sites only. One with a single pair is far from the coast. The biggest breed¬ ing colony (about 60 pairs) is situated at the Gulf of Gdansk near the mouth of the Reda. In Lithuania and Latvia only single pairs breed on some sites along the coast and far from the coast. In Estonia the breeding population constats of at least 1000 pairs. Dunlins breed mainly along the coast there. The biggest concentration (about 30 pairs) is in the Matsalu reserve. 1108 ZUSA1™EIfPALLEN DER MAUSER UND DER NESTPERIODE BEI SPERLINGSVÖGELN (PASSERIFORMES') B.M. Gubin, A.F.Kowschar Institut fur Zoologie, Akademie der Wissenschaften der Kasachischen Republik, Alma-Ata, USSR 2J”«nd r ““““ de. reprodnkti™, ’ - ' Meueer wenig«»», 1,1 ,5 Arten den Sper_ Ung,vog,l», den Ver.net™ den reisenden ,3 P„uien bek„n„ Hlrul,dlnld„ w„JJ“,;.r2?7äT.!3,,.5^äS! t«. Pycnonotldqe (5!, Troglodytlde, (1). - - — ^5), Sylvlidae (7), Muscicapidae (I), Prunellidae m m„+ (4), Sturnidae ( 2) .Ploceidae (j)T Fringiïlidal (if " Diese Erscheinung wurde zuerst als Anpassung zur Fortpflanzung t* », », ltl r*8?1' simin' ,966; h',u“oj*' i9?,i simi“' ”74; z » Hoohgeblng, (Koweeher. 1977, 1981) betreoht... Dl,,, Eneokelnung i« 1 75 bi“ "T n” ™ °S,"e 197« Noskow, ' 75 j bis zum Sibirien (Moskwitin, 1972) und Femen Osten (Neufeldt 1971 Netschajew 1974, 1975); in den ariden Regionen von Australien (Keast 19^ hab ^lka,(j0neS> 1978' Stutterheim, 1980) zu bemerken. Ähnliche Angabel haben wir in dem Halbwüstenregionen im Norden des Kaspischen Meeres «^lL len L M AnalySe d6r at6llte 63 Si0h *~aus, ^ ^s Zusammenf^ Nahrung “f P°rtpf.lanzU^ weder v°» her Nestbauart noch von der siclfL n\ ^raa°he d6S Zusanmenfal1^ dieser Vorgänge ist, voraus- hittes ^ , Fall6n 6lnZig ^ Sllein • diS hes Zeitabsch- tes zwischen der Beendigung der letzten in dieser Jahreszeit Brut und dem PheUSb!r “T V*’/** nl0ht V°n d6n Paktoren ab- w°durch diese Knap- it bedingt ist (polyzyklische Fortpflanzung; Spätbeginn der Fortpflanzung derh f m°"0zykll30hen Art> klimatische Bedingungen der Gegend, Wetterbeson- rbeiten des entsprechenden Jahres usw. ). Die Erscheinung des Zusammenfallens der Mauser und der Fortpflanzung bei beka^tT^0™1611 i3t WahrSchelnl±oh viel mehr verbreitet, als es heute SOCIAL ORGANISATION AND ROLE OF HELPERS, IN ANTEATER CHATS (MYRMECOCICHLA AETHIOPS) AND MOURNING WHEA TEARS (OENANTHE LUGENS SCHALOWI) Volker Haas Max-Planck-Institut für Verhaltensphysiologie, Abteilung Wickler D-8131 Seewiesen, FRG ^ Anteater Chats (AC) and Mourning Wheatears (MW) overlap in their distri¬ bution and sometimes even share the same habitat. Both species have helpers 3 the nest that aid in feeding the young during breeding. They are highly ^erntorial which may be due to the lack of suitable breeding sites. AC breed deep holes while MW breed in shallow holes or niches. In contrast to MW, have no sexual dimorphism. This difference is reflected in the female's ® aviour. MW females sometimes go from one male's territory .to others, ereas AS have a lasting pairbond. Young AC stay with the parental group 11 they °Btain a chance to pair. Before leaving the group, males and fe- a es act as helpers. Female MW leave the parental territories soon after 1109 fledging, while males remain longer and serve as helpers for later broods. At most, two helpers were observed feeding the young in MW. Differences between the two systems, for example, group size, feeding rate of group members, breeding success and availability of suitable breed¬ ing sites, are discussed. THE VARIATION OF THE KINGFISHER' S PREDATION DURING THE REARING OF THE NESTLINGS (ALCEDO ATTIS L. ) Catherine Hallet Laboratoire d'écologie des eaux douces (UNECED) , Facultés Universitaires M.-D. de la Paix Namur, Belgique During our field studies on the kingfisher's ecology, we have found that this bird selected the size of his preys according to the age of the nest¬ lings. During the first ten days of the rearing period, the adults catch small fishes ( ci 5 cm). Larger preys are preferentially brought as soon as the nestlings are able to ingest them. Sometimes we observed that in respect to the size selection, a strong variation existed in the relative abundance of the various species caught. Smaller species or age groups are caught at the beginning of the rearing period. We also found variation in the feeding intensity. The food intake rate of the young rapidly reaches the level of about 9 fish per day but in the last five days before they fledge it falls to about 6 fish per day. Our results show that the kingfisher's predation varies quantitatively and qualitatively in relation to the age of the nestlings. THE EFFECT OF A PREY SPECIES, MICROTUS PENNS YLVANICUS. ON NESTING, POLYGYNY, AND POPULATION DYNAMICS OF A PREDATOR, CIRCUS CYANEUS HUDSONIUS Frances Hamerstrom, Charles J. Burke, Frederick N.Hamerstrom College of Natural Resources, University of Wisconsin, Stevens Point, WI, USA; Wisconsin Department of Natural Resources, La Crosse, WI, USA On a 16.000 ha study area in Wisconsin the abundance of voles (Micro tus pennsylvani eus/ determined how many harriers (Circus cyaneus hudsonius) bred, at what age young males bred, and how many mates old males had. (These re¬ lationships were interrupted during a period of heavy aerial spraying with DDT* > The effect of the voles on the hawks may be physiological (in the in¬ testinal flora of the voles?) or psychological (repeated stimulation of fe¬ male being fed small prey?). Adequate quariy is available when voles are scarce, but tends to be larger. Birds that have reared young successfully tend to return to breed again. During vole highs especially, a "gypsy" co¬ hort of harriers of unknown origin appears on the area. These two cohorts make up most of the breeding population. The possible role of polygyny in population regulation will be discussed. This 23 year study is based on 275 nests, 541 nestlings banded and 208 color-marked breeding harriers. 111o MIXED SINGERS: THEIR RELEVANCE TO SONG LEARNING AND SYSTEMATICS Hans-Wolfgang Helft, Hans-Heiner Bergmann Department of Biology, University of Kaiserslautern; Department of Biology, University of Osnabrück, PRO som , r,!PeCle3 eXhiMWng 8 COnstant — species-specific song structure son* T maleS incorP°rate song features of alien species into their The i °°mpletely replace their aong ^ the alien one, respectively These individuals are called "mixed singers". Mixed singing appears to result from song tradition incidents, e.g. loss L: 3°ng m°delS’ rSther th“ ^ —«a mutations oT ein . COmparlnS a11 ^own and well documented cases for Europ- model i 1P 3’>,We °Und thSt ln the maJOr number of casaa the imitated alien “odel is a member of a v6Iy close relative species (e.g Certhia ffl ■ 4££££g£halus__acirpaceus - A, palusli" Sfgggr' Bh. collybita) . With regard to song learning, this~t^ir^7^in. Sica! o 6 ^leCtl°n °f the model not onlM toy acoustic but also by morpholo- trivialis) ::eCrtera- In S°me °ther CaSeS (e-S* -rlngilla coeleb3: Anthus ; îhe 8pectj™n of raodela ia wider, these species not being cl^7~ b U merely exhibiting similar song structure. This is interpreted toy a selection mechanism of models which relays mainly on acoustic fTaluts.- ly sun8 T T , Senerally ls a rare event whi°to does not seem to be specifical- ratedPt°r 6 I seleotlon* On the contrary, mixed singers have been demonst- ated to reproduce successfully only in a small number of cases. Hence, mixed 3 ihging cannot be an effective way of competing with alien species. SOUND PRESSURE LEVEL AND FREQUENCY SPECTRUM IN THE SONG OP THE AQUATIC WARBLER (ACROCEPHALUS PALUDICQLA) IN Relation to habitat acoustics Hubert Heuwinkel Zoologisches Institut der Universität, Hindenburgplatz 55, D-4400 Münster, FRG |Je he sound pressure level in the songs of several aquatic warblers was easured in the natural environment (Hortobägy, Hungary). The average sound easure level of 100 syllables of one individual e.g. amounts to 63.5 dB fi n 50, max 80 dB) at a distance of 2.5 m in an approximately free sound d. 1/3 octave analyses show that the "churning" syllables with a wide ^equency spectrum have their maximum levels in 1/3 octave bands with filter ^htre frequencies of 4, 5 and 6.3 kHz (3.548-7.079 kHz) while more "melo- us syllables have them in 2.5 - and 3*15 kHz 1/3 octave bands (2.238- -’•548 kHz). v Ve8etation in the habitats of the aquatic warbler mainly consists of rioUs kinds of grasses that can reach a maximum height of 1.50-1.80 m. The The tatS di:ffer from those of other Acroceohalua species in wanting of reed, transmission of pure tones, random noise and played back songs of the Qtic warbler as well as of other species, typical and non-typical for the e described habitat, was measured in the natural environment with a loud- sker - sound pressure level meter combination. 1111 INVESTIGATIONS ON TERRITORIAL REQUIREMENTS OP THE RINGED PLOVER (CHARADRIUS HIATICULA) AND THEIR POPULATION-ECOLOGICAL CONSEQUENCES Rainer Holz, Peter Kneis, Axel Siefke Vogelwarte Hiddensee, Kloster/Hiddensee, GDR Territory size has been analyzed in relation to various intra- and ex- trapopular factors. The material was recorded for a colourringed population of avg. 34 (24-42) breeding pairs, which have bedh investigated for size de¬ termining mechanisms since 1974 a3 well as for 8 control areas with a total of 49 breeding pairs in 1980, all situated at the southern coast of the Bal¬ tic. Territory sizes have been ascertained by mapping of clutches being cor¬ rected by sample ethotopograms. The territory is determined by the male and codominated by the female, serving for reproduction and for feeding which may also take place outside. Approx. 56% of territories are occupied by males faithful to their territory, 8% by males switching territories and 36% by newcomers. The size of territories in 4 beach habitats was between 0.03 and 0.49 ha (avg. 0.28+0.11 ha; n=183) and included a shore line of 0 to 193 m (avg. 86+46 m; n=154). The corresponding size in two field habitats distant from the shore was avg. 3.49 ha (n=12). Findings indicate negative dependences on settling pressure upon the in¬ dividual area, on the structural resources of the habitat, and on the usable food supply. The social status is only important for the position of the ter¬ ritory, but not for its size. Efforts for maximizing territory size are not evident. Within the first days after hatching of the chicks, during which the family feeds almost exclusively within the territory, ownership of a shore-sector may be significant. Territorial requirements have been evaluated as a component that determines the carrying capacity of a breeding area. They only limit the actual populat¬ ion size on small sites and short times. This does not exclude affecting po¬ pulation size in larger areas by spacing of individuals into suboptimal habitats and thereby reducing fertility. INTERNATIONAL SURVEY OP ANTARCTIC SEABIRDS: AUSTRALIA' S CONTRIBUTION R.S.C. Horae, G.W. Johnstone, K.R. Kerry Antarctic Division, Department of Science and Technology, Kingston, Tasmania, 7150, Australia At present, many nations are examining the possibility of commercial ex¬ ploitation of Antarctic krill. This planktonic crustacean is the major food of several species of whales, seals, seabirds, fishes and squid in Antarctic waters. Informed management of krill as an exploitable resource requires knowledge of the stocks of krill and of their consumption by natural predat¬ ors. Recognising the lack of relevant information for Antarctic seabirds, Scientific Committee on Antarctic Research has implemented the International Survey of Antarctic Seabirds. Penguins were selected for special study as they comprise about 80 per cent of the avian biomass in the Southern Ocean; most of these are Adeli’e 1112 Penguins in the Antarctic, and Macaroni and Royal Penguins in sub-Antarctic regions. Australia has undertaken to census breeding colonies of Adelie Penguins along the 6000 km coastline of the Australian Antarctic Territoiy, and Maca¬ roni and Royal Penquins on Macquarie Island, Heard Island and the McDonald Islands. All existing population data have been compiled and detailed ground and aerial photographic surveys are underway. The paper will include results from the 1981/82 season, with new information on the food of Adelie Penguins. THE FEEDING ECOLOGY OF AMERICAN FOREST VULTURES David Charles Houston Department of Zoology, University of Glasgow, Glasgow G12 8QQ, Scotland, UK The 5 species of small American vultures (genus Cathartes Coragyps and garcorhamphus) have distributions centred in the neotropical rain forest region of central and South America. By comparison, none of the 15 species of vultures in the Old World are found in. forests, and all species live in open habitats. The current study considers why several species of scavenging birds should have evolved in the tropical forests of the New World, while hone have developed in forested regions of the Old World. Studies on the food supply available for scavenging birds in forest re¬ gions suggest that this may be more abundant in neotropical forests than in African forests. Studies in Brazil and Panama on the exploitation of carrion °h the forest floor indicate that the invertebrate community is important, hhd that and activity results in carcasses remaining available for scaveng¬ ing birds for long periods of time. The foraging behaviour of forest vultures ih being studied to determine their efficiency at locating carcasses. PITCH AND RHYTHM MATCHING: AUDITORY FACILITATION AND TRIGGERING EFFECTS OF ACOUSTIC STIMULI Henrike Hultsch Abt. f. Verhaltensbiologie; Zoologisches Institut der F. U. Berlin Haderslebenerstr. 9; D-1000 West Berlin A prime concern of this paper is to add to the results on song type match¬ ing, further forms of vocal responsiveness which suggest a selective read- °ut of auditory information on the part of the stimulated bird. In nightin- ®aies (Luscinia megarhynchos B. ) pure tone series and rhythmically structured tnU Series are two characteristic song type features which are variable in iehms of either pitch or temporal patterning. By playback experiments, it c°uld be evidenced that both pitch and temporal patterning were responded to in a selective manner. Correspondence between syllable morphology (modulat- i°h, duration, etc.) did not prove to be an essential feature here. There are specific characteristics of pitch and rhythm matching which might point 0 different communicative functions. 1115 BIRDS NESTING IN BUILDINGS OF TOWNS IN THE LITHUANIAN SSR R. Idzelis Institute of Zoology and Parasitology of the Academy of Sciences of the Lithuanian SSR, Vilnius, USSR Over the last 10 years at least 16 species of birds nesting in buildings were recorded in Lithuanian towns. Synanthropic species made the majority. A number of species formed sedentary populations with changed behavioural stereotype. I. House martin (Delichon urbica), swallow (Hirundo rustics) , swift (Apus apus) , feral pigeon (Columba livia) , black redstart (Phoenicurus ochrurus) , house sparrow (Passer domesticus) nest only in buildings. II. Jackdaw (Corvus monedula) , starling (Sturnus vulgaris) , spotted fly¬ catcher (Muscicapa striata) , white wagtail (Motacilla alba), great tit (Pa- rus maj or) , tree sparrow (Passer montanus), blackbird (Turdus merula) .little owl (Athene noctua) nest in urban green plantations and buildings. III. Wheatear (Oenanthe oenanthe) , tree creeper (Certhia fa mi Haris) sel¬ dom nest in buildings. INTERPRETATION OF PHY LOGEN! OF YELLOW WAGTAIL COMPLEX (MOTACILLA FLAVA - M. LUTEA - M. FELDEGG) V. Yu. Iliashenco Zeysky Reserve, USSR The original form of the yellow wagtail seems to have been very close to the resident Egyptian form — Motacilla flava pygmara which had the most pri¬ mitive plumage colour similar in both sexes. In their first winter plumage the adult birds of this form are similar to the young of other forms. The study in the alteration of the plumage colour and pattern of the head in ontogenesis (admitting the archaic nature of female plumage) showed 4 ways of dispersal. (1) Middle-Palearctic - the development of yellow pig¬ ment; (2) Nor th-Eas tern-Palearctic-the intensification of pigmentation; (3) Central-Palearctic - depigmentation; (4) South-East ern-Palearctic - the development of black pigment. The last group seems to give two secondary ways of dispersal - to the East and to the West. In the boundaries of each way of dispersal the female plumage is progressing until the plumage of both sexes becomes fully identical. THE BLACKISH NIGHTJAR IN SURINAM Dr. Johan Ingels Galgenberglaan 9, B-9120 DESTELBERGEN, Belgium The Blackish Nightjar Caprimulgus nigrescens is a small, sexually dimor¬ phic, neotropical nightjar. Its distribution range is restricted to the Ama¬ zon basin, including Surinam.lt exhibits a wide ecological tolerance. The habitat of this nightjar includes sandy savannas, open sites in second growth and rain forest, and river banks. It is uncommon in more open savannas with scattered bushes and more common on stony areas and rocky outcrops in forests and on rocks and stony sand areas along rivers. 1114 A population of this nightjar was studied on a large granite outcrop with scattered vegetation near Voltsberg in the Raleighfalls-Voltzberg na¬ ture reserve managed by the Foundation for Nature Preservation in Surinam (Stinasu). Roosting during daytime and foraging at night were investigated. l7TaVTVi°Ur WSa StUdled St 3eVeral neSt8‘ 1116 P^icular preference of the Blackish Nightjar for these granite outcrops in rainforests and the living conditions involved are discussed. Financial support for this study was provided by the F.M. chapman Memo¬ rial Fund. ECOLOGY OP THE GOLDEN EAGLE (AQUILA CHRYSAETUS L. ) IN NORTHERN BYELORUSSIA V.V. Ivanovski Byelorussian Society of Hunters and Fishers, Vitebsk, USSR During 1972-1981 15 breeding territories (including 7 living nests) of he Golden Eagle were located over a 40000 km2 study area in the northern part of Byelorussia rich in lakes and bogs. The total population of the Gol- en Eagle in this region is estimated 20 pairs. Common nesting habitats are l® Upland b0fis exoee(iing 18-20 km2. Nests are usually made on pines and aspens growing in forest isles and -noses" amidst the bogs. The minimum dis¬ tance between neighborering pairs was 15 km. Egg-laying begins approximately in the middle of March (13.3.1977). Nest¬ ings hatch out at the end of April or at the beginning of May (7.5.1976 and •5.1979 chicks were about 7-8 days old). By the middle of June (15.6.1979) young were completely feathered. They left their nests ’in the second half of uly (28.7.1979 a fledgling was seen near the nest). On the average, a pair of Golden Eagles lays 2.0 eggs (by 3 clutches), nooks 1.8 nestlings (by 6 nests) and rears 1.1 fledglings (by 9 broods). °ung Golden Eagles disperse in October. Among 444 food items predominated lrds (67.2%) as well as hares (28.3%). In winter they regularly feed on carrion. b The only dajiger for the Golden Eagle is Man. In winter both young and old yds die in traps near animal carcasses and from poisoned baits. As a result of drainage and cultivation of upland bogs the population of the Golden Eagle has considerably declined lately. In future breeding pairs might survive mainly in reserves where the principal elements of the land- Scape are bogs and woods. WEIGHT AND CHICK-MORTALITY IN THE BLACK-HEADED GULL (LARUS RIDIBUNDUS L. ) M. Janaus Institute of Biology, Academy of Sciences of the Latvian SSR, 1 Riga, USSR Chick mortality was studied in 1974-1981 on the Lake Enguré (Latvian SSR) (Sing the method of fenced areas. Birds which reached their 25th day of life a Minimal age of flight) were considered as surviving, in tbe 3Urv,ival rate and average- hatching-weight have the highest values early clutches and then decrease during the season. The first and the 1115 second chick in the clutch are the heaviest and survive best, the weight of the third chick is about 7% less, its mortality is higher (both differences are statistically significant). Differences in weight and mortality in 2- ohick nests are insignificant. Pood plays the main role in chick survival. In 1976 in one fenced area only one chick was left in each nest (indepen¬ dently of the sequence of hatching) and their survival was significantly (p ^ 0.001) higher (91%) than in other areas (60%).-The cause of lower sur¬ vival of the third chick is not in its weight itself but in the lack of food. In 1981 when either the first or the third chick was left in the nests, their survival did not differ significantly (correspondingly 82 and 79%; p ? 0.05), although the difference in weight was 6.6%. Totally 63% of chicks survived in this fenced area, survival in the neighbour control area and in other areas with a normal number of chicks was signif icantly less - corres¬ pondingly 38% (P-^0.01) and on the average 46% (p^d.0.05). INTERPRETATION AND SIGNIFICANCE OF TEMPORAL MIGRATION PATTERNS AT AN ALPINE PASS IN COMPARISON TO STATIONS IN THE LOWLANDS Lukas Jenni Swiss Ornithological Station, Ch— 6204 Sempach, Switzerland The autumn migration of Passeripes in the area of influence of the Alps is being investigated by a Swiss research program. Its aim is to describe migration patterns according to sex, age and population, and, through com¬ parisons with different ringing stations and radar studies, determine migra¬ tory strategies is response to the Alpine barrier. Capture statistics from an alpine pass (Col de Bretolet, VS) over a period of 20 years are used to determine patterns of migration and differences with lowland ringing stations. Particular emphasis is given to the? analysis of premigratory movements, the influence of the nearest breeding grounds, the sources of the migrants, the site of the ringing station, the time of migrat¬ ion, the distance of migration and the temporal distribution according to age. Once the significance of these factors have been determined, capture sta¬ tistics can be used to determine migration strategies and may be used as de¬ mographic indices. COMPARATIVE BIOLOGY OF THE GIANT-PETRELS MACRONECTES GIGANTEUS AND M.HALLI ON MACQUARIE ISLAND G.W. Johnstone Antarctic Division, Department of Science and Technology, Kingston, Tasmania, 7150, Australia The giant-petrels Macronectes giganteus (Gmelin) and M.halli Mathews are now widely accepted as a pair of sibling species. These largest members of the family Procellariidae breed only on islands in Antarctic and sub-Antarctic waters. They are sympatric at at least four locations near the Antarctic Con¬ vergence, including Macquarie Island, but otherwise breed only either south (giganteus) or north (halli) of the Convergence. Known attempts at hybridi¬ zation have been unsuccessful. 1116 Studies of their morphology, breeding biology and feeding ecology on acquarie Island( sub-Antarctic) , supplemented by information for giganteus from Antarctic stations and for halli from the Chatham Islands close to the Subtropical Convergence, suggest that giganteus is better adapted to Antarc¬ tic conditions and halli to those prevailing in the sub-Antarctic. Informat¬ ion on their dispersal from Macquarie Island, derived from distant recoveries of banded individuals, supports this view. The extent to which their eggs are contaminated with anthropogenic chemicals provides additional evidence. Studies of their morphology, breeding biology and feeding ecology on Mac¬ quarie Island (sub-Antarctic stations and for halli from the Chatham Islands close to the Subtropical Convergence) suggest that giganteus is better adap¬ ted to Antarctic conditions and halli to those prevailing in the sub-Antarc¬ tic. Infonnation on their dispersal from Macquarie Island, derived from dis¬ tant recoveries of banded individuals, supports this view. The extent to which their eggs are contaminated with anthropogenic chemicals provides addi¬ tional evidence. Populations of giganteus and halli that have been studied differ from those in the South Atlantic Zone north of the Antarctic Convergence. The giant-petrels breeding in this zone may be regarded as a third sibling apecies. fuhther observations on the population analysis op black WOODPECKER INHABITING AN APPENNINIC REGION OP SOUTH ITALY Mario Kalby, Gabriele de Filippo, Maurizio Fraissinet Istituto e Museo di Zoologia, via Mezzocannone 8, 80134 Napoli; World Wildlife Fund-Italy, Delegazione Campana, Riviera di Chiaia 200, 80121 Napoli, Italy This study presents some data on the ecology and distribution of Dryoco- £ug__martius in Campania, where this species is considered to represent a relict of the last glaciation. This population in Campania, isolated from file rest of the Black Woodpecker population in South Italy, is probably bound the progressive and continuous destruction of beech and spruce forests through the centuries. At the beginning of this century, the species was Present in Central Appennino, and is at present found in the forests of Pol- lin° Sila. The Black Woodpecker was first observed in Campania about 25 ^ears ago, mainly in summer months. Presently it is found through all major ®°untains of the area: Albumi, Picentini, Cervati, Gelbison, Maddalena. Dur- thg winter months single individuals are seen, while in August they are seen Pairs. This information was also confirmed through hunters' activity. In area shepards used to eat young individuals. Known stuffed specimens are 0 which have a 1:1 sex ratio. The habitat is composed mainly of vegetation 'vith beech, white spruce and yews at 1100-1400 a above sea level, exposed ®ainly to the north and east. In 1975 a female bird was captured in the rem- ûaht of a mesophil forest, ca 20 km. from sea (70 m above sea level). Feeding ahd breeding habits were also studied. Omithometric comparisons were made stween this population and these from the Alps. In addition to this we have to study the ecological relationships of this species with other Pici- dae and man. We consider the presence of this species as the index of blolo- 1117 gical and ecological integrity of the area and propose with strong conviction that these areas he established as nature reserves. PROBABILITY METHOD OP AGEING OP THE PASSERINE NESTLINGS AND ITS USAGE IN THE INVESTIGATION OP THE BREEDING PHENOLOGY Wojciech Kania Ornithological Station, Institute of Zoology, The Polish Academy of Sciences, Gdansk, Poland The method consists of the field determination of the nestling growth and in the subsequent conversion of growth stages to age. The conversion tables show the most probable age of the nestling's life and the probability of this age being longer or shorter by one, two, etc. days. To show breeding phenology, the probabilities of hatching on a given day in all nests should be summed up, thus the obtained sums will form a distribution of probability for the hatching period in the investigated population. Determination of the growth stage is identical for different species but conversion tables must be prepared separately for each. Growth is expressed by wing length or the degree of feather development. Both these parameters are strongly dependent on age and almost independent of food supply (there are few exceptions, e.g. swallows), at least for the nestlings which are big¬ gest among its siblings. The collection of both parameters in the field is very easy. The method seems to be especially useful in gathering data on many species by a number of researchers as is the case in collecting data for nest record cards or for ringing nestlings. ADAPTATIONS OP THE PASSERINE BIRDS FOR THE LIFE IN KIRGHIZIA MOUNTAINS V. N.Kataevsky Institute of Biology of the Kirghiz SSR Academy of Sciences, Frunze, USSR In the Tien-Shan mountains small passerine birds begin their breeding earlier than in lowlands. The nesting density of the naturally lowland birds is always below in mountains. Open-nesting Turdus merula and Lanius criatatug have a higher nest-stand in middle mountains. The weight of house- and tree- sparrows nest-stands flooring (feathers, hairs) increase with absolute height' It is bound directly with low temperatures of the middle mountains. On the other hand a weight of the vegetative materials of the nest is higher in l°w' land nests of the same species. The statistical reliable difference of the sizes, volumes and weight are considered in lowland and mountain eggs of the Hirundo rustics and Passer domesticus. The smallspottiness of the egg’s colour increase in Hirundo rustlca and Lanius crlstatus with absolute height The tendency of decrease of the egg’s number in the nests is considered in mountains, the broods number is smaller here on the single pairs. The breed¬ ing of the Passer domesticus and Passer montanus terminated almost simulta¬ neously in the end of August on all altitudinal belts. 1118 DO NIGHT MIGRANTS USE THE SUN FOR ORIENTATION? Y.B.Katz Institute of Biology of the Latvian SSR Academy of Sciences of Salaspils, USSR European robins were held in closed rooms and exposed to a single light rr: °r att*r it iha «4 ™ 'ri Î ! 1P6d f°r SOlne Wme in visual Eolation from stellar that s (I'^Irds °f1“tatJ0n °f exPerlmental birds in round cages showed Preferred re li'T " “tU"1 C°nditions’ gradual^ shifted their reaction °°Ur3e exPeriment’ The azimuth of their r .. 63 atlonarY ÜSht cue corresponds to maintaining their mig- b I" n * the WhlCh ia belOW the at ihi^time (2 young birds grown in isolation of stellar cues, or adults kept in Eolation during ÏL nigh^„aTn ^-tation without compensate** shifts g night in autumn experiments. The direction relative to the set- shZeTl ~ °0n3tant alm°8t the Wh°le night‘ In n,0niin« houra bi^a aorni anSS ln dlrection corresponding to one according to the accord^* th'36 IT aU°W ^ ^ Pr°P°ae that aUt,'Unn ^^ratoxy direction Pensati h-n-! ^ WnS ^ riSlng sun is ^ inborn character, while com- n ability to the visual sun shift is foimed and corrected during to th01TJf thS Mrd'S llf6! (3) in a11 gr°Ups the Erections according Port *«, V CUS at SUn8et rSmain constant during the season. This fact sup- J nlT hyp0tfeSia D.A. Vleugel, that direction of migration is selected g migrants on the basis of a constant angle to the setting sun. BIRDS’ HEART RATE IN FLAPPING FLIGHT AND SOARING Jüri Keskpaik, Raivo Leht Institute of Zoology and Botany of the Eston.iao SSR Academy of Sciences lartu, USSR aut^he P^Per deal3 with tba analysis of the data presented by different 197n°rS Ke3kpaik> H°rma, 1972, 1973; Berger, Hart, 1974; Kanwisher et al., bi ri ' But1'e:r’ Woakes, 1980; Keskpaik, Leht, 1982) on the heart rate (HR) of j in flight obtained by telemetry. -'■’or maximum HR values during flapping flight and lower values during soar- S and at rest, the allometric relationships "HR— body mass" were calculat¬ ed expressed as follows: at rest (32 species) . HRR - 20.3m’0’333 per sec, 71 flaPPi"« flight (38 species) . HRp - 27.4m’0’176 per sec, H soaring (3) species . HR^ - 182.0m’0’574 per sec, 111 ■* mass of a bird in grama. 10 11116 reSression lines HRR and HRp have slopes, that when a body mass is aiiae’ ^R ia about twice as high as HRp and at body masses of 100 g, 1000 g 10000 S tbe former is about 3, 4 and 5-6 times higher respectively than Ae latter. ^The regression line HRg crosses both HRR and HRp in the points of body ®es of about 4000 g and 100 g respectively. ''ith SSe caloulations indicate that soaring is more economical in comparison T-*-aPPing flight. Moreover, .the larger the bird, the greater is the trect. 1119 OK REVEALING CAUSES AND TARGETS 0? BIODAMAGING EFFECT OF BIRDS IN THE INDUSTRIAL ZONES OF SOUTH EAST EUROPEAN PART OF THE USSR V. I. Kharchenko Donetsk State University, Donetsk, USSR As a result of observations mace In the period of i960 to 1982 and in various seasons 340 species of wild biros were registered in industrial zo¬ nes of densely populated anthropogen landscape of the observed territory. About 10% oi them are agents of tied usage.; oi' various objects. Targets of their biodamaging effect are airplanes, powersupply devices, insulating, lacquer-colouring materials, plastics, glass, organic glass, wood. New data about biodamages of technical devices and living objects by lin¬ nets, wagtails, tomtits are obtained. The increased biodamaging effect of starlings and woodpeckers is registe¬ red at fish reception centres and fish breeding ponds, hunting industries. Biodamages of insulators of the electric transmission lines caused by grey herons are also registered. MAIN DIRECTIONS OF MIGRATIONS AND WINTERING PUCES OF LARIDAS 0? THE SOUTHERN WEST SIBERIA G. I. Khodkow Research-Project Expedition P.0.212, Novosibirsk 630099, USSR Based on the analysis of 150 recovered rings from the birds which had been ringed in 1966-1979 on the lakes of the Baraba and Kulunda steppes, ge¬ neral directions of the seasonal migrations and the places of wintering of the four species of Laridae have been ascertained. Common Gull (Larus canus). In autumn, birds from southern Siberia fly off in -different directions, but mainly inside the west-south sector. In October- November 3ome part of Common Gulls mainly reach the places of wintering, those places covering the zone of the Azov Sea with the system of reservoirs in the Low Don and also the non— freezing coasts of the Caspian Sea and the inland reservoirs of Iran and Iranscaucausia. Some part of immature birds remain I** the places mentioned above. Great Black-headed Gull (Larus ichthyaetus). The main direction of the autumnal passage is south-western. While flying the birds keep close to the large fish basins of Kazakhstan (Naurzum lakes, the Aral Sea etc.). Winter¬ ing gulls ringed in oiberia were met near the coasts of the Caspian Sea and in northern Pakistan. Herring Gull (Larus argentatus). The main direction of the autumnal mig" ration is also south-western. At first some birds fly to the north, north¬ west or eastward, then they change their direction and turn to the south¬ west. Herring gulls winter in Mesopotamia (Dementiev, 1951) as well as at the south-eastern coast of the Caspian Sea and the southern part 'of Indost011' During the spring migrations the birds were seen in the region of the Amu- Darya middle stream. Black-headed Gull (Larus ridibundus). The main routes of the autumnal migration are in the south-western sector. Some birds from the forest-stepPe Western Siberia cross the Aral Sea and fly to the Iran coast of the Caspi 0X1 1120 Sea and to Mesopotamia. The other part of birds pass eastward from the Aral Sea (between the Aral Sea and the Balkhash Sea) to the places of wintering ic are situated on the inland reservoirs in the south of Middle Asia Af ganistan and India. Thus, black-headed gulls nesting in the south of West eria winter on the spacious territory from Mesopotamia to the western coast of Indostan. stern NESTING BIRDS OP LENINGRAD V.M. Khrabry Zoological Institute of the USSR Acader^ of Sciences, Leningrad, USSR differl\wneStln£ blrdS °f LSninSrad waa ««*«d out in 1977-1981 in with b nd thS °ity’ namely ln gr6en in the regions with buildings erected in different years and in new districts not yet co¬ vered with buildings. y 82 breeding species have been recorded, 21 are non-passerine species, 61 asser ne ones. Of these 47 species are common, 24 are rare, and each of the maimng 11 species has been found once. Nesting of 6 additional species has been suggested. y es AcMTh;t™ber °f nestin® sPeoiea families is as follows, Anatidae - 2, - f v,' ’* yalC°nidae * 2î Rallidae - H Charadriidae - 5; Laridae - Hil’ 1 - 1; Strigidae - 2; Apodidae - 1; Pioidae - 2; Alaudidae - 1; rundinidae - 3; Motacillidae - 4; Laniidae - 1; Turdidae -10; Sylviidae - dae ! fS°1Capldae - 2: Paridae ~ Sittidae - 1; Certhiidae - i, Snberlzi- - 4, Pnngillidae - 9; Ploceidae - 2; Stumidae - 1; Oriolidae - 1- Corvidae - 5. ’ Location of nesting species of birds within Leningrad is heterogenous, ey are particularly abundant in old city parks and eemetaries-about 40 eating species. 5-7 of them nest on the ground, about 10 nest in hollows the rest nest in deciduous trees. There are 5-6 species nesting in built-up areas of the city: Columba li- domestica, Agus apus (L.), Passer domesticus (L.). Cor vus monedula L. ~ — ^5ug vulgaris L. . Delichon urbica (L. ), Motacilla alba L. me PePresentatives of meadow and field complexes (Charadriidae, Passerifor- 6s"' nest in sites not yet covered with buildings. Ch Colonies °f Laridae nest near water. Some representatives of Anatidae and ^aradriidae nest only in the south-western part of Leningrad located near 0f M° urLanized populations of Columba palumbus L. . Turdus merula L. typical western Europe inhabit the city. potential fertility of waders in tengiz- Kurgaldzhino depression V- V. Khrokov Lhstitute of Zoology of the Kazakh SSR Academy of Sciences, Alma-Ata, USSR Said*16 investigations were carried out in 1969-1972 and 1977 in Reserve Kur- tent2ilin0* Neats witil full clutches were taken into account to determine po- (2,4 al fertllity- Au average clutch-size of Haematopus ostralegus was 2.7 3s-, egga’ n=3) , Çharadrius alexandrinus - 3-2 (3-4, n=6) , Glareola nordman- • JaK.9g, - - 1121 ni - 3-5 (2-4, n-42), Chettusia gregaria - 3.6 (2-4, n«l65, Charadrlus du¬ bius - 3.7 (3-4, n»19), Vanellus vanellus - 3.7 (2-4, n-79) , Trlnga totanus - - 3*7 (3-4,n*64), Recurvirostra avosetta - 3.8 (2-5, n«78), Limosa limoaa - - 3.8 (3-4, n=37), Himantopua himantopus - 3.9 (3-5, n-59), Trlnga stagnati¬ ng - 4.0 (4, n=7), Two clutches of three eggs of V. vanellus. Ch. gfegaria and H.himantopus were apparently repeated after destruction of the previous ones as they appeared in the end of May and in June. There were double lay¬ ings of 6-8 eggs in some nests of H.himantopus and L. limp sa. Infertile eggs and eggs with dead embryos were: 1.7% of Ch.gregaria, 4.Q% of R.avosetta, 6.8% of V. vanellus. 9.8% of L. limosa. 13.3% of T. stagnatilis, 13.5% of G. nordmanni , 18.1% of T.totanuB, 20.3% of H.himantopus. Addle eggs were not recorded in the nests of Ch.alexandrinus and Ch. dubius. 131 (41.4%) nests of 316 observed were destroyed; they contained 430 eggs. The highest destructi¬ on of clutches was recorded among Ch. alexandrinus (66.7%) and T, totanus (48.5), the lowest among Ch. dubius (33.3) and G. nordmanni (34.1). The main reasons were as follows: robbing by Corvus cornix. crushing by cattle, flood¬ ing and desertion by parents. THE MOULT OP ADULT CALIDRIS MINUTA LEISL. IN THE TERRITORY OP KAZAKHSTAN V. V.Khrolfov, A. E. Gavrilov Institute of Zoology of the Kazakh SSR Academy of Sciences .Alma-Ata, USSR No Calidris minuta Leial. with moulting remeges or rectrices was known within the Soviet Union (Kozlova, 1962). During 1969-1972 and 1975-1980, we found that 15 adult individuals out of 5903 examined (in Central and South- Eastern Kazakhstan) had renewed remeges or rectrices. Complete postnuptial moult begins with the replacement of body feathers in mid-July. Two specimens captured at Lake Sorbulak (Alma-Ata region) in August, 23 and September 9 were in winter plumage with the exception of up¬ per tail coverts. In July, quill feathers were moulted in 2 individuals(0. 06% of 3240 examined), in August - in 1 0 (0.4% of 2230), in September - in 3 (12.0% of 25). Nearly all of them were captured at Sorbulak Lake. Out of 12 Calidris minuta with moulted flight feathers, 7 individuals renewed primaries only, one - primaries and secondaries and 4 - flight feathers and rectrices. Three birds renewed rectrices only. The rectrix moult began about 13 July, the primary feathers moult about 8 August, and the secondary feather moult about 20 August. The maximal moult score (Snow, 1970) was in specimens caugb* on 23. August (21; 3 new and 2 growing feathers) and on 9 September (26; 4 »e* and 2 growing). After this the last bird renewed secondaries (moult score 15^ and rectrices (moult score 8). It is likely that these birds continued the moult during migration, to winter quarters. ECOLOGY OP CAPERCAILLIE ( TETRA 0 UROGALLUS L. ) •'IN THURINGIA (GDR) Siegfried Klaus Jena, GDR 2 In the Thuringian area today about 100 capercaillies live in about 470 K® of woodlands in the Thuringian State Mountains and in the Saale-Elster San^-3 1122 MrlT (diS!ri,°+t8 ßera 811(3 SUhl)> The SlZe °f the the number of crease within the last decade to about 40% as compared with 1970 Causes of the decline have been changes in the habitat, increlsiL den' sity of predators and the wild boar (Sus scrofal „„rf . . S activities in the woodlands. - SÇrofa) , and increasing recreation forest'*' Prefe”*ed habitat3 of capercaillie in Thuringia are seconda^ pine T '0I ’ *lth ah"b V. i °tructure* *itt hi»> “»>»* -<■ b«.ee„ «F. S T “ "1",rt ’V *»• M«,. Bird. ™,„ gher parts of the mountains (Tops, ridges crest* »„„tv Plateau regions). S ’ tS’ aoutha^ slopes, ductZ1!8 Sener0lly mlld °limate con^ttions of the whole area, the repro- mure of d 7 f°Und t0 be °0rrelated P°alti-ly with ^ mean t2P7 bird* Î negatively with the amount of rain fall. The density of ing de^TflT SUCCeSS WSS alS° negatlVely c°^mted with increas- ?i 7 TS ^ WUd b°ar (aS m6a3Ured b^ the h^«ng bag best hab ' t +aS ^ ^ protection of capercaillie in Thuringia the 3uf f ! W6re Sele0t6d mi a system of reserves was established, which ubject to special habitat and hunting management (predator reduction). POSSIBILITY OP USING-HOLE-NESTING BIRDS AS BIOINDICATORS OP IMPACT EFFECT OP AIR POLLUTION ON FOREST ECOSYSTEMS A. J.Khystautas lithuanien Agricultural Academy, Kaunas, USSR Plant ^ t00ÎC Place_ln the zone of activity of Jonave nitrogen fertilizer from ln °®^tral Hbhnania. Data compared with those collected in 1970-1980 (maim f P In J°naVS di3triot» air is polluted by S0? and NO for 3mf ! In dlfferent distances from the plant, 400 nest-boxes were placed **nce f f fSerine Mrda‘ DUrlng 1979-1981 *eara* occupation of boxes, pre¬ in 0nm , Herent species, breeding success, quantity of second clutches Were 7 * with flrat* quantity of abnormal eggs and other parameters ihg en’ Considerable differences were found between clutch size, breed- fei, f SS’ between indices of form of eggs and egg measurements in dif- Ohlv • lstanoes from the Plant. Common Redstart bred in considerable density Tit' f0reSt Pl°te Wlth high levels of Pollution. Weight of eggs of Great ea Wifllghter nearer the Pi“** comparative density of this species increas- Ihcron greater distance from the plant. The density of the Pied Flycatcher ases closer to the plant. contribution to the knowledge of antropic influence on the HMATION OF ORNITHOCENOSES IN WESTERN TATRA ( 2APADNE TATRY) ludovit Kocian ^Partment of Systematic and Ecological Zoology Comenius iversity, 886 04 Bratislava, Moskovskâ 2, ÎSSR cidence of omithocenoses at the mountainous, supramountainous , subal- ioth 7 alpine level of the Western Tatras (Slovakia) is analyzed. Based on e quantitative and qualitative evaluation it could be stated that all 1123 Pihe values analyzed (quality, trophic , associations, quantity, biomass) were lower or low at the mountainous, subalpine and alpine level while being high at the supramountainous level. Human activities exert an influence in a de¬ cisive way mainly at the mountainous and in several areas of supramountainous level; they have interf erred in the past as well as in the present into the nature of these sites. Although the supramountainous level bears some signs of human activities, old trees can still be found and there is a relatively rich bush level at the forest edges. Original natural conditions are found at the upper limit of the forest which- is especially attractive to birds. A stepwise decrease in all values analyzed could be observed at the mountainous/ subalpine border level. Climatic fluctuations together with a shorter vege¬ tation period are decisive factors. Natural factors are decisive at the al¬ pine level. In nesting species at the subalpine and alpine level, a highly concentrated dominance occurs which creats labile relations and a low level of homeostasis. The bird component of zoocenose in this extreme ecosystem is small, though belonging to the highest level of the trophic hierarchy with an important role as regulators of heterotrophic processes. Comparing present species composition of birds with that in 1870-1885 (according to the papers of A.Kocian), certain differences can be observed. Decline in number of avian species, both qualitative and quantitative values, is due to the interference of man on vegetation, and on water biotopes, to various human constructions, and to the year-around frequently enormous movement of people across the area under observation. HATCHING REGIMES OP TUNDRA SHOREBIRDS AND FACTORS DEFINING THEM A. Ya. Kondratyev Institute of Biological Problems of the North of the Far- East Scientific Centre of the Academy of Sciences of the USSR, Magadan, USSR Incubation regimes of 22 species of Shorebirds of Chukotka and Kolyma tun¬ dras were studied in 1972-1980. The hatching period of all these species has 3 distinct stages: egg laying, "hatching proper" - until nestlings begin re¬ lease out of the eggshell, and the last period-incubation. Each stage is cha¬ racterized by certain behavioural patterns of birds behaviour and certain re¬ gimes of clutch warming. During the egg laying period Charadri i f o rme s spend in nests daily from 2 to 55% of time. When the temperature falls the warming time increases; open nesting birds show more intensive clutch warming. With every next egg the warming period grows by 5 to 15%. Late and repeated clutches require 1.5 t0 5 times more intense hatching. At "hatching proper" stage different individuals and species of shorebird3 spend daily from 83.9 to 98.8% of time on clutch warming. Apart from specif1*3 and individual pecularities the hatching density is affected by many other factors. Most important of them are: predation, weather conditions, and fo°^ supply- Hatching period of clutch with incomplete egg set is 5 to 12% less* The intensity of warming increases considerably during the first 2-3 days later on remains relatively constant. 1124 When incubation l8 coming t0 ^ end the total hatching period remains ahoîï telT at "'T’ bUt there 18 S ShSrP ln°rea3e in the f-quency «* TZ "Z T thS nS8t’ “d in the frequen0y °f the gg . These changes are most evident in fair weather. The behavioural va- a les in the last incubation stage enable hatching birds to regulate to a certain extent, the time of hatching proper. ' ’ URBANIZATION IMPACT ON THE FAUNA AND BIRD-POPULATION OVER FOREST LANDSCAPES IN THE CENTRAL REGION OF THE USSR V.M. Konstantinov, V.G. Babenko The Moscow State Pedagogical Institute; Muzeum of Zoology, Moscow, USSR on Ah°0"Par^On Waa drawn betwe® the birds- nesting and winter fauna on the hand and the bird population on the other over various kinds of lands- pes; s ightly altered ones, greatly altered landscapes of suburbs, and scan! T Urban liVlng quartera- The degree of change in the land- p was ndicated by the per cent of square meters of anthropogenically ered landscape, of population density and of the value of recreational oad. The data were gathered in 1971-1980 in the Central region of the USSR ropean part by a universally - adapted methology for birds' count over es- îshed and random routes 7-13 km long, crossing the most typical sites of ev>ery area. The more man-changed the landscape is, the less nesting species there ï'-- over slightly changed wood areas - 54 species, over greatly altered ^ ndscapes -35 species, over urbanized territories - 20 species while the ensity of birds population (on the average) increases: 376.6 - 591.7 _ t 9‘8 °0Uples Per sq/km respectively. The same regularity holds true in win- er period too. The more urbanized the landscape becomes, the fewer species „ ^ are: corresPondingly there are 27-21-18, while the mean populations ^nsity increases: 210.2 - 687.7 - 1413.8 individuals per sq/km. Stenobiont ev drophyll species, stenophagus and those species that cannot bear any man- ^voked disturbances appear in urbanized landscapes. The main body of city ^ird population is formed by ecologically plastic species - polyphages using ^0od of anthropogenic origin. The composition and the density of bird popu- ^ion are less influenced by seasonal fluctuation in. urbanized landscapes 011 i*1 ti*e slightly changed ones. MEETING CB THE BLACK VULTURE OF THE NVRATAU RIDGE (UZBEKISTAN) S’ N. Korshunova 1 *ï'itinsky Reserve, Dzhizak, USSR kl^ck vultures begin to nest in Februaiy. They mate in the nest two or 5litt'i ti.es a day. They actively guard their nest site, though .they often e in 1 50-200 m from each other and soare assembled by 2-3 pairs and ch'6* ^atcb;ins i0 from late February up to early April. Most intensive hat- id ^ 000urs in March. On the average clutches are 1.01 eggs (n=72). During ®e U ation (54-56 days) eggs lose 10-12 per cent of their initial weight. ^iinga weigh 70-80 per cent of the initial egg weights. Fledging period 1125 is 104-120 days, their weight at that moment is 7. 2-8.8 kg. At this age the youngs still cannot take off a flat surface. At the beginning of October adults still feed the young in nests despite the ability of the young to fly over dozens of kilometers. At the end of October some vultures leave the area. On the 7th of November 1979 a young vulture was registered 1000 km southward' from the nest site. Breeding success on the average is 0.48 fledg- ings per pair or 0.52 fledgiDgs per nest. There were 3 6-40 pairs of black vul¬ tures per 200 sq.km of Nuratinsky Reserve in 1980. Number and breeding success of black vultures during 1978-1980 were rela¬ tively stable, howerver in 1981 due to weather conditions the number of clutches was reduced by 30 per cent. ’ BEHAVIORAL REGULATION OP NESTS DISTRIBUTION OP THE COMMON EIDER (SOMATERIA MOLLISSIMA) A. S. Koryakin Kandalaksha State Nature Reserve, USSR The data were collected in the Veliky Island area (the ' Kandalaksha Bay of the White Sea). The feeding of the common eider on marine food restricts their nesting area to the coastal zone (within reach of the sea for duck¬ lings). There are no special requirements for abiotic conditions, which po¬ tentially allows the species to nest evenly along all the coast rich in food, though the degrees of nest safety in various areas differ radically. In the areas available for terrestrial predators almost all the nests are practical¬ ly destroyed, but in the areas unavailable for predators (99% of females nes¬ ted) - only 30% of the nests are destroyed. The total square of the places, where the majority of destroyed nests were observed is much larger than that of the relatively safe ones, i.e. the birds are clearly capable of evaluat¬ ing the safety of nesting. The played recordings of the males' breeding calls revealed that their recorded calls attracted the birds (particularly, the young specimens and male-bachelors) and stimulated their breeding activity. In spring the allocation of males over the area is determined by the distri¬ bution of females. But, because of great nest site fidelity (Wakeley, Men- dall, 1976) the successfully breeding females concentrated near the previous year's nesting. Therefore, the intensity of sound background created by males was maximum in the area, where the greatest number of females nested success¬ fully the previous year. As a result, the majority of the females nesting f°r the first time settle in the relatively safe places. The positive response to the specific sound background of common eider fe- males, which are not very attached to any concrete nesting places, gives a possibility to actively influence the nesting distribution of birds, to create optimal conditions for safety and the exploitation of the species. TRANSKONTINENTALE VERBINDUNGEN VON DURCHZÜGLERN DES NORD-WESTLICHEN SCHWARZMEER-GEBIETES A.Korzjukow Staatliche Universität von Odessa, UdSSR In nord-westlichen Schwarzmeer-Gebiet sind 332 Arten von Brut-, Zug-, In" vasions vögeln und Wintergaste verzeichnet. 220 Arten dafon (das beträgt 66. 26# 1126 von der ganzen Avifauna des Gebiets') =dnri j „ den. Während der Frühlingszeit werden hier 79 ArteTtfeuS?1 ^ Nur m den letzten 4 Jahren waren in diesem Gebiet 3 für die Ukraini^^’ fauna neue Arten gefangen das sinrt d Ukrainische tïïîMüJüe). KOt-J«. <«.« “ 'ÏÏÔiMooïu. («. für dl. Um der MssT».»« Art, J“ ^-lvl‘ . 1974 begonnsn) .rl.ubt. dl. “°t“‘ “““ zeitlichen Verteilung und Winterungen für einzelne A ^ratl°nen’ der 'iahres~ ss rr,rs ~ Schweden, BRD, Dänemark, Holland, Frankreich England’ l ? ’ WOrWegen> rien, Senegal, Marokko, Südafrika! sehe ££i£* “ *i! T' ’ Shcwarzmeer-Gebiet beringte Saatkrähen ssuTssr rsrr ! - in ut p , . ’ aldschnepfe in Griechenland; Säbelschnäbler - in Tunesien TTl SiM" * in ”*11’ Sœ's*i; ’ auf Malta, in England, Spanien; Fischreiher - in Italien. COLONIALITY OF GREBES (POUICIPIDIfqrmes) IN SOUTH-WEST SIBERIA AND ITS ADAPTIVE SIGNIFICANCE •A* I. Ko shelev Institute of Biology USSR Academy of Sciences, Novosibirsk, USSR StrÎcufsnelïi0" grfe; ln S°Uth-West Siberia is »»*• or lesl pronounced, conditions^ 5 7 gg5USa?S caspicua is really colonial, under certain colon V ® — rl3tatU3 311(1 red-necked P.auritus. The size of the sett/ -S 5~150 neStS* the area they occupy is 0.1-3 ha. Most colonies (90%) 1500 couplf (~~) set'tlements* Grebes' nesting density reaches 150- smt «. f PerHha' L0SS °f clutches - 40-10«. So far as the ultimate re¬ tend Î concerned, colonial and solitary nesting do not differ. Very ex- dens I P,eri°d °f reproduotion ls characteristic of both cases. Over small se colonies reproduction is 70-90% syncronized. Grebes colonies are pas- Ing a33emblagea of Uirds, their structure depends on the character of nest- and to a less degree on the neighbourhood of gulls. Is i!e^daPUVe pature of colonial nesting when compared to the solitary one bet1.0 6 proteotion of their nests by gulls from birds of prey and also in r use of nesting basins and stations. OECOLOGY OF NESTING OF RED-BREASTED GOOSE (BRANTA RUFICOLLIS) !• 0. Kostin Ihe Central Reséarch Laboratory of Game Management & Mature Reserves Moscow, USSR theIn 1977-1980 studies of red-breasted geese nesting were carried out in ta°rphUmy:r Peninsula' 021(1 in particular, of the conditions for hatching and ology of an egg with a view of cultivating the captive species. 1 e red-breasted goose begins its hatching from the first egg and the egg- period lasts 4-5 days. The hatching period lasts 26 days, the actual 112'7 hatching lasting 1.5 days. The temperature in the nest comes to 16.2°C at the low level, to 36.2°C in the middle and to 40.3°C at the point of the body contact with an egg. The temperature inside an egg is 37.5°C, the rate of temperature drop of an egg in the open nest is 5°C per half an hour. All in all 100 eggs were examined. The longitudinal diameter is 67.8+7.7; the la¬ titudinal diameter is 44.3+2.4; formindex - 54.0+18.0; average index of dis¬ placement of the cross-section surface - 14.0; average index of difference of the polar zones - 9.9. With an average weight of an egg of 77.5 g its specific weight ranges from 1.075 to 1.077. The composition of an egg is: eggwhite - 52.6 percent, yolk - 37.5 percent and the eggshell - 9.9 percent. The height of the air chamber ranges from 3.5 to 4.2 mm. The thickness of the shell is 324 — in obtuse end, 362 — in equatorial part and 372 — in the sharp end. Average number of pores - 1500 per 1 sq.cm, which more than three times exceeds the usual porosity for a goose egg. POPULATION OP RED-BREASTED GOOSE (BRANTA RUPICOLLIS) IN THE TAIMXR IN 1978-1979 V. G. Krivenko, G.K.Ivanov, I. 0. Kostin The All-Union Research Institute of Nature Protection, USSR Ministry of Agriculture; The Central Research Laboratory of Game Management & Nature Reserves RSPSR, Moscow, USSR In 1978—1979 the authors estimated the population of the red— breasted goose in the Taimyr peninsula. The land estimations covered 1450 km while the aerial ones covered 5300 km, the total number of registered birds reached 6640. When making estimations, the data of land registrations of 1977 were taken into consideration (880 km with 1778 registered birds); the registrat¬ ion was carried out by V.F.Dorogov, V. A. Zyrianov, L. A.Kolpaschikov (1979). Results have shown that about 75 percent of the total number of red— breas¬ ted geese make their nests and moult on rivers and only 25 percent - on lakes. Within the nesting area of 183 thousand sq. km, the total length of rivers suitable for red-breasted geese was estimated 7.000 km (700 sq.km) and the area of lakes - 650 sq. km. Total frequences of cases when birds were found present (single, nesting birds and nestlings) varied from 30-43 to 15-25 individuals per 10 km on the rivers of the Western Taimyr; from 15-29.5 to 1.8-3 individuals per 10 km in the Central Taimyr; 3. 5-6. 5 to 1.8-3 individuals per 10 km in the Eastern Taimyr. In the year of 1978 favourable for propagation, nesting birds made up 24 percent of the autumn population, single birds - 17 percent and the young ones - 59 percent. The total number of the red-breasted geese was estimated 19.3 thousand individuals. In 1979 which was a bad year for propagation, nest¬ ing birds made up only 12.7 percent, single ones - 55.1 percent and young birds - 32.2 percent, the total population being 17 thousand individuals. 1128 BIRDS IN RESERVOIRS' ECOSYSTEMS (BIOGEOCENOTIC AND ENVIRONMENTAL ASPECTS) 2« A. Kri vonosov Astrahan Reserve, USSR "!rolr," "•*: °° ■ n"“er °f - *■» »i«- thp. !” * .secies, their enhanced numbers and enlarged value of t«,"L n“"r*Uï ^ l“d >«*- «... in .L ” *“ ,lli ™«. and Golden Eagle was sent to foresters throughout Poland. Based on 112P the results of this inquiry and on information from years 1975-1980 given by many ornithologists, numbers of Sea Eagle in Poland were estimated as 70-30, Osprey - 30, and Golden Eagle - 10 occupied territories. Previous estimation (1970) was following: Sea Eagle - 50, Osprey - 30, Golden Eagle - 8-10 pairs. The increase in numbers of Sea Eagle is an effect of better knowledge of these birds by foresters and greater activity of or¬ nithologists rather than real increase, though in Barycz Valley (Silesia) the numbers of breeding pairs increased as compare with 1970. In 1980 breeding success of 25 pairs of Sea Eagle was 0.64 young per ter¬ ritorial pair. In 1981 the Committee for the Protection of Eagles was created to coor¬ dinate the study. NEW NESTING BIRDS OP THE ALTAI ALPINES A. P. Kuchin Mountain-Altai State Pedagogical Institute, Gorno-Altaisk^USSR In the last fifty years a number of bird species known to have habitats in the plains at the foot of the Altai have been found nesting in the moun- tainions part notwithstanding the severe climatic conditions. Botaurus stel- laris started nesting on the lakes of Kanskaya steppe, on the Tenginskoye lake and the lakes, situated in the Chuyariver valley. Previously Mergus mer¬ ganser were not ever met on the Dgulu-Kule lake and the lakes of Tchulishman- skoye plato with their marshy banks (Sushkin, 1938). Now during the nesting period they are regular birds here. Moulting birds were also met here. Alcedo atthis also appeared in the mountain part. Fulica atra started making their nests on the lakes of the Central and South-East Altai the banks of which are rich in near-water vegetation. Gallinula chloropus and Crex crex were met in South-East Altai during their nesting period. Among the new nesting spe¬ cies of South-East Altai there are Riparia riparia, Hirundo rustica and Re- miz pendulinus. In the past years Coturnix cotumix have been found in the mountainious tundra of Central and West Altai, along the river valleys and in the larch light forests of South-East Altai. Streptopelia orientalis has also appeared in Central Altai. Pyrrhocorax pyrrhocorax used to make their nests in South-East Altai, in its rocks and clay precipices but in 1975- 1981 their nests were found in settlements, at the garrets of shepherd stand buildings and behind the window platbands. Because of the changed landscape (the felling of forests made it more steppelike) Alauda arvensis and Perd Lx rd ix moved over and penetrated into the mountanious part. Change of habitat and adaptation to mountainous conditions are prompted by abundant food avail¬ ability and ecological flexibility of the species on the one hand and by an- tropization of environment on the other. THE DYNAMICS OP THE EIDER POPULATION IN THE EASTERN PART OP THE BALTIC AREA IN THE LAST HUNDRED YEARS A.Kullapere Vilsandi Reserve, Estonian SSR.USSR The first data on the nesting of eiders in Estonia go back to the year of 1873 (Russow, 1874). At present the nesting distribution of the Eider in *be 1130 eastern part of the Baltic area ia mainly limited to Estonia. In Latvia and Lithuania the Exder does not nest for lack of the main habitat - the marine islands* The main tendencies in the dynamics of the number of eiders in this cen¬ tury: 1900-1913 the number of eiders increased in Estonia, Sweden and Den¬ mark (Stoll, 1911; Olsson, 1951; Hilden, 1964), during World War I their number decreased rapidly, a new rise occured in 1920-1930 (Härms, 1928,1934), q 35-1 945 the number of eiders fell, epidemics, World War II (Kumari, (I, ’ fT" T!f"195° °n S ^ lncreaâe “d it's going on at present (Grenquist, 1965; Joensen, 1974; Onno, 1970; Kullapere, 1980). According to the results of I960 count more than 8 500 breeding pairs of anÎT/T regl3tered ln E3t0nia> 65* them were nesting at the Vilsandy and Matsalu State Nature Reserves. The Common Eider is the most numerous . estmg diving duck in the eastern part of the Baltic area. DISTRIBUTION OP SOME BIRD SPECIES AND THEIR nests in the forest biocenosis S.D.Kuligin, V.S. Shishkin Prioksko-Terrasny State Reserve, Moscow Region, USSR; Severtzov Institute of Evolutionary Morphology and Ecology of Animals of the USSR Academy of Sciences, Moscow , USSR To estimate the role of birds in a biocenosis, it is first necessaiy t etermine the distribution patterns of each species and communities under tudy* Traditional bird census methods based on the preliminary subjective ivision of the territory at a number of stations and further comparison of 6 lndioes of the species abundance, diversity etc., yield rough relative Results. We 3tudied the distribution correlation using the Krylov formula (Krylov, 368). This method permits the following three conclusions: (l) there exists 3 correlation between a pair of distributions; (2) there is a negative asso¬ ciation; and (3) the distributions are independent. To obtain the distribut- l0h, we generalized the results of mapping counts, i.e. each bird’s occur¬ ence and each nest during the breeding season in a sample plot (25 ha). The ^atter was divided into 100 squares (50 m x 50 m) . The sample plot was coated in the old coniferous forest of the. southern part of Prioksko-Ter- I'a8ny state Reserve (Moscow region). The distributions of pair of species Recurrence points being compared, the correlation proved significant only ® Ween pied flycatcher (Musclcapa hypoleuoa) and greater-spotted woodpecker -ghdrocopus major). The comparison of 4-year-long nest distributions (1977-1980) between Rair8 of species revealed no correlation. A correlation was shown, however, ween the nest distributions of tree and ground nesting birds. The com- Pari3on °f the nest distributions of all species between pairs of years owed correlations between 5 pairs of the possible 6. This indicates a si- ilarity of the nest disposition in the entire bird community from 1977 to ri31 ECOLOGO-TAXONOMICAL OBSERVATIONS OP SPECIES COMPOSITION OF HELMINTHS OF BIRDS IN GEORGIA B. E. Kurashvili Institute of Zoology of the GSSR Academy of Scieooes [Tbilisi, USSR The area of Georgia is very variable geomorphologically with a great di¬ versity of climate, vegetation, soil and fauna. All of these determine the helminthfauna of game birds. The results of our investigations show that water birds were infected mostly with nematodes (63%) of 92 species, next with trematodes (55%) of 66 species then cestodes (47%) of 60 species and last acanthocephales (19%) of 14 species. A total of 222 species of helminths were recorded in game birds. The greatest percentage of infection was recorded for Aoserif ormes birds (95.4%) with 57 species of helminths , followed by Pelecaoif ormes(95. 0% with 6 species of helmiths) , Larif ormea(93.9% with 7 species), Charadriif ormes (93.8% with 24 species) .Ciconiif ormes(92.6% with 25 species) , Col,' ymbif ormes (79.4% with 8 species), Ra informes (78.5% with 5 species). Analysis of the helminthfauna of the water birds of Georgia demonstrated the correlation with feeding, mode of life and systematic position of the host. Comparative study of the helminthfauna of systematically related species of water birds in Georgia and of systematically unrelated but eco¬ logically similar species that the helminthfauna depended not only on the phylogeny of the host, but to an even greater degree on its mode of life, feeding and climatic factors, that is on the complex of ecological and en¬ vironmental factors that influence the host. DIE BIOTOPISCHE VERTELUNG DER BRUTV/ ALDVÖGEL P. Kurlavicius, A. Kurlavicius Institut für Zoologie und Parasitologie der Litauischen Akademie der Wissenschaften, Vilnius, Litauische Akademie für Landwirtschaft, Kaunas, UdSSR Es ist f estgestellt , daß in flächenförmigen Flurgehölzen des Festlandes von Litauen mit einer Fläche bis zu 20 ha, dank der Mosaik der Biotopen, entstehen besonders günstige Bedingungen für das Leben mehrerer Vögelgrup- pen (es brüten 83 Arten mit durchschnittlicher Siedlungsdichte - 145.3+4* 3 Paar pro 10 ha, Diversität nach Funktion von Shannon - 3-257). Die Sied¬ lungsdichte der Vögel wächst nach dem Schema:Kiefer - Laub - Fichten - Ge¬ hölze, d.h. nach einem anderen Prinzip, als in Waldmassiven. Die Brutvbgel- dichte in flächenförmigen Gehölzen hängt von der Charakteristik der Baumar¬ tenanteile, der senkrechten Struktur der Gehölzstöcke, hydrologischem Re¬ gimes des Bodens u. ä. ab. Die Kronenbedeckung des unteren Stockes, die Fichten-menge im oberen Stock auch die Mosaik der ökologischen Bedingungen vergrößern die Siedlungsdichte der Brutvögel. Es ist ein Modell geschaffen! das die Dichte der Brutvögel in flächenförmigen Wäldern von kleiner Fläche beim Einfluß der Veränderungen der Komplexfaktoren der Umwelt characteri- siert. 1132 ADAPTIVE FEATURES IN THE WILLOW WARBLER'S ANNUAL CYCLE (PHYLLOSCOPUS TROCHILUS) IN THE CONDITIONS OR NORTH-WEST USSR TAIGA AREA N. V. Lapshin Institute of Biology, Karelian Branch of the USSR Academy of Sciences, Petrozavodsk, USSR The biology of the Willow Warbler was studied in 1968-1977 by trapping and individual marking, examination of 18 thousand birds and 600 nests, by recording the total number. The main adaptive biological features of the Willow Warbler in the conditions of north-west USSR taiga are as follows: Partial coincidence of nesting with the postnuptial moult, overlapping of Post-juvenile moult with autumn migration, the increasing rate of post-em- tiyonal development and of post-juvenile change of plumage in young in¬ dividuals from late broods, reduction of some behavioral reactions. In the short period of favorable conditions all these features facilitate the syn¬ chronization of individual cycles. THE NUMBER OF WHITE STORKS IN THE USSR M. I. Lebedeva Centre for Bird Ringing, Moscow, USSR The number of the nesting pairs of white storks (Ciconia ciconia cico- ) registered during the All-Union census of 1974 in the USSR was 49726. Compared with 1958, the number of white storks increased especially ln the Estonian SSR and in the RSFSR. The number of their nests registered ln 1 558 in Estonia was 354 and in 1974 amounted to 1060. In 1974 in ten reg¬ ions of the RSFSR were 3299 nesting pairs of recorded white storks. A remar¬ kable growth of the number of these birds was noted in the Kaliningrad, Pskov ahd Bryansk regions (three times as many and even more) and also in the Smo- iensk, Kursk and Belgorod regions as compared with the respective data of 1958. it is noted that they have populated the new territories in the Nov- Scrod, Kalinin, Kaluga and Voronezh regions. The nesting areas of the white siork in the USSR are spreading in the northeast and east directions. MIGRATION OF BARNACLE GEESE THROUGH ESTONIA A.Leito The Naturalists' Society of the Estonian SSR, Tartu, USSR The Barnacle Goose population of the Barents Sea (Eastern Europe) mig- *'atea on a rather narrow front. The width in Estonia is 100-150 km. The du- ■^tion of the migration in autumn is 8-37 days, on the average 23 days(n=12). The average period of the migration in spring is 40 days, the maximum is days. Mostly the size of the migrating flocks of the Barnacle Geese is Ul°0 ind. (31%) and 101-200 ind. (30%). The morning and evening maximums ^d the midday minimums can be distinguished in the daily rhythm of the mig- ^bion. Fair wind and the reduction of the air temperature in autumn trig- Sers the migration of Barnacle Geese. During migration wind and air tempe- 3?ature do not influence significantly the intensivness of the migration. Ac- corcj lnS to the data obtained from, aerial surveys up to 30 000 Barnacle Geese toP in West-Estonia every spring. 1133 TESTING THE SIGNIFICANCE OF INTERNAI CLOCK IN THE NIGHT ORIENTATION OF THE ROBIN (ERITHACUS RUBECULA L.) UNDER NATURAL SKY V. Liepa Institute of Biology, Latvian Academy of Sciences, Riga, USSR * In closed cameras Robins displayed a time-compensated night orientation in relation to a fixed point of light (Liepa, 1978; Katz, 1980). There is no conformity of opinion on the functional basis of this reaction (see Vilks at al. , this issue). So since 1978 we have been studying the orientati¬ onal behaviour of the Robin in a round netwall pen (diameter and height 5 m) under the open sky. About 20 birds are let into the pen simultaneously and their distribution under the ceiling of the pen is photographed in the cour¬ se of the night by means of a flashlight. In autumn, irrespective of how cloudy the sky is, of direction of wind, presence of azimuth of the moon, the time of letting birds into the pen (before sunset or after the astrono¬ mical darkness sets in) , the Robin prefferred the direction corresponding to that of its migration. Spring orientation, on the contrary, was to a con¬ siderable extent affected by wind (positive anemotaxis). The internal clock of birds was phase-shifted by +4, +4 and *?3h in spring and +6, -6 h in autumn. The experimental and control birds, supplied with light reflectors for group separation on the photos, were let into the pen simultaneously after astronomical darkness set in. The effect of vernal phase-shifts is obscure at present. In autumn the experimental birds in their first test under clear sky and a new moon showed a deviation from the mean direction of controls, as could be expected in the case of time compen¬ sated celestial orientation. These results are in agreement with author's supposition that compensatoiy reactions of the Robin under the single light clue reflects ability of this species to make use of the night celestial in¬ formation on the basis of the internal clock. SOME QUESTIONS OF OOLOGY W.W.Leonovitch The Pushkin State Museum of Fine Arts, Moscow, USSR The possibility of using the study of egg colour for systematization of birds has protagonists (Kusiakin, 1954) as well as adversaries (Lack, '1958). D.Lack, taking the Turdine as an example has shown the dependence of shell pigment on the character of nesting, more that on the degree of relationship betweèn different species. Accepting the conclusion of D.Lack, it is possib¬ le, after the same example with the Turdine, to establish the "first-type" of the egg colour and also of the nesting character of the whole group. Then the degree of egg-pigment lightening can show the age of the transition in different species from the open to the hole nesting. In cases of similar types of nesting inside relatively narrow systematic groups of birds, the egg colour can help to determine the degree of relationship between differ¬ ent species. So, the study of the egg colour can help classification, and to a great¬ er degree comprehension of the development of separate species and groups. 1134 THE STERNA AIiEUTICA BAIRD POPULATIONS ON THE TERRITORY OP THE USSR (RECENT SURVEY) E.G.Lobkov, V. A. Nechaev Kronotsk State Reservation; Institute of Biology Par East Research Center, Academy of Sciences, Vladivostok, USSR The Sterna aleutlca Baird is a rare species distributed sporadically within a limited areal. It inhabits separate sites along the Par-East coasts and lives in colonies. Not more than 100 pairs nest in the southern parts of the Sakhalin (the Aniva bay, the Lebyazhye and Nevskoye lakes); about 700 Pairs - on the north-east coast of the Island (Nabilj, Nyivo, Dagy, Chayvo, Hljtun bays and others) and about 200 pairs - on the north-west coast (en¬ virons of the Pogiby cape, the coast of Amur liman, the Baykal bay and others). According to the records of 1976-1979, the total number of species in the colonies observed on the Sakhalin amounted to about but not less than 1000 pairs. In 1972 the colony of 40 pairs (Leonovich, 1976) was observed along the north-west coast on the Okhotsk Sea in the Tauyskaya bay near Ma¬ gadan. Only four colonies consisting of 120 pairs were observed along the west coast of the Kamchatka peninsula; however, this region was not given Proper attention and it's very likely that the nesting birds of this species are much more common there. Seventeen colonies of 500 pairs have been recor¬ ded on the east coast of the Kamchatka though some of the possible sites have not been examined at all. According to the records of 1975-1979, the total number of species in the colonies observed on the Kamchatka came to ®°re than 600 pairs and, the total of about 3000 pairs seem to inhabit Kam¬ chatka. The site of the species in the south of the Koryak Highland (coast of the .Korf bay and the Apuka river mouth) was not established (Kistchinskiy, 198°). Th® total number of the Sterna aleutica Baird in the Soviet Par East aPpears to come to approximately 4000 pairs. THE STRUCTURE AND EVOLUTION OP AVIAN GENOME A. A. Lomov, B.M.Mednikov A. N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, Moscow, USSR Comparative studies of avian DNA that have been carried out in the recent years allow certain conclusions to be made about the principles of organizat- ion of the genetic material in these vertebrates and its specificity compared to other classes, Avian DNA has a characteristically low content of middle Repeated sequences that are represented in the genome by dozens to dozens pf thousands of copies; the number of unique sequences (individual genes and se¬ mences with the number of copies up to ten) is on an average one and a half times higher. The unique and repeated elements in the avian genome have an Ol>ganization of the type that has been previously described for insects only. n this respect the birds drastically differ not only from fishes and mam- ■'■a but also from reptiles, the evolutionarily closest class. The content of DNA per cell in birds is much lower than in other groups of vertebrates. 111 the taxa of birds of different rank studied, the divergence of DNA se¬ mences estimated by DNA/DNA hybridization, is comparable with that in other Masses of vertebrates, though it differs from it. The level of homologies in 1135 the class of birds is similar to that of fishes and mammals. At the same time, hybridization of DNA of the species from one genus of birds has re- vealed a degree of divergence that is characteristic of the interpopulat- onal and interracial differences between the species of fish and mammals. The DNA/DHA hybridization technique is used for solving certain problems of taxonomy. It has helped to make some conclusions about the relatedness of Gallif ormes and Ratitae, of some species, genera and tribes in the family of Anatidae. ^ HYDROPHIL BIRDS IN THE TROPHIC CHAINS OP THE AZOVO-BLACK SEA ESTUARIES V.I.Iycenko Melitopol State Pedagogical Institute, Melitopol, USSR Qualitative and quantitative dynamics of avian population is best dis¬ played in the exchange of dominant groups (in summer fauna-Charadriifor.es. m spring and autumn-winter-Anserlf ormes'). ~ Trophic chains of ecosystems with participation of two types of birds- those locked in estuaries and mixed (locked in estuaries and agrocenosises) . According to their trophic peculiarities all the hydrophil birds can be di¬ vided into three groups: (1) those feeding in estuaries mainly (feeding with macrophytes, ichthiophages, euiyphagous) ; (2) those feeding in estuaries and agrocenosises (a wide spectrum of feeding, including water and earth orga¬ nisms), (3) those feeding only in agrocenosises (a spectrum of feeding is represented only with earth forms). Species and groups of species which are predominant in size and importance for the biological exchange of substances belong to the category of migrants, their total number is estimated to be 4.5 min individuals. The role these migrants play in the trophic chains is determined by the duration of their stay in estuaries. When the changes in the block of estuaries' producers are reversible the consumers of the first order become transit migrants. For the birds of other trophic groups, changes in the dynamics of their feeding behavior are ob¬ served. In the ecosystems of the northern Azovo-Black Sea coast birds are the most labial part, and still it is the peculiarities of their trophic con¬ nections and of their position in trophic chains that define the qualitat¬ ive nature of the avifauna. A SCANNING ELECTRON MICROSCOPE STUDY OF PRIMARY FEATHER BARBS Ian H.J.Iyster Royal Scottish Museum, Chambers Street, Edinburgh, EH1 1JF Scotland, UK ’ uT“ «“■* « tH. ...1» .f primary feather. of tto Gold.. Eagle 13.11» ohrye.et„._ and ti, wtlte_t,lloa ^ u .1- Sienna rerealea the pre.e.c. „f . of . high, on the sides of the barbs hoi™. ». -, „ alow the barbules. Cell boundaries were els* arly visible and small indentations in ». , „ . . canons m the barb surface suggested the sites of collapsed nuclei. 1136 A general survey of primaries from specimens representing most Orders of birds showed that the micropapillae were present in some members of the Ti- namif ormes, Pelecaniforaes, Ciconiifoim.es, Gallifoxm.es, Gruiformes, Capri- fflulgxfoxm.es and Piciformes as well as in the Falconiformes. However, not all the members of a particular Order necessarily possessed the micropapillae, fhe survey also revealed some rather different surface features, the most complex being the surface mat of reticulated fibres notes on the primaxy arbs of the Curlew Numenius arquata and of the Herring Gull Larus areen- tatus# - a — A study was also made in the Golden Eagle of feathers other than prima¬ ries which showed that micropapillae were present to a varying degree on the barbs of all the feathers examined. Examples illustrating the different types of structure and the range of variation are given, and the taxonomic implications and possible functional roles are discussed. MICRATION PATTERNS OP THE BLACK SWIFT D.S.Lyuleeva Rybachy Biological Station, Institute of Zoology 0f the USSR Academy of Sciences, USSR Migration of black swifts was observed for 20 years (1960-1980) in the Courland Spit of the Baltic Sea. Regular summer migration side by side with sPring and autumn one was established. As compared to the unstable character of spring and autumn migration, summer migration is characterized by fixed ^ates, established regular dates of black cwifts' crossing the flight's route and a large number of migrating individuals (from 6 to 35 thousand per d8y, from 20 to 75 thousand .per season). Annually 92%, of swifts en route cross the Courland Split in the period from June, 5 - to July, 20. The num- er of summer migrants and their age groups seem to relatively correspond to the number of reproductive black swifts (the lower is the per cent of ef- fectively reproductive individuals, the higher is the number of summer mig- rants, specially in July). The black swifts moved in day time as well as in the night. High concentrations of flying black swifts during night feeding ^lights were established, most, numerous in the peripd of summer migration, hbjs of regular flight during summer migration were established. Black ^ifts concentrations in the night time seem to have a regional character 811(1 they are always related to large nesting colonies of the species. The migration of black swifts might be seasonal - spring, summer and &Utuffln, but also day and night ones which in their turn include regular mig- ^atory and feeding flights. FACTORS DETERMINING FORMATION AND STRUCTURE OF BIRD POPULATION, OF THE ALPINE SON-KULE LAKE IN TIEN SHAN A. K. Kydyraly ev Institute of Biology, Kirgiz Academy of Sciences, Frunze, USSR The Son-Rulg Lake (3020 km above the sea-level) has very harsh natural cHmatic conditions. Its banks are mash-ridden with lagoon-type small lakes. 36.3sk. 981 1137 In the past 20-25 years noticeable changes in the population of nesting and migrant birds have occurred on it alongside with, species endemic for Central Asia mountains such as Anaer lndicus and Charadrius mongo lu a and such com¬ mon species as Anas platyrhynchos. Anas strepera. Ay thv a ferina. A.fuligula, Tringa totaous etc. lately Cygnus cygnus. Ansei* anser. A.alblfrons. Llmosa llmosa etc. have started nesting here. Originally the Son-Rule Lake did not have any fish. Pish started there in 1959 and it took root. As a result those previously very few and scarce nest¬ ing species became numerous and even predominant (Podiceps, Laridae, Sterni- dae, etc.); Ardea cinerea, Phalacrocorax carbo. Larue argeotatus etc. start¬ ed nesting there. On the whole the number of nesting species has gone up from 25 to 36 species. The Anaer if ormes prevail over nesting sites (13 spe¬ cies). Of primary importance for forming the ornithocomplex of the Son-Rule Lake were: the flight route over this lake, available écologie conditions includ¬ ing abundant food, no disturbance during nesting.' PECULIARITY OP THE HELMINTH PAUNA OP THE FLAMINGO PHOENICOPTERUS ROSEUS PALL A. P. Maksimova Institute of Zoology 0j> ^e Kazakh SSR Academy of Sciences, Alma-Ata, USSR As a result of many years (1968-1977) ecological and parasitological in¬ vestigations of the biocenosis in the extremely salty Lake of Tengiz (Central Kazakhstan) it was found that the flamingos nesting and molting there are greatly infected with cestodes, mainly with hymenolepidids. Invasion of the birds with other groups of helminths was inconsiderable. Peculiarity of the flamingo helminth fauna (the prevalence of cestodes in it> is conditioned by the peculiar specific composition of the invertebrates inhabiting the lake Tengiz which are represented by Branchiopoda . (Artemia salina , Branchinella spinosa) and Ostracoda (Eucypris inf lata) mainly, since they are obligatory intermediate hosts of cestodes and the main feed-stuff of these birds. , The parasitological data received complement the information on feeding and seasonal migration of Central Kazakhstan population of flamingos. FEEDING ECOLOGY AND BEHAVIOUR OF EUROPEAN WIGEON Peter Watts Mayhew Department of Zoology, University of Glasgow, Glasgow Cl 2 8QQ, Scotland, UK Plant digestion has been studiëd extensively in the domestic ruminants, but there has been little work done on the smaller herbivorous mammals and birds. The small body size of these animals accentuates the problem of ob¬ taining sufficient energy from a food which is difficult to digest. Among birds the European wigeon Anas penelope is one of the smallest species which feeds on a plant leaf diet, and these problems are therefore particularly acute. 1158 This study examines the behavioural and physiological strategies which this species employs to maximise its energy intake during the winter. Data ill be presented on the behaviour of wild birds to demonstrate their site di !î^/00d qUallty manipulation* «» selection of food for quality and digestibility, and feeding time allocation. Studies on the physiology of di¬ gestion cover changes in the gut morphology with season, and changes in the digestive efficiency of birds with grass quality and height, using both wild and captive birds. Preliminary results indicate that the birds are able to graze efficiently on relatively poor quality grassland, but that they demonstrate clear prefe¬ rences for certain feeding sites and that these preferences are related to digestive efficiency. ON THE SIBERIAN WHITE CRANE IN CHINA Ma Yi-ching Institute of Natural Resources, Hapin Road, Harbin, China The Siberian White Crane (Grus leucogeranus) is a migrant and winter bird in China. In the past, they were recorded as breeding around the margin of alainor Lake and Qiqihar of northeastern China (Lou et Lee, 1932; Meise, 1934; Cheng, 1976); according to Wilder and Hubbard (1938) they breed in' Diactung in northeast China (reference to two eggs similar to those of the ommon Crane, with larger markings, 95 x 63 mm) . However the reliable brred- ihg records of this crane have not been registered in recent years. In late May and early June 1981 a flock of 24 white cranes we saw in Wuyur river near Qiqihar of Heilongjiang Province; they were all subadults and we considered them as migrants at the stopover. During the spring and autumn migrations, they migrate along the Nen- Jiang iyer in central parts of Heilongjiang Province and also southward along the coastal province to their wintering grounds. In spring 1945 a migrating Ilock of about 600-700 and in autumns (1943-1945) 357 White cranes were seen y Hemmingsen at the Beidaihe Beach, Hebei Province (Hemmingsen, Guildal, ^B). The wintering grounds of White crane in China are known at the Lower Yangtze River (Cheng, 1976). In Januaiy 1981 a wintering flock of more than 100 White cranes were found at the west shore marshes of Poyang Lake in horthwest Jiangxi Province (Chou et al., 1981). In addition a wintering flock °T White cranes was seen by Wang (1981) in the Anqing district of Anhui Pro¬ vince. THE DISTRIBUTION OP BLACK-NECKED CRANE IN CHINA Ma Yi-ching Institute of Natural Resources, Hapin Road, Harbin, China The Black-necked Crane (Grus nigricollis) is a world'-s only alpine crane sPecies, its nesting areas are between 3500 to 5000 m above sea level, and 6ven in winter it is the exception for cranes to migrate to warm lowland ■ ai>eas. The Black-necked crane has been known to breed in the Qinghai Provence, horthwestem Sichuan Province and southern Xizang Autonomous Region, and also 1139 has been seen in the vicinity of upper reaches of the Indus River in south¬ western Xizang (Lavkumar, 1955). Stresemann et al. (1938) have reported its breeding at nothwestem Kansu Province, but not in recent years. The density of breeding population is 1.45 cranes per km2 (mid-April to mid-May) and 0.76-0.78 cranes per km (June) in 45.0 km2 of breedipg area at Lonbaotan (4200 m altitude), southern Qinghai Province according to preliminary sur¬ veys in 1978-1979 by Lu et al. (1980). During the fall migration it has been seen sometimes in large flocks. Cheng wrote (1981) that a migrating flock of about 300-400 cranes was seen in September 1973 at the Tangra Range pass (about 5000 m altitude) flying southward; and in mid-October 1979 a' flock of at least 600 cranes was seen in Nuomuhong in the Tsaidam Basin. The cranes spend the winter is southwestern Sichuan, southern Xizang, western Guizhou and Yunnan. In early December 1979 a wintering flock of 70- 80 cranes was found at the Caohai (grass sea, 26°51'N; 1 04°1 4’ E; El. 2200 m) m Weining of western Guizhou Province, they shared roosting together with Grus grus lilfordi (Chou et al., 1980). CAPTIVE CRANES IK NORTHEASTERH CHIHA Ma Yi-ching, Li Zhong-zhou Institute of Hatural Resources, Hapin Road, Harbin, China; Harbin Zoo, Hexing Road, Harbin, China A number of 7 species of cranes are kept in zoos or parks of Kortheastem China. According to a rough estimate the species and numbers of captive cra¬ nes in 1980 are presented in Table 1. Cranes a number of zoos or parks number male female sex uni¬ dentified juve¬ nile Total Grus japonensis Grus grus Grus vipio Grus monacha Grus leucogeranus Anthropoides virgo Balearica pavonine 18 49 38 5 13 50 28 10 8 17 10 3 3 2 3 2 - - 2 11 15 9 12 1 2 2 6 6 1 98 88 33 8 2 37 4 ADAPTIVE FEATURES OF COLONIAL NESTING UNDER FLUCTUATING ENVIRONMENTAL CONDITIONS Ju. I. Melnikov * Irkutsk State University, USSR The study was carried out in the delta of the Selenga River (Southern Bai¬ kal) (1973-1980) on 8 species of Gull birds: herring gull, common 'gull, black¬ headed gull, little gulls, common tern, white-winged black tern, whiskered tel® and Caspian terns. The peculiarity of the Selenga River is the mountain-flood- lands character of the water regime, resulting in fluctuations of water level by seasons as well as by years.' At the beginning of the season the location of colonies depends on water level which is stable by that time and by the pe¬ culiarities in the distribution of food resources. Since the fluctuations in he water level lead to qualitative changes of the inshore biocenoses, the location of colonies changes not only annually but what is more essential all throughout the breeding season. Since the value of fluctuations is rela¬ te, the search for optimal nesting sites is made by the -'trial and error- method. The birds nest in. small colonies of 50-80 nests, with high degree of synchronized breeding, occupying the maximum number of habitats. With the changes of hydrological regime and with the loss of colonies the birds nest ofS?Sn T m°Ving UP t0 thS SUrvival habitâtes and foiling complex colonies °f 150-200 or 1000 and more pairs. Nesting by small colonies makes the birds very sensitive to any changes in the conditions of the habitat and promotes most rapid occupation of best avourable sites. Synchronized breeding in the colony helps to make use of most favourable conditions in the shortest time possible. BIRDS ADAPTATION TO CONDITIONS OP RESERVOIRS ON the dneper river V. A.Melnichuk Kiev State University, Kiev, USSR Pilling - in of reservoirs- causes a concentration of birds mainly water¬ fowl in the shallow islandic zone. New species nest there. Bird concentration eads to their increased activity as well as to antagonistic behaviour in the habitats of high nesting density. Territorial fidelity is very marked and is accompanied by ecological plas- isity , i.e. change of nesting habits and use of unusual sites for nests. The Tatter is temporaiy though it is extremely frequent. During the formation of the reservoir the density of islandic birds popu- ation is decreasing while the duration of the breeding period because of un¬ stable hydrological regime is considerable. At the same time birds tend to °°hcentrate on separate islands and the number of colonies goes down. Molting hirds concentrate on reservoirs. A number of migrants and the Oration of their stay on new reservoirs is essentially increasing. Frost¬ proof parts of reservoirs near dams are favourable sites for wintering of a°me waterfowl. the energy requirements and routes op heat loss op incubating great tits Joseph A. L. Mertens Institute for Ecological Research, Kemperbergerweg 67 Arnhem, the Netherlands Recent investigations of the amount of heat lost by Great Tits during in- chhation showed that the heat loss increases considerably during the transi t- T°h phase from egg-laying to incubation. There are indications that the female will not start incubation when low femperatures woul(j force her to exceed a certain level of heat production, T those cold spells after the onset of incubation do not bring about an in- 6hruption of the incubation. 1141 An analysis of the changes in the heat loss pattern during the egg-laying and incubation period will be presented and discussed. ADAPTATION OP BIRDS TO THE CONDITIONS OP RESERVOIRS OP SOUTHERN UKRAINE O.M.Miasojedova Dnepropetrovsk State University, USSR The following types of adaptation of birds to the conditions of reservoirs are established: 1 . Biotopic. This occurred due to abrupt changes in land ecosystems in the areas of reservoirs. This type of adaptation is manifest in the change of sites ,and breeding stations. Many typical crowners come to nest in bush, in tree stubs, in old demolished buildings (Mllvus korschun, Buteo buteo, Corvus co rax) . Species, which previously nested on glasslands, sand banks, spits moved to placor conditions. 2. Phenologic. This arose from changes in the characteristics of ice dirfting from readily evailable feeding objects. Many typical migratory birds became permanent residents (Anas platyrhynchos. Anas strep era. Anas querquedula. Larus ridibundus. Stumus vulgaris'. Migrant species (Aythya ferina. Anas penelope, Colymbus crl status, Aythya marlla, Oidemia fusca)came to winter; Larus argentatus, Colymbus nigricollis, Philomachus pugnax have begun to nest in the area. 3. Migrational. This is manifest mostly in the change of time and inten¬ sity of transmigration. Earlier the transmigration of northern populations .of birds was simultaneous with the departure of local populations. The stop of northern migrants was short (up to 3 to 5 days). After the formation of re¬ servoirs a gap was formed between the departure of local populations and the arrival of northern ones. The transmigration of northern populations became more prolonged and shifted 20 to 40 days later. 4« Reproductive. This is manifest in change of birds' fecundity. Average number of eggs in a clutch of reed and bush birds is 6.3 to 8.1 percent smaller. On the contrary , land birds in water biotopes, crowners and hole- nesting birds have larger clutches (increased by 15.2, 6.4 and 3.2 percent respectively) . TRAPPING AND MEASURING MIGRANT BIRDS IN LOMBARDY, ITALY G.Micali, V.Vigorita, R. Massa Department of Pharmacology, University of Milano and Society "A.Ghigi" for Vertebrate Biology, Italy Passerine birds have long been trapped in Lombardy during the autumn. The proper standardization of this activity is now needed since it might allow the collection of vast amount of new information. To this end, we measured body weight, total length, wing, tail and tarsus lenghts in several thousand- specimens of some common .passerine birds trapped in Lombardy from August 25th to December 10th. The data have been submitted to statistical analyses and simple correlations between parameters have been calculated. Due to the large number of birds trapped, this approach seems promising to collect basic data for population studies. -1142 SOARING BIRDS' MIGRATIONS IN BULGARIAN BLACK SEA COSTAL AREA Tanyu M.Miohev, Lyubomir An. Profirov, Pavel St. Simeonov BAS, Sofia, Bulgaria In this paper the results of visual observations of soaring birds' migrat¬ ions during three consecutive years in the period from 10th to 30th of Octo¬ ber is given. In the Autumn of 1981 the results of the visual observations were supplemented with radar met's data. The information about quantity, bates of passings, top migration days, spending of nights and ways of pass¬ ing above the Bulgarian Black Sea costal area was collected on each to the observed species. The dépendance between the migrating species' quantity and meteorological conditions (direction and power of wind, atmosphere pressure, cloudness, fall of precipitations, air temperature etc.) was assertained with the help of' e> c.m. The results of this are of fundamental scientific, nature preservational and practical importance. SELP-REGULATION OP NUMBERS IN BREEDING DUCKS AND ITS PROBABLE RELATIONSHIP WITH CARRYING CAPACITY OF NESTING HABITATS LH.Mihelson 1 Institute of Biology, Latvian Academy of Sciences, Riga, USSR Recent banding results of the Tufted Duck have been summarised according to a special program from 1961 on the Engure Marsh (Latvia). Relationship has been observed among the yearly fluctuation in numbers of nesting females, yearly changes in carrying capacity of nesting habitats and self-regulation in female numbers. The basic indirect proofs on the role of fluctuations in carrying capacity of nesting habitats in the dynamics of number are analyz- etl: (D lack of synchronity in yearly fluctuations of number of nesting fe¬ hles in various areas, and (2) correspondingly, a considerable autonomity °f self-regulation of numbers in these areas. More definite are the variat- iona i» survival of juveniles with the change in numbers of nesting females C°®Pared with their number in the previous year. In years of various rate of decrease of nest numbers, a gradual rise in survival of juveniles correlated b° slowing in the increase rate has been observed; it usually continues to rdse after a slight decrease in nest numbers. Maximum is reached at 80-90% wbich is close to the mean per cent of returned adult female-residents (65- At further drop in nest numbers, survival of juveniles also falls ®Rarpiy supposedly due to sharp competition among the residents for nesting aites. The similarity of survival curves under various conditions allows the ^Egestion that even little noticed variations in environment lowered car¬ ding capacity of nesting habitats is often the reason for drop in nest num- bers. Within the limits of usual fluctuations in number of breeding females, tbe mechanisms of quantitative self-regulation practically eliminate the pos- 81ble negative consequences of yearly fluctuations in carrying capacity. 1143 METERNAL ALARM CALLS OP MALLARD DUCKS (ANAS PLATYRHYNCHOS) : PRODUCTION AND 'PERCEPTION David B. Miller Department of Psychology, University of Connecticut, Storrs, Connecticut 06268, USA While brooding their young on the nest, female mallards occasionally LlThLh7m?VaiV ^ 6lert P08tUre (i,e” ne°k °ut8tr*tched and head tered wh T « l0W’ampllt4de ala™ cal^‘ These calls, which are ut- ered when there is some disturbance in the vicinity of the nest (i.e. p0- oT:: ip::da;;r3)’ have “ inhibitine effect « ^ ■»* tor activity (i.e., "freezing- and cessation of vocalizations). This effect occurs both in the field and in the laboratory, the latter involving mater- nally-naive (i.e., incubator-hatched) , one-day-old wild and domestic (Pe¬ king) mallard ducklings. This poster describes the specific acoustic features of maternal ala™ calls that effect behavioral inhibition in ducklings. References, Miller, D.B. (i960) J. comp, physiol. Psychol. 94: 606-623. Miller, D.B. and Gottlieb, G. (1978) Anim. Behav, 26: 1178-1194. Miller, •B. and Gottlieb, G. (1981) J. comp, physiol. Psychol. 95: 205-219 (Supported by grants to D.B.M. from the National Science Foundation under Grant No. BNS-8013502 and the University of Connecticut Research Foun¬ dation, and by Research Grant HD-00878 from the National Institute of Child Health and Human Development to Gilbert Gottlieb.) HERRING GULLS POPULATION IN CAMPANIA DURING THE LAST 20 YEARS Mario Mi lone, Maria Grot ta, Morrone Lucia Capo Istituto e Museo di Zoologia, via Mezzocannone 8, 80134 Napoli, Italy There is little inforaation on the gulls (Laridae) from southern Italy; IqPrn7ata r the fir3t °f their kind °n herrin* ***■ C-pania. These are observations on nesting sites, on population size and on social behaviour. We have noted a decline in the nesting sites found mainly along the rocky surface of calcareous origin of the islands and on the rocks in the Gulfs of Naples and Salerno. Today the herring gulls tend to abandon the coastal sites and prefer to breed on the islands, concentrating their colonies along the rocky surface of Capri Island. Capri, today, is practical ly at the center of the distribution area of this species in Campania. A decline of nesting sites or total lack- 7 (,ol;aj- J-aclc of them occurs in areas with ma.lor tourist activity (specially in 1967-1971). An increase in the number of j 01 nesting sites was found in areas of high fish density and with a high densitv . 8 , , sn aenslty of shipping lanes. The colonies are mainly oriented toward south and , , 8X1(1 southwest. An analysis of size of these po- pulation indicate, that they consist 0l ^ in3lvli^ 3l„cë u , considerable decrease in the number of immature individual, a, a percentage of mature Individuals, there is „ consistent decrease in the to.L pepul.t- ion. It may be due to decreased reproductive activity. The immature indivi- duals use different roost«* fn-n _ _ • , sleeping and for fishing. They prefer mainly 1144 anchovies, herrings, mullets and Lamellibranchi . There is high competition in winter with the migrator Blackheaded Gulls. TOWARDS A NEW CLASSIFICATION OF BIRDS J. Mlikovsky Department of Evolutional^ Biojogy, MBIÎ SsAV, Praha, CSSR During the last 50 years of stagnation in the development of avian clas¬ sification, new data has been acquired making a rearrangement of avian fami- les possible, because the orders in the FÎirbringer-Gadow-Wetmore tradition are more ecological than systematic groups. The most valuable contributions have been studies on egg-white proteins (Sibley, Ahlquist), columella morpho¬ logy (Feduccia), brain morphology (Mlikovsky), and numerous paleontological studies (Olson, Feduccia and many others). A large amount of data gathered were evaluated by means of new methods of biological systematica (developed by Mlikovsky') which have been based espe¬ cially on new achievements in mathematical logics. The classification presented here is by no means definite: it will rather stimulate new omithosystematical research. The following categories are used: classis, subclassis (-ida), ordo (-formes), subordo (-formia) , and iamilia (-idae). The families refer, if possible, to those of Wetmore (i960). The orders within the Archaeopterygida and Hesper-omithida are artificial. Aves: Archaeopterygida (for the Jurassic radiation): Archaeopterygiformes: Archaeopterygidae, Preomithidae Hesperomithida (new subclass for the Cretaceous radiation; type: Hesperor- his Marsh 1872): Hesperornithiformes: Hesperomithidae, Baptornithidae, Enaliomithidae (incl. Pelagomithidae) , Elopterygidae, Cimolopterygidae (incl. ?Laomithidae, ?Torotigidae) , Ichthyomithidae (incl. Apatomithidae, Angelinomithidae) '■'elmatomithiformes (new ordo; type: Telmatomis Marsh 1870): Telmatomithi- lae, Palaeotringidae Alexornithiformes: Alexomithidae °truthioniformes: Struthionidae (incl. ?Eleutheromithidae) , Aepyomithidae, Rheidae (incl. Opisthodactylidae) , Casuariidae (incl. Dromiceidae, Dro- momithidae) hasserida (new subclass for the 1st branch of the Cenozoic radiation; type: Passer Linné 1758): Alciformes: Prophaethontidae, Stercorariidae, Rynchopidae, Alcidae, Anoidae Ardeiformes: Phaethontif orraia: Gaviidae, Phaethontidae; Ardeiformia: Ardei- hae (incl. Cochleariidae) , Sulidae, Phalacrocoracidae, Plotopteridae, Anhingidae, Optsthocomidae (incl. ?Onychopterygidae) ®ucerotif ormes: Bucerotiformia: Upupidae, Phoeniculidae, Bucerotidae; Eury- laimiformia: Eurylaimidae, Philepittidae Ralliformes: Rallidae (incl. Ortho cnemidae, Aramidae, Psophiidae, Indiomi- thidae), Gallinulidae, Heliomithidae, Rhynochetidae, Buiypygidae, Mesi- tomithidae, Turnicidae (incl. Pedionomidae) , ?Raphidae, Cariamidae (incl. Phororhacidae, Psilopteridae, Brontomithidae , Cunampaiidae, Her- ftosiomithidae) , Bathornithidae (incl. Geranoididae) , Gastomithidae (incl. Diatrymidae, Dasomithidae) 1145 Accipitriformea: Cuculif ormia: Cuoulidae, Centropodidaej Accipitriformia: Accipitridae (incl. Pandionidae) , Sagittariidae; Phasianiformia: Phasiani- dae (incl. Tetraonidae, Numididae, Meleagrididae, Rhegminomithidae) , Cra- cidae (incl* Gallinuloididae) , Megapodiidae Strigiformes: Strigiformia: Strigidae (incl. T*t»nidae, Protostrigidae) , Leptoaomatidae, Steatoimithidae; Caprimulgiformia: Archaeotrogonidae.Cap- nraulgidae (incl. Nyctibiidae) , Podargidae Oincl. Aegothelidae) , Muaopha- gidae (incl. Couidae, Apopempsidae) ; Falconif ormia: Palconidae Columbiformes: Meropifomia: Halcyonidne, Todidae, Momotidae, Meropidae, Tro- gonidae; Columbif ormia: Columbidae Trochili formes: Coraciiformia: Primobucconidae, Bucconidae, Galbulidae, Co- raciidae (incl. Brachypteraciidae) ; Trochilif ormia: Apodidae, Trochilidae Tyranniformes: Tyrann! form! a: Tyrannidae (incl. Oxynuncidae)., Querulidae (incl. Phytotomidae) , Pipridae; Fumariiformia: Thamnophilidae (incl. Co- nopophagidae) , Scytalopodidae, Furnariidae, Dendrocolaptidae Passeriformes: many families with leaa known relationahipa Ciconiida, (new subclass for the 2nd branch of the Cenozoic radiation; type: Ciconia Brisaon 1760): Apterygi formes: Procellariiformia: Procellariidae (incl.Diomedeidae, Hydro- batidae, Pelecanoididae) , Spheniacidae; Apteiygifoimia: Dinornithidae (incl. Anomalopterygidae) , Apterygidae; Tinamiformia: Tinamidae; Podici- pediformia: Podicipedidae; Dromadiformia: Dromadidae; Chionif ormia: Chio- nididae Ciconiiformes: Ciconiif oimia: Ciconiidae (incl. Balaenicipitidae) , Pelecani- dae (incl. TCyphonithidae), Fregatidae, Scopidae; Odontopteiygifoimia: Odontopterygidae (incl. Pseudodontomithidae) ; Vulturiformia: Vulturidae (incl. Neocathartidae, Teratomithidae) ; Charadriif ormia: Charadriidae, Glareolidae, Pterocletidae, Laridae Anserifoimes: Phoenicopteriformia: Presbyomithidae (incl. Telmabatidae) . Phoenicopteridae (incl. ÎAgnopteridae, ÎScaniomithidae, Palaeolodidae) , Recurvirostridae, Haematopodidae, Burhinidae; Anserif ormia: Anseridae (incl. Paranyrocidae), Anhimidae; Otidiformia: Otididae (incl. Giyzadi- dae); Jacaniformia: Jacanidae, Roatratulidae; Gruifoimia: Gruidae (incl. Eogruidae, Ergilomithidae) Plataleiformes: Plataleidae, Scolopacidae (incl. Phalaropodidae) Pi ci forme a: Pteroglossidae, Capitomidae, Indicatoridae, Picidae Avea inc. aedis: Aegialomithidae (incl. Hemiprocnidae) , Cladormithidae, Dakatomithidae, Halcyoraithidae, Marinavidae, Primoscenidae, Thinocori- dae, Zygodactylidae Passerida inc. aedis: Acanthi ai ttidae, Pittidae Ciconiida inc. aedis: Coliidae, Psittacidae not avian: Bradycnemidae, Caenagnathidae, Gobipteiygidae. ENCEPHALIZATION OF BIRDS J.Mlfkovsky Department of Evolutionary Biology, MBÛ ÎSAV, Praha, CSSR The study of the brain weight (E) to body weight (S) relationship in dif¬ ferent taxa is a basic prereguisite to the investigation of brain size evo¬ lution. 1146 In this study encephalization of 409 non-passeriform and 9 passeriform species was estimated by measuring volume of their cavita cranii. Additional data on 139 non-passeriform and 107 passeriform species were compiled from literature resulting in a knowledge of encephalization of 438 (=11,6%) non- passeriform and 109 (=2.7%) passeriform species. For each species, brain size of 1-127 individuals has been measured. The results are presented in the foim of allometric equations; correlat¬ ion was tested with Kendall's tau. All correlations are significant at P = 0.01. Avea: log E - log 0.1528 + 0.5389+0.0414 log S tau = 0.6947, n = 547 Non-Passeriformes : Passeriformes: log E = log 0.1529 + 0.5369+0.0453 log S tau = 0.7059, n = 438 log E = log 0.0865 + 0.7257+0.0066 log S tau = 0.9086, n = 109 MORTALITY OP BIRDS ON THE ROADS AND THEIR DENSITY Attilio Mocci Demartis C/o Istituto di Zoologia (Université) Viale Poetto, 1, Italia It is easy to see on the roads, a relation between the increasing traffic smd a larger number of bird corpses, dead on impact with the passing oars. Although the collision between birds and cars happens casually, however it Is the number of dead birds that is directly proportional to: a) the local density of birds; b) the frequency of passing cars, in relation to the im¬ portance of that particular arterial road; c) the model of the straight and flat road, where the speed of the cars is greater; d) the different seasons. contrary, the number of dead is inversely proportional to the mountain roads, full of bends, where the slower speed reduces the probability of im¬ pact. Naturally the number of deaths differs according to the specimens and their ethology, and it's higher for the Passeriformes, that like feeding on the road borders and in the adjacent grounds, especially in winter-time. This technique has been applied in Sardinia for different models of road (straight, tortuous, etc.); on different altimetry (plain, hill, mountain, 6tc.); across some different types of botanical associations (cultivations, w°°d, forest, etc.); and during all the seasons of year. Prom this study we Stained an approximate idea of density of various bird specimens, in dif- ferent habitats, during the year. This method of relative census brings us again to the technique "Breed- *hg Bird Survey", since it is remarked the number of impacts between cars ^d birds, rather than the visual meeting between the observer and birds. FRUIT SELECTION BY TROPICAL FRUGIVOROUS BIRDS Timothy C. Moermond, Julie S. Denslow Department of Zoology and Department of Botany University Wisconsin-Madison, Madison, Wisconsin 53706, USA Fruit choice experiments were conducted with captive individuals of se— Veral species of small frugivores at the La Selva Biological Station in 1147 tropical lowland rain forest in Costa Rica. We tested preferences for type size, and ripeness of fruit and for several aspects of accessibility of fruits from perches. All birds tested made repeatable discriminations among the choices offered. Species different in their abilities and preferences corresponding to differences in morphology. Detained field observations of the foraging repertoire of these species corresponded closely to the abili¬ ties and preferences determined in the avian trials. ECOLOGICAL FOUNDATIONS OF FLOCK-FLYING OF BIRDS A. V.Molodovsky Gorky State University, USSR In 1956-1980 food gathering and flight of 100 Ö00 bird-flocks were studied m the Volga-Caspian region. Based on species behaviour stereotype (mainly on food gathering), flock structure is connected with peculiarities of avian eye structure (angular indeces of vision, keenness of sight etc.). Two trans- forming classes of flock structure were singled out, composite and linear, each of them changes into the other. Succession of flock construction, their altitude and the number of forms depend on specific peculiarities, the num¬ ber of birds in the flock and the conditions of flying (altitude, strength and direction of wind etc.). From the point of view of evolution, flock structure developed from initially amorphous (both diffuse and compact) through the stage of strictly composite or linear (or directly from the lat¬ ter) to secondarily amorphous composite. BODY COMPOSITION AND METABOLISM IN SPITZBERGEN PTARMIGAN (L.MUTUS HYPERBOREUS) A.Mortensen, S. Unander, M.Kolstad, A.S.Blix Department of Arctic Biology, University of Troms^, Tromsÿ, Norway The Spitzbergen ptarmigan is the only herbivorous bird tolerant to the hostile winter of 3 months of continuous darkness, low temperatures and scar¬ city or even temporary lack of food at the high arctic islands of Svalbard (77-81° NL). Fundamental for survival in this species is an unusual ability for depo¬ sition of fat in the fall when food is readily available. Thus, fat made up as much as from 12-31 per cent of total body weight (reaching 1 . 2 kg in old males) in early October. In early April when the sun returns, this energy depot is almost drained. Resting metabolism in this species was the same both in summer and winter, being 75 kcal/kg-day and 120 kcal/kg-day at thermoneutrality and at an am¬ bient temperature of -30°C, respectively. Assuming that the caloric value of the ptarmigan fat is 9.5 kcal/g the fat deposits in this bird could cover its total energy expenditure at rest and thermoneutrality (above an ambient temperature of -5°C) for 18-39 days. This period could even be further extended if metabolism is depressed dur¬ ing episodes of starvation. Studies of weight change and metabolic response to starvation at different timeq nf „„„ nmes oi the year are currently under way in our laboratory. 1148 Supported in part by The Norwegian Research Council 'for Science and the Humanities (NAVF) and The Norwegian Polar Institute. DINAMIK DSR NESTAREALE DER VÖGEL DER WESTSIBIRISCHER TIEFEBENE S.Moskwitin Die Staatsuniversität Tomsk, UdSSR letzten 50 Jahre andern die Vorstellungen Uber die Nestareale einiger Dut- 1 Vogeiarten, die in erster Linie zu den Spatzen gehören Passerifomes. gingillidae, Muscicapidae, SJlyiidae, Turdidae, ünberizidae,“ Columbidae ggiradriif ornes , Rallidae, Falconlformes. Bei den meisten vögeln war es mit rem Ansiedeln verbunden, wobei 6 Arten zum ersten Mal auf dem Flachland zu Nisten begannen. Bei den bestimmten Vogelarten (Eiythropus vesoertm,,. . ggnatili3, Columba oenas, CVpalumbus, Pseudaedon sibilans. Phragmaticola P^lloscopus schwarzii) ging das Ansiedeln in einer bestimmten Rich- ung vor sich, und der wichtigste Faktor war dabei die Veränderung der Um¬ weltverhaltnisse außerhalb des ehemaligen Areals, die mit der Temperatur¬ steigerung, der Sukzession der Wälder, den Landwirtschaftlichen Veränderung •3.W. verbunden worden war. Bei den anderen Vogelarten (Sterna albifrons. ^Iloscopus borealis, Corvus frugilegus) war die Nèstgebietsânderung in ver¬ miedenen Teilen des Areals zu beobachten, und das Auseinandersiedeln hatte eine radiale Tendenz, die wahrscheinlich mit der bestimmenden Wirkung der en- ogenen Faktoren und mit den Besonderheiten des Verhaltens der Vögel verbun¬ den ist. Bei der zweiten Gruppe der Vögel (Podiceps nigricollis. Anatidae, Hydro- 6-gogne caspia) ist das Ansiedeln an den neuen Orten mit der Pulsieren des Nes- areals verbunden, dessen Maximum früher nicht fixiert worde- war. Die meis- eN dieser Arten gehören zu der Gruppe, die Intrazonenlandschaften besiedeln. Zur dritten Gruppe gehören wenige Arten (Pemis ptllorhvnchus. Accipiter lifiys, Limosa limosa) . die einen gegliederten Nestareal haben, und von deren Mhamik nur einzelne Funde an den früher unbekannten Orten zeugten. b Der Umfang der Veränderung wird durch die Besonderheiten des Territoriums estimmt, sowie durch das Vorhandensein der Gebietspopulationen in Westsibi- r:ien, die bekanntlich ihre innere Spezifik haben. polymorphism in the synantropical columba livia u. POPULATIONS S.Moskvitin, A.Ksenz Tomsk State University, Tomsk, USSR Th the peculiarites of their plumage pigmentation synantropical populati- Ns of rock pigeons are polymorphous. All in all, 6 coloured morphs are dis- Nguiahed as a result of survey of 10 000 species (Moskvitin et al., 1981). e nock-coloured (from 1 2 to 53%) and black-checkered with characteristical- marked picture of the wing (from 37 to 84%) pigeons dominated and totally ^ eY amounted to 88-98% in each of the eight examined populations. According ° The data collected in Tomsk in 1979-1980 (456 copies) the fundamentally ■^Phological, interior and some ecological and ethological characteristics Of cnese morphs were analysed. 1149 Reliable differences between, rock-coloured and black-checkered pigeons ere estabiisheä by following indices: adult males differ by the body weight, adult hens - by the length of the body and the relative weight of masticato¬ ry stomach. Both hens and males differ by the character of correlations among the above mentioned signs. Among the rock-coloured pigeons there are more under a year hens than among the black-checkered ones. Brooding rock- coloured pigeons are more cautions which was determined by the distance at which they left the nest when, watcher was approaching 195 individuals. For rock-coloured nestlings protectively agressive behaviour is often characte¬ ristic in the interactions with the watcher. Assortive mating in the rock Pigeons wasn't regularly observed every year. Evidently, this is related to the sexual and age dynamics of the populations. Thus, the rock-coloured and black-checkered morphs are original genetic groups that respond differently to the combination of exterior influences and this determines the dynamics of their correlations within the area. AKUSTISCHE SIGNALISIERUNG DES FRANKOLINS ( FRANKOLINUS FRANCOLINUS) TN DER BRUTZEIT A.Musaew Severzow-Institut fur Evolutionsmorphologie und Ökologie der Tiere AdW der UdSSR, Moskau t UdSSR Es wurde die akustische Signalisierung Frankolins in der Brutzeit unter¬ sucht. Man stellte fest, dass der funktionelle Aufbau des akustischen Signal¬ systems des Frankolins keine prinzipielle Unterschiede vom gesamten für Hühnervögel eigenen Typ hat. Für die Altvögel sind in der Brutzeit Balz-(0.8- 3.6 kc), Lock- (0,8-3. 2 kc), Fütter- (0.6-2. 8 kc) und Warnsignale (1.2-2. 6 k°' charakteristisch. Jungvögel haben Orientiemmgslaute (1. 8-3.8 kc) Rufe des Wohlbefindens (1.2-4. 2 kc) , Weinensignale (1.0-4. 5 kc) und Alarmsignale (2.0-3. 5 kc). Die ermittelten Besonderheiten des Verhaltens und akustischer ignalisierung können bei der Zucht der Frankoline in der Gefangenschaft aus¬ genutzt werden. Fur die erfolgreiche Züchtung der Jungvögel hat die Stimulie¬ rung des Nahrungsreflexes eine besonders grosse Bedeutung. Dieser Reflex wird bei Jungvogeln durch FÜtterlaute der Alten stimuliert. Das Vorhandensein bei Jungvogeln der ''empfindlichen'' Periode(8-l6 Stunden nach dem Schlüpfen) und dre Fahigket der Jungen akustische Reizmittel einzuprögen ermöglicht nicht nur Signale der Eltern als Stimulierung auszunutzen, sondern auch Monofre- quenzsignale im Frequenzgebiet 0.6-1 *2 kHz. HYBRIDISATION OF ROCK PIGEON (COLUMBA LIVIA) AND EASTERN HOCK PIGEON (COLUMBA RUPESTRIS) IN MONGOLIA AND COMPARATIVE ECOLOGICAL INVESTIGATIONS Tilo Nadler Institut für Luft- und Kälte Dresden, GDR . The ge°graPhioal ranges of the mostly allopatrically distributed Rock Pxgeon and Eastern Rock Pigeon overlap in the southwestern parts of Mongo- *a* , ° contact zones between the two species exist by the presence of eral Pigeon in several towns and settlements with in the compact distri¬ butional range of Eastern Rock Pigeon. Up to the present no information was available on morphological and ethological criteria suitable for field identification. The pattern of tail coloration serves as the main morphological field mark for differentiation of Rock Pigeon from Eastern Rock Pigeon, and from wildtype Feral Pigeon respectively. The voices of both species are easy to distinguish. The synanthropic preference of the species leads to a weaken¬ ing of ecological isolation and encourages hybridisation. The different phe¬ notypes within the Pigeon population of Ulan-Bator were analyzed. Mixed pairs as well as intermediate individuals were observed. Differentiation of intermediate colour types suggests fertility of the hybrids. However, distribution of the numbers of each type indicates the maintenance of an intraspecific mating preference. ON THE PLUMAGE POLYMORPHISM IN THE INDIAN REEF HERON, EGRETTA GULARIS (BOSC) R.M.Naik, B.M. Parasharya Dept, of Biosciences, Saurashtra University, Rajkot, 360 005, India The Indian Reef Heron was studied with respect to the plumage polymor¬ phism in the breeding colonies, feeding sites and aviary in Gujarat, north¬ western India. Three morphs, namely, (1) grey without wing patch, (2) grey with wing Patch and (3) white are clearly recognisable in the Juvenal as well as adult Plumages. So called 'intermediate' is extremely rare and of questionable status. 'Lavender' is the Juvenal grey in worn out condition. The frequencies of the grey (with or without wing patch) and white in a Population is dependent upon (1) the proportion of fresh water and marine habitats available for feeding (2) extent of gene flow from the neighbour¬ ing populations of Little Egret (E. garzetta) and (3) incomplete assortive nating. The frequencies of the grey and white on a costal strip is related to the substrate structure and (2) timing of the tide cycle. ABOUT THE URBANIZATION OF BULGARIAN BIRDS Dimitr N.Nankinov Bulgarian Ornithological Centre, Institute of Zoology BAS, Sofia, Bulgaria The question of Bulgarian birds' urbanization has not been investigated At the same time the country's cultured landscape is of great interest, ^cause its territory is a part of the zone of penetration of European, Asian ahd African fauna urbanization elements. In this report the quest'ion of the utbanization of ‘Larus argentatus Pontopp, Streptopella decaocto Friv, Columba Ë^lumbus L. , Corvus monedula L. , C. comix L. , Pica pica L. , Garrulus glan- ^grius L. , Apus apuB L. and some other species is being examined. Barns argentatus Pontopp is at its new stage of synantropization, i.e. p0Pulating big cities far from the costal area. Columba palumbus L. make its first attempts in building nests in city parks. Streptopelia decaocto Friv. Appeared in Bulgaria being fully, shaped a synantropical bird. Together with its expansion to the north before 1970 they populated cities and villages 1151 inaide the area. Nowadays more and more often we can observe a reverse phe¬ nomenon, i.e. nesting of separate couples inside wild nature. Other bird spe- “ lea"Vftlementa* The — this antiurbanizational process can be a very high populational density in settlements, a big drop in spe¬ cies number as a result of real destruction, detriment to forage reserve shortage of places good for making nests etc. The process of birds' urbani¬ zation is as complicated and multilateral as complicated and multilateral is e influence of a human being upon nature. That's why we not always can di- T,\IT rrli0n ^ dl“erent 8tageS Escape's culturing, the ways and scales of urbanization of this or .that bird species. ON FAUNISTIC CICLES: EXTINCTION-EXPANSION-EXTINCTION... (WITH SPECIAL REFERENCE TO THE EAST PALEARCTIC DENDROPHILOUS AVIFAUNA) A. A. Nazarenko Institute of Biology and Soil Science, Far-East Scientific Centre, Academy of Sciences of the USSR, Vladivostok, USSR Comparison of the present distribution of dendrophilous avifaunas in iberia and Far East with the natural environment of these territories 19000-16000 years BP (the period of the broadest expansion of the deforested czyoxerophi lous landscapes) suggests that forest fauna could not exist over the most part of the regions at that time span. Their formation occurred within the Lateglacial - Holocene, and expanded in a strictly one-way trend rom south to north out of adjoining territories of Europe and Inner and East Asia. This indicates a deep faunistic "vacuum" which was a consequence of the large scale extinction of forest (mainly small insectivorous passe¬ rines, birds of the fauna of previous interglacial. In Siberia the extinction was determined by considerable destruction of forest refuges in the southern r^onL'^nnn61011 * ba°kground «««, cold and arid.clima- 19000-16000 years BP. This phenomenon as yet has no satisfactory explanat¬ ion for the territory of southern Far East. It is suggested that in alternation of the stages of extinction-expansion was the most typical mechanism of regional faunagenesis for the East Palearc- tic dendrophilous avifaunas over the Late and upper part of the Middle Pleis¬ tocene. in accordance with the tempo of species turnover, a considerable share of the species is of southern origin, and extinction is mainly of the microfaune (-selected species), and autochthonous faunagenesis has a negli-' I r° e" S 13tory of avifannas of the studied regions probably differs substantially from that of avifaunas of the Western sector of Eurasia. SPINAL SOMATOSENSORY MECHANISMS IN PIGEONS Reinhold Necker Ruhr-Universität Bochum, Inst. Tierphysiol. , D-4630 Bochum 1 , FRG Ih. afferent fibers of cutaneous reeeptors (nechenoreceptors, themorec.p- tors, nociceptors) project to second order ».„one In the dore.l bom of the spins! cord. There is a different projection of thick), nyellnsted A -fiber. and thinly meylmated A -fibers anti r iuers and C-fibers. A -fibers which innervate 1152 mechanoreceptors project primarily to deeper layere of the dorsal horn (la¬ mina IV). Correspondingly both evoked potentials and single units responses ave short latencies, and units in lamina IV are generally excited by gentle mechanical stimulation of the skin. As can be seen from evoked potentials and single unit recordings A -fibers and C-fibers project primarily to the dorsal superficial layers of the dorsal horn (lamina I/II). since both ther¬ moreceptors and nociceptors are supplied with thin fibers, many neurons in lamina I/II are excited by thermal or noxious stimulation of the skin. Some dorsal horn neurons with high spontaneous activity are inhibited both by electrical skin nerve stimulation or by natural stimulation of the skin. DEATH OP THE HISSING SWAN (CYGNUS OLOR) UNDER THE CONDITIONS OP ANTHROPOGENIC LANDSCAPE V.S.Nedzinskas "Zhuvintas" Reserve, Lithuanian SSR, USSR In the period of 1975-1980 the staff of the reservation received 106 re¬ ports of hissing swans' deaths on the territory of Lithuania. 68 grown-ups and 38 cygnets (with juvenile plumage) died. The sex structure of grown-up swans is the following: 11 (16.1%) cobs, 8 (11.7%) pens, 49 (72.1%) of unde¬ termined sex. Cygnets' sex was not established. Principal causes of swans' death under the conditions of anthropogenic landscape are: collision with aerial electric conductors (39.8%), predatory animals (19.7%), diseases ^0*5%), poaching (9.2%), traumas (3* 8%), etc. Collision with aerial high tension electric conductors, telephone and telegraph wires occurs in the spring (March-May) and autumn (September-November) when fledgelings try their wings. THE FECUNDITY OP THE BLACK-HEADED GULL (LARUS RIDIBUNDUS) ON LAKE DRUZNO Czeslaw Nitecki Dept, of Animal Ecology, University of Gdansk, Poland The breeding colony on Lake Druzno in northern Poland was studied over a Period of four years (1976-1979). Each year, 2-3 test areas (average total surface area 50 m2) were enclosed with suitable wire netting. These areas Were so chosen as to include all the habitat types occupied by the breeding °°lony. Most of this colony of some 4 thousand pairs is distributed on small islands largely overgrown with Solanum dulcamara, while some of the birds ala° heated among sedges and reeds. All nests in the test areas were marked ^ the hatched chicks ringed. The test areas were checked every 4-5 days. Chicks were considered to have survived if they reached the age of 25 days. average number of eggs per pair over the four years was 2.75, while the average number of surviving chicks was 1.39 per pair. Significant differen- Ces were found in the breeding success in different types of habitat. This Access was least among the pairs nesting in the sedges and reeds, and over years ranged from 0.13 to 0.56 chicks per pair. The reasons for such low °undity in these habitats were analysed. Data on the mortality rate of kicks in various stages of their development are given. 37-3aic.98i 1153 PROPOSAL CONCERNING A " SAVING-PROJECT " FOR THE CRESTED SHELDUCK TADORNA CRI3TATA 1 (KURODA. 1917) Eugeniusz Nowak Institute for Nature Conservation and Animal Ecology of the BFANL, D5300 Bonn-Bad Godesberg, FRG The Crested Shelduck (Tadoma cristata) is only known from 3 museum-spe¬ cimen, some observations in the open landscape and also from historic Japa¬ nese writings and pictures. Obviously it ranks among the rarest birds in the world. Since there are no recent observations it is often classified as an extinct species. All available information concerning this bird (which has never been com¬ piled!) permits the following as well as other conclusions: (a) Tadoma cristata is a tertiary boreal duck species of East-Asia which was on the verge of extinction in the ice-age; the only relict ranges exist in Ussuri- land, Korea and perhaps in NWKNR; (b) In these areas there are still living several other animal and plant relicts; (c) Tadoma cristata is most probab¬ ly still living here. Proof for this: Since about 300 years there have been about 15 records of the bird, indicating still its existance and rarity (last in 1964); (d) The extinction of this species in the near future (be-, cause of the increasing anthropogenic effect’s and detrimental factors to their habitats) is very likely; (e) Therefore, in the interest of worldwide nature conservation, an attempt towards autecological research as well as conservation actions for this species should be made. The following suggestions for an effective "saving-project" for the Ta¬ doma cristata are addressed to the Nature Conservation Authorities of the five countries with possible ranges of this duck (USSR, Peoples Republic of China, both Korean States, Japan) : 1. Concentrated search in the breeding and wintering areas (distribution of colour-leaflets, expeditions etc.); 2. Breeding and reproduction in captivity; 3. Research of Tadoma cristata autecology; 4. Selection and (if possible and necessary) management of appropriate habitats; 5. Réintroduction in the natural area; 6. Legal protection and its execution (national nature conservation acts and hunting laws, Soviet-Japan Agreement of Migratory Bird-Protection, Bonn- Convent ion on the Conservation of Migratory Species of Wild Animals etc. ) . THE THIN EGGSHELL PHENOMENON AND ITS TREND IN THE WHITE-TAILED EAGLE (HALIAEETUS ALBICILLA), ESPECIALLY IN THE POPULATION OF THE GERMAN DEMOCRATIC REPUBLIC (GDR) i Günter Oehme Pädagogische Hochschule: Halle N.K.Krupskaja, Sektion j Biologie/Chemie, GDR Eggshells and shell fragments of the population of Haliaeetus alhlcil^ in the northern GDR from 1954-1981 were investigated for changes in the shell parameters and compared with eggshells from 1851-1946, originating 115^ from North-Central Europe (North GDR and present territory of People's Re¬ public of Poland). The recent eggs showed a highly significant reduction of % of the previous eggshell thickness. The lowest level was found in the years from 1968-1975. The eggshell thickness of more or less normally re¬ producing breeding pairs was significantly higher than that of none or Poorly reproducing pairs. The thin eggshell phenomenon, caused by DDT/DDE- contamination in the adult eagles, proved to be one of the fundamental fact¬ ors for the low reproduction of White-tailed Eagles in the GDR. Since 1976 there appeared a significant trend of partial recovery of the eggshell hickness, which is reflecting a decreased biocide contamination in connecti¬ on with the restricted use of DDT in the GDR and other countries in the 19703 ' The statement that putrefaction causes eggshell thinning is discussed. The recent level of shell thickness in the GDR-population of White-tailed ®agles is compared with those from Mongolian People’s Republic, Sweden, Fin- and and Greenland. The importance of investigating the trend of eggshell thickness in Haliaeetus albicilla and other exposed species for biological “onitorlng (bioindication) of the DDT/DDE- re sidue level in natural environ- ®ents is indicated. THE EFFECT OF CORVID (CORVIDAE) REMOVAL ON WILLON PTARMIGAN LAGOPUS LAGOPUS POPULATION DXNAMICS Howard Parker Department of Arctic Biology, Institute of Medical Biology, University of Tromsji, 9000 Troms/Ä, Norway Nesting and non-nesting corvids (hooded crows Corvus corone cornix. Ravens Corvus corax, magpies Pica pica) were removed each year for 4 years 78-1981) from 4 km^ of willow ptarmigan island habitat for the period Prior to ptarmigan nesting until broods averaged 3 weeks old. Decimati- ^ was accomplished primarily by baiting hens eggs with alpha-chloralose. adjoining area served as a control. Ptarmigan broods were censused on br a1,603 4 weeks after the mean hatching date and classified as first nest ^°ods, renest broods or pairs without chicks. The proportion of first nest renest broods and the combined mean brood size did not vary between areas Su ln years- Predation by corvids on ptarmigan chicks was negligible. Ceaa °f renest clutches and survival of renest chicks equaled that of layings. Nest predation in the absence of corvids was attributed to ^ 8 jjUBtela erminea. the only other predator of ptarmigan eggs on the and^^' '^arm:*-£an nesting densities on both areas were similar at the start Tinish of the experiment. In conclusion, corvid control during these 4 was not an effective means of increasing ptarmigan production or nest- 6 densities. Reproductive success of the black-headed gull (larus ^SigUNDUs L. ) JJJ THE NORTHERN PART OF BELGIUM * A.Paulasen, A.F. de Bont, K.U. Leuven aaraae straat 59, B. 3000 Leuven, Belgium meaRepr0dUOtive auc°ess in the Black-headed Gull (Larus ridibundus L. ) was aured during 1978, 1 979 and 1980, with individually marked nest in dif- 1155 ferent areas in the Snepkensivijver colony (Lichtaart 51°, 14N; 04° 54E Belgium) consisting of resp. 1400, 1825 and 1560 breeding pairs. In spite of the age of this colony (started 1940), we measured a low mean clutch size of resp. 1.88 (85 nests), 1.90 (1169 nests) and 1.95 (730 nests). Hatching success in small clutches (1 egg) was significantly lower than in full 3 egg clutches. There were no significant differences in breeding success between studied areas with different nest densities in the colony. The overall breeding success was lower when the mean laying date was late in the breeding season. Comparisons of breeding success and reproduction rate per pair were made with studies already described in literature. These comparisons have shown uhat great attention must be paid to the method of measuring reproductive success. The low breeding success observed in our study was specially due to great number of egg losses (41.11%) and low mean clutch size. SPRING MORTALITY AS A MECHANISM IN REGULATION OP NUMBERS OP SOME NORTHEASTERN EUROPEAN SONGBIRDS V. A.Payevsky Biological Station Rybachy of the Zoological Institute, USSR Academy of Sciences, Leningrad, USSR Age structure and mortality rates of 6 European passerine species was studied by trapping and ringing at the Rybachy Biological Station in the Courish Spit (eastern Baltic). The study of demographic parameters was based on 298 thousands of migrating birds trapped during 1970-1980. Main data for the analysis were annual fluctuations in numbers of trapped birds, age rati¬ os during fall and spring migration, and the annual mortality rates of adult birds through ringing recoveries. Trapping data during spring showed that proportions of first-year birds in the migrating populations were high¬ er compared with that necessary for the maintenance of stable populatioh den¬ sity. It was found that the mortality in the period between spring migration and outset of breeding forms 22-50 per cent of the mortality in the whole period between fall migration and outset of breeding. It is suggested that the number of breeding pairs is limited by spring mortality of surplus sur¬ vivors. AGGRESSIVE REACTIONS IN MALE OP DOMESTIC AND HOME PIGEONS S. I.Pechenev Moscow State University, USSR Aggressiveness of male pigeons in wild and domestic individuals was established in 1004 experiments. Pigeon couples were landed on neutral, their own and foreign territory. Domestic male pigeons turned out to be mo¬ re aggressive than the wild ones (differences were significant at n=81 4 p=0.01). It is supposed that the differences are due to population density which is much higher for domestic pigeons. High-level aggressiveness for densely-populated colonies is a necessary condition for successful nesting- 1156 COMPARATIVE GEOGRAPHICAL ANALYSIS OP RAPTOR PREDATION IMPACT ON POPULATIONS OP SOME TERRESTRIAL VERTEBRATES V. I.Pererva All-Union Research Institute on Nature Conservation and Reserve Management of the USSR Ministry of Agriculture, Moscow, USSR Raptors of the northern Kazakhstan "island" forests (Naurzum Reserve, 972-1974 data) exert greater impact on prey populations than those breed- 1^5, 111 fore3ts 111 the aouth of Moscow Region (Prioksko-Terrasny Reserve, 976-1979 data). In northern Kazakhstan the rate of raptor predation on’to- a prey populations through summer season was 10-14% of prey number, nameiy on steppe marmot - 8-10%; microtine rodents - 18-23%; skylark - about 12%- awny pipit - 7-16%; sand lizard - 5-6%. In the south of Moscow Region the corresponding indices were much lower - 3-6% on microtines, about 3% on araall Passerines, less than 1% on woodpeckers, 1-2% on Galliformes. and '•5% on frogs. The decrease of principal prey populations was estimated to be an import¬ ant factor causing the growth of raptor predation rate on additional prey species. For instance, the microtine depression in northern Kazakhstan had etermined higher predation upon Passerines, rooks and susliks. The main reason of revealed differences in rates of raptor predation on prey popula- ions on northern Kazakhstan and Moscow Region is in different degrees of complexity and stability of those ecosystems. JACKSAW (CORVUS- MONEDULA) AND KESTREL (FALCO TINNUNCULUS) AS BIOLOGICAL INDICATORS Hans-Ulrich Peter Universität Jena, Sektion Biologie, Wissenschaf tsbereich Ökologie Jena, DDR Examples of biological indicators can be found in a 18 year investigation a colony of kestrels and jackdaws near Jena ( GDR) . The yearly number of reeding pairs, the clutch size and the beginning of the breeding season oan be used to characterize the food supply (density of mice - Micro tus sPec.) prior to and during the breeding season of the kestrels. Between 1 949 and 1957, the number of pairs of jackdaws is dependent on e number of breeding pairs of the predominating kestrels. In the last 9 7ear3 anthropogenic influences have changed the population of jackdaws. The crease in the number of pairs and in the number of young birds per breed- 8 Pair indicate the influence of anthropogenic factors. formes du comportement-reproductif de MARTIN-PECHEUR D'EUROPE (ALCEDO ATTHI5 L. ) A*U.Podolski Université de Saratov, Saratov, USSR tes ii Bans la région de Saratov, d'apres de contrôle sur cinquante- trois coup- de ^'0:tseaux marqués on a déterminé cinq formes du comportement reproductif Martin-pêcher d'Europe (Alcedo atthis L. ) , ci-dessous: • Monogamie typique. Les oiseaux ont deux couvées par saison (32 coup¬ as). 1157 2. Monogamie à "superposition» des couvées dans le même nid, ce que assu¬ re trois couvées par saison (4 couples). La femelle pond les oeufs de la deuxieme et de la troisième pontes juste après l'apparition des petits de a ponte précédente. C'est le mâle qui couve la 2-e et la 3-e pontes car la femelle éleve les oiselets de la couvée précédente. Les deux partenaires elevent la 3-6 couvée. 3. Monogamie à -superposition» des couvées dans de différents nids (la 1-e et la 3-e pontes dans un nid, la 2-e dans l'autre). 6 couples 4. Bigamie à »superposition» des couvées. La situation est analogique à celle précédente mais la 1-e et la 2-e pontes sont faites par une femelle et la 2-e par l'autre dans un autre nid (5 couples). Alors la 1-e et la 2-e couvees sont élevées par les femelles, la 3-e par les deux partenaires. Le male prend part au couvaison de trois pontes. 5. Polygamie typique (en tout, 6 couples: 5 cas de bigamie, 1 cas de tri- gamie) . Les femelles couvent parallèlement deux couvées. Le male participe au couvaison de la 1-e ou de deux couvées. Avec le passage de monogamie à polygamie l’efficacité de reproduction augmente (4-6 pontes d'un mâle au lieu de 2 par saison). Il est possible que a po ygamie soi-t consequence de la prédominance des femelles dans les popu- ations de Martin-Pêcheur ( A. D. Noumérov, Y. V. Kotukov, 1979). COMPARATIVE ECOLOGY OP SYMPATRIC LARKS DURING THE WINTER AND SPRING MIGRATION S. A.Polozov The Lenin State Pedagogical Institute, Moscow, USSR Tne species of Laris are recorded in Sumbar valley (West Copetdag, Turkme¬ nia) during the winter and spring migration. Melanocorypha leucootera *nd Ijh_ biraaculata are rare. Other species are common. Ammomanea deserti. Galeri- — ;r.3tata Mi_palandra are resident, Alauda amenais and EremonMi» al- Eestrxs are wintering species, Calandrella cinerea and C. rufe^ns are met on migration only, Lullula arborea breeds. All species have wide similar ul6 tS. Only S^n.r.a la atric.ly iaol.t.d fnom C. mfeacena. E. alpaatri. and A. arven3is by the time of their stav in ^ - • I » — ' stay the region. The majority of species Z’l ? T\T The gr'a,s“* n”b" °f “>«»» **»*°pi° and the Ugh... to.lt» of Ito. population are n.glatn.t.d In «mid,«,. hi temtarlee. He apeoie. neat ap.alallz.d In choice or foraging alte. are separated there by using different • , , . 8 45 . „ , , 6 anrerent feeding microhabitats. E. alpestris prefers steep slopes (inclination is ifi . — - - - . , . * ' , on 18 Tb-35°), C. rufescens prefers wavy re¬ lief (steepness of the slopes is 6-iaoi m Ö , ~ _ , . 10 '> M. calandra prefers gently sloping surfaces (inclination is under 5°) Onlv rt »oi« , , . 3 uniy calandra and much less speciali¬ zed species like G. cristata nnfl 4 _ _ _ habitat (gently aiding ^.o,a)^ - ~ " ““ ”10”' ».Ohto In e“"al 13 3“11“ *» 311 *>“ •■»«... Simpl® . °° rora e ground aunlace la moat common. Specific featurea of foraging strategies of various , . . . 3 3Pecies are determined by differences in using less common feeding method .= . ® . .. „ S methods, namely getting food from the ground, vegetable feeding, active pursuit »„wi & P suit of mobile prey and kleptoparasitism. 1198 VISIBLE BIRD MIGRATION AND THE SYNOPTIC SITUATION IN THE AUTUMN A.M.Poluda Institute of Zoology of the Ukrainian SSR Academy of Sciences, Kiev, USSR Investigations of bird migrations (1974-1980) in the Kiev Reservoir regi¬ on do not confirm the leading role of anticyclonic weather upon the visible ird migration dynamics. Cyclones result in the appearance of unfavourable weather conditions for bird migration, nevertheless migrational waves of many diurnal birds (Wood Pigeon, Tits, Buntings, Chaffinch, Bramble Pinch Thistle Pinch, Rook, etc.) take place in this situation. Under cyclonic we¬ ather, the migration wave of Chaffinch starts. During the period of our in¬ vestigation, 48 waves have been distinguished. Among them (in 73% of the cases) the barometric pressure during the period of 6 hours preceeding the beginning of the migration on the first day of the wave had fallen, and in 27. per cent had risen. Usually the visible bird migration was poor during anticyclonic weather, except when there was no drop in the temperature. therwise, when anticyclones pass through the European territory of the USSR, or by appearing in the rear of cyclones, the intensity of the migration was igh. Besides the species mentioned above we have observed the migration of aome other species (Diver, Geese, Crane, Lapwing, Song Thrush, Mistle Thrush) the migration of which is correlated with temperature drop. distribution, nesting biology and prospects por captive breeding of the houbara BUSTARD IN USSR T. S. Ponomareva All-Union Research Institute of Nature Conservation and Reserves , Moscow, USSR . Prom year to year the range and number of the eastern subspecies of the Houbara, inhabiting the USSR, are declining. The principal causes of this are destruction of the habitats, growing disturbances, poaching in the nest- ttigs areas and unrestricted shooting in the wintering areas. Now the Houbara survives only in those parts of the USSR that are least °f al1 affected by anthropogenous factors: the northern part of Kaspii ands, south Kasakh3tan, Usbekistan, Turkmenia and Tuva. The range of the aPeciea everywhere is discontinuous, sometimes dotty, the distribution is Mosaic. The centre of the present day range of the Houbara in the USSR is Usbeki- stan (Buchara district UzSSR, KazSSR). The number of the Houbara Bustard in ^Protected areas is low and varies from 1 bird per 27 1cm2 to 1 bird per km , on the average - 1 bird per 20-25 km2. °ver the protected areas of the Buchara Persian Gazelle nursery the den- ity °f Houbara on the nesting grounds is much higher, than in other parts the range. The size of the nesting plots of the Houbara is comparatively mall (i_i45 km2), on the protected areas they are found one near another are even contigious. Disconnection of the spatial links and pairs cha- acterizing the territorial structure of the population in unprotected p aa is secondary and caused by a sharp growth of the anthropogenous stress. °aliarities of the distribution and nesting biology of the Houbara enable 1159 ua to envisage a considerable growth of the birds' concentration on areas where they are not disturbed on the nesting grounds. This fact once more underlies the necessity and perspectivity of the creation of the nature re¬ serve to protect the Houbara in USSR. For the conservation of the Houbara it is necessary to establish the nur¬ sery for the captive breeding of this species. The experience of our college es abroad and the results of our experiments in the incubation of eggs and raising the nestlings of the Houbara show that this way of preservation of species is feasable. Probably captive breeding of the Houbara followed by the réintroduction of the birds in protected areas is one of the most work¬ able methods of preservation the endangered population of this species. STRUKTURVERÄNDERNDE FAKTOREN IN DEN TETRAONIDEN- BIOTOPEN DER OSTSUDETEN (ÖSSR) Jan Porkert Dipra, Praha, ÖSSR Untersuchungen anthropogener Faktoren, Klimas, Vegetationsstruktur, Pre- datoren- und Nahrungskonkurrenten-Wirkung auf Tetraoniden in Ostsudeten weisen auf die wichtigste Rolle der Biotopstruktur-Degradation in Verbindung mit dem Unruhefaktor auf die Entwicklung dortiger Restpopulationen hin. Ver¬ grasung des Waldbodens mit hochwüchsigen Grasarten, Schwinden von Vaccinium f-rtlllU3 Und "A"« Nahrung oder Deckung mit günstigem Mikroklima bieten- en Pflanzen degradiert die Biotopstruktur. Absterbensquote von V. myrtillus ateht im ursächlichen Zusammenhang mit zunehmenden Schadstoffimissionen. Beo¬ bachtungen über Nebelfrostablagerungen und Schneedecke sowie chemische Ana- iysen der Nebelfrostproben zeigen, dass die Umweltbelastung durch Rauhfrost und Nebel infolge ihres vielfach höheren Schadet of fgehalts grösser als durch Regen und Schneefall ist. Für den Schädigungsgrad der Organismen sind ins¬ besondere hochkontaminierte Niederschlagsepisoden massgebend, deren Wirkung vom jeweiligen physiologischen Zustand und Kondition der Pflanzen und Tiere abhangt Durch Verbiss und Zertrampeln von Vaccinien, Farnen und Laubbäumen vernichten Cerviden und besonders in Jesent'kv • *,-• n q r\r»o ^ < M i. senlky-Gebirge eingebürgerte Rupi- capra die Nahrungs- und Deckungsressourcen der Tetraonidenarten. Fort- schreitende Biotop degradation durch Immissionen, moderne Bewirtschaftung, uberhohen Schalenwildbestand sowie menschliche Aktivitäten haben die in kleinen Gruppen überlebenden Tetraoniden der Ostsudeten Verhaltensänderungen entwickeln lassen Ausgeprägte Territorialität und Aggressivität an der Re¬ produktion teilnehmender Vogel i3t als iflnnto+< ~ nj . _ ais Adaptation auf Biotopverschlechterung anzusehen in restlichen vegetationsstxnkturmässig entsprechenden Biotop- Adaptabilitat auf menschliche Störung festgestellt. POPULATIONAL VARIATIONS IN THE ENERGETICS OF SOME AVIAN SPECIES S.N.Postnikov Institute of Plant and Animal Ecology, Acadeœy of Sciences of the USSR, Sverdlovsk, USSR Population characteristics of energy growth expenditure in Tree Sparrow, Passer m. montanus (L. ). p nilaris (1 ) ^ — S Vulgaris Fieldfare, Turdus pilaris — ( L. ; and existence energy of adult- -+ oi aauit birds at different summer and 1160 winter temperatures were studied. Birds for experiments were obtained from Subarctic, Middle Urals and Khasakhstan regions. In nestlings of northern populations higher daily energy requirements with Simultaneous shorter growth periods were observed compared to birds from southern populations. Energy cost of biomass increase in the nestlings of northern populations was greater than in southern populations due to an increased energy expenditure on thermoregulation; it fluctuated to a greater extent. 80% pterilium of subarctic Fieldfare nestlings fledged earlier than m the Middle Ural ones. Northern nestlings must have earlier energy main- tainance because it means decrease in heat irradiation. When held under si¬ milar captive conditions, adult birds of various populations differed in autumn and winter in the amount of energy consumed. Comparison of latitudi- onally distant populations revealed differences in energy input as well as differences in body mass, reaching 20-30% in Jakutsk, Swerdlovsk and Khasakh¬ stan Tree Sparrows. PSEUDOPHYLLIDEA OF BIRDS IN THE ECOLOGICAL SYSTEM OF THE BAIKAL N.M. Pronin, A. V. Nekrasov, S.V. Pronina Institute of Biology of the Buriat Filial Department of the Siberian Branch of the USSR Academy of Sciences, Ulan-Ude, USSR Composition of species and the infection of birds by cestodes of the Pseu- d°phyllidea order have been established. The Pseudophyllidae order is re¬ presented by seven species: Diphyllobothrium dentriticum, D. ditremum, Ligu- iiLjjitestinalis. L. colymbi, Digramma interrupts, D. nemachili, Schistoce- fi^alus solidus. Peculiarities of the biological cycle of Pseudophyllidea (the first in¬ termediate hosts are Copepodes, the second ones - fishes) predetermine the imposition of their definitive hosts only of fishivorous birds (Larus ar- êijatus. L, ridibundus, L. canus, Podiceps cristatus, Mergus merganser, croc orax carbo , Gavia stellate). Unfavourable abiotic conditions for the first intermediate hosts and free-living phase of Pseudophyllidea (co- Pacidium) , as well as the low size of Cyprinidae fishes in the littoral sys- tem of the Baikal cause a slight infection of birds and fishes by cestodes higulidae family. At present there are no pre-conditions for the origin of ePizootics of liguleous and digrammos in the bays of the Baikal. Ecologi- Cfi 1 conditions for their outburst may be only in isolated Baikal lakes. The high infection of sea-gulls by Diphyllobothrium dendriticum is caused Y the fact that their colonies are set in certain regions of .the Baikal he delta of the Selenga river, the Cliivyrkui bay, the Little Sea, the ï'th-Angarsk bay) and the concentration there of the second intermediate ats - fiahes of Salmoniden in the period of feeding and spawning migrati- °ns as well. The isolation of the main regions of the nesting of colonial rds create pre-conditions for forming local populations of D. dendriticum. 1161 ECOLOGY OF THE WHITE STORK (CICONIA CICOHIA) IK POLAND Piotr Profus Nature Conservation Research Centre, Polish Academy of Sciences, Krakow, Poland Information from about 5000 neats occupied by breeding pairs of storks was obtained in southern Poland in 1973-1981. In 1928, 1934 and 1975, respectively, 367, 654 and 774 pairs nested in the area of 14.000 3q.km. The mean clutch size was 4.05+0.74 (SD; n=73). Breeding suocess for all pairs was 59.1% and for pairs with fledged young 61.4%. Clutch size and breeding success decreased during the season. A negative correlation was found bet¬ ween the density of breeding pairs and the number of fledged young. In 1 973- 1981 each pair raised on the average 0.6 chick less than in 1928-1934. The main reason for the decreased production of young/pair is probably the rise in the density of White Storks, which leads to the enhancement of intraspe¬ cific competition. This is indicated by numerous fights of storks for nests and by the destruction of broods which results in a increase in the percenta¬ ge of such pairs is higher in densely populated regions. Breeding pairs con¬ sumed yearly in Poland about 5100 tons (25.6 x 109 kJ) and their young about 2720 tons (13.7 x 109 kJ) of food, totalling 1.85 kg per meadow and pasture hectare. HORMONAL DEVELOPMENT IN MALE ZEBRA FINCHES (TAENI0PYG1A GUTTATA CASTANOTIS GOULD) Ekkehard Prove Universität Bielefeld, Fakultät für 3ioiogie, Lehrstuhl für Verhaltensphysiologie, Postfach 8640, D-4800 Bielefeld, FRG The morphological and behavioural development of male Zebra Finches is well known from various investigations. In contrast, however, as for other small passerine birds, our knowledge about basic processes of the physiolo¬ gical development is still rather scarce. The present investigation deals with the early development of hormone secretion in male Zebra Finches. The latest state of chromatographical and radioimmunological techniques allows to separate different hormones even from very small plasma samples (about 1 ml) and to collect quantitative data on their occurrence and change over age. Between day 10 and day 70 of life, the development of the hormones progesterone, dihydrotestosterone, testosterone, and 17 -estradiol has been followed by consecutive measurements in individual birds (blood samples being taken every five days). Testosterone development, for example, 3how3 some remarkable characteristics which are in accordance with the development of the testes and with 3ome derails of the behavioural development (for example, of song development in the male). DISTRIBUTION OF HOLLOW- NESTING DURING WINTER TIME A.I.Rakul, G.Z.Guaan Institute of Zoology and Physiology of the Academy of Sciences of the Moldavian 3SR, Kishinev, USSR During winter, the basis of birds population in Kodry forests i3 repre¬ sented by 19 species (density - 715 indiv. /sq.km) . Common species, such as 1162 Sltta europaea L. (67 indiv. /sq.km) , Certhia familiaris L. (61 indiv./sq. km) , Parus oaeruleua L. (56 indiv. /sq. km) , Parue major L. (52 indiv. /sq. km) toge¬ ther with the other, hollow-nesting species form multispecies agrégations. Nuthatch and Marsh-Tit accounted for 84% out of total agrégations (which makes 25 to 30% out of total quantity of individuals), respectively Great Tit and Blue Tit - comprise 65 to 70% and 16%; Tree-Creeper and Woodpeckers make 35% and 7%. Two types of agrégations have been selected. The first type combines individuals of resident populations into small (up to 15 indivi¬ duals) multispecies agrégations, distributed mainly on the lower part of slopes of eastern exposure with preference for oak and ash forests and utilizing same territory for a few years. In their daily movements, a gene¬ ral pattern is followed, expressed in changing the preferred slopes exposure from eastern and south-eastern towards south with movements up the slope and back to the place of overnight stay. The second type (up to 22% out of accounted agrégations) is represented by migrants appearing in October in widely nomadic flocks. Agrégations contain 20 to 25 individuals with the Predominance (up to 90%) of one type - Great Tit or Marsh-Tit. When the two types of agrégations meet, mixing of individuals does not occur. ON THE REPRODUCTION STRATEGY OP THE POPULATION OP THE COMMON GULL (LARUS CANUS) Kalev Rattiste, Vilju Lilleleht, Aime Laidna Institute of Zoology and Botany of the Academy of Sciences of the Estonian SSR, Tartu, USSR The report is based on data collected in 1962-1980 on colonies of the Common Gull (making up altogether 212-390 pairs). Every year an average 82% °f the breeding adults and 95% chicks were checked and ringed. Breeding success was estimated according to the offspring which had reach- e,,,■« , , „ x caused by a general increase in bird numbers due to a greater amount of artificial nesting sit.es. 1166 TROPHIC NICHES OP PASSERINE BIRDS IN SUBARCTIC, "THE GAUSE'S PRINCIPLE" AND NORTH ECOSYSTEMS RESISTANCE V.K.Ryabitsev, M. G. Golovatin Institute of Plant and Animal Ecology, Ural Scientific Center of the USSR Academy of Soienoee, Sverdlovsk, USSR .According to dominant competition theory, species which have common habi¬ tats and similar food must have different localization of feeding areas. Contrary to this our investigation of Phylloscopus trochilus and Ph. borea- Ü2 in the north tajga of Ural in 1977 shows almost complete foraging niches similarity in its common habitat conditions. Feeding behaviour was studied under favourable weather conditions and under abrupt .cold periods in South tundra of Yamal in I960. Distant taxonomic species Ph. trochilus (Syl- Yiidae) and Emberiza pusilla (Emberlzinae) which also lived here and fed their chicks similar food were used for comparison. Niche breadth and over¬ lap were defined by standard formulas ( Hubert, 1978). The overlap was quite large along all seven dimensions. Under change .for the worse feed con¬ ditions, niches of both species narrowed, however overlap coefficient in¬ creased. The species reacted to change in the feeding conditions in the same w&y. High trophic plasticity is a property of the majority of species of Sub- arctic birds. It is necessary in unstable existence conditions. Ecological Polyfunctionality of species secures counterpart relations in ecosystems with a low species diversity that is important to increase its resistance from disturbances. A possibility of trophic counterparts coexistence may be explained by presence of energetic reserve in ecosystem, which turns on under unpredicted climatic disturbances. Many facts contradicting to Gaus.e's Principle of competition exclusion are also known in other zones with un¬ stable climate. VARIABILITY OP THE NESTING DENSITY OP THE PASSERINE BIRDS ON THE OB POREST-TUNDRA V.N. Ryzhanovsky Institute of the Plant and Animal Ecology of the Ural Scientific Center of the USSR Academy of Sciences, Sverdlovsk, USSR For the ten years (1970-1979) on the territory of the forest-tundra Nation "Harp" the nesting of 17 passerine species of birds occured. The 'Harp" area ^as 270 ha. Ten species nested eacH year here. Their nesting density was very variable. Motacilla alba had the comparatively constant density only. The variability of the nesting density of Anthus cervinus was Motacilla flava - 3.8, Emberiza schoeniclus - 3-9, Phylloscopus trochi- iüä - 4.3, Anthus pratensis - 6.6, Calcarius lapponicus - 10, Acanthis - 20 times. One half of the species which have a northern border of Ceding area in station region nested irregularly here. The second group of species have a northern border of breeding area to North or to South. Between these species of the nesting irregularity is below two times. Mean dating density of numerous birds varied less than in not numerous species for ^n years.' Apparently, it is bound with their territoriality, which establiah the upper density level of numerous species. 1167 SPATIAL AND SEASONAL DISTRIBUTION OP 'DERMATITIS', A DISEASE OF CYSTERCATCHERS ON STOKHOLM AND ITS ECOLOGICAL EFFECTS Uriel N. Safriel, Michael P. Harris The Hebrew University of Jerusalem, Jerusalem, Israel, Institute of Terrestrial Ecology, Banchory, Scotland, UK ■Dermatitis’ is a viral disease of Oystercatchers, presumably akin to Puffinosis. Its symptoms are blisters, usually on various parts of the feet, and partial paralysis. It affects mainly chicks for which it is usually lethal, but also adults that often recover. During a long-term population study on Stokholm Island (1963-1978) it was found that the spatial distribution of the disease on the island was not random. Rather, diseased birds occurred in contiguous territories, concen¬ trated around relatively wet areas, which provided better feeding conditions than the drier areas. In the infected areas disease affected young hatched early in the season in a significantly greater frequency that young hatched later. It is proposed that the Oystercatcher' s exposure to this disease is associated with Its relatively new habit of utilizing terrestrial habitats for young-raising; the activity of the vector is presumably associated with moisture, which declines later in the season. Usually, early-breeding Oystercatchers are more successful in raising young than others. But in terrestrial feeding individuals, a selection against early breeding may be now operational. NICHE SHIFTS OF BIRDS IN MAN-MADE ENVIRONMENTS Lajos Sasvari Department of Systematic Zoology and Ecology of Eötvös Lorand University, Budapest, Hungary Species diversity, average niche breadth, average niche overlap and niche shifts of three dominant species, great tit, blue tit and tree sparrow, were compared for oak forest, acacia woodland and urban park, as well as for various tree species within the park. The survey was based on records of in¬ dividual birds feeding in various macrohabitats during the breeding season and winter. Bird diversity was lower in the urban park, with its mixed tree species, than in homogeneous oak forest, but higher than in homogeneous acacia wood¬ land. Average niche breadth and niche overlap were assessed using formulae suggested by Pilou for standardized measures (E.C. Pilou: Ecological Diversi" ty. 1975. New York, p. 135-H2). During the breeding season, average niche breadth and niche overlap were lower in the urban park than in oak forest, but they were lowest in acacia woodland. It might be supposed that the decrease in number of breeding spe¬ cies is consistent with increased segregation of species in the poorer and poorer man-made environments. However the niche breadth of the great tit and blue tit decreases (oak forest > urban park > acacia woodland) without increasing their segregation because their niche overlap is greatest in the urban park, with acacia woodland next, and the lowest value in oak forest. This suggests that competition between these two species increases in the 1168 man-made environment during breeding season. The niche breadth for the tree sparrow is highest in urban parks, where the greatest niche overlaps between tree sparrow and great^ tit, and tree sparrow and blue tit also occur. In oak forest and acacia woodland, when temperatures are between -1°C and -10°C, and the soil is covered by snow, the average niche breadth and niche overlap are lower than when temperatures are between 0°C and +10°C, without snow. This situation is reversed in the urban park. In severe weather the urban environment is advantageous for the winter bird population, but without the evolutionary divergence of these species, interspecies competition in¬ creases. INVESTIGATIONS ON REPRODUCTIVE PERFORMANCE OF THE LITTLE TERN (STERNA ALBIFRONS) Reinhard Schmidt, Axel Siefke Vogelwarte Hiddensee, Kloster/Hiddensee, GDR The secondary fertility has been analyzed in relation to various extra- and intrapopular factors for a colourringed population on the southern coast of the Baltic, consisting of avg. 41 (23-54) breeding pairs, which have been investigated since 1973 on size determining mechanisms, etc. Reproductive maturity is achieved at an age of avg. 3.0 years (n=44). Eggs are laid in an interval of avg. 1.7 days (n=147), main laying period 16*5 - 10.6 days. Hatching takes place (19-23 days thereafter and 3 weeks iater the young birds fledge. After loss of a clutch or early death of the chicks, up to 3 additional clutches may be laid, possibly following resettle¬ ment of the breeding pair as far a3 150 kms away from the original nest site. Totals per female avg. 1.7 (initial and additional) clutches (n=6l1) with each 2.25 eggs (n=1375; = 3-7 eggs per female) have been registered. Initial dutches with 2.54 eggs are clearly larger as the subsequent ones. First ^reeding females are producing fewer eggs (avg. 2.3; n=10) in initial clutch- es ^d rarely have additional clutches. Of the total number of eggs 28.6$ (= 1.10 per breeding pair) were hatched. Moat losses were caused by predators (78$), flooding (6$) and human activity (7*5$). Among predators, foxes and large gulls played the most important Part. They may destroy all offspring in some locations or in particular 7e&rs. In 1975, 45 breeding pairs laid 160 eggs in 92 clutches, none of which hatched. The number of fledging birds is also determined particularly by predators, but also is affected by the weather. The results lead to the conclusion that reduction of fertility caused by Predators is a key factor in population dynamics of this threatened species. Ökologie und schütz des Steinkauzes, Athene noctua. in der ddr Siegfried Schönn DDR-7260 Oschatz, 8.8.81 H.-Mann-Str. 11b, DDR Bis zur Mitte dieses Jahrhunderts gehörte der Steinkauz, Athene noctua. 2U .. - aen häufigsten Eulenarten auf dem Territorium der DDR. Danach erfolgte ®lïle starke Bestandsabnahme, so daß, die Eule heute zu den "vom Aussterben drohten Arten" gehört und besonderen Schutz erhält. Dafür sind Untersuch- 38-3» 981 981 1169 ungen über Habitatansprüche, Ursachen de3 Rückganges und die Erarbeitung eines Artenschutzprogrammes dringend erforderlich. Diese Schwerpunkte werden nachstehend dargestellt. Habitatansprüche: Von Gro^vegetation weitgehend freie ( "offene" Landschaf t) , artspezifische Jagdmöglichkeiten (keine geschlossene Gras- und Krautvegeta¬ tion). Dadurch Möglichkeit zur Bodenjagd, Vorhandensein relativ niedriger Ansitzpunkte (Koppelpfähle, Steinhaufen u.a. ) , kontinuierliches Nahrungsan- gebot in Form von Kleinsäugern, Vögeln und Insekten auf begrenztem Raum, 2instand3- und Brutplätze wie höhlenreiche Baumbestände, Baue erdbewohnender Säuger, oder verfallene bzw. von aiyjen zugängliche Gebäude, gemäßigter Klima¬ bereich, geringer Feind- und Konkurrenzdruck. Ursachen des Rückganges: Lebensraumzerstörung, verstärkte Verluste, kli¬ matische Faktoren, Biozide, Feinde und Konkurrenzdruck. Artenschutzprogramm: Schutzmaßnahmen für artspezifische Habitate (Erhalt¬ ung von Brut- und Einstandsmöglichkeiten und Nahrungsräumen) , systematische Vergrößerung von Restpopulationen (Anbringen von Niströhren), Schutz der Brutplätze vor Raubwild, Raubzeug und Ratten, Pflegemaßnahmen geeigneter Höhlenbäume, Anpflanzung geeigneter Holzarten, keine Förderung, des Waldkauzes durch Nistkästen, in Brut- und Nahrungarevleren Einsatz von Bioziden zwischen Naturschutzorganen und landwirtschaftlichen Betrieben exakt abstimmen. Place of employment: Sachsen und Thüringen, DDR. THE INHERITANCE OF SOCIAL DOMINANCE IN BEWICK'S SWAN (CYGNUS COLUMBIANUS BEWICKII) D. K. Scott, P. Scott Wildfowl Trust, Slimbridge, UK In Bewick's swans, the social dominance of cygnets during their first winter of life is closely related to their parents' dominance. This is a result of parental protective behaviour, which cygnets 3oli.eit as soon as they are threatened by an opponent. However, this 'inheritance' of dominance i3 not confined to the first winter. Evidence from longterm records of indi¬ viduals and their offspring at Welney Wildfowl Refuge, Norfolk, suggests that offspring of highranking parents are themselves high-ranking as adults, and offspring of low-ranking parents are low-ranking as adults. PHENOLOGY OF SPRING MIGRATION IN UKRAINE V. V. Serebryakov Chair of Vertebrate Zoology, Kiev State University, USSR An analysis has been made of the phenological observations on bird migra¬ tion in Ukraine in 1975-1981 and of abundant literature data of similar in¬ vestigations. Since 1843 phenological observations of migration of more than 100 species in Kiev region were carried out. As a result many years' average dates of birds' arrivals and their variations were established, fpur "coming waves" were ascertained, a wide variation of the arrival dates in first spring migrants were discovered and a tendency of definite changes was es¬ tablished. In one group of species (Starling pattern) average dates were earlier, in a second group (House Martin pattern) - average dates were late 1170 and in others (White Stork pattern) - no changes. The positive and negative pair correlation in dates of arrival between species has been discovered as well. The observations of the numerous correspondents offered an opportunity to draw a map_ of arrival of eight species in Ukraine. According to curves of isophenological line, three migration ways are .clear. The first lies over the northen districts of the Ukrainian 3SR from the west to the east. The second goes from the south-west to the north-ea3t across the complete terri¬ tory of the republic. And the third one lies along the coasts of the Black and Azov Seas. Besides this, the map 3hows how the birds avoid the Carpathi¬ ans early in the spring, going arround the main chain of the mountains. Geographic variation analysis of the arrival dates of Starling, Geese, Sky Lark, Golden Oriole, Nightingale Thrush and some others shows that the dates of their arrivial in the northern regions varies minimally compared to species that arrive late in spring in south regions. COMPARISON OP THE SOCIAL SYSTEMS OP SEVEN SPECIES OP DUCKS IN THE GENUS ANAS N. R. Seymour Xavier University, Canada Aspects of the ecology and behaviour of seven species of ducks in the genus Anas were studied from 1968 to the present in an attempt to describe ^d contrast the social systems of epch species. The Mallard (A. platyrhyn- Pintail (A. acuta), Gadwall (A. strepera), Wigeon (A. americana), Shoveler (A. clypeata) and Blue-winged Teal (A. di3cors) we re observed in t»o habitats in southern Manitoba, Canada. The Black Duck (A, rubripes) was studied in three habitats in northeastern Nova Scotia, Canada. Data was col¬ lected on home range size, territory parameters, pair bond strength, tenure ^d duration, and other aspects of the breeding biology of pairs. Data was alao collected on the behavior of unpaired males and on interactions between Pairs and unpaired males. The seven species represent a continuum with re- Sards to these ecological and behavioral characteristics. For example, the Pintail has the largest home range, is not territorial and ha3 a poorly de— Vsloped pair bond. The Shoveler is the other extreme and defends a well-de¬ fined territory, on a small home range and has a strong pair bond. The vari- °Us ecological and behavioral characteristics of each species are discussed ahd each species is placed relative to the others in the continuum. CONTAMINATION OP WATER SUPPLY BY GULLS, AND A SOLUTION Colin Buchanan Shedden Department of Zoology University of Glasgow, Glasgow G1 2 8QQ, Scotland, UK Concern has been mounting in recent years over the role of gulls (narus as dissemenators of potential human pathogens. During the last ten yeara the level of bacterial contamination in two service reservoirs m the Weot of Scotland, during the winter months, was high and was correlated with tho numbers of gulls using these reservoirs as nocturnal roosting sites. 1171 The roosting gulls were predominantly Herring gulls (Larüs argentatus) though numbers of Blackheaded gulls (Larus ridibundus) and Common gulls (Larus canus) were also present. Attempts were made, using taped distress calls of these three species of gulls, broadcast over the reservoirs, to dispersa this roosting population of gulls in 1980/81 and 1981/82. The results show that there was little habituation of the gulls to the taped distress calls and a dramatic improvement of raw water quality due to the disoersal of the gulls to alternative roosting sites. ?he e. iectivene ^ > of these behavioural tearing techniques h respect to local climatic con¬ dition.-. and species composition of the roosting flocks is also considered. RELATIONSHIPS BETWEEN RAPTORS AND MICROTIRE RODENTS IN AGRICULTURAL AREAS OP PERM REGION. A. I. Shepel Perm State University, Perm, USSR During the years of 1976-1979 the population of 10 raptor species (mainly rodentivorous predators) fluctuated rather synchronously with that of their prey - microtine rodents. The most considerable fluctuations were a function of population of such common species as the Buzzard (from 2.5 to 12.2 pair per 100 sq.km), the Kestrel (2.5-11.9) and the Long-Eared Owl (3. 2-6. 8). In rodent peak years all the raptors, which had arrived in the study area, began to breed. Predominant food items in their diets were microtine rodents, mainly the common vole (from 49-7% of Eagle Owl's to 94. 7% of Short-eared Owl' 3 total prey). In the years of decline mioro-rodent populati¬ on there occured specific and individual reactions of raptors to the lack of food. For instance, some Buzzard individuals abandoned their breeding area some time after their arrival, others did breed, switched over to a wide range of other food sources (birds, amphibians, reptiles, etc. ) , some pairs continued to feed on scarce common voles, without even making any attempt to breed. Clearly- observed preferable prey were pregnant females (36.1% of total prey versus 13.8% from rodents' count data). Raptors more often preyed on adult individuals (from 62.3% for Tengmalm's Owl to 80.2% for Buzzard); no preference for male or female prey was discovered. STUDIES IN GEOGRAPHIC ASPECTS AND INTERASPECTS OP THE ACOUSTIC-REPELLENT IMPACT ON BIRDS IN DIFFERENT REGIONS OP THE USSR V. Sheviakov, A.Putramantene Zoological and Parasitological Institute of the Lith. SSR Academy of Sciences, Vilnius, USSR Prom 1978 to 1981 the geographic aspects and interaspects of the acoustic repellents' impact on birds characteristics of most coastal and inland air¬ fields ( Corvidae. Laridae . Sturnus vulgaris ) were studied. The research co¬ vered Lithuania, the Baltic, Black- Sea and Caspian coasts, Soviet Central Asia, Chukot and Kamchatka peninsulas and the Island of Bering. 1172 Local birds were subjected to acoustic repellent relays recorded from these and other species but in geographically remote areds. About 1500 relays were analysed. The studies indicated that no geographic aspects of the acoustic repellent impact were manifest for Corvidae, Lari- dae and Sturaua vulgaris while the geographic interaspects of the acoustic repellent impact were manifest both among congeneric species and systemati¬ cally remote and depended on ecological relations of birds within a concrete biotope. STATUS OP GRUS JAP0NENSI3 AND G. VIP 10 POPULATIONS IN PRIMORYE TERRITORY Yu. V. Shibaev, N. M. Litvinenko Institute of Biology, Par-East Scientific CeDter of the USSR Academy of Sciences, Vladivostok, USSR Two regions of vital importance for G. japonensi3 and G. vipio are known in Primorye. Khanka lowland is a place of regular breeding and the Tumannaya river mouth (southern Primorye) is the place of regular stations during mig¬ rations. There are three isolated sites of nesting in Khanka lowland: Ilistaya river mouth (3-t pairs of G. japonensis and 1-2 pairs of G. vipio); bogs on the north-east part of Khanka (about 15 pairs of G. japonensis and 3-4 pairs of G. vipio); upper reaches of Chornaya river (6-8 pairs of G. japonensis) . The following results of aviacensus (August of 1980) were obtained: 116 spe- ciments (18 juv) of G, japonensis and 8-10 specimens of G. vipio; about fourth one of Grus japonensis of the world population probably inhabits the Khanlca basin (including birds occuring on China territory). More than 100 specimens of G. japonensis and about 200 of G. vipio stayed unnually during spring migration over the marshy area of the Tumannaya river mouth scarred with numerous mostly salt waters. G. japonensis arrives in early March and stays at the lowland till late March-early April. G. vipio Migration was observed in late April. In spring the main forage of G. japo- Sgbsis is dead fish, mostly Carassius auratus. In autumn the birds migrate transit. PAUNA AND THE RELATIVE NUMBER OP RAPTORS IN ZABAIKÀLIE (EAST OP BAIKAL) A.P. Shkatulova Altai Medical Institute, Barnaul, USSR In the period of 1959-1979 32 species of raptors have been recorded in 2abaikalie including 20 nesting and 7 supposedly nesting species. Total number of raptors in summer season was on the average 1.7 indivi¬ duals per 10 km of route (from 0.3 bo 4.0) over open habitats and 1.3. indi- viduais per 10 km of route (0.3-4. 7) over forests. Fominanting species were Buta a buteo (0. 4-2.0 individuals per 10 km of roube), Milvus migrans (0. 3-3-0), Accipiter nisus (0.1-3. 3). Circus cyaneus (°.1-1.3)', Falco subbuteo (0.2-1. 2) and Falco tinnunculus (0.1-1. 2). Some- tiMes great flocks (up to 137 individuals) of Milvus migrans (probably bach- eI°r-males) were recorded. INTERRELATION BETWEEN THE COMPONENTS OP VERNAL MIGRATORY STATE IN CHAPFINCH AND B RAMBLING M. E. Shumakov Biological Station Rybachy of the Zoological Institute, USSR Acadomy of Sciences, Leningrad, USSR The analysis of vernal migratory orientation experiments in chaffinches and bramb lings in automatic round cages at the Kurische Nehrung shows diffe¬ rent correlations between the fat reserves level and migratory behaviour at the end of the migratory phase and similar relations of these components in the middle of migratory period. When birds of both species have precise vernal migratory orientation (for chaffinches n=3S0, for bromblings n=260), a positive correlation has been established between fattening, activity rate and orientation power (vector length). Correlation value for the fat reserv¬ es level and activity level in the chaffinches was 0.73+0.12, in brarablings 0.71+0. 14; for the fat reserves level and vector length 0.69+0.09 and 0.51.+0.12 respectively. At the end of migratory period, precise orientation occured in birds with low fat reserves; fatty birds often had poor orienta¬ tion. It indicates and independent regulation of different migratory state components by internal and external stimuli. FORMATION AND FIDELITY OF PAIRS IN POPULATION OF RINGED PLOVER (CHARADRIU5 HIATICULA) Axel Siefke Vogelwarte Hiddensee, Kloster/Hiddensee, GDR The composition of pairs according to origin and age of mates a3 well as their fidelity re3p. their replacement during breeding time and from year to year has been analyzed for a colourringed population on the southern coast of the Baltic, consisting of avg. 34 (24-42) breeding pairs, which have been investigated since 1974 on size determining mechanisms, etc. Adult birds faithful to breeding area appeared singly or in pairs in 26.2/49.8'S °-£- t'lle Pail>s (n=237), first breeding birds faithful to their birth place in 11.8/2.5% and (unringed) newcomers in 26.2/15.6%. The age difference between the mates may be up to 9 years, in average it was 1.5 years (n=95). Of the 61 males, which have bred more than one year (avg. 3.5 years; n=i53) in the area, in 80.2/5 of cases the old territory was reoccupied and in 46.4% the pair bond from the previous year was maintained. A change of .he female (22. 9/.) occured particularly in territories of inferior quality as well as in the case of change of territory of the male from one of poor quality, to a better one. Losses of mates during breeding are ' compensated immediately. In case a female is lost (rarely) still unmated older or (mostly) first breeding com¬ pensating mates of the male remaining in the territory appear, in experiments up to 5 females per male. in contrast, the females resettle in case the male is lost and mate at other localities with territorial (mainly first breeding) males. The discussion concentrates mainly on the population-ecological consequ¬ ences of the settling behaviour and the importance of the so-called popula¬ tion reserve. 1174 THE ROLE OF GULLS IN TROPHIC CHAINS OF GROUND AND WATER ECOSYSTEMS OF THE NORTH-WESTERN BLACK SEA COAST V.Siokhin State Pedagogical Institute, Melitopol, USSR If a species is a member of the land and/or aquatic ecosystems influences these biocenose considerably. Three groups can be determined on the basis of their feeding biotope, namely: (1) Feeding in aquatic ecosystems (Laru3 fchtyaetus Pall. , Hydroprogne caspia Pall. , Sterna sandvicensls Lath. , Ster- ha alblfrons Pall.); (2) Obtaining food on seaside steppe (Larus melanocepha- iH®__Temmi, Gelochelidon nllotlca Gm. ) ; and (3) Feeding in tenestrial and aquatic ecosystems (Larus argentatu.s Pontop. , Sterna hirundo L. ) . Gulls influence separate links differently in trophic chains of the eco¬ systems under study. The greatest number of connections are formed according to block saprotroph components (38.3$), and a smaller number of connections to zoophages (22.5$) and to phytophages (21.6$). Participation of gulls in biotic cycles was studied from both sides - as U3es of biological production ^d as a source of biological products. In general, trophic connections were formed with respect to components of aquatic ecosystems. In aquatic biocenose, the ecological chains are closed because the pro¬ ducts of birds (excreta, carcasses) ehd in the water. These influence prima¬ ry production. Other trophic links are formed by primary productions; gulls are the lost link. In this case, cycling of materials occurs within a single biotope. In terrestrial biocenose, biotic transfer occurs mainly in one direction from land to water. Although some birds feed in terrestrial biotopes, the Products of their vital activity reach bodies of water. Because these birds participate in food chains of aquatic ecosystems, they are links between terrestrial and aquatic biocenose. HEAR WATER BIRDS OF THE ECOSYSTEM OF THE LARGEST ASIAN LAKES (ON THE EXAMPLE OF THE LAKE BAIKAL, THE USSR AND THE LAKE KHUB3UGUL, MPR) N. G. Skryubin Kesearch Institute of Biology of Irkutsk State University, Irkutsk, USSR "he lakes Baikal and Khub3ugul are. the deepest 'natural water- reaervours °r Asia. Connected by the Selenga system they differ from each other only in and in their situation above the sea-loval. On the lakes 85 specie* of !lfeur-wator birds were registered ( i.;aviifomes - 2, PodioLpadif qr.iaea. - 4, L-gLgcaniformes - 1, Clconiiformes - 4, Anscri formes - 30, Grulforme3 - 5, -^Sgadrjjf ormea- 49). Out of this number 67 species nest on the lakes (Bai- kaI ~ 64, Khubaugul - 40). Near -water birds make up 27$ on the ornithofauna °n the Baikal and 29$ on the Khubaugul. Because of their great population thi3 group of birds plays a noticable part in the functioning of the lakes' Sc°3ystem, 37 species are common for the lakes (the most typical are G avia arctica Podiceps njgricollis C.L.Brehm, P. auritus (L.j, P. cristatus iLj , Ardea cinerea L. , Ciconia nigra (L* ) , majority of Anseriformes and Charadrii- dae, Chlidonias and Sterna, Larus) . On the Khubsugul only 3 species which do not nest on the Baikal were found (Phalacrocorax carbo (L.), Eulabeia indi- Ç5» Tringa totanus L. ) whereas on the Baikal 17 species which were not re¬ gistered on the Khubsugul were noted (Gavia stellata (Pontopp. ), Podiceps griseigena (Bodd. ) , Botaurus stellaris CL.). Oygous cygnoide3 (L. ), Mela- nitta deglandi (Bp.), Anas falcata Georgi.A. acuta L. , Aythya ferina (L.). Historionicus histrionicus ( L. ) , Mergus serrator L. , M. albellus L. , Calidris subminuta (Midd. ), Limosa limosa (L.), L. canus L. , Hydroprogne caspia (Pall. ) , Chlidonias hybrida (Pall.) . Both lakes, especially the Baikal, due to the mountainous character of extensive territory surrounding them are the places of near water birds con¬ centration - birds both on flight and nesting. Birds distribution along their littoral is also irregular: the main part concentrates in the outfalls of big tributaries, on shallow sections and on marsh-ridden plains. Numbers of lamme-lirostrals on the Baikal in such places reaches from 200 to 400 nest per 100 ha of areas suitable for nesting, and the total numbers of Larus, nesting on the Baikal reaches 22-25 thousand, Chlidonias and Sterna - 40-45 thousand. On the Khubsugul the nesting population of Larus argentatus Pontopp. is 4 thousands of birds. The main factors determining the number and distribution of aquatic-marsh birds are the seasonal and interannual changes of water level of water- reservoirs and the anthropogenic effects which have lately considerably increased. THE IMPRINTING OP THE NEST TERRITORY L. V. Sokolov The Biological Station Rybachy of the Zoological Institute of the USSR Academy of Sciences, USSR The analysis of the data of the birds nesting at the Kurishe Nehrung re¬ vealed that most of the one-year-old individuals of the Fringilla coelebs, oylvia nisoria, Phyllo3copus trochilus ( 90 % ) and some of the Hippolais icterina, Lanius collurio, and Carpodacua erythrinus ( 26 % ) returned to their birth site in the following years. Most of the H, icterina, L. collu- £i£. 6114 ?-• erythrinus returned to another territory, which they inhabited after they left the birth site. Young £_. — coelebs and S. nisoria imprinted on the territory of the future nesting during the sensitive period" of an age between 30—40 days, before the beginning of the intensive postfledging movements. The imprinting of the nest site of most H. icterina, L. collurio and C. erythrinus took place im¬ mediately after they left the birth site, at the age of more than 30 days. The formation of the site tenacity to the nest territory in migrant birds took place at juvenile age. It was characterized by the existence of a reli¬ able "sensitive period" for imprinting. Reasons exist to support the conclus¬ ion that site tenacity of these species is the result of imprinting. 1176 NESTING OP THE SIBERIAN CRANE IN ’VEST SIBERIA A. G. Sorokin, J.V.Kotjukov All-Union Research Institute of Nature Conservation and Reserves, USSR Ministry of Agriculture; Oka State Nature Reserve, USSR Fhr more than a hundred years after the Siberian Crane was described the breeding places of its western population remained unknown. In 1981 special investigations were undertaken. Aerial surveys were performed over the ter- 2 ritory of more than 30 000 km between 63°-67° of North in the low Ob region. On the 14-th of June in the region of the right tributary of the Ob niver - the river Kunovat - 5 pairs of the Siberian Cranes were discovered. The birds held to the edge of a large (about 200 km ) bog area with numerous lakes among the larch forest of the northern taiga. The minimum distance bet¬ ween the nests of this group was 1.5 km, the maximum - 10 km. On the 16-th and the 25-th of June 3 more pairs were discovered on raised bogs to the north from the river Kunovat. For 5 of the 8 discovered pairs breeding was proved. Two of the four carefully examined clutches contained 2 eggs, and 2 clutches contained 1 egg. The nests were situated on up-raised sphagnum bogs close to the border of the depressed larch forest. They were open nest on moss covered hillocks or ridges with rare larches and birches. Common Cranes were found breeding (4 nests) together with the Siverian Cranes in the same habitats. In two cases the nests of the two species were in less than a 1 km distance from each other. On the 25-th of June in one of the Siberian Cranes' nests a chick hatched, two other pairs judging by their behavior had already had chicks. The eggs were apparently laid in the last week of May, when the first patches of earth appeared on the 3now-covered surface. The behavior of these birds in the vicinity of the nests differs from the behavior of the Jakutian Siberian Cranes. The cranes stayed on in their nests when the airplane was quite low. Often after leaving the nests the frighten¬ ed birds did not fly away, but tried to hide under trees and fairly soon re¬ turned to their nests. A similar reaction was observed among the Common Cranes. ON BIOGEOCENOLOGICAL TYPOLOGY OP CE3T0DE3 OP HYDROPHILOUS AND LAND BIRDS A. A. Spassky Institute of Zoology and Physiology, Moldavian SSR Academy of Sciences, Kishinev, USSR Five main biogeocenological types among the helmlnts of the vertebrates "Uch as the primary hydrobionts, the primary amphibionts, the primary atmo- bionts, the secondary amphibionts and the secondary hydrobionts can be point- eti °ut judging by the nature of ecological links and also taking into account ■o •apir evolution. Among the cestodes of the birds one can distinguish hel- rniuts of three types: T* The primary amphibionts - their larvas develop in the organism of the v,uter invertebrates and the fishes, while the nature forms develop in the destine of hydrophilous birds. These are Liguilidae (Ligula, Digramma, '^jigtocephalus). some of Diphyllobothriidae (Diphyllobothrium dendriticum, 'U-jlUrimum and so on), Tetrabo thriidae (Tetrabothrius) . They descend from ~~ . 1177 cestodes - primary hydrobionts, the intermediate and definitive hosts of which were the water animals. II. The primary atmobionts - the cyclophyllidean cestodes of the land birds, which use the ground or soil invertebrates as intermediate hosts, and sometimes (Paruterina, Cladotaenia and some other species) - the small ver¬ tebrates such as the rodents. III. The secondary amphibionts, such as ?imbriariidae. Ophryocotylidae. Gryporhynchidae, some Dilepididae (Lateriporini, Anpmotaeniini) and other of the cyclophyllidean cestodes. Their larvas contaminate the water animals, while adult cestodes contaminate hydrophilous birds. It is accepted, that the amphibious type of the life cycle of these cesto¬ des is a phenomenon of a primary sequence, phylogenetic research has demon¬ strated, that their ancestors were the land forms (primary atmobionts). Contemporary hydrophilous birds (such as Laridae. Colymbidae and so on) may have at the same time both primary and secondary amphibionts among the tape- warms. OBSERVATIONS ON THE DIURNAL RHYTHI.l OR THE LITTLE AUK PLAUTUS ALLE L. IN CONTINUOUS DAYLIGHT Lech Stempniewicz Department of Animal Ecology, University of Gdansk, Czolgistôw 46, 81-378 Gdynia, Poland The rhythm of attendance at the colonies and foraging flights of the Little Auk in Spitsbergen was studied during 3 years. Observations showed: (1) the distinct rhythm of activity; (2) the changes of the periodicities, from a period of several days at the prelaying stage to a 24 h period at the chick feeding stage; (3) some independence of the activity rhythm of birds breeding in different subcolonies; (4) the influence of the meteorological conditions on birds activity. FEEDING ECOLOGY OF THE STARLING (STURNUS V. VULGARIS L. ) IN DIFFERENT HABITATS '' Jan Stevens, A.F.De Bont, K.U. Leuven Laboratorium voor Systematiek en Ecologie, Haamsestraat 59 B. 3000 Leuven, Belgium The feeding ecology of the starling (Sturnus v. vulgaris L. ) was investi¬ gated in summer 1980 in different habitats in the Belgian cherry- growing area during the cherry-period. Fillerent habitat variables were * n ftv,n>4-u “ were, grass length, grazing cows and ripenin- mg cherries. Marked differences occurred between fnn'j „„„„ v. . . “ ue tween tood searching behaviour and food in¬ take in different habitats. There also were strong differences between adults, and first- and second- brood juveniles. The data are presented and dlacuseed in relation to theoretical optimal foraging model3 and to literature data concerning the feeding beha.ionr of the starling. 1178 GEMMOP HAGIA AMONG EUROPEAN PASSERIFORMES Stefan Strawinski Department of Animal Ecology, University of Gdansk, Poland Feeding on winter buds of 30 species of trees and shrubs by birds from the families of Jturnidae, Paridae, Sittidae, Turdidae, Ploceidae, Fringil- Udae and Emberizidae was studied. The kind of plant bud was analyzed in 18 apeoies of birds and the quantity of birds in 14 species. The birds were found to feed on buds of European cone-bearing trees and shrubs, except Taxus baccata, and on all leafy phanerophytes, except Vacci- nium vitis-idea. Some marked preferences were, however, noted for various Plants. In the food of the Fringillidae. buds constitute essential calorie Providing components. The' amounts of buds eaten by these birds during expe¬ rimental starvation may increase two- to fourfold. Gemmophagia is therefore a means of homeostatic adaptation to food shortage in periods of scarity. For insectivorous birds wintering in central Europe, the inside of buds ®ay be a source of vitamins and other biologically active substances. The amount of winter buds ingested by birds was found to increase consi¬ derably between autumn and spring. Observation on Carduelis ehloris showed that female birds eat somewhat larger amounts of winter buds than males. Young greenfinches feed more inten¬ tly on winter buds than do adult birds, which feed more on last-year's sprouts. The proportion of plants preferred by birds in the biocenosis may influ- ence the composition of the winter avifauna of wood3 and shrub areas. EIN BEITRAG ZUR POPULATIONSÖKOLOGIE VON MILVUS MILVUS (D. , 1758) UND BUTEO BUTEO (L. , 1758) IN DER DDR Michael Stubbe Sektion Biowissenschaften der Martin-Luther-Universität Halle-Wittenberg, Wissenschaftsbereich Zoologie, DDR Im 1300 ha großen Laubmischwald Hakel am Rande der Magdeburger Börde, im Nordharzvorland der DDR, wurden zwischen 1957 und 1967 sowie seit 1978 popu- l&t ionsökologische Untersuchungen an den dort siedelnden Greifvogelarten durchgeführt. Im Vergleich der beiden Untersuchungsperioden zeichnet sich fhr den Rotmilan (Milvu3 milvus) ein eindeutig positiver, für den Mäusebuss- Qrd (Buteo buteo) ein leicht negativer Populationstrend ab. Für den Rotmilan 1st dies besonders bemerkenswert, da die Hauptbeutetiere Feldhase (Lepus !H?opaeus) und Feldhamster (Cricetus cricetus) einen rapiden Populätions- 8°hwund verzeichnen. Zwischen 1957 und 1967 wurden im Hakel 749 Rotmilane und 282 Mäusebussar- 116 als nestjunge Vögel beringt. Die Wiederfundquote beträgt für die beiden ^len bis Ende 1981 18.2 bzw. 16 %. Die Wiederfunddaten werden in lebenstaf- eln aufgerechnet. Die Rotmilan-Wiederfunde entfallen auf 9 Länder, Tl% von ■'■Nhen waren in Frankreich und auf der Iberischen Halbinsel vorwiegend durch A^schu^ oder Fang zu verzeichnen. Dagegen spielt der Abschuß von Mäuse¬ bussarden aus der Hakeipopulation infolge des geringeren Migrât ionsverhal't- 6113 in die genannten Länder eine weitgehend untergeordnete Rolle. Ein um- äsender Greifvogelschutz in Westeuropa würde sich positiv auf die in 1179 vielen Ländern rückläufigen Bestände ausvvirken. Die zwischen 1957 und 1967 geborenen Rotmilane aus dem Hakel erreichten eine mittlere Lebenserwartung von nur 2^/4 Jahren, dagegen betrug diese beim Mäusebussard 4 Jahre. Die Hauptverluste der Rotmilane sind auf dem Herbstzug, jene der Mäusebussarde in der Winter- und Nachwinterperiode zu registrieren. E3 wird darauf verwiesen, da/i die Feldmaus-Massenvermehrung (Microtus arva- lis) des Jahre3 1978 möglicherweise erst 1981 einen phasenverschobenen An¬ stieg der Brutdichte des Mäusebussards bewirkte,, was für ein Erreichen der Geschlechtsreife mit 3 Jahren bei einem größeren Anteil der Jungbussarde sprechen könnte. HISTORICAL CONCEPT OP THE EUROPEAN AVIFAUNA ORIGIN AND STRUCTURE Petr 3vec Department of Paleontology, Faculty of Natural Sciences, Charles University, Albertov 6, 128 43 Praha 2, C3SR The complexes of recent avian species, constituting the present avifauna, are conventionally divided into some variously constructed groups, termed a3 the "faunistic types" (Stegmann, 1938), or some classes of the same"types of distribution" ( Voous, 1 9o0) . The theoretical basis of this concept are built nearly exclusively on the present distribution of the avian species. Content of a historical aspect in the presented schemes is nearly always negligible. Climatic and/or ecological changes during the Quaternary are accepted as decisive factors for the origin and development of the present European avi¬ fauna. But it is necessary to inquire further back into the earth's history for the origin of nearly all elements of this avifauna. Analysis of the fossil and recent avifaunas indicate, that the European avifauna arose and developed in three waves of the evolutionary radiations. 1 ) Mesozoic radiation: Nearly no information i3 known from Europe, but some taxa may persist to the present (Gaviidae. Procellariidae etc.). 2) Paleogene radiation (from Paleocene to Miocene): The North American and European avifaunas were very similar (contrary to the different Asiatic avifauna), consisted of the related ancient forms, limited now mostly to the oouth America and Old World tropics, but 3ome taxa persist also in the Euro¬ pean avifauna (Phoenicopteridae. Gruidäe etc.). 3) Neogene radiation (from Miocene to Recent): The ancient European, forms spread through climatic changes and through food competition with some more advanced avian species which appeared as immigrants from the subtropics of Asia after- the Tethys regression. They form a major part of the present avi¬ fauna of Europe. During the Neogene, a passeriform radiation also started. The Quaternary changes had a character of the repeated emmigrations and re immigrât ions of the same groups rather than extinction of the old' avifauna and formation of a new avifauna. 1180 AN ATTEMPT OP THE JOINT RESEARCH ON THE BIOLOGY OP THE BLACK HEADED GULLS BY ORNITHOLOGISTS OP JAPAN AND USSR Hisashi Sugawa, Shiroh Ot3uki, Nikolay Gerasimov Department of Zoology, Kyoto University, Kyoto, Japan, 20 Omiya-yakushiyama-higashi , Kitaku, Kyoto, Japan, Kamchatka Office of Hunting Economy, PetropavIov3k-Kamchatsky, USSR The breeding colony of the black headed gull3 Laru3 ridibundus at the reserve around Lake Klamov3ky in the delta of Avacha river, Kamchatka, was observed. The number of breeding pairs of this colony was only several ten3 in 1967 and increased into several thousands in 1980. Many gulls lay egg3 through June, and first fledglings are seen in the middle of July. Gulls leave the colony in August, and migrate southward in September and October. Only since the 1973-1974 winter, many black headed gulls have appeared in winter in Kyoto, Japan. Prom November to April they spend daytime hours on rivers in Kyoto and go over mountains to roost in Lake Biwa. Recently the gulls also expand their wintering areas in many places in Japan. In the Klamovsky colony, 4100 juvenile gulls have been banded since 1973, including 2600 in 19S0. Many banded gulls are recovered widely in Japan, so a great part of gulls from this colony are thought to winter in Japan. In 1980-1981 winter, about two percent of wintering juvenile gulls in Kyoto had rings which can be judged as the Klamovsky colony members. In Kyoto, gulls were also banded, and their return records show their strong homing tendency -to the same wintering area. REPRODUCTION CHARACTERISTICS OP THE STARLING (STURNU5 VULGARIS) IN NESTBOXES IN BELGIUM (1976-1981) J . Tahon Station de Zoologie appliquée de l'Etat, Centre de Recherches Agronomiques, Chemin de Liroux, 8, B - 5800 Gembloux, Belgium Since 1976, 1250 to 1650 nestboxes were placed each year all over Belgium. During these six years (1976-1981) a grand total of 22.368 chicks were ring¬ st. Different parameters of reproduction are analyzed: dates of the first, replacement and second layings; relative frequency of these layings; numbers °f fledged young; favorable and unfavorable biotopes; regional abundance of the species; competition with other species of birds, mammals and insects; Predators. ON "DESERTION PERIOD" IN THE NESTLING LIFE OP THE PUPPIN (PRATERCULA ARCTIC A L. ) !• P. Tatarinkova • Kandalaksha State Nature Reserve, USSR Puff in- parent s cease feeding their chicks some days before the latter leave their burrow. This phenomenon acquired the name of a "fasting period" 037 a "desertion period" (Lockley, 1953; Kartashev, I960; Myrberget, 1962; •’•tokova, 1967; Korneyeva, 1967; Tatarinkova, Chemyakin, 1970). However, it nas been recently stated (Harris, 1976), that no "desertion period" takes Place in the puffin chicks life since some of them continue putting on weight * -1 'I C aîteTîh M t , ? “d the adUltS keeP on 3ta^g ^ the colo- " Ï7 fled^ed- 0ur observations of puffins on the Aynovy Isles (West Murman) showed, that the majority of adult birds leave their nestrng place simultaniously. Some puffins keep on staying in the colony after their chicks' fledging until their general take-off whereas others abandon their half-grown youngs which are to leave the burrow at a certain developmental stage. Thus the presence and duration of a "fasting period" is n the long run dependent on the time for the beginning of nesting which is! its turn, related to either spring conditions or to the colony's geogra- p ic position. Hence - the differences in "fasting" duration reported by va- ; -TT 7; (6_9) " LOCkley-^53); 8.2 days (5-11) - Myrberget, fo6 ’5:4A7 " Tatarnikova' Chemyakin.0 970). In the warm spring !f 967 °f the pUffin aynovy Isles started on June 29, and the mSi Ty bISan t0 fledSe’ the m6an "fastinS" duration was 3 days, maximum - 7. 28% of nests were already left by chicks while their parents July^o nednS±ng ^ ^ ** °°ld 1968 etching °f chicka on July 10, fledging - on August 19, "fasting period" made up 5.7 days (1-15). tt e Chicks departing from the burrows were weak and often fell prey to big sea gulls or starved to death. OSMOREGULATION IN PELAGIC MARINE BIRDS (PROÇELLARIIDAE) David H. Thomas, Michael Wink ' Department of Zoology, University College (University of Wales) Cardiff, UK; Institut für Pharmazeutische Biologie, Technischen Universität, 3300 Braunschweig, ERG IP.V10U, studies on „1, gland Motion g.nerally used c.ptiv. bird, ad.p- ed to « ««itlci.1 s.l, and nater r.gi™, „ ,peol„ „hlci „„ ” Id ! ”” P*1‘8lC '‘““*a,*r3 “»“T «np.ri.ns. non. conditions (no .sees, to freoh ..ten), »j interapacifie diffsp.no.. in proportions of fish an„ invert.br., e, m th„ al,t3 pla„ il; ■and. on salt gland secretion and renal-intestinal excretion. The excretory responses to standard oral loaHa „„„ n excretory (P Duffimis Hi t . wa er were tested in Manx Shearwaters 7:/mn7 g> . “ly J and C°ry'3 ^bear waters (Calonectris diomedea, diet mainly cephalopoda), using freshly caught birds to œaure that their ’ ! °f funotlon3 were fully adapted to natural conditions. In Puffi- nus, NaCl accounted for 98% of salt h 01 „Mdh i. t . U Sl d secretlon osmolalityf 1.63 osm/kg H20), which is not exceptionally concentrated compared to other birds (as ex- pected from is diet). Renal- intestinal excretory fluid was only Ugh ly hyperosmotic 0.72 osm/kg H20, typical for marine birds) compared to a ma, but hyperosmotic compared to seawater ( i m „ /, „ plasma, r bu seawater (1.03 osm/kg H-0). In resDonse to a seawater load, Puffinus secreted 80 „f i .. 2 P to .. . . lea ö0-85% of osmolytes via the salt glands and the remainder via the renal- in+eeti- no i x. 8 eauivalent to of tn i inteatlnal system, with a net gain of free water 7 . ^ °f the l0Sd V0lume- Remits for Calonectris will be report- 1182 TERRITORIAL DISTRIBUTION AND BIRD POPULATION DENSITY IN NORTH-WEST CAUCASIAN MOUNTAINS P.A.Tilba Caucasus State Biosphere Reserve, Sochi, USSR 225 bird species of 15 orders are recorded in the North-Western Caucasus avifauna (within the limits of Caucasian reserve and its bodering zones). 152 among them are nesting, 48 - passing en route, 25-wintering. The variety of the region's avifauna is due to high geographical mountain belt. 92 bird species are nesting in oak-hornbeam- liana forests belt (from 0 up to 300 ra below sea-level), among them 18 (19.6%) are typical only for this belt. Bird population density is 884.4 individuals per 1 km2. Erithacus rubecula, Turdus merula and Frlngilla coelebs dominate here in different years. In beech and beech-horn-beam forests (from 700-900 up to 1600 m) 96 species are nesting and 14 ( 14.6%) species are typical of this belt. The po¬ pulation density is 621.2 individuals per 1 km2. Erithacus rubecula, Turdus Merula, Parus ater, Sltta europea and Fringilla coelebs dominate here in different years. Only 5 (6.2%) species out of 81 those nesting are typical for dark coniferous forests (from 1200 up to 1500-2000 m). Bird population density is 680.7 individuals per 1 km2. Among the species which predominate in different years we observe: Troglodytes troglodytes, Erithacus rubecula. jhtrdus merula and Turdus philomelos, Turdus viscivorus, Acrocephalus pa- iustris. Phylloscopus trochiloides. Parus ater. Fringilla coelebs. 3pinus gpinus, Loxia curviroatra. Subalpine belt (from 1500-2200 m) is a transiti¬ onal zone from forest to meadow mountain landscapes. Obviously this determi¬ nes a very low specificity of its avifauna. 2 species (4.8%) are nesting in the above mentioned belt, and 42 species were registred in all at the nest- ing place. Bird population is 268.3 individuals per 1 km . Lyrurus tetrix, jj^thus spinoletta and Phylloscopus collybita dominate in different years. 33 bird species are nesting in Alpine belt (from 2200 up to 2500 m) and their population density is 211.9 individuals per 1 km2. 7 species (21.2%) are typical. Anthus 3pinoletta is the only dominant here. Subnivalny belt is slightly expressed. It includes 8 nesting bird species and none of them is typical for the belt. Thus, the number of nesting bird species is decreasing with the increas¬ es of locality height above sea-level. Their population density i3 the high- eat in the lowest belt-oak-hornbeam-liana forests. Bird species of this belt avifauna are very specific. A bit higher a number of typical nesting species decrease and again it goes up in the Alpine belt. Low mountains area is gre- atly changed by economic activity of people and is accessible for penetrati- °n of plain species. Their presence creates the peculiarity of ornithocom- plexe3. The avifauna specificity increases in Alpine belt due to the nesting 0:E a number of typical Alpine species. 1183 EFFECT OF DEAFENING OR HYPOGLOSSAL DENERVATION ON PAIRBOND MAINTENANCE IN DUET- SINGERS Dietmar Todt Abt. f . Verhaltensbiologie; Zoologisches Institut d. F. U. Berlin Haderslebenerstr. 9; D-IOOO^West Berlin In songbird species which develop antiphonal duets, the exchange of vocal signals is considered to play an important role in the maintenance of pair¬ bonds. We examined its significance in the duet-singer Cossypha heuglini H. with two kinds of experiments. In the first, we modified the vocal output of males by sectioning the left N. hypoglossus in control of the left syrinx; in the other, we deafened females by removing their cochleas. Both operations resulted in characteristic alterations of the vocal communication between mates. In spite of these effects, that will be described in detail, pairbonds between mates remained nevertheless stable. This was particularly significant when the subjects were confronted with conspecif ici3. TERRITORIALITY OF SOME MONOGAMOUS SPECIES OF CALIDRIDINAE SANDPIPERS P.S.Tomkovich Zoological Museum of the Moscow State University, Moscow, USSR Four monogamous calidridinae sandpiper species were studied near Uelen in Chukotski Peninsula, N. -E. Asia, in the summers of 1978-1980. Two patterns of territorial systems are found among these species. One of the characteristic features of the Rock Sandpiper (Calidris ptilocnemis) and the Dunling (C. al- pina) is their high return rates to the breeding region (75.0 and 73.0% of all colour-banded birds, respectively) and often to the same territories. This leads to a high degree of mate fidelity in these species. Their terri¬ tories are large (5. 2+1. 5 and 2. 9+0. 8 ha) and males establish them on the first snow-free patches of tundra and defend them during most of the period of nesting. Worsening weather conditions before egg-laying may lead to tem¬ porary- breaking down of the territorial dispersal and as a result to the re- appearence of small sandpiper flocks. The territorial boundaries change re¬ latively little throughout the season. Only the absence of snow-free patches of tundra can make these sandpipers breed in an area adjacent to the one occupied by them in the preceding year. Only some adult Red-necked Stints (C, ruficollis) and Western Sandpipers (C. mauri) return to their former breeding sites (21.7 and 10.0%, respecti¬ vely). The males of these species defend their fairly small territories (1 .25+0.55 and 0.55.+0.3 ha) on relatively large patches of the newly exposed tundra. Usually several males establish their territories close to each other and the settlement exists for some days. Later unmated males form settlements in other places whereas mated birds keep close to one place near the previously defended male territory. The final breaking down of territo¬ ries takes place at the beginning of incubation. In bad weather unmated males of C. mauri can leave the unfavourable region. Both of the sandpiper territorial systems show some features of opportu¬ nism and have certain advantages in changeable environments. 1184 POOD NICHE SEGREGATION IN THE GREAT TIT (PARUS MAJOR), THE BLUE TIT (P. CAERULEUS). AND THE COLLARED FLYCATCHER (FICEDULA ALBICOLLIS) , IN A HUNGARIAN OAK FOREST Janos Török Department of Systematic Zoology and Ecology of the Eötvös University Budapest, Hungary Three food niche dimensions (prey taxa, prey size, prey functional group) in three common species of hole nesting passerines were measured over three consecutive breeding seasons. Food samples were collected from nestlings with neck collar method. Total niche breadth increased in the order P. caeruleus, P, major. F. albicollis. It was the most variable in the Great Tit and the most conser¬ vative in the Collared Flycatcher from year to year. Niche breadth was the greatest in the Collared Flycatcher along the food composition and the prey functional group while the Great Tit had the most variable prey by size dis¬ tribution. Niche overlap between years was the smallest in the Great Tit. Patterns of dietary overlap (along all three food dimensions) among species were quite inconsistent from year to year, although the food composition overlap between the Collared Flycatcher and Blue Tit was consistent. The food composition seemed to be more important than the other two niche dimensions in niche segregation of these three species. DIE BESONDERHEITEN DER FRÜHLINGSMIGRATION DES ALPEN- STRANDLÄUFERS IM NORDWESTLICHEN SCHWARZMEERGEBIET 1. 1. Tschemitschko Die staatliche Universität Odessa, UdSSR Der Fang und die Beringung dieser Art wurde in der Frühlingszeit in den Jahren von 1977 bis 1981 im südlichen Teil des Tiliguler Limans durchge- fuhrt (42 km. östlicher von Odessa). 950 Vogel wurden beringt, unter ihnen waren 61 Vögel mehrmals in verschiedenen Jahren gefangen worden. Gegen 30% ^er Vögel halten sich derselben Zugrichtung auch in den nächsten Jahren. Anfang April kommen die Alpen-Strandläufer in das Gebiet, das untersucht wird, geflogen, vorwiegend im Ruhekleide, einzelne Vögel im Stadium der Teil- toauser. In dieser Periode beginnt die Kleingefiedermauser, die gegen Ende Mai zu Ende geht. Die Jungvögel mausern sich später. Die Alpen-Strandläufer besetzen Plätze des Limans mit gutem Nahrungsangebot für lange Zeit, für etwa 20-38 Tage. Ein besonders langer Aufenthalt ist bei Vögeln festgestellt, bie in der dritten April Dekade beringt worden sind. 50.9% der Vögel gehören zu den nordöstlichen, 39.1% zu den nordwestlichen und 10% zu den zentralen Kopulationen. Die gemauserten Vögel erreichen die maximale Wohlgenährtheit Uad von Mitte Mai an bis Anfang Juni beginnen einzelne Schwärme ununter¬ brochene Wanderungen zum Brutgebiet. Zu derselber Zeit steigt die Gesaratanzahl äer Art, was vermutlich mit dem Zug verschiedener Populationen, die sich irgendwo südlicher gemausert haben, verbunden ist. Im Frühling wurden die Vögel gefangen, die im Herbstzug in Finnland, Schweden, in der DDR oder auf den Überwinterungsstellen in Frankreich, Tune- aien beringt worden waren. Die Analyse dieser Tatsache gibt die Möglichkeit, die Vermutung aus zu sprechen, da£ die Alpen-Strandläufer de- obengenannten 39 3«k.98| ' 1185 Populationen zur Überwinterung die nördliche europäische Küste entlang flieg¬ en, und über das westliche Schwarzmeergebiet und über das Binnenland des Kontinents zurückkehren. Davon zeugt der im August bei Gdansk (Polen) ge¬ fangene Alpen- Strandläufer, der im Mai desselben Jahres im südlichen Teil des Tiliguler Limans beringt worden war. WIEVIELE BRUTPAARE DES WEISSEN STORCHES BRÜTEN ERFOLGLOS? H. G.-H. Veromann Institut f. Zoologie u. Botanik der Akademie der Wissenschaften der Estn. SSR, UdSSR Die Zahl der erfolglos brütenden Brutpaare des Weissen Storches schwankt nach Jahren und Gebieten. Nach verschiedenen Autoren blieb in Oldenburg (BRD) in 50 Jahren im Mittel 45% der Brutpaare des Weissen Storches ohne Nachwuchs, in der Umgebung Hamburgs betrug die Zahl solcher nachwuchslosen Brutpaare in 1 2 Jahren durchschnittlich 38.2%, in den Niederlanden in 1 4 Jahren durchschnittlich 33.9%, in Dänemark in 24 Jahren durchschnittlich 32%, im Gebiet Hannovers in 12 Jahren durchschnittlich 38,2% usw. Diese Vergleichs¬ zahlen stammen sämtlich aus dem Gebiet der rapiden Abnahme des Storchbestand¬ es. In mehr östlich liegenden Gebieten der Storchverbreitung ist die Zahl der nachwuchslosen Brutpaare des Weissen Storches jedoch bedeutend geringer: im Nordteil der DDR beträgt sie 19.5%, 27.6 % und 28% in den einzelnen Zähl- jahren, in Polen 13-4%, 19.0% und 23.4%, in Estland in 27 Jahren durch¬ schnittlich 26.4%. Auffallend wenig erfolglose Brutpaare des Weissen Storch¬ es zählte man in Ungarn (2% in 1958), Litauen (5.7% in 1974) und Lettland (3% in 1934 und 4% in 1974). Es ist nicht ausgeschlossen, das3 in diesen Ländern viele mit jungenlosen Brutpaaren besetzte Horste nicht erfasst wur¬ den. Diese Angaben lassen den Schluss zu, dass in Estland, wo in 27 Jahren durchschnittlich 26.4% von den Brutpaaren jungenlos blieb, die Brutpaaren- zahl sich in dieser Zeitspanne 3.3 mal vergrössern konnte, in Westeuropa bei mehr als 30% jungenlosen Brutpaaren aber eine allgemeine Abnahme des Bestand¬ es eingetreten ist. DER "ATLAS DER VERBREITUNG PAL AEARKT I SCHER VÖGEL" - AUFGABEN UND ZEIL Erika v. Vietinghof f-Scheel, Klaus Wunderlich Forschungsstelle für Wirbeltierforschung (im Tierpark Berlin) der Akademie der Wissenschaften der DDR, Berlin, DDR Der "Atlas der Verbreitung palaearktischer Vögel" wurde 1957 von Akademie- mitglied Professor Dr. Erwin Stresemann, Berlin, als tiergeographisches und ökographisches Kartenwerk gegründet und mit Professor Dr. Leonid A. Portenko, Leningrad, herausgegeben. Es sollte ursprünglich aus den etwa 800 Brutvogel¬ arten der Paläarktis etwa 200, größtenteils den Singvögeln angehörend, aus¬ wählen, von deren Kartierung man sich einen besonders großen wissenschaft¬ lichen Gewinn versprechen konnte. Verbreitungskarten geben festen Anhalt für die Rekonstruktion des Vorgangs der Ausbreitung, sind wichtig für Ökologen, Faunisten, bvolutionsf orscher, Taxonomen, Paläographen, ferner bedeutsam für alle, die sich mit dem Schutz oder der wirtschaftlichen Nutzung freileben¬ der Vögel befassen, Jenes Auswahlprinzip wird beibehalten. In gegenwärtiger 1186 Zeit, da der Rückgang der Artenzahl an Vertebraten weltweit und rapide in Erscheinung tritt, ist unserem "Atlas" als weitere Aufgabe zugefallen, die¬ sen Prozeß anhand markanter und vorzugsweise betroffener großer Vogelformen zu verfolgen und zu dokumentieren. Insofern werden ab Lieferung 7 (1978) zu¬ nehmend Non-Passeres bearbeitet, deren einst groAe Areale - fast immer aus umweltproblematischen Gründen- heute zu kleinen Refugien zusammengeschmolz¬ en sind, z. B. Nipponia nippon, Geronticus eremita. Grus leucogeranus. Grus i^P£nensis, Grus vipio, Grus monacha, Grus nigricollis. Larus relictus. Bis dato sind 10 Atlas-Lieferungen mit 130 Arten erschienen. Die Verbreitungskarten, Fundortlisten, Literaturlisten und Begleittexte (Kriterien: Subspezifische Gliederung, Verbreitung, Ökologie, Wanderungen) werden von Mitarbeitern der Akademie-Forschungsstelle für Wirbeltierfor¬ schung in Berlin (DDR) und des Zoologischen Instituts der Akademie der Wis¬ senschaften der UdSSR in Leningrad gemeinsam erarbeitet. Als Herausgeber fungieren Professor Dr. Dr. Heinrich Dathe, Berlin, und Dr. Irena A. Reufeld, Leningrad. LONG-TERM STUDY OF POPULATION DEMOGRAPHY OF THE BLACK- HEADED GULL (LARUS RIDIBUNDUS L. ) IN LATVIA J. Viksne Institute of Biology of the Latvian SSR Academy of Sciences. Riga, USSR Different aspects of the demography of generally increasing population of the Latvian Black-headed Gull (1944 - 10000, 1979 - 97000 pairs) were studi- ed since 1 962, mainly on Lake Engure (1949 - 200, 1972 - 26000, 1980 - 20000 pairs). Mass-scale trapping of adults on ne3ts, analysis of random re¬ coveries as well as productivity studies applying the method of fenced areas are used. Mortality of chicks up to the 25th day of life (data of 1974-1981) ave- raged 42.9% (in separate years 33.6-54.3%). On the average 60.5% of lost 'Licks died by the 4th day of life and about 80% - by the 10th day. Number °f fledged young per pair decreased from 1.55 in 1974 to 0.94 in 1981 (ave¬ nge - 1.19). Mortality in the first year of life after fledging is 38%, and 15% in the f °1 lowing years. Distribution (per cent) of bird3 nesting for the first time in their life old ^Sma^e3 Is : ^ year old - 5%; 2 - 64%; 3 - 3-1%; and for males: 2 year ^ ~ 40%; 3 _ 4905. 4 _ -\-\%, This distribution is likely to change according the density of population. ^ith 1.55 young fledging per pair (1974) and other indices a3 mentioned above +-U f ) the population would have the growth rate observed on the Lake Engure 1 950s-1 960s, if the immigration and emigration are approximately equal. 1187 FEEDING FLIGHTS OF THE BLACK-HEADED GULL LARUS RIDIBUNDU3 L. J. Viksne, M.Janaus Institute of Biology of the Latvian SSR Academy of Sciences , Riga, USSR Feeding places of the Black-headed Gull of Lake Engure (west coast of the Gulf of Riga in the Baltic, 35.4 sq. km, 26000 nesting pairs in 1972, about 20000 in 1980) changed during the last decade and the distances of feeding flights increased probably due to decreasing possibilities to get anthropo¬ genic food near the lake. Feeding flights have been studied in 1980-1981 by means of trapping and painting (picric acid) birds in feeding places (fish-canneries, mink farm) located 3-70 km away from the breeding colonies. Painted birds were recorded visually both on the lake and outside it. Totally 4085 birds were painted; number of sight records of them on the lake and outside it were no less than 330 and 180, respectively. Feeding flights at distances up to 70 km from the breeding colonies are proved, and gulls flow regularly in big numbers up to 40 km. Feeding terri¬ tories of the Engure gulls and those nesting of Lake Kanieris (35 km apart, about 3000 breeding pairs) overlap considerably. There are no colony-specific feeding places during the whole breeding season, although birds nesting in the northern and southern half preferred to feed north and south of the lake, correspondingly. These differences were more pronounced in 1981. BIRDS IN THE FOREST ECOSYSTEMS DESTROYED BY HERBICIDES IN SOUTH VIET-NAM Vo Quy Faculty of Biology University of Hanoi, Vlet-Nam The US carried out a massive herbicidal programme during the Second Indo¬ china war. It was aimed, for the most part, at the forest of South Viet-Nam. Herbicidal attack has a serious impact not only on the autotrophic component of this ecosystems, but on the higher level, heterotrophic ones as well, among bird3. District A-luoi, a typical humid forest was sprayed many times from 1965 to 1969. All vegetation cover was destroyed and has not been reestablished. The decimation of the vegetation brought about the long-term changes in the biotic community. In the past, the fauna of birds was very rich (about 150 species), but today, only 18 species are found. The use of herbicides may have placed in jeopardy the actual survival of some endangered endemic spe¬ cies. An estimated 125000 ha of true mangrove along the southern coast of Viet Nam was subjected to military herbicide spraying. Virtually noting remained alive after a single herbicidal attack. More than 50 breeding species of birds were found in the avifauna. They formed a number of special communiti¬ es called "birds' field". After chemical attack they were destroyed and now several new ones have been reestablished. Two formally abundant species are entirely absent and many others have become rare. 1183 THE VARIABILITY OP LAG OP If 5 LAGOPUS CLUTCH SIZE IN THE NORTH-EAST TUNDRAS OP THE EUROPEAN PART OP THE USSR R. N. Voronin, Ju.N.Mineyev, A. A. Jestafyev, A.A.Jermakov Institute of Biology, Koray Branch of the USSR Academy of Sciences, Siktivkar, USSR In Bolahezemelskaya tundra and on the Jugorsky peninsula 160 finished clutches with eggs from 3- to 12 were inspected. Clutches of 8 (22.5%) and 7 (17.5%) prevailed and nests with minimum (3-4) and maximum (11-12) eggs made accordingly 5.5. and 3.7%. During 11 years the middle laying size oscillated within the limits of 6.09+0.39 (n=22, 1970) and 8.48+0.47 (n=27, 1980). The extreme laying limits were modified too. In the years of high number and active participation of one-year-old individuals in the reproduction process l'ne modification of egg reaches 28-29%. In the years when mainly two-year- olds and older Lagopus were reproducting, the variability of the laying size went down to 10-12%. Annual deviations from the middle of many years laying size (7.7 eggs) are insignificant , and only twice they reached 21-22%. The analysis of dependence of middle size laying on meteoconditions (35 parame¬ ters were taken) didn't show any kind of connection with most of them: corre¬ lation was observed only with the sum of temperatures in the last decade of ‘“ay (r=0.672) and the number of precipitations in June (r=0.554). CACHING AND RECOVERY OF POOD BY ROCKS AND CARRION CROWS: RELATIVE CONTRIBUTION TO THE WINTER DIET R.K. Waite Department of Psychology, University of Keele, Xeele, Staffs., ST 5 5BG,UK ^ocks (Corvus frugilegus) and carrion crows (C. corone) were observed to cache acoms (fruit of Quercus robur) during autumn, and invertebrates (ma- large earthworms, Lumbricidae) throughout the year. Artificial food¬ stuff (mainly bread) were also hidden. Rocks cached acorns at a time of Relative food abundance. Rocks and carrion crows cached invertebrates on daYs when their intake rates of invertebrate prey were higher than the mean ■^0r that season. Recovery of acorns occurred on days when intake rates of 0 tVi ner prey were lower than the mean for that season. In periods of prolonged fl,°zen soiiai tind fn ia-te winter when stubble grain was depleted, recovery cached acorns provided higher intake rates of calories, and comparable ratea of protein-containing material, compared to other available prey. Reco- Ver“y of invertebrate caches was not proven conclusively to occur. The rela- ^ive Value of recovering other cached items could also not be quantified. 00 very of some items gave evidence of exact-location memory, but recovery ac°rns indicated only memory of the general area in which caches had been It is concluded that acorns, cached by rocks (and perhaps crows) at a c°at, could prove important as an "insurance" source of high-energy food dup: lng periods of temporarily-reduced availability of normal winter prey. 1189 POLYGYNY IN THREE PASSERINE SPECIES PROM THE PRIMAEVAL FOREST OP BIALOWIEZA Tomasz Veselovsky Department of Avian Ecology, Wroclaw University, 50-335 Wroclaw, Sienkiewicza 21, Poland During 4-yr study carried out in Bialowieza National Park (NE Poland) re¬ gular occurrence of polygyny in Phylloscopus sibilatrix, Phylloscopus colly- bita and Troglodytes troglodytes was recorded. As a rule the polygynous males were paired simultaneously only to two females, trigamy was exceptional. The polygynous birds were recorded almost exclusively in optimal habitats. Production of young per female in polygynous groups was not smaller than production of young by females mated to monogamous males. THE DISTRIBUTION AND NUMBER OP THE MUTE SWAN IN POLAND Maria Wieloch Polish Academy of Sciences, Institute of Zoology, Ornithological Station, 80-680 Gdansk 40, Poland Analyzing the data provided in questionnaires it has been estimated that during the period 1978 and 1979 about 2500 prs of the mute 3wan nested in 1500 localities. Only a few bodies of water had larger concentrations of breeding birds. With an increase Ln the number of new localities and die range expansion of this species to the south, many of the large breeding concentrations which were known during the period 1930-1960 disapeared. Mute swans breed over almost the whole of Poland except in the piedmont area, especially in the south-eastern part of the country. Their density shows a large variation and fluctuates from 25 to 0.1 prs/1000 km2. The high¬ est density is found in Gorzow and Bydgoszcz areas (voivodships) . The north¬ ern and northeastern parts of Poland are the areas of high density of mute ' swans, about 10-20 prs/1000 km2. It appears that the Masurian lakes are almost fully saturated with breed¬ ing birds and a strong expansion has been recorded on new reservoirs in the western and southern parts of Poland. During the 40 years 10-fold increase in the number of nesting mute swans occurred in areas west of the Vistula and only a 50% increase in the area east of the Vistula. SEXUAL SIZE-DIMORPHISM IN THE GROWTH OP MACRONECTES PETREL CHICKS Dr. A. J. Williams University of Cape Town, South Africa Sex had a marked effect upon the development of chicks of Northern and Southern uiant Petrels, Macronectes halli and M. giganteus respectively, during studies of development from hatching to fledging during two breeding seasons at Subantarctic Marion Island (46S; 37E). Chicks could be sexed by a clear bimodality in the rativ between culmen length and tarsus length at an age of 105 days. In both species, more female 1190 ohicka existed than male chicks. Sex of the hatchling was uncorrelated to fresh egg weight. Significant sexual differences in culmen length existed in each species at hatching and throughout the chick- rearing period. significant sexual differences in body weight and in tarsus and manus length developed in giganteus soon after hatching but only later in halli. Male halli chicks fledges significantly later than female chicks but there was no sexual difference in the fledging time of giganteus chicks. In both species male chicks received heavier meals than female chicks but in gigan¬ teus male chicks also received significantly more meals than females. DISPERSION OP CARRION CROWS C0RVU3 C. CORONE DURING THEIR FIRST YEARS OF LIFE UP TO TERRITORY FORMATION Jochen Wittenberg, Helmut Sternberg Oral thologis che Arbeitsgemeinschaft für Populationsforschung Braunschweig, FRG Near Brunswick (FRG) we are carrying out a long-term study of a crow popu¬ lation of about 60-80 breeding pairs. Since 1971, the nestlings are marked with plastic wing-tags for field identification. 1.1. Shortly after fledging, losses of young seem to be considerable. 1.2. Some weeks after fledging, part of the young leave their birthplace either alone or with their parents. 1.3. A considerable number of birds stay near their birthplace whereby the family bond may continue. 1.4. Of those mentioned under (1.3.), some additional birds leave the area at the beginning of the next breeding season when their parents and °ther territory owners become more and more aggressive. Dispersion of young birds is as follows: 2. 1 . The dispersing birds spread in all directions up to about 70 km from their birthplace. 2.2. The birds still near their birthplace at the end of their first year °f life 3how a strong tendency to stay there until establishing a territory (Geburtsortstreue) . 3.1. After leaving their parents, the young birds join a flock of non- deeding birds of various ages during the breeding season. 3.2. Pair- format ion seem3 to take place in the flock and when the birds are 2-3 years old, they leave the flock to establish their own territory. ' SETTLING AND START OF REPRODUCTION AS A SEVERAL YEARS PROCESS IN CARRION CROWS CORVUS C. CORONE AT HIGH POPULATION DENSITY - Jochen Wittenberg, Helmut Sternberg Grnithologische Arbeitsgemeinschaft für Populationsforschung Braunschweig, FRG The habitat of the crow population studied in N. of the country by means °f wing- tagging of nestlings (see other poster paper of the authors) con- aiats of high- intensity farmland with several small woods. The population is 3'table on a high-density level with only little disturbance by man. Nearly suitable sites are occupied by pairs, mostly holding their territories oughout the year. Moreover there are flocks of non-breeding birds of 1191 various ages. The pairs establish territories when 2-4 years old, but most are unfavourable, some lacking any nest-site. The following years, the birds seek to improve their territory by moving its borders or taking over a near¬ by territory. The activities of the birds as far as they were paired and territorial are : 2- year-old: partly nest-building, only one case of breeding. 3- year-old: some without any nesting activities, about half the remaining majority building only a nest and half breeding. 4- year-old: mostly breeding, but some recently settled pairs only build a nest or do not even do that. 5- year-old: nearly all birds breeding. Reproductive rate in the first years of breeding is very low but rises later. The gradual development of reproductive activities is considered a consequence of high population density operating mainly through territorial behaviour, thus proving part of a self-regulating mechanism. SOME EC OLOGO-MORPHOLOGIC AL PECULIARITIES OP THE JAW APPARATUS IN LARKS (ALAUDIDAE) M. A. Yesilevskaya Kharkov State University, USSR The larks show a wide rangs of bill shapes - from the weak beak in Lullu- la and rilauda to the thick coniform one in Me lanoc orypha and Rhamnho c o r y s . This variation in bill size and shape is reflected in the differences observ¬ ed in the unusual internal morphology of the jaw apparatus of this family. The morphological pattern of the lark jaw apparatus is also known from lite¬ rature on the gallinaceous birds. It includes features such as the aberrant quadrate-mandibular joint structure and the false zygomatic arch (ossified aponeurosis of the M. _ adductor mandibulae externus medialis fused with the postorbital process). These features are considered to form part of adapta¬ tion for tearing off flat pieces of food. Additional information about the diet and feeding habits of larks suggests detail adaptations in this group which are parallel to those in the fowls based on the different original con¬ ditions in the two groups. ENERGETIC CONSTRAINTS OP CLUTCH SIZE AND TIME OP BREEDING IN TEMPERATE ZONE BIRDS - Yoram Yom-Tov, Ray Hilborn Department of Zoology Tel Aviv University, Israel; Institute of Animal Resource Ecology, University of British Columbia, Vancouver, Canada The timing of breeding and clutch size of birds have been extensively dis¬ cussed in the literature. We produced a comprehensive model, using the great txt m Oxford as a subject, which integrates climatological, physiological and ecological data. The following factors have been incorporated in the model: (1) day length during the breeding season (i.e., available foraging hours); (2) daily and seasonal fluctuations in ambient temperatures and their effect on (a) nest 1192 box temperature; (b) female's metabolic rate (during night and day); (c) at¬ tentiveness at the nest; (3) cost of egg formation; (4-) clutch size; (5) cost of brooding the chicks; (6) energy requirements of the chicks; (7) feed¬ ing of the female and chicks by the male; (8) energy reserves of the female; (9) availability of food. The results of the model are in good agreement with many of the observa¬ tions made in nature and explain fully the following negative correlations: (1) brood size (above mean brood size) and chick weight; (2) mean ambient temperatures prior to laying and laying date; (3) breeding density and clutch size; (4) brood size and time interval between successive clutches. It also fully explains the north-south decrease in clutch size in great tit, and partially the following field observations: (1) the larger clutches of early breeders; (2) the early breeding of hole nesting birds; (3) the late laying in some polygamous species. Simple field experiments are suggested to test some of the assumptions and predictions of the model. FLUCTUATIONS IN THE GROUPSIZE OF THE WHITEHEADED BABBLER TURDOIDBS AFFINIS V. Jerome Zacharias, Daniel N. Mathew Department of Zoology, St. Joseph's College, Devagiri, Calicut 673 008, Kerala State, India The population size of the Whiteheaded Babbler Turdoides af finis and the Patterns of changes in numbers undergone by its groups v/ere studied in a 2*27 km' tropical dry secondary scrub in Calicut, South India, for a period °f four years from September 1973. The Whiteheaded Babbler lives in groups °f 3-14 bird3 in the study area. The size of a particular group seems to vary within fairly narrow limits. Over 4 years most groups varied up to twi- Ce their minimum size. This suggests that factors influencing group size tend to adjust quite rapidly. The groups of Turdoides affinis living in the residential areas were larg- er and had a larger rate of increase. In most case3 the group size was bet- v,een 4 and 8 and only four groups reached the maximum size of 14. None of the Si’oupa contained 14 members for longer than 8 months and after reaching this aize all of them underwent a reduction in size. The groups with 10 or less kfrd3 were more persistent. Intergroup movements of all age classes were n°ticed frequently in Turdoides affinis. These movements help to regulate the Group size, increase interbreeding between unrelated birds, and improve the chances of a low ranking bird to breed in another group. The Whiteheaded Babbler breeds throughout the year, and the overall breed- lnG season of the ap.ecies is probably the longest of any passerine bird found the study area. The average nesting success of 4 years was 41.6%. On the whole the overall tendency was increase in population numbers. 1193 BIRD MIGRATION AND WEATHER IN SOUTH-EASTERN PART OP THE BALTIC REGION M.ïalakevicius Institute of Zoology and Parasitology of the Academy of Sciences of the Lithuanian SSR, Vilnius, USSR In 1974-1977 radio-location studies on bird migration were carried out day and night in the continental part of Lithuania and on the coast of the Baltic sea. 8 processes of the intensity of diurnal and nocturnal, spring and autumn migration were compared with 20 meteorological and synoptical pa¬ rameters of weather using factor analysis and stepwise multiple linear re¬ gression. The main parameters influencing the intensity of flight in spring (registered by the radar) were oloud type and weather temperature, while in autumn the flight was dependent on cloud type and wind direction. One or another weather parameter influencing migratory intensity was significant as far as that parameter caused unfavourable conditions for bird flight. ADAPTIVE BEHAVIOURAL MECHANISMS OP THE CORVIDAE SPECIES Z. A. Zorina Moscow State University, USSR As is known, there are birds in the Corvidae species which have a very high organization of the brain. Their brain is relatively large and has a fine differentiation of the micro and macro-structures. In natural environ¬ ment the behavior of Corvidae birds is characterized by high adaptivity and individual peculiarities. It has been shown that their manipulatory - in¬ vestigating activity is variable and changeable both in its form and inten¬ sity. It is supposed that this developed manipulatory - investigating acti¬ vity is an essential part of instrumental activity which. was observed in the Cordivae in natural and experimental conditions. The study of the Corvidae ability to operate with the empirical dimensi¬ ons of objects has proved that they are quite capable of solving this task and in this indication of their reasoning ability they are very close to carnivorous mammals such as bears, dolphins and monkeys (Krushinaky, Zorina, Dashevsky, 1979, 1980). We used also a new more complicated test, previously applied only for probing human mentality. In this test the birds had to re¬ veal the algorythm of change in the food bait position, when the algorythm was determined by the experimentator. Our data showed that several individu¬ als among the observed birds solved the test and their performance was quite comparable to that of young children. Our data prove the existence of Corvidae's high level of reasoning acti¬ vity und allows a conclusion that their advanced behavioral adaptivity in natural habitats is partly due to this ability. SPACE RELATIONS IN SOME BIRD SPECIES IN THE CAUCASIAN REGION R. G. Zhordania > Tbilisi State University, Tbilisi, USSR The Caucasus is that part of Palearctic where very particular space rela- tions among taxomically close bird species occur. Buteo buteo is an example 1194 - Of secondary integration of conspecific, though divergent enough, forms. Re¬ lations typical of the subspecies notion are characteristic for Phylloscopus çollybitus and Ph. lorenzii. Besides, a member of markedly different races - isolationists of some widely-spread species ( Saxicola torquata aimenica) dwell here. These and some other situations connected with distribution and taxonomic relations of birds in the above-mentioned retion are very good mo¬ dels for research on allopatric species formation and apace isolation of po¬ pulations. BIOLOGICAL BASIC FEATURES OF TIME CODING OF ACOUSTIC INFORMATION IN BIRDS B.M. Zvonov A.N.Severtzov Institute of Evolutionary Morphology and Ecology of Animals of the USSR Academy of Soiences, Moscow, USSR The transmission of acoustic information using time coding is clearly dis¬ played at early stages of bird vocalization. The analysis of sound signals of embrions and chicks of different orders showed that the physical structu¬ re of these signals is identical for all orders, but the rhythm pattern is dependent on lung breath. Any alarm situation or a sense of hunger cause raore frequent breathing, leading to shorter time intervals between individu- al calls. This i3 an important mechanism in the transmission of situational changes in behaviour by an acoustic channel. The use of time coding of acous- tic information is characteristic of adult' birds too. The analysis of mari- tal signals of close bird species shows that time variations are the basis f°r the acoustic isolating mechanism.The principles of time coding are respo asible for individual recognition inside the species.This becomes quite obvious when the method of "sound trap" is applied. The breach in acoustic recogni¬ tion is shown by the denervation of the sirinx in one of the mating pairs. *hen this technique is applied the time structure of the song is changed, while the frequency spectrum: remains the 3ame. Birds' extensive .use of time coding acoustic information is determined by the work of the birds' acoustic Filzer. Fine analysis of time coding in sound signals is already distin¬ guishable on the cochlea and on primary hearing nuclei. EARTH'S MAGNETISM AND THE SUNSET ORIENTATION OF HAND- REARED AND WILD MIGRATORY SPARROWS Yerner P.Bingman Fachbereich Biologie, Zoologie, J. W. Goethe Univ., E-6000 Frankfurt/M. Siesmayerstrasse 70, FRG Recent studies have suggested that nocturnal migrants can use the positi- °n °f the setting sun as an independent orientation stimulus. None of these studiea, however, controlled for directional information, gained from earth's ^Snetiam. I examined the importance of directional information from magnet- i3m on the sunset orientation of hand-reared and wild Savannah Sparrows (Pas- ^££dj-us sandwichen ai nl. During spring migration, 1981, six hand-reared and Sl* wild birds were tested for their sunset orientation on alternate days in the normal earth's magnetic field and a magnetic field with a null horizon- 1195 tal component. Testa began when the disk of the sun fell below the horizon and ended when Polaris became visible. The handreared birds oriented north¬ west when tested in the normal earth's field. The hand- reared birds were randomly oriented in the null field. Directional information from magnetism was necessary of hand-reared birds without prior migratory experience were to orient at sunset. The wild birds oriented northwest when tested in the normal earth's field. The wild birds were bimodally oriented along a north¬ west-southeast axis when tested in the null field. The two wild bird distri¬ butions, however, did not differ statistically. Wild birds with prior migra¬ tory experience could use sunset position as an independent orientation sti¬ mulus, but information from magnetism may be important for these birds as well in a way not yet determined. MIGRATORY ACTIVITIES OP SOME EMBERIZA SPECIES EXPOSED TO DIFFERENT ARTIFICIAL LIGHTS AND TEMPERATURES Tsukasa Nakamura, Makoto Ito, Kantei Cho Department of Biology, Yamanashi University, Kofu 400, Japan The migratory activities in cages of Emberiza rustics and E. school plus have been studied in comparison with those of non-migratory Passer m. satu- ratus. The first experiment was conducted by placing the above-named species in three chambers at different artificial temperatures 23°C, 15°C and 8°C, res¬ pectively. The period of light increased gradually from 9 to 15 hours theii decreased from 15 to 9 hours. In E. rustics, all the three different temperatures induced the onset of Zugunruhe in spring, whereas Zugunruhe was induced again only at the low tem¬ perature, 8°C in autumn. In B. achoeniclus. the onset of Zugunruhe was indu¬ ced at the favorable temperature, 23°C, only in spring, whereas the Zugun¬ ruhe has not been observed at the low temperature, 8°C. On the other hand, in P. m. saturatus, on Zugunruhe was found in the three bird groups through¬ out the experiment. The second experiment was conducted by placing E. rustics in three cham¬ bers equipped with three different artificial lights, 16L, 12, and 8L. The temperature increased gradually from 8°C to 22°C then decreased from 22°C to 8°C. The results from the second experiment show that the increased Zugunruhe appeared in the temperatures between 14°C and 18°C. > 1196 POSTER PRESENTATIONS P.N. BECKER COMMON TERN BREEDING SUCCESS AND NESTING ECOLOGY UNDER PREDA¬ TION PRESSURE OF HERR1NÖ GULLS P.N. BECKER, M. ERDELEN DISTRIBUTION OF HERRING GULL EGG SIZE AND NEST DENSITY IN THE MELLUM-COLONY IN RELATION TO VEGETATION HEIGHT I.N. DOBRYNINA CHARACTERISTICS OF SOME BIRD SPECIES MIGRATIONS ACCORDING TO THE RINGING DATA V.M. GAVRILOV ENERGY OF EXISTENCE AT 0° AND 30° BASAL METABOLISM OF INSECTIVO¬ ROUS AND GRANIVOROUS PASSERIFORMES: THEIR SEASONAL CHANGE AND DEPENDENCE ON BODY MASS S.P. KHARITONOV ON STRUCTURE OF BLACK-HEADED GULLS (LARUS RIDIBUNDUS) COLONIES O.L. SILAJEWA SOUND IMITATION IN THE FORMATION OF COMMUNICATION BETWEEN MAN AND BIRDS S.M. SMIRENSKY, A.L. MISHCHENKO TAXONOMIC STATUS AND HISTORICAL FORMATION OF THE AREA OF COM¬ MON SWALLOWS (HIRUNDO RUSTICA) IN THE AMUR REGION L.S. STEPANYAN THE GEOGRAPHICAL CORRELATION OF MORPHISM PHENOMENA IN BIRDS ,N CENTRAL ASIA V-A. ZUBAKIN TYPES OF COLONIALITY IN THE FAMILY LARIDAE cor, MON TERN BREEDING SUCCESS AND NESTING ECOLOGY UNDER PREDATION PRESSURE OP HERRING GULLS Peter H. Becker Institute für Vogelforachung "Vogelwarte Helgoland", PRO STUDY AREA AND METHODS Subject of this study is a Common Tern colony on Mel 1 um ( 1 979r 80, 1980: 125, 1981: 160 pairs) adjacent to a Herring Gull colony of about 10,500 pairs. During checks every 2 days (1979: 4 days) nests, eggs and chicks were marked and recorded until the end of the breeding period (end of July) (Pigs. 1 , 2). Chicks of £ 18 days were counted as fledged (1979: ^ 14 days). By cartog¬ raphy of nests we measured the nest density (number of i^ests in r ^ 5 m around each nest; only nests having taken part in =» 50ft of the reference nest's breeding time). In 1981 the colony area was fenced with chicken wire (height of about 30 cm). Results mainly refer to early nests (pentade 20- 34). In addition in 1979 and 1980 wo observed the colony during 72 h reap. 144 h from a hide (half the hours spent on incubation, and half on time af¬ ter hatching) (rable 1,2). T a b 1 e 1. Age groups, death causes a Age group 1-5 6-10 Chicks (n = 248) (n = 128) dead (n = 90) 65 16 % dead 72.2 17.8 * chicks 26.2 12.5 disappeared (n=1G8) 55 28 * disappeared 50.9 25.9 % chicks 22. 1 21.8 id survival of chicks in 1980 11-15 16-17 18 (n = 34) (n » 55) (n = 51) 7 1 1 7.8 1 . 1 1. 1. 8.3 1.8 1.9 22 9 V 9 20.4 2.8 26.1 5.4 Table 2. Number of predation in 1 98 ^ chicks disappeared compared with observed chick observation period number of chicks watched cases of chick predation disappeared (9 /day, x 2; () = including cases with uncertain result) 21.-24.6 18 14 (20) 29.6. -2.7 27 26 (48) RESULTS 1. Egg loss increased with laying time (Pig. 3, Table 3). 3ggs of lat(J nests were robbed by an Oystercatcher (Haematopus ostralegus). 2. Breeding and fledging success is with the pen- 3>- 0011 ”'StS <*«»* *»= Mr« - ' pentades (1980: 3) achieved fledged chicks. 3. This was mainly caused by an increasing chick loss with advancing breeding time. The investigation of chick fate had the following results: a) More than 70* of the dead chicks and more than 50* of the chicks having 1198 p i g. 1. The Common Term colony (black) on Mellum next to the Herring Gull breeding area (hatched) Fig. 2. Age groups, death causes and survival of chicks in 1980 age group in days % chicss % Fig. 3. Breed iog success in relation to time of egg laying in I960 (columns: eggs resp. nests) disappeared were 1-5 days old (Fig. 2, Table 1). Most dead chicks were found after peak of hatching . Disappearance was the main cause of chick loss in each of the 3 years (Table 3). b) Refering to 1980.' After hatching of about 1/4 of chicks (c.60), the number of disappeared chicks increased constantly up to a maximum of about 11 chioks/day; Thereafter - again at about 60 chicks alive - the dis¬ appearance rate decreased rapidly (also in 1979 and 1981,). 4. Besides Larus ri dibun dus (2 cases) in 1980 we mainly observed Herring Gulls robbing chicks (29 attempts, at least 19 successful; in 1979: 5, at least 1 successful). Watched chick predation changed according to the course of disappearance (Fig. 5), and the numbers of chicks disappeared and robbed corresponded during the observation time (Table 2). Therefore predation by gulls caused the disappearance of chicks. 5. Younger chicks were robbed preferably, more than expected, according to age distribution (Fig. 9). 6. Hatching-, breeding- and fledging success (Fig. 8) increased with nest density as the percentage of disappeared chicks decreased (Fig. 6, 7). 7. Breeding success is very low (Table 3: 0.2-0. 4 chicks/nest). 1200 Nest, egg and chick numbers, chick fate and breeding success from 1979 to 1981 CO CT\ CT\ cr\ CO © av pi VO -M- CM T- m o vo co o (TV VO CO OJ VO w -p © © iz; w bO # IP « w o H to bo * IP 03 © O bO IP TT © X! o ■p © ^ « O bD •H bO x! &q o ra ra © o o 3 w bO a •H XI o ■p £ o o o » I m t- m ■vf- m « • • • • C- in t- m cn co t*- oo CM CM c*- o vo cn CM CM cn CM o o rn o vo 'a © © © CL Qi © •3 TJ © O •H X o 'V © © TJ © W Jsd ^ U O *H •H XJ -Ö Q O ^ Er» CO T3 © bO 'D © W O •H .© O © O •H » © © o .id o •H XI o m vo © bD If © © © O O 3 « bD a •H bO TJ © / — I vo r— • o m o CM 'St’ 00 vO co t- in ■M- • CM « • • v • vo \ m vo m D'¬ in O CTv O CM t— o GO cn in x— ? — in 1 — CM m ■«tf* VO C— n- VO CM o • » • « • • « CM in vO CM in CM r~ T~ o t'¬ CM CM T“ D*- CM en t- vO T- CO co m • • • • • • • CO VO r— t- co CM •M- C- C^ CM o CM in t- o vO CM CM ■t— ■P © © c U © h. © © © o o © © bO a •H © © fi (TV in C*- T” cn 40'3aK.981 1201 Nest success /^Nests with 1 fie. Chick % oests 28.4 ChicKS DISCUSSION Herring Gulls were the main factor for chick mortality. Although there was some compensation between mortality by other causes and by gulls (Fig. 6, 7). the latter oppressed breeding success with 0. 2-0.4 chicks/pair below the value necessary for maintaining colony size (after literature c. 1 chick/pair and year;. Presumably the increasing number of breeding pairs is recruited by terns from other colonies. 1202 U _ fledged Decreasing breeding success with breeding time may be attributed to age and experience of the breeding birds. Early breeders select more favourable nest sites in areas with greater nest density, where defensive behaviour is more effective (Pig. 6, 7). The course of chick predation shows that Herring Gulls were attentive to tern chicks not before hatching of a greater number Pig. 4). At about the same chick number predation fell down again (pig. 4, 5) , presumably pre dation on chicks wasn't effective any longer (small number, older chicks). This suggests that predatory gulls were not specialized in feeding on tern chicks. 1203 % chines 72 100 r 80 60 00 20 56 29 22k 22 n I 29 n chlCKS chicKSi It day g 1 m chicKg digap peared chicKg found xg t our dead 0 12 3 0 F i g. 6. Chick fate in relation to nest density in 1980 (success: 11 days) y nest density 0 nests r 4 dm. Pig. 7. As Pig. 6 for 1981 % 1204 Pig. 8. Breeding success in relation to nest density (columns: eggs resp. nests) a. °/o 100 - BO - BO 10 20 0 20 10 60 00 WO % b 17. 23. June 123 ade in days i i i i N 23. 25. June 25. 27. June 27. 23. June 29. June 2 July period 138 120 110 78 n, chi CKS I 0 / 33 Kl 1 I Z P Z ^3gTCT viSiît: I I I I s "^Ka age in dags 13 5 - 3 7 2 - 10 2 2 - 11 0 G 1 11 9 5 - n.s. <0,05 n. s. < 0,01 ohicKS disappeared plSlß-17 days Fig. 9- Age distribution of a) chicks alive and b) chicks disappe¬ ared during the breeding period in 1930. P - values: chicks disappe- ared compared with the expected number according to a) x test SUMMARY This study, started in 1979, is dealing with the breeding biology of a little Common Tern colony (Sterna hirundo, 80-160 pairs), adjacent to a Her¬ ring Gull (Larus argentatus) colony of about 10,500 pairs, on the Wadden Sea island Helium, frg. The results are based on records of marked nests, eggs and chicks and on observations from a hide. Egg loss by gulls occured rarely. But predation on chicks by Herring Gulls was the main cause of the chick mortality increasing with advancing breeding period. More than 40% of the chicks were robbed, mainly the younger ones. The changes in frequency of chick predation during breeding time sug¬ gest that the predatory gulls were not specialized in feeding on tern chicks. The greater the nest density of terns the lower was the probability of chick loss by gulls. Breeding success is negatively correlated with advanc¬ ing time of egg laying and with nest spacing. Due to predation by gulls the breeding success of Common Terns is low (1979/1980/1981: 0.3/0. 4/0. 2 chicks/nest) and seems not to be sufficient to maintain the size of the breeding colony. 1205 DISTRIBUTION OP HERRING GULL EGG SIZE AND NEST DENSITY IN THE MELLUM-COLONY IN RELATION TO VEGETATION HEIGHT Peter H. Becker, Martin Erdelen Institut für Vogelforschung "Vogelwarte Helgoland"; Zoologisches Institut der Universität zu Köln, 1. Lehrstuhl, Weyertal 119, D-5000 Köln, 41, PRG STUDY AREA, AND METHODS In 1979/1980 data were collected at the end of egg-laying-period of Her¬ ring Gulls on 0,25 ha sample areas along a line transect through the breeding colony Me Hum, FRG (Pig. 1; in 1979s eastern areas, in 1980s western areas). For measurements see Table 1. Breeding habitats are shown in Table 2. For comparison of nest numbers per sample area between 1979 and 1981, study plots at the eastern transect side were sampled again in 1981. Table 1. Measurements of nest vegetation and eggs Nest measurements: nest vegetation: height (cm) density surrounding index (% cover of the nestplace) vegetation (degrees) (/height/max height + density/ max density + vegetation stand/ max vegetation stand/ : 3) egg: length breadth volume index shape index (mm) (mm) o 2 (mnr; breath x length) (breadth x 100/length) a) X nest b) longest egg/nest Nesting areas Fig. 1. The studied bre- J transect and sample areas eding colony of Herring Gulls on the Wadden Sea island Mellum with line 1206 RESULTS 1. Most Herring Gulls selected nest places with vegetation of 20-60 cm height, not covered by plants (only 0-10%) and with 40-90% of the nest cir¬ cumference surrounded by vegetation (Pig. 4). 2. Nest number per study plot was positively correlated with the vegetat¬ ion measurements (Pig. 5 ). With greater height of nest vegetation the number of breeding pairs decreased. 3. The distribution of mean values of nest vegetation and, eggs is shown in table 2. In "Zwischensand", which is occasionally flooded, and the northern part of the "North dune", we found nests in sparse vegetation, greater egg dimensions and lower breeding pair density. 4. Egg length and volume decreased with vegetation height and index, egg length also with surrounding vegetation (Table 3). The shape-index was positively correlated with surrounding vegetation and index. 5. Looking at the means of sample areas (Table 4), egg length, breadth and volume were negatively correlated with nest vegetation measurements (except x egg breadth/density and surrounding vegetation). Two of these relations are plotted in Fig. 2-3. • 6. In sample areas 3-9, the former colony center, and area 1 6 , descreases in breeding pair numbers occurred from 1979-1981 (x/year about - 16%). In areas 1 , 22-23, however, where new breeding places originate from formation of dunes, we found increasing pair density (x/year about +29%). mm egg Length mm egg volume 76 75 71 7t Z05 ~ ZOO - 195 ~ 190 ~ 165 ~ ■ • « ISO - . • 175 - * . • 170 — • 70 165 - LLjlJ _ I _ I I I I I H _ I _ U - 1 - 1 - 1 - 1 - 1 - 1 - L* — I - 1 — 20 25 30 35 HO 15 50 55 60 65 cm 20 25 30 35 HO H5 50 55 60 65 mm vegetation height P i g s. 2, 3. Mean egg length ’and volume in relation to vegetation height at the nest (n = 50 areas) 1207 Table 2. Mean values of nest measurements per ha (2-3 sample areas' and greater than the median are underlined sample area 1 2 3 4 5 6 7 8 9 10 nest Per ha 58 80 96 66 108 128 98 68 104 84 number change, % * (79-81) +80 -60 -41 -33 -27 -24 + 16 -36 height (cm) 54 52 61 59 56 54 51 51 45 39 nes1: density(%) 15 12 30 29 12 12 12 10 9 12 vege- tation surround" ing vege- tation(°) 204 219 265 273 262 236 235 249 221 241 length 71.9 71,8 71,1 71 ,6 71,1 71,3 71 ,2 71,6 71 ,2 72,2 breadth 49,2 48,9 49,1 48,3 48,9 49,1 49,0 48,8 49,1 49,3 egg volume 178 172 171 167 171 172 171 171 172 177 shape index 69,3 68,2 69,1 67,5 68,9 68,9 68,9 68,3 69,1 68,4 n nests measured 29 40 48 33 54 64 49 34 52 63 Table 3« Spearman correlation coefficients of egg and nest vegetation 4* ^ ^ maeasurements (n = 790) p-values 0.05, ^ 0.01, ^ 0.001. First value: x of eggs, nest, second value: longest egg/nest ^''-'--jregetation egg height density surrounding vegetation index ** -0.11 -0.07 ** -0.10 *** -0.12 length ** -0.05 * * 1 o o o • o i -0.11 -0.05 -0.03 -0.14 -0.03 breadth -0.03 -0.01 -0.03 -0.01 -0. 09* -0.05 -0.03 -0.07* volume -0. 08* -0.03 -0.02 -0.06 0.06 0.04 ** 0.09 0.08 shape index 0.07 0.04 * * 0.10 0.08* 1208 changes in breeding pair numbers from 1979 to 1981. Values 11 12 13 14 15 16 17 18 19 20 21 22 23 59 44 19 6 14 25 16 14 39 96 122 49 20 -43 + 48 +113 34 22 24 23 29 23 21 24 31 33 36 34 31 9 1 3 0 0 1 0 4 3 5 8 6 1 187 143 153 197 167 159 132 154 195 191 188 135 1 68 72,0 72,1 72,2 69,1 73,2 72,8 72,4 72,7 72,7 72,0 71,9 71 ,7 72,1 49,6 49,3 49,4 49 ,.5 49,7 49,1 49,7 50,1 49,7 49,3 49,2 48,8 49,9 177 175 177 170 181 176 179 183 180 175 174 171 180 68,9 68,4 68, 6 71,7 67,9 67,4 68,7 69,1 68,4 68,6 68,5 68,1 69,3 44 33 14 3 7 19 12 7 29 48 61 37 10 Table 4. Spearman correlation coefficients of egg and nest vegetation means per sample area (n = 50; p-values, first and second value as in Table 3)* See also Pig. 2, 3 '\j£egetation egg height density surrounding vegetation index - - ^ X — 4<:4n|c -0. 47 -0.34* -0.34 -0.44 length -0.46*** -032* -0.34* ** -0.43 -0. 34* -0.23 -0.20 -0. 28* breadth -0.35* -0.31* -0.27 -0.31 ** *** -0.47 * -0.33 -0.35 -0.43 volume ** -0. 45 -0.36 -0.38 -0.43** 0.14 0. 18 0.14 ,0.18 shape index 0.12 0.02 0.06 0.11 1209 ne$ts -P 0 CD CD X ! ■P cd -p cd -p V O cd +» 03 60 C •H TJ □ P O U 03 § O V -p X3 if CD XJ «P cd ■p CD bO CD ? •P 03 CD a V o 03 CD p H cd > a as ■ I «H 0) □ 0 TJ +5 x5 60 -H 0 Xl o -p a o •H -P as r— I 0 a •H O lA 0 •H •3 V V 0 O ü a o •P aS H 0 O O . ä /-“N d) 0 CL ^ CO 0 0 u 1210 0 u 0 0 /"N > o i — C Qi 5 B • 0 0 O -p 0 0 \ V 0 0 Qj □ •P 0 Vl 0 □ O a O •H Vi ■P o o 0 a •P 0 U 0 P 0 60 cf X3 0 0 B > U 3 Is a • • •H 0* LA TJ a • • 3 60 60 o n •H •H a pcj , r=- p m DISCUSSION We can explain these results by age related differences in egg size. In larids first breeders have smaller eggs; the size of old females’ eggs of many bird species becomes smaller again. Unfortunately, we have only some suggestions for this in larids. Herring Gulls show fidelity to their nest site, which is characterized by growing vegetation over years on Wadden Sea islands. Therefore older pairs with smaller eggs may breed in nesting areas with higher and denser plant cover (area 3-9, the former colony center). The earliest time ”Zwi- schensand" could be colonized by presumably younger birds was about 10 years ago. Now these birds being mature occupy the small number of possible nest places. This is why we find on an average bigger eggs in these areas. Birds breeding for the first time, but also resettling birds, will prefer optimal breeding areas, great nesting density and the edge of the colony for breeding (areas 1, 2, 21-23). Therefore we found reduced means of egg size in such regions. SUMMARY About 10,500 Herring Gulls pairs (Parus argentatus) are breeding on the i/adden Sea Island Mellum, PRG Due to formation of dunes and chan¬ ges in vegetation the population is expanding and increasing during the last years. Data from Herring Gull nests were collected in 1979/80 on 50x50 m sample areas placed along a line transect, running through the typical zones of nest density and vegetation. Nest sites in high or low vegetation are avoided by the Herring Gulls. There is a decrease in nest numbers in areas with high vegetation within a period of two years. Egg size (length, breadth, volume) is negatively correlated with vegetat¬ ion-height and -density at the nest. We explain this by the age of breeding females, nest site tenacity and nest site choice. SIC. OWORflLJ DE FSANäE 1 - feil ; ( BIBLIOTHÈQUE ! , i'OK\î i - ’ " y 'V.r,-;- i CHARACTERISTICS OP SOME BIRD SPECIES MIGRATIONS ACCORDING TO THE RINGING DATA I. N. Dobrynina Ringing Centre of the Institute of Evolutionary Morphology and Ecology of Animals of the Academy of Scienc.es of the USSR, Moscow, USSR The great part of peculiarities of the seasonal distribution, ways of migration and wintering places of the birds from different populations be¬ comes clear due to the investigation of the repeated recoveries of the ringed birds as a result of ringing and marking of birds. In this paper some pecu¬ liarities of migration of 5 bird species of different orders and type of mig¬ rations are examined: Goldeneye (Bucephala clangula). Lapwing (Vanellus vanel- lus) . Robin (Erithacua rubecula). Great Tit (Parus ma.lor), Brambling (Frln- gilla montif ringilla) . MATERIAL AND METHODS The repeated recoveries of the ringed birds of both sexes and different age have laid down the foundations for the present work. 175 recoveries of Bucephala clangula. 256 of Vanellus vanellus. 105 of Erithacus rubecula. 236 Parus major and 313 of Fringilla montif ringilla were used for the work. The recoveries of birds ringed in the USSR and found both on the territory of the USSR and abroad as well as the recoveries of birds ringed overseas and found in the USSR were used for the work, RESULTS Bucephala clangula. The goldeneye ringed in the Murmansk region (mainly in the Lapland and in the Kandalaksha Reserves) have two migratory routes (Fig. 1). In autumn some of the birds fly along the western seashore of the Baltic Sea and spend winter mainly in Denmark, others fly along the eastern shore of the Baltic Sea and winter either in south-western or western Europe, or in southern and south-western regions of the USSR European part. The ringing of the goldeneye in the Arhangelskaya, Kalininskaya, Vologod- skaya and Leningradskaya regions of the USSR has indicated that birds from these regions winter mainly in central and southern Europe and in the south¬ western districts of the USSR. More northern populations of birds winter more northwards than the southern ones. The ringing of the goldeneye in more eastern districts of the USSR (Komi ASSR, the Chelyabinskaya region) has shown more eastern areas of their wint¬ ering sites: in south-western and southern districts of the USSR. The chief directions of the goldeneye's migration is south-west and south¬ wards. Speed of their autumn flight is up to 80 km per day. Vanellus vanellus (Fig. 2). The lapwing banded in the Leningradskaya regi¬ on, in Estonian, Latvian and Lithuanian SSR and in the Okski Reserve in the Ryazanskaya region spend winter in Holland, Belgium, northern parts of Italy, in Spain andin the North of Africa (in Algiers, Morroco), though most of them winter in the western parts of France. 1212 o*£r^o» g ♦ 1214 The lapwings marked in England when on route in autumn and spring were later seen in western and central regions of the USSR European part and even in the Tyumen region. Birds marked in the Scandinavian countries are mostly observed in north-western districts of the USSR European part; some - in the central districts of the USSR European part, part of them in the central districts of the USSR European part and even in the Novosibirsk region. The lapwings banded on their wintering sites in Holland, Belgium, Prance and Italy and while en route in spring and autumn over GDR , FRG, Hungary were then observed mostly in western, northern and central districts of the USSR European part as well as in the Kazahskay SSR and Siberia including the Tymenskaya, Tomskaya regions and the Krasnoyarsky district. The farthest recoveries are from Holland and Belgium and less distant recoveries are from Prance and Italy. In spring the lapwings coming back to their nesting sites might take dif¬ ferent routes, their finding themselves either in Scandinavian countries or in south-western districts of the USSR. Erithacus rubecula (Pig. 3). The robins banded in the north-western dist¬ ricts of the USSR European part are seen on the territory of Poland, GDR, PRG, Holland, Belgium, but most of the recoveries of wintering banded birds are from southern Prance, central Italy, Corsica, Sardinia and Spain. In reality there are no differences in the territorial distribution of recover¬ ies from various areas though there was observed a tendency for the robins marked in Latvia and the Kaliningradskaya region to winter somewhat more southwards as compared to birds banded in other localities. Part of the robins winter in northern Africa (Morocco, Algiers, Tunis) and Turkey. The wintering sites of adult birds as a rule are situated in more northern dist¬ ricts than those of the young birds. There is evidence to the fact that robins in different years in autumn might fly along different sides of the Baltic Sea (either through the USSR or through Sweden), they might radically change the routes and wintering sites. Parus major (Pig. 4). Wide ringing of the Great Tit in the USSR shows that these birds are not only resident or travelling short distances but that they fly considerable distances espectally when they are young. The great tits marked in the Karelian ASSR, Leningradskaya, Pskovskaya regions and in the Estonian SSR were seen en route and in winter in Finland, Poland, GDR, Holland, Belgium and in the north of France. The birds banded in the Lithuanian and Beylorussian SSR reach central and southern districts of Prance and Portugal which means that the more northern populations of the grsat tit winter more northwards than the southern ones. Mean speed of the great tit is about 20 km per day. Fringilla montifringilla (Pig. 5). Bramblings ringed in the Murmanskaya region (the Lapland and Kandalaksha Reserves), the Leningradskaya, Pskov¬ skaya regions, the Latvian and Lithuanian SSR in most cases take the Italo- Spanish migratory route south-south-westwards to northern Italy, southern Prance and Spain. The bramblings marked in the Kaliningradksaya region have two migratory routes. Some, mostly adult birds, take the so-called seashore route, west- 1215 south-westwards across the northern and central parts of the GDR, FRG, Hol¬ land and Belgium. Others, mostly young birds, fly the Italian-Spanish route. Later on these birds might spread into the central and southern France. Then, closer to spring time they more over to Switzerland, FRG, Czechoslovakia and 1216 P i g. 4. Parus major. Places of ringing birds and meeting places of ringed birds 1 - Places of ringing the great tit in Karelian SSR, the Lenin- gradskaya, Pskovskaya regions and in the Estonian SSR. 2 - Meeting places of birds ringed in Karelia, the Leningradskaya and Pskovskaya regions and in Estonia. 3 - Places of ringing birds in the Latvian SSR and the Kalinin- gradskaya region. 4 - Meeting places of birds ringed in Latvia and Kaliningradskaya region. 5 - Places of ringing birds in the Lithuanian and Beylorussian SSR. 6 - Meeting places of birds ringed in the Lithuanian and Beylo- ruosian SSR. 7-9 -Direct recoveries 41.3aK.981 1217 P i g. 5. montlfrlngilla. Places of ringing the brambling and meeting places of banded birds 1 - Place of ringing the brambling in the Kaliningradskaya region (Rybachii). 2- Meeting places of birds ringed in Rybachii. 3 - Places of ringing the brambling in the other districts of north-western USSR European part. .4- Meeting places of birds ringed in the other districts of north-western USSR European part 1218 Poland. Bramblings which spend winter in the weste™ Europe might change their routes and wintering sites in various years. Mean speed of bramblings- autumn migration is 45-50 km per day. SUMMARY The paper deals with the results of recoveries received by the Center of Ringing of Birds. The species were those ringed on a mass scale; they were; Bucephala clangula (Anserif ormes) , Vanellus vanellus (Charadriif ormes ) ; Erithacus ribecula, Parus major. Frlngilla mont.ifringllla (Passeriformes). All the examined species marked in the north-west regions of the USSR European region winter in central and south-west countries of Western Europe some of them - as far as Spain (the lapwing, the robin, the brambling), Por¬ tugal and countries of Northern Africa (the lapwing, the robin). Birds which are marked in more eastern regions of the USSR winter mainly in south-western and southern parts of the USSR European part. Birds marked in more southern areas, spend winter more southwards than those marked in more northern districts. In all species individuals of both sexes migrate simultaneously and winter in the same localities. In all species we observed young birds winter more southwards than adult ones. All bird species which have fixed migrator routes, wintering and nesting sites might change them depending on age, weather conditions and other reasons. Different populations of birds might have the same or different migratory routes, wintering and nesting areas. For instance, the goldeneye of the Murmansk region (USSR) in winter flies along either the westera or the eastern shore of the Baltic Sea. The lapwings might fly back to their nesting sites by different routes coming either to the Scandinavian count¬ ries or to the north-western districts of the USSR. Robins might also fly along different sides of the Baltic Sea, changing their flying routes and wintering sites. Bramblings from more southern areas of the north-west dist¬ rict of the UoSR (the Kaliningrad district) have two migratory routes. Some of them, mostly adult birds, take the seashore migratory route west-south¬ west bound. Year in, year out bramblings wintering in western Europe might also change routes and wintering sites. 1219 ENERGY OP EXISTENCE AT 0° AND 30° AND BASAL METABOLISM OP INSECTIVOROUS AND GRANIVOROUS PASSERIFORMES: THEIR SEASONAL CHANGE AND DEPENDENCE ON BODY MASS V.M. Gavrilov Department of Vertebrate Zoology of Moscow State University, Moscow, USSR The present paper is concerned with energy requirements of Passeriformes consuming different kinds of food, i.e. granivorous and insectivorous. Ana¬ lysis is performed of different parameters of their bioenergetics: energy of existence at different ambient temperatures and basal metabolism. Not only species differences are analyzed but also those between groups of species forming a particular size series. Analysis is aimed at revealing the relat¬ ionship between metabolic rate and body mass described in a general form as a power function M = ain where M, metabolic rate index, m, body mass; a sets the elevation of regression line, and b, its slope. All the regression equat¬ ions are calculated using the method of least squares. MATERIAL AND METHOD 52 passerine species mostly captured at the Kurische Nehrung (the Baltic Sea) were used. All the birds were maintained in open-air cages from 1 to 4 weeks prior to the beginning of experiments, in which they were exposed to ambient temperatures and photoperiod characteristic of the given site.. Tro¬ pical, subtropical and warm zone wintering birds (i.e. migrating to warm zones from October to May) were maintained at 12-22°C. In winter (from Decem¬ ber to February) only non-moulting birds were used in experiments; in spring wild birds were measured in late April - early May, i.e. towards the end of or at the end of migration to the north. In summer measurements were made in late June - early July, i.e. between the termination of breeding and initiat¬ ion of moult. Fringillidae and Proceidae were used in experiments during moult and breeding -free periods in summer and in winter. Both winter and summer measurements were made only for part of the species under study. Oxygen consumption was measured in fasting birds during the night. Large birds were made to fast beginning at noon; the smaller ones - 3-4 hours be¬ fore dark. Each bird was put into a small cage and subsequently into an acryl plastic chamber in the dark. The chambers varied in size from 3 to 1 depend¬ ing on the bird size. The air flow through the chamber was regulated, and, following stabilization of the temperature, switched to the recording in¬ struments. Actual measurements of oxygen consumption were started 2-3 hours after dark and completed 1-2 hours before dawn. Each experiment lasted from 1 to 4 hours. The rate of basal metabolism was determined as a mean value ob- tainted for the zone of thermoneutrality (l crn^Og = 20.1 J). Energy of existence was measured at 3-6 different ambient temperatures, mostly from 0° to 30°, occasionally - up to -10° (in winter). Small birds were maintained in 40X30X25 cm cages, medium size birds - in 150X75X75 cm cages. A single experiment lasted 3-4 days and occasionally daily experi¬ ments were performed (if during that time the weight of the experi¬ mental birds did not change). The birds were weighed early in the morning 1220 (before dawn), at the beginning and at the end of measurements. If body weight changes were insignificant, corrections were made, using the calorific equivalent of body weight change 25.122 kj/g (Dolnik, Gavrilov, 1971). if body weight changes were considerable, these data were neglected. The insec- tivorous birds were fed with boiled homogenized hen eggs, which were thinly sliced (25.75 kj/g of dry mass) and flour worms; granivorous birds were given various seeds, mostly of cultivated plants. RESULTS AND DISCUSSION Basal metabolism was measured in relation to oxygen consumption rate after a nef period of fasting. Food àssimilation did not take place, and the ma¬ jor source of energy was fat oxidation. This is indicated by the low respi¬ ration coefficient. The understanding of how basal metabolism is changed in birds consuming different kinds of food is the groundwork on which are based energy requirements for all other types of activity, nomal existence including. Our measurements of the level of basal metabolism in all the 52 passerine species under study separately for two seasons (winter and summer) are pre¬ sented in Tables 1,2, Figl. In species, for which data are available both for winter and. summer, basal metabolism is largely higher in winter than in sum¬ mer. This is mostly characteristic of granivorous birds. An increase in basal metabolism in winter is one of the major adaptations to climate seasonality Gavrilov, 1979, 1980a, b, 1982). These adaptations are naturally more pro¬ nounced in northern birds, which invariably include more granivorous species. The scanty data on respiration coefficient available indicate that it is practically similar within a single season in all the species under study. In winter it is somewhat lower than in summer. This is indicative of a great¬ er proportion of fats utilized at that period. The energy of existence (EM) is the rate of metabolism at which energy is utilized by cage birds retaining a constant body weight during a certain period free of productive processes, e.g. moult, migration agitation, growth or fat storage. Species, for which data are available for both winter and summer seasons, display energy of existence which is higher both at 0° and 30°C in summer. This is explained by the fact that the total amount of met¬ abolized food is larger under a longer summer photoperiod (Table 1, 2,Fig.1), on the one hand, and as to the 30° value, it is accounted for by a decline in heat conductivity of the integuments. The energy of the 3ame avian species at the same body temperature varies with diet (species were tested which consume both animal and grain foods) (Table 3). On grain diet food consumption increases both in summer and in winter, the summer increase being greater compared with winter. This is ac¬ counted for by the fact that utilization coefficient for different foods varies seasonally. The birds under study normally turn to feeding on insects in summer (except the nutcracker); hence, feeding on grain diet decreases iheir coefficient of food utilization. Nevertheless, feeding on grain diet Provides more energy, and this additional energy must be dissipated. The relationship between bioenérgetic indices and body mass (Table 4, ■^ig. 2) - data on Estrildinae are excluded from the equations - is indi cat- 1221 T 'a b 1 e 1. Summer measurements of bioenergetic parameters in passerine birds Species Body mass, g Mqo h 30° MR Fhylloscopus sibilatrix 7.6 57.8 1.14 23.5 15.1 Estrilda troglodytes 7.7 67.0 1.48 22.6 13.0 Tiaris canora 7.8 67.4 1.44 24.3 13.4 Aegithalos caudatus 8.8 62.0 1.22 25.4 17.2 Troglodytes troglodytes 9.0 62.4 1.1,8 26.8 18.4 Uraeginthus bengalis 9.2 66. 0 1.35 26.8 13.4 Parus ater 9.7 65.3 1.23 28.4 20.5 Phylloscopus trochilus 9.8 68.2 1.59 20.5 18.0 Lonchura striata 10.3 71.6 1.37 30.5 17.2 Sylvia curruca 10.3 68.2 1.24 30.9 17.2 Parus palustris 11.1 67.8 1.17 32.7 19.0 Acrocephalus schoenobenus 11.5 72.8 1.34 32.7 18.8 Spinus spinus 12.0 68.7 1.10 35.8 25.1 Serinus canaria 12.8 70.6 1.34 30.5 18.0 Acanthi s flammea 13.5 71.2 1.05 39.5 24.7 Phoenicurus ochruros 14.0 77.9 1.37 36.8 20.9 Erithacus nubecula 14.0 78.7 1.45 33.1 26.0 Hippolais icterina 14.1 80.4 , 1.45 36.8 21.8 Motacilla flava 15.4 81.6 1.38 40.2 22.2 Saxicola rubetra 15.7 82.9 1.39 41.1 20.9 Anthus pratensis 17.5 89.6 1.59 41.9 26.0 Motacilla alba 18.0 87.1 1.43 44.1 26.0 Sylvia atricapilla 20.0 97.1 1.75 44.8- 33.0 Sylvia nisoria 20.6 101.3 1.81 46.9 33.1 Carpodacus erythrinus 21.0 110.5 1.75 58.2 31.8 Passer d. bactrianus 22.2 110.1 1.77 57.0 31.8 Passer domesticus 25.0 103.4 1.31 64.2 41.0 Lanuis collurio 25.3 101.3 1.39 59.5 33.1 Chloris chloris 26.5 108.0 1.37 66.9 41.0 Emberiza hortulana 26.5 114.7 1.74 62.6 36.0 Emberiza citrinella 27.1 112.6 1.73 60.7 37.7 Loxia curvirostra 44.7 135.6 1.39 93.8 51.9 Oriolus oriolus 65.1 169.1 2.22 102.6 56.1 Turdus philomelos 80.0 218.1 2.92 130.6 62.8 Turdus merula 83.0 193.9 1.93 135.8 80.4 1222 Table 2. Winter measurements of bioenergetic parameters in passerine birds Species Body mass, g EMR^ h BMR Aegithalos caudatus 8.8 60.7 1.09 28.1 21.8 Troglodytes troglodytes 9.0 58.6 0.96 29.7 20.9 Parus ater 9.7 62.0 1.05 36.6 23.4 Phylloscopus trochilus 9.8 66.1 1.23 29.4 18.0 Ficedula hypoleuca 11.2 70.3 1.30 31.3 20.1 Phoeniourus phoenicurus 11.6 69.1 1.18 33-5 20. 1 Spinus spinus 12.0 66.6 0.99 36.8 28.5 Serinus canaria 12.2 70.3 1.05 38.9 19.7 Acanthis flammea 13.5 67.4 1.00 37.3 29.3 Erithacus rubecula 14.0 76.2 1.34 36.0 24.3 Acanthis cannabina 14.5 79.5 1.34 39.4 29.3 Carduelis cardueli-s 15.9 78.7 1.18 43.2 30.1 Motacilla alba 18.0 82.1 1.36 41.4 24.3 Emberiza schoeniclus 18.2 87.1 1.39 45.3 26.0 Luscinia svecica 18.2 90.4 1.59 42.7 31.0 Fringilla montifringilla 21.0 94.6 1.37 53.5 33.1 Carpodacus eiythrinus 21.0 98.4 1.60 50.3 31.0 Sylvia borin 22.0 95.9 1.45 52.3 36.0 Passer d. bactrianus 22.2 96.7 1.56 49.9 31.8 Passer domesticus 25.0 98.8 1.14 64.5 42.3 Passer montanus 22.5 97.1 1.56 50.3 Anthus campestris 23. 1 101.3 1.59 53.6 Anthus trivialis 23.2 104.3 1.79 50.6 29.3 Chloris chloris 26.5 98.4 . 1.29 59.7 48.1 Emberiza hortulana 26.5 107.2 1.59 59.5 35.2 Emberiza citrinella 27.1 101.7 1.30 62.7 43.1 Pyrrhula pyrrhula 30.4 110.1 1.56 63. 6 47.7 Loxia curvirostra 44.7 128.1 1.24 90.8 58.2 Coccothraustes coccothraustes 48.2 141.9 1.64 92.6 60.3 Loxia pytiopsittacus 53.4 138.2 1.16 103.4 69.1 Turdus iliacus 57.0 157.0 2.09 94.2 62.4 Lanius exoubitor 71.3 177.1 2.27 108.9 70.3 Stumus vulgaris 78.0 179.2 2.05 117.6 77.5 Turdus philomelos 80.0 187.2 2.55 110.5 65.3 Turdus merula 83.0 180.9 1.91 123.5 89.6 Turdus viscivorus 112.0 223.6 2.52 147.8 95.5 1223 5 a 10 20 50 181b ucaIa) v*«isy 0 /0 20 J(7 1224 Pig. 1. Relation existence energy (ordinata, kJ bird-1 day“^)to ambient temperatures (abscissa,?^, °C) in summer in passerine birds 1 - Phylloscopus sibilatrix. 19 - Motacilla alba 2 - Estrilda troglodytes 20 - Saxicola rubetra 3 - Tiaris canora 21 - Anthus pratensis 4 - Aegithalos caudatus 22 - Motacilla alba 5 - Troglodytes troglodytes 23 - Sylvia atricapilla 6 - Uraeginthus bengalis 24 - Sylvia nisoria 7 - Parus ater 25 - Carpodacus erythrinus 8 - Phylloscopus trochilus 26 - Passer d. bactrianus 9. - Lonchura striata 27 - Passer domesticus 10 - Sylvia curruca 28 - Lanius collurio 11 - Parus palustris 29 - Chloris chloris 12 - Acrocephalus schoenobenus 30 - Emberiza hortulana 13 - Spinus spinus 31 - Emberiza citrinella H - Serinus canaria 32 - Loxia curvirostra 15 - Acanthis flammea 33 - Oriolus oriolus 16 - Phoenicurus ochruros 34 - Turdus philomelos 17 - Erithacus rubecula 35 - Turdus merula 18 - Hippolais icterina 1225 Table 3. Gross energy in three species at different diets Species Winter Summer grain egg grain egg Parus major 60.3 54.0 77.5 62.4 Fringilla coelebs 76.2 62.8 97.1 67.8 Nucifraga caryocatactes 238.2 244.1 309.8 Table 4. Relation of bioenergetic parameters to body mass (m) Summer EMRqq, kJ bird”1 day-1 EMR30o, kJ bird”1 day”1 BMR, kJ bird 'day V/ inter EMBRqq, kJ bird"1 day”1 MR30o» kJ bird”1 day”1 J -1 -1 BMR, kJ bird day Granivorous Insectivorous n=9, lim n=12.0-44.7 g n=20, lim m«7. 6-83.0 g 18. 6 m 6. 1 m 0.5434 .0.7221 19.6 m' 0.5268 5.5 m ,0.5899 5. 6m 4. 2 m ,0.7122 0.6358 n=18, lim m=12.0-53.4 g n=18, lim m=8. 8-112.0 g 20.5 m 6. 3 m’ 0.4912 20.1 m ,0.5074 .0.6916 6.7 m ,0.6528 4.3 m .0.6853 4.8 m ,0.6234 ive of the fact that the same values at different seasons.(existence energy at 0°C and 30°C; basal metabolism and heat conductivity under normal conditions) are characterized by a specific inderdependence between these indices and body mass both in granivorous and insectivorous. During the other seasons this interdependence changes. Basal metabolism in insectivorus birds is lower than in granivorous, es¬ pecially in summer (Table 4, Fig. 2). Energy of existence at 30°C is also higher in granivorous birds (Table 4, Fig. 2) , its relationship with basal metabolism being similar in granivorous and insectivorous passerines, but varies seasonally. In summer the energy of existence at 30°C is 1.66 times as high as that of basal metabolism rate both in insectivorous and grani¬ vorous, and in winter 1.51 and 1.53 times, respectively. The energy of existence at 30°C in winter is practically similar in in¬ sectivorous and granivorous birds, but in summer it is higher in insecti¬ vorous species, suggesting that cold conditions are much less favourable for insectivorous birds, especially in summer. If basal metabolism is a peculiar measure of power(Benett, Ruben, 1979) and the general amount of energy expended invariably increases proportionat¬ ely to the basal, and by an equal number of times, these data indicate that granivorous species have greater existence power, and under cold conditions have a greater safety margin. 1226 F i g. 2. Relation between existence energy at 30 (ordinata, kJ bird-1day-1) to body mass in winter (above) and summer (lower) in insectivorous (white ctrcles) and granivorous (dark circles) passerines birds Energy requirements of a granivorous passerine for existence, as well as various types of activity, are greater in comparison with an insectivorous one. Consequently, granivorous birds consume a disproportionally large amount of food and exert an appreciably greater impact on lower trophic le¬ vels compared with other organisms of similar size (the metabolic rate of passerines is higher than in all other animals) . Thus, there is a reason to believe that adjustment to granivory provides passerines with a greater energy flow and they have a good deal of power, which can be additionally enhanced, for other types of activity and thermo¬ regulation under a cold stress. Granivory is an ecological niche with a great energy flow. References Benett A.F. , Ruben J.A. - Science, 1 979, 206. N 4419. Dolnik V.R. , Gavrilov V.M. - In: Ecologitcheskie i fisiologitcheskie aspekty pereletov ptits. Leningrad, Nauka, 1971, p. 226-235. Gavrilov V.M. - Zool. Zum. , 1979, 58, N 4, 5, p. 530-541 , 693-704. Gavrilov V.M. - In: Ecologia, geographia i okhrana ptits. Leningrad, 1980a, p. 73-97. Gavrilov V.M. - Omitologia, 1980, N 15, Moscow, p. 208-210. Gavrilov V.M. - Omitologia, 1982, N 17. 1227 ON STRUCTURE OP BLACK-HEADED GULLS (LARUS RIDIBUNDUS) COLONIES S.P. Kharitonov Institute o f Evolutionary Morphology and Ecology of Animals of the USSR Academy of Sciences, Moscow, USSR It was studied the way of some black-headed gulls shift their territories inside the colony during a breeding season. In the very beginning of the seasons of 1980 and 1981 106 and 112 gulls were stained with different co¬ lours and wing-tagged at the same time. These marked birds resettlements were observed. In 1982 300 gulls that had been wing-tagged in previous years were observed. Prom 30 to 71 per sent of the gulls which territories were in peripheral or in pericentral parts made attempts to resettle and occupy a territory in the centre. On the average 23% of the gulls managed to do it. Some of the abandoned places were occupied by the new arrivals, some remained vacant. Thus, throughout a breeding season these is a pronounced centripetal stream of the resettling individuals in the colony of black-headed gulls (Pig. 1, 2). On the average 7% of gulls resettled from the centre to pericentre. In 1982 isolated cases of resettlements from the centre to peripheral parts were observed. Thus, a centripetal stream is much more expressed than a cent¬ rifugal one. The latter may possibly be explained by a strong competition. in gaining territories in the centre of colony. The observations were carried out in the colony of black-headed gulls on the Kiyovo lake (Moscow region) in the springs of 1980, 1981 and 1982. The colony had: 1980 - 15400 breeding pairs, 1981 - 15000 b.p. and 1982 - 16500 breeding pairs, rne functional centre, the pericentre and the peripheral I960 1981 198Z ' 1 e: ’• sc“*~ ^ served resettlements (arrows) in seasons of 1980, 1981 and 1982 1 — centre; 2 — pericentre« 3—9 , .37- peripheral parts and edge of the colony 1228 Pig. 2. Scheme of the Black-Headed Gulls colony and directions of their re¬ settlements inside the colony throughout a breeding season. The arrows thick¬ ness reflects the number of resettlements parts of this colony have been separated from one another spatially and si¬ tuated on different floating mats. The first gulls that arrive from their wintering grounds always settle in the future centre of the colony. Then all the colony area becomes occupied in 2-3 days, but the density of gulls po¬ pulation is low. -Further on the density is increasing since the new arrivals intrude into the colony. The number of intrusions to occupy some territory increases from the edges to the centre of the colony (/> 2=46. 9/S; n=28; f=30. 2; p < 0.001; see Table). The number of intruders in a twenty chosen gulls flying over the different parts of the colony Date of the observation The number of intruders over the centre over the pericentral parts over the peripheral parts 10.4.80 3 not counted 1 11.4:80 3 1 2 12.4.80 5 4 1 16.4.80 3 • 4 1 21.4.80 9 4 3 26.4.80 10 9 4 27.4.80 9 6 2 27.4.79 9 not counted 1 29.4.80 10 2 0 1.5.80 10 3 0 1229 SOUND IMITATION IN THE FORMATION OF COMMUNICATION BETWEEN MAN AND BIRDS 0. B. Silajewa Institute of Evolutionary Morphology and Ecology of Animals of the USSR Academy of Sciences, Moscow, USSR Folk and onomatopoeic names of birds. The method of biolinguistic inter¬ lingual parallelisms (Dementiev, IlyJLchev, 1963) was used to study the folk names of 8 species of birds based on sound imitation in 10-40 Indo-European, Finno-Ugric and Turkic languages. The diachronous formation of onomatopoeic names based on the first imitat¬ ing reflexes of man is a part of the process, of losing environmental sounds by man to form his own accoustic behavior (music, sound imitating names, inter- jectory vocabulary of communication with animals). As a result of acoustic comparison of onomatopoeic names and their corre- lates in the signalization of birds by means of sound analysing instruments it was found that: 1. In a onomatopoeic name consisting of three syllables the initial fre¬ quency maximums are approximately in the same ranges as in birds' call. 2. The intervals between the syllables in a bird’s call correspond to those of the name uttered by man. 3* The amplitude characteristics of a bird's oall also correspond to those of a "human" signal. 4. The initial and terminal energetic maximums are traiïsfered from a bird's voice into an onomatopoeic name. Ecologo-acoustlc studies suggested that in most cases the imitation of contact calls of birds served as a basis for the formation of onomatopoeic names. A biolinguistic comparison of Russian and Bashkir folk names of birds as well as ecological analysis of onomatopoeic names of the Bashkir language showed that: 1. Of 235 species of birds in the fauna of the Bashkir ASSR and the South Urals 113 names are associated with birds' voices, moreover, the names of 84 species are only onomatopoeic without non-onomatopoeic synonims. Some species have from 2 to 7 onomatopoeic synonims. 2. The principle of nominating a species by voice- in Russian and Bashkir names coincides for 37 species (30%). Ten biolinguistic parallelisms were found among them. 3. The greatest number of onomatopoeic names in the Bashkir language is found among water fowl (45%), forest and bush birds come next and then the names of open space birds. Predators account for the smallest number of onomatopoeic names in the Bashkir language (the names of only 5 species of 25 are onomatopoeic). 4. The ecologically related character in the nomination of birds is es¬ pecially pronounced in the Bashkir language. The attracting call of Cuculus canorus and its species name in Russian "kukushka" (cockoo) were analyzed. 1230 Man-bird bioacoustic contacts. Attracting and repellent signals based on onomatopoeia which had appeared during domestication of wild animals were ascertained. These signals gradually enriched the vocabulary of various lan¬ guages. The similarity of such lexical attractants and repellents transform¬ ed by man was noted in the languages of various linguistic groups. Biolinguistic analysis was used to ascertain interlingual parallelisms (in 9 languages) of the most ancient lexical repellent "kysh" (Russian) , "ksch" (German). Its role as a conglomerate of defense signals not only of birds but also of other animals was shown. The role of acoustic communication based on sound imitation between man and birds ("speaking" in particular) was evaluated in the creation of sig¬ nal-orienting medium necessary for ethological comfort of caged birds. The ability of birds to imitate human speech is regarded as an effective means for controlling the behavior of birds. The bird's voice foiroed on the basic of nature acoustic medium partici¬ pates it self in the formation of the acoustic medium of the man. Scheme shows the interinfluence between the bird's voice and the acoustic medium (nature sounds and sounds of humen origin): Noises of inanimate nature and vegetation Sounds connected with human activi¬ ties Human speech and music Imitation by human voice I Imitation by human voice and/or decoy-device Acoustic repellents bird's voice Onomatopoeic names Animals and birds voices Onomatopoeic melodies for the voice I Onomatopoeic melodies for musical instruments I References Dementiev G.P., Ilyichev V.D. - Ornithologia , 1963, N 6, p. 401-407. Ilyichev V.D. , Silajewa O.L. , Tikhonov A.V. - Omitologia, 1983, N 18, p. 156-162. Ilyichev V.D., Silajewa 0. - In: Zvukovaya sreda kak stimuliruyusthyi i vozdeistvuyustchyi faktor. Moscow, 1985, p. 217-226. Ishberdin E.F., Silajewa O.L. - In: Zvukovaya sreda kak stimuliruyustchyi i vozdeistvuyustchyi faktor. Moscow, 1985, p. 226-236. Silajewa O.L. - Ornitologia, 1981, N 16, p. 183-185. Silajewa O.L. - Der Falke, 1981, H. 12, S. 408-413. Silajewa O.L. - Ornithologia, 1982, N 17, p. 189-191. 1231 TAXONOMIC STATUS AND HISTORICAL FORMATION OF THE AREA OF COMMON SWALLOWS (HIRUNDO RUSTICA) IN THE AMUR REGION S.M.Smirensky , A. L. Mishchenko Department of Vertebrate Zoology, Moscow State University, Moscow, USSR Our collections and observations made in various localities of the Amur river region in 1970-1980 involving other extensive collection material ser¬ ved as a basis to show that common swallows of the Amur region occupy the intermediate position between the two Asiatic subspecies Hirundo rustics tyt- leri Gerd. (Baikal region) and H. r. guttural! s Scop. (Far East Maritime reg¬ ion and China). The polymorphism of these birds resulted from hybridization of the given subspecies which had long been separated by the territory with no places suitable for nesting. The appearance of common swallows in the Amur region coincide with the beginning development of this region by new settlers from Russia in the 17th century and stem from the emergence of structures suitable for nesting. The use of size features and ascertained coloration types makes it possible to clearly identify the subspecies of H.rustica in their time under field conditions. This is particularly import¬ ant for the identification of migratory, flown in and wintering birds as well as for fixing the dynamics of subspecies areas. Common swallows occur in the Northern hemisphere from deserts to forest tundra. They inhabit North Africa, Europe, Asia(North America. Their synant- ropy (almost everywhere the birds nest on man-made structures) and food spe¬ cialization (they feed mostly on small flying insects) account, on the one hand, for a wide distribution of the species and, on the other hand, an ex¬ tremely irregular distribution of the birds inside the area. This species reaches the greatest numbers in livestock breeding regions with plenty of food and places suitable for nesting. The common swallow is characterized by a great geographic variability of coloration and size. Certain geographic populations are also polymorphous in a number of features. The Amur region is completely incorporated in the nesting area of the species, however the birds are numerous only in populated agricultural reg¬ ions. Common swallows nest here only on man-made structures, and in localit¬ ies remote from them only migratory and non-nesting individuals can be found. In the heart of taiga and along mountain ranges these birds can hardly be found at all. The climatic conditions on the coasts of Okhotsk Sea and Gulf of Tatary are unfavorable for them. To define the taxonomic status of the birds inhabiting the Amur region, we carried out observations and collected material in various localities of the entire territory in 1970-1980, 112 specimens of the birds were ob¬ tained and 79 of them were investigated in their life time. We studied the material for other regions from the collections of the Zoological Institute of the USSR Academy of Sciences (Leningrad) , the Zoological Institute of the Ukranian SSR Academy of Sciences (Kiev) , Zoological Museum, Biological and Geographical departments of the Moscow State University, Biological depart¬ ment of the Kiev University. We are greatly indebted to the research workers of the indicated institutions, to S.V. Vinter who offered 12 specimens of 1232 Size features of common swallows of the Baikal region, Amur region and Par East Southern Maritime territory* Region Sex Wing length Lim M 5 M n Baikal 6£ 1 14.0-125.0 117.7 3.12 1 16.66-1 18.74 21 38 ?? 105.2-123.8 116.3 3.61 115. 11-117.49 Amur 106.0-1 18.0 112.7 3.22 111.79-113.21 80 n 103.5-118.5 111.3 2.85 110.66-111.94 79 Par East 105.5-119.0 112.6 3.17 111.63-113. 37 22 31 Southern ÎS 104.0-117.0 110.1 3.18 108.95-110.25 Maritime Region Sex Length of extreme rectrices Relative Lim X 6 D n length of tail Baikal 66 82.5-123.5 103. 1 9.46 99.68-106.52 32 0.88 n 80.0-113.0 90.9 6.78 88.61-93.19 36 0.78 Amur 66 82.5-119.0 100.0 8.53 98.10-101.90 80 0.89 ?? 71.5-96.6 83.9 4.85 82.81-84.89 79 0.75 Par East jj Southern Maritime 00 80. 0-116.5 96.0 8.60 93.60-98.40 52 0.85 99 63.0-90.0 80.9 5.34 78.91-82.89 30 0.73 * Common swallows from the Baikal region and Par East Southern Maritime territory differ significantly in the length of the wing, extreme rectrices and relative length of the tail birds from the Central Amur region, to N.D. Poyarkov handed over at our dis¬ posal 2 specimens of birds from Lake Chukchagir, as well as to R.L. Böhme, N.N. Kartashev and A. A.Kishchinsky for their useful advice on the given ar¬ ticle. “*2. 3aK. 98 1 1233 ANALYSIS OP TAXONOMIC FEATURES All the subspecies of common swallows are characterized by a certain variability of features, however' only the tail length has its individual (apparently age-related) changeability. Common swallows from the Amur region seem to stand spart in this respect. Even among the few birds obtained here by the beginning of the 1970s there are individuals both similar and dissi¬ milar in size and coloration. The situation is complicated by the fact that the places where the birds with palely- and dark-ocherous lower part of the body were captured are distributed in a mozaic pattern throughout the entire territory; in some cases birds with different coloration were found in the same district (Stegmann, 1931; Spangenberg, 1940). The incompleteness and diversity of the material were responsible for contradictory evaluations of the taxonomic status of these birds (Hartert, 1910; Buturlin, Dementiev, 1937; Portenko, 1954; Vaurie, 1959; Stepanyan, 1978). Each author determined the number and composition of subspecies (from two to four) and the boun¬ daries of their distribution in the Amur region in his own way. Size features. The study on birds' variability included: the length of the wing, the extreme and middle rectrices (from the site where the feather comes out of the skin to its tip, of the metatarsal bone, bill (from the nostril and from the forehead plummage to the bill tip), the width and height of the bill at the nostril, the tail to wing length ratio. Due to lack of material for birds, from the Baikal region, Par East Maritime ter¬ ritory and China we failed to compare such indices as the weight and the total body length of the birds. This also explains the fact that while cal¬ culating the tail index we related the tail length to the wing length, though for remote migrants the comparison of the tail length with the total body length yields more reliable results. It was found that the birds from various places of the area do not dif¬ fer significantly in the length of the middle rectrices, metatarsal bone, bill, in the width and height of the bill. The birds from the Baikal region and Par East Southern Maritime territory (both males and females) differ signif icaotly(P=0. 95) from each other in the length of the wing and ex¬ treme rectrices as well as in the tail index, the birds from the Baikal region being greater in size. Common swallows from the Amur region as a whole occupy the intermediate position between the birds from the Baikal region and Par East Southern Maritime territory (see Table; Pig. la, b). There are no significant differences between males from the Amur region and the Baikal region in the length of extreme ractices, at the same time no dif¬ ferences are found between males and females from the Amur region and Par East Southern Maritime territory. The females occupy the intermediate posit¬ ion in relative length, while the males from the Amur region are superior to the birds from the Par East Southern territory and Baikal region. Coloration. A study was made on the variability in the coloration of the lower and upper parts of the body, neck, forehead, spots on the rectrices, 1234 Pig. 1. Diagram of variability in the length of the wing (a) and extreme rectrices (b) of common swallows in the Baikal Region (A), Amur region (B) and Par East Southern Maritime territory (C): vertical section - total amplitude of variability; wide stripe - 2; light rectangle - M (confidence limits of general mean; transverse section - M (mean value) transverse stripe on the breast. It was found that the coloration of the abdomen, forehead, neck, spots on the rectrices had individual variability and in general correlated well with the coloration of the lower part of the body. We found no significant geographic differences in the coloration of the upper part of the body. The coloration of the lower part of the body in common swallows within their area is characterized by a wide variability which is hard to describe 1235 verbally. The wide diversity of ocherous shades is impossible to define even by Bondartsev's scale (1954). Examination of the collections (more than 600 specimens) showed that the common swallow inhabiting the USSR territory may be visually distinguished into 16 groups by color intensity of the lower part of the body. Further analysis showed that such detailed description was unnecessary, and the definition can be confined without any deterioration in determination to the following five main types: 1) pure white; 2) palely- ocherous; 3) light-ocherous ; 4) ocherous;»5) dark-ocherous. With some skill, it is possible to distinguish precisely the coloration type in nature without comparing with collection specimens. Analysis showed that within the boundaries of every geographic region the coloration of the lower part of the body varied to a small extent. At the same time, birds from the Baikal region and Far East Southern Maritime ter¬ ritory (both male 3 and females) differ significantly (P = 0.95) from each other in this feature. Birds from the Baikal region lack the first colorat¬ ion type, while those from Far Bast Southern territory - the fourth and fifth coloration types of the lower part of the body. Moreover, the males from the Baikal region show the predominance in the fourth and fifth coloration ty¬ pes, and the males from the Southern Maritime territory - the second type. The birds from the Amur region occupy the intermediate position in this feature. They are characterized by the second-fourth coloration types noted for all the colonies investigated. The coloration of the lower part of the body in the males and females making up a pair may be similar or different. The coloration of young birds is duller, but their individual differences within a colony are as great as in adult birds. The transverse stripe on the breast is observed in most common swallows: ocherous feathers on the neck and the plummage on the breast are separated from each other by a stripe of black feathers. Frequently among black feath¬ ers of the transverse stripe there are some feathers or groups of feathers partly or completely ocherous; these feathers are similar“in intensity to those of the neck. In some birds the black feathers of the transverse stripe are retained only on the body flanks. The descriptions of the transverse stripe previously employed (continous, interrupted, etc.) had not reflected the whole extent of its variability and precluded an objective evaluation of this feature. In order to describe the diversity in the structure of the transverse stripe as completely and as objectively as possible, a scheme was made up (Pig. 2). The coloration types were distinguished by the intensity in the development of ocherous feathering. The reference of one or two va¬ riants (a, b j to one type is associated with difficulty of their discriminat¬ ion when the distal part of a feather has two colors (black and ocherous). It was found that within the boundaries of each region this feature has little variability. Common swallows from the Baikal region and Far East Southern Maritime territory differ from each other in this trait (P = 0.95). The males from the Baikal region are found to have the third-eighth types (fifth-seventh are predominant) , the males from the Far East Southern Mari¬ time territory have the first-fifth types (third-fifth are predominant) . The transverse stripe among the females of the Baikal region is of the fourth- 1236 P i g. 2. Structure of the transverse stripe on the breast; 1-8 - tipes of transverse stripes; b - type variants eighth types (fifth-seventh are predominant), and among the females from the Par East Southern Martime territory it is of the first-seventh types (third-sixth are predominant). Common swallows from the Amur region occupy the intermediate position by this index. They lack the eight type of the transverse stripe, while both males and females show the predominance of the second-sixth types. This pattern was observed in all the colonies investi¬ gated. The structure of the transverse stripe in males and females making up pairs is usually different. The young birds from one colony also differ in this index. Simultaneous comparison of two indices (structure of the transverse stripe and the coloration of the lower part of the body) in common swallows from the Baikal, Amur and Southern Maritime regions reveals even more distinctly the intermediate position of the birds from the Amur region (Pig. 3) • Thus, all the colonies investigated are characterized by polymorphism. No clinal variability within the investigated territory of the Amur region was ascertained. All the colonies were found to have birds, the features of which were characteristic of both Hirundo rustics tytleri Gerd., inhabiting the Baikal region, and H.r.gutturalis Scop. , inhabiting the south of the Par East Maritime territory and China. All this confirms Stegmann’ s opinion (1931) that the Amur region is a transitional zone between H.r. tytleri and H.r.gutturalis. Therefore, there are no grounds for including the Amur re¬ gion in the area of H.r.rustica, H.r. tytleri, H.r.gutturalis, or refer the swallows of the Amur region to H. r. erythrogaster. 1237 P i g. 3. Variations in the coloration of the lower part of the body and the transverse stripe on the breast of common swallows in the Baikal region (A), Amur region (B) and Par East Southern Maritime territory (C): I-V - coloration types of the lower part of the body, 1-8 - types of the trans¬ verse stripe on the breast; upper - males, lower - females COLONIZATION OP THE AMUR REGION BY COMMON SWALLOWS When establishing the taxonomic status of common swallows from the Amur region, the biological features of this species were not taken into account and the distribution of subspecies of common swallows in the south of the Par East and their interrelations were regarded as static. Colonization of this territory is believed to coincide with the period following the last glaciation (Stegmann, 1929). However, a rise in temperature is the neces¬ sary, but not the only condition of habitation of common swallows. As men¬ tioned above, almost everywhere the birds nest only on man-made structures and feed mainly on small flying insects. The colonies of common swallows The use of size features, coloration types of the body's lower part and the structure of the transverse stripe makes it possible to identify precisely to what subspecies the given common swallow belong under field conditions in its life time. This is particularly important for identifi¬ cation of migratory , flown in and wintering birds, as well as for fixing the dynamics of subspecific areas. Incorporation of data on the weight and body length will enhance the precision of their identification. 1238 are especially numerous on livestock farms. The birds procure their food near grazing animals, where "air plankton" is concentrated. The close relation of common swallows with herbs 'of ungulate animals is attested by the fact that an increase in the size of farms leads to a greater number of nests in the colonies. Other conditions beding equal, the size of colonies in bams with livestock is greater than in empty bams. For instan¬ ce, in Razdolnoe village (Far East Maritime region) in the bams where cal¬ ves were kept there were 27 nests with swallows, while in the neighboring bams, from where the calves were taken to summer pastures, none of the 32 nests were occupied by the birds. A similar situation was observed in other districts of the southern Far East. Apparently, this is explained by a more favorable microclimate of habitable places and by the abundance inside such structures of insects which are active throughout the year. This accounts for unusual cases of wintering of common swallows in a large cow bam in the village of Russkaya Polyana (Khabarovsk region), of which we were informed by local residents. Wintering swallows were observed on farms in the Amur region (Efremov, Pankin, 1975). Permanent settlements and the first rudiments of producing households of people populating the Amur region began to emerge as far back as the stone age. However, up to the 20th century their main occupations were hunting and fishing; this was largely responsible for a low total population and their confinement to large rivers and lakes. Even in large settlements the dwellings were of the underground type (Okladnikov, Derevyanko, 1973) un¬ suitable for nesting of common swallows. In 1664 the first Russian explorers headed by Vasily Poyarkov reached the Amur river. This marked the beginning in the colonization of this territory, which became particularly intensive from the middle of the 19th century. Up to the 19th century the territory of neighboring Manchuria also remained sparsely populated. In 1850 the po¬ pulation of the Amur district reached 10,000, by the beginning of the 20th century - 50,000. The population growth became particularly rapid beginning from the 30s of the present century (Sychyovsky, Sapunov, 1974). Taking into consideration a number of biological features of common swallows, 'it may be assumed that they started to nest in the Amur region, with the emergence of the first Russian settlements. This is testified by the following: 1) the birds are regularly found in summer in regions unsuit¬ able for nesting (the lower part of the Ob river, Taimyr, New Siberian Is¬ lands, Chukotsk Peninsula); 2) the appearance of the first, even temporary structures in regions uncolonized by the species as well as that of do¬ mestic animals leads to an immediate colonization of the new territories by common swallows. For example, in Sakhalin the first common swallows were found to nest in 1923 immediately after a fur farm and fish cutting facilit¬ ies had been built (Yamashina, 1931); 3) the birds colonize new structures in the first summer. In the Amur region we saw no swallows during the nest¬ ing period far from populated areas, but near a tent or a car the birds appeared the next day. Colonization of the Amur region by common swallows seems to have proceed¬ ed from different sides and reflected the successive emergence of populated areas on this territory. Common swallows from the Amur region are characte¬ rized by polymorphism and intermediate (as regards H.r. tytleri and H.r. gut- turalis) features. The birds from the Uda river make up an exception. All the six specimens obtained here in 1844-1845 by the expedition headed by A. T. Middendorf and a male obtained in 1914 have dark-ocherous coloration (fifth type) of the lower part of the body and the seventh-eighth type of the transverse stripe. Middendorf (1867) specially emphasized that he had encountered birds here having a dark lower part. In our opinion, this pro¬ vides evidence for the fact that by the beginning of the 20th century the northemparts of the Amur region had been colonized only by H. r. tytleri , whereas the penetration of H. r. gutturalis and hybridization of these sub¬ species here started later on. It is rather hard to map the territory inhabited by the hybrid form. This is due to not only irregular exploration of the Amur region and adjacent territories, but also to incomplete hybridization of the two subspecies. ■Thus, the north of the Far East Maritime region and the south of the Khaba¬ rovsk region to the west of Sikhote Alin, which were unanimously included in the area of H.r. gutturalis, as well as the north of the Amur region, where H.r. tytleri initialy penetrated, are inhabited now by the hybrids. In conclusion we would like to consider a possible influence of H. r. ery th— rogaster on the birds of the Amur region. The common swallow is a day mig¬ rant and the migratory and feeding activity of this species coincide with each other (Lyuleyeva, 1971). The daily migrations of this species are not long, therefore the possibility of common swallows to cross extensive water spaces of the Pacific is very small. The American and Asiatic subspecies show dissociation not only in nesting areas but also in wintering areas and migratory routes. Commcin swallows widely occur in the south of the Far East and of North America, but no migrations between these regions have been ob¬ served. According to studies involving banding (Lebedeva, 1968), the birds nesting in the Amur region winter together with those from the Baikal region, Far East Southern Maritime territory and China in the South East Asia. A few birds which occasionally cross the Pacific can not influence substantial¬ ly the continental subspecies and their descendants should acquire the ap¬ pearance of the native subspecies, as shown for other classes of vertebrates. The polymorphism of common swallows in the Amur region resulted from the al- lopatric hybridization of the two Asiatic subspecies which ha3 been separa¬ ted by the territory for a long time, where there were no places suitable for nesting. SUMMARY Polimorfism of these birds is the result of allopatric hybridization of the swallows from Transbaikalia and China separated for a long time by a ter¬ ritory hatching in places suitable for nesting. The appearence of the Barn Swallows in the Amur territory and the hybridisation of subspecies are due to the appearance of dwellings made by immigrants from Russia in the 17th cen¬ tury. The use of meristic characters and types of collor allows to identify precisely the subspecies of the Hirundo rustics vitally in the field condi¬ tions, which is especially important for the identification of migrant, vagrant and wintering birds and the fixation of dynamics of the subspecies ranges. 1240 References Bondartsev A.S. Coloration scale. A manual for biologists for scientific and science applied investigations. Moscow; Leningrad; USSR Acad. Sei. Publ., 1954, p. 1-27. Buturlin S.A., Dementiev G.P. Polnyi opredelitel ptits SSSR. Moscow; KOGIZ, 1937, 4, p. 1-334. üfremov V.P., Pankin N.S. - Tn: Zhivotnyi mir Dalnego Vostoka, Blagovesh¬ chensk, 1975, 3, p. 58-63. Lebedeva M.l. - In: Ornitologiya. Moscow, 1968, N 9, p. 270-276. Lyuleyeva D.S. - In; Ekologicheskie i fiziologicheskie aspekty perelyotov ptits. Trudy Zoologicheskogo Institute Akademii Nauk SSR. Leningrad, 1971, 50, p. 183-225. Okladnikov A.P., Derevyanko A.P. Dalyokoe proshloe Primorya i Priamurya. Vladivostok: Dalnevostochnoe knizhnoe izdatelstvo, 1973, p. 1-140. Portenko L.A. Ptitsy SSR. Part 3. Moscow; Leningrad: USSR Acad. Sei. Publ., 1954, p. 1-325. Spangenberg E.P. - In: Trudy Moskovskogo zooparka. Moscow, 1940, 1, P* 77- 136. Stepanyan L.S. Sostav i raspredelenie ptits fauny SSSR. Vorobinoobraznye. Passeriformes. Moscow; Nauka, 1978, p. 1-391. Sychevsky E.P., Sapunov B.S. - In: Amurskaya oblast. Blagoveshchensk, 1974, p. 357-459. Shvarts S.S. Ekologicheskie zakonomernosti evolutsii. Moscow: Uauka, 1980, p. 1-278. Hartert E. Die Vogel der paläarktischen Fauna. B., 1910, 2» P* 832. Middendorff A.Th. Sibirische Reise, säugethiere, Vogel und Amphibien, 1867, 2, p. 1-256. Stegmann B.K. - In: Ezhegodnik Zoologicheskogo muzeya Akademii Nauk SSSR, 29. Leningrad, 1939, p. 83-242; J. Ornithol. , 1931, 79, N 2, p. 137-236. Vaurie Ch. The birds of the Pacific Fauna. Passeriformes. L. , 1959, p. 7-762, Yamashina J. - J. Ornithol., 1931, 79, N 4, p. 491-541. 1241 THE GEOGRAPHICAL CORRELATION OP MORPHISM PHENOMENA IN BIRDS IN CENTRAL ASIA L. S.Stepanyan Institute of Evolutionary Morphology and Ecology of Animals of the USSR Academy of Sciences, Moscow, USSR The phenomenon of morphism, widely distributed in the class of birds ma¬ nifests itself in a wide range of phenotype aspects. As was demonstrated in the relatively recent survey by Huxley (1955), this problem deserves close attention since morphism manifestation which are genetically determined, are associated with major adaptive properties of the organism. The latter ex¬ plains their general significance in the evolutionary process. As a phenomenon of balanced genetic polymorphism, morphism in birds in¬ volves a variety of phenotypic aspects, ranging from morphological to eco- physiological features and behavioural responses. It is currently though that all its manifestations are based on the same genetic mechanism. But the outward manifestations of morphism are so diversified that morphism studies are necessarily differentiated. One can see from the aDove-mentioned survey by Huxley, and also from the practice of ornithological research, that one of the forms of morphism which immediately meets the eye and whose functional significance is still obscure, is discrete balanced genetic polymorphism of plumage coloration. The present paper is concerned with this form of morphism alone. The Palearctic avifauna provides some examples, which well illustrate the above phenomenon. Among them, polymorphous populations of Accipiter gentilis, Falco rusticolus, Oenanthe picata, Oenanthe hispanica, Terpsiphone paradisi and some other have been studied in detail. The geographical variability of morphism manifestation is noteworthy. Ac¬ cording to Huxley, it is this aspect that should receive particular atten¬ tion at the initial stages of investigating the entire phenomenon. The study of the external patterns of quantitative ratios of morphs in space is in fact an important starting point of such studies. It is well known that within the population species systems, some species are characterized by coloration morphism while others are not. Populations characterized by co¬ loration morphism are also differentiated in terms of a degree of its mani¬ festation. Thus, it can be inferred that within a species population and, hence, species range, the phenomenon of morphism is not infrequently record¬ ed only in a portion of the population confined to a definite part of the range. The above is not a rule but a most common pattern. There are only few species characterized by morphism at the level of the entire species popu¬ lation, with the level of its manifestation not varying in space. The geog¬ raphical aspect is undoubtedly an important feature of the entire phenomen¬ on concerned. Its study will undoubtedly throw light on the problem. The spatial variability of morphism with special reference to some par¬ ticular species has been. studied fairly well. For instance, within the range of Oenanthe picata, three colour morphs have displayed such a rigid distri¬ bution pattern, each dominating within its distribution range to such an ex¬ tent, that it gives grounds for a taxonomic interpretation of the entire 1242 Situation. A population with an almost absolute dominance of a single morph is in good agreement with the subspecies concept taxonomieally. Other spe¬ cies show a different pattern. Within the boreal zone of Eurasia, a gradual eastward quantitative increment in the proportion of white morph in the po¬ pulations of Falco rusticolus is well known. Its maximum incidence (about 50%) of the population occurs at the extreme northeast of the continent. Si¬ milarly, the northeast of Asia is the'region of maximum incidence of mor¬ phism in Accipiter gentilis. It is exactly in the populations of this spe¬ cies that white morph is represented (also about 50%) of the population), which is absent throughout the entire species distribution range. This is the best-known case in the avifauna of Palearctic when spatial localization of parallel morphs coincides (white in the case concerned) in two different species that ever received attention (Dementiev, 1951). True, these species belong to the same order (Falconiformes) , which is suggestive that the cor¬ relation of forms is determined by their fairly close affiliation and hence a similar response to a single complex of the environmental conditions. There is one more point that deserves mention. The dark morphs of Palco rusticolus and Accipiter gentilis of polymorphous populations of the north- eaet Asia are represented by lighter birds compared with other portions of the ranges. Finally, some polytypic species with vast ranges within the boreal zone of Eurasia which are not characterized by coloration morphism are represented in the northeastern Asia by the lightest— coloured strains (Aegolius funereus magnus , Dendrocopos leucotos woznesenskii , Dendrocopos minor immaculatus, Picoides tridactylus albidior. Parus montanus anadyren- âi§» Parus montanus Kamtschatkensis, Sitta europaea arctica. Sitta europaea albifrons). The above subspecies are characterized by a lighter coloration of the dark parts of plumage .and in the case of the normal proportion of white plumage by its hypertrophy. Thus, a clear-out parallelism in the mor- pho-physiological responses of birds in different systematic groups to an entire complex of the environmental conditions is in evidence. It is most pronounced in species which are characterized by morphism. The extreme northeastern Asia is an area where similar processes of depigmentation in groups of distant affiliation are operating. In the light of the above well known evidence, it would be interesting to look for other regions where one could observe the development of the processes concerned. But the ranges of numerous species characterized by coloration morphism do not coincide spatially, and hence one can assume from the very outset that there are few sites with a phenotypical effect similar to that observed in the birds in the northeastern Asia. It makes the prospect of their finding all the more interesting. Another region with parallelism in the manifestation of avian morphism can be indicated. In the general form, this region can be reffered to as the northern edge of Central Asia. Mountain systems situated in the geographical centre of the Asian Mainland are implied. These are Dzungarian Alatau, Altai, Sayany, Mongolian Altai, Khangai , Khentei. The region concerned is the home of the populations of some widely-distributed species which are characteri¬ zed by morphism. Interestingly, morphism is recorded either in the populati¬ ons of this region only, or is manifested there to the greatest extent. The 1243 above is true of Buteo buteo, Palco cherrug. Cinclus cinclus. Turdus atrogu- laris. - While the correlation of morphism incidence in different species in the northeastern Asia previously received some attention, for the Central-Asian region theTe are no data available. The situation with respect to each spe¬ cies concerned has been described in systematic surveys, but the parallelism in terms of spatial correlations o'f morphism have not been emphasized. The latter is worth while doing since the Central-Asian region is the only area in addition to the northeastern Asia where the above effects is observed. All the four species are represented there by polymorphous populations. In addition to the "normally" coloured species the latter include dark me- lanistic morphs. Since the problem of the Central-Asian Region has never been considered from this angle before, it is necessary to dwell in more detail on the manifestation of morphism in the above species. Buteo buteo ranges Eurasia from the Atlantic eastward through Pacific coast northward up to the 62nd - 66th paralleles, exclusive of Kamchatka, southward to the Mediterranean, Asia Minor, northwestern Iran, in northern Kazakhstan to the 50^ parallel. Eastward the range covers Tarbagatai, Saur, Dzungarian Alatau, Tien Shan. To the east, the southern boundary pas¬ ses along the frontier regions of Khangai, Khentei, the middle parts of the Great Khingan, the middle parts of the northeastern China. An isolated port¬ ion of the range covers the provinces Gansu, Szechwan, Tzinkhai and eastern Himalayans. It nests in the majority of palearctic islands. The species is characterized by a complex geographical and individual variability. The phenotypical picture is complicated by the presence of zones of secondary intergradation. In addition, the species is distinguished by morphism, which manifests itself in the presence of three coloration morphs, brown with a rusty tinge and a motley dorsal side; brown, with a tinge of ochre on the ventral side; melanistic, monotonously dark-brown (fuscoater). There are birds of intermediate coloration types, and hence, the discrete¬ ness in the manifestation of morphism is not distinctly pronounced here. However it is so marked, that the majority of the individuals display a farrly complete set of diagnostic features of a particular morph. The melanistic morph is the rarest and its distribution within the spe¬ cies range varies geographically. In places it does not occur at all (north¬ west of the range). But it is recorded in the majority of the Asian portion of the range although its proportion within polymorphous populations notably varies geographically. In fact in the temperate zone of the European USSR it is 4%, in the Volga Region, and Cis-Urals Territory .1* (Dementiev, 1951,. In the Altai and adjacent regions, its contribution to populations notably increases to become maximum within the species range. Based on some data available (Sushkm, 1938) expressed in per cent, the proportion of the melanistic morph in Altai populations roughly is 27-28%. This is the highest percentage within a species range. The above is supported by some older studies (Kaschenko, 1899). Also n -roi <»+•,■ i.- Aiso, a relatively high percentage of this morph is recorded for the Western Sayan area (Sushkin, 1914). Pale? cherrug populates the space of eastern Czechoslovakia, Austria and northern Hungary to the east up to the Great Khingan and to the horth to 1244 Karpathians, Chernigov and southern parts of the Moscow Regions, lower Kama, to the east up to the 52 ^ - 57^ parallels and to the south to the northern parts of the Balkan Peninsula, northern coast of the Black Sea, Crimea, lower reaches of Don and Volga, east of the Caspian Sea to the south to the Kho- rosan mountains, northern Afghanistan, Himalayans, eastern Tzinkhai, eastern Gansu. The species is characterized by pronounced geographical variability, with considerable individual variations. No stable manifestations of morphism are recorded in the populations of the bulk of the range. But in northeastern portions of the species' distribution range, morphism is highly pronounced. There are two colour morphs there: light (common in terms of coloration) and dark melanistic ("altaicus") . As in the previous case, no rigid discreteness in morphism manifestati¬ ons is recorded there. On the one hand, there are birds which to some ex¬ tent combine the features of both morphs, on the other, each morph represents a wide range of individual variability, which results alternatively in great¬ er or lesser manifestation of the specific features of the respective type of coloration. But on the 'whole, the light and dark morphs are to a great extent discrete and the general phenotypic pattem is in conformity with our concepts on the balanced genetic polymorphism of a discrete type. The above is well illustrated by the history of discoveiy and attempts of taxonomic interpretation of the dark morph status. This morph was assigned to an independent species (Hierofalco altaicus), and currently it has been regarded either as such or as a geographical strain Falco rusticolus. This discussion of this problem is beyond the scope of the present paper, I shall only point out that the abundant new evidence available leaves no doubt that altaicus is only a morph of the polymorphous populations of Falco cherrug characterized by hypertrophy of melanin colorat¬ ion compared with other variants of this species. Polymorphous populations of Falco cherrug populate the area covering Al¬ tai, Western and Eastern Sayany, Khangai, Khentei, Tarbagatai, Mongolian and Gobi Altai, Dzungarian Alatau and presumably northern and central Tien Shan. The dark morph is, within the area concerned, accounts for a large propor¬ tion of the population, but the actual ratio of the above morph to the light morph has not yet been clarified. There are grounds to believe that its pro¬ portion in the localities of the largest numbers of dark-coloured birds (At- tai, Khentei, Khangai and Mongolian Altai) attains 20-25% of the population. In that, the northern edge of Central Asia differs from all the other porti¬ ons of the species' range. Actually, pronounced morphism is characteristic of Falco cherrug only within the region concerned and the melanistic morph displays a rigid geographical localization, being confined to this region alone. Cinclus c inclus shows a very complicated discrete distribution pattern within Palearctic and northern Indo-Malayan Regions. In northwestern Africa it populates the Atlas Mountains. In Europe, it ranges from the coast of Norway and Northern Seas, the coast of the Bay of Biscay to the Pirenean Peninsula and eastward to the Ural Ridge. To the south this portion of. the 1245 range extends to the Mediterranean, southern Carpathians, Baltic Republics, the valley of the Onega River, the upper reaches of Mezen and Pechora (along the Ural Mountains southward to the middle parts of the Southern Urals). The Asia Anterior portion of the range extends from Asia Minor to the Khorosan Mountains and farther northward to the northern piedmont of the Great Cau¬ casian Ridge, the north-facing slope of the Khorosan Mountains, to the south to the southern edge of the Armenian Upland, Zagros s Mountains and southern edges of the Khorosan Mountains. The largest section of the range stretches from the western piedmont of Tien Shan, Alai System, Paropamiz and Middle Afghan Mountains eastward to the Aldan-Uchur Ridge, Arguni, Khentei, the ridges Alashan and Tzinlin, the Sino-Tibet mountains, to the north to the ridges: Kirghiz, Trans-lli, Dzungarian, Tarbagatai, Saura, Northern Altai, Salair, Kuznetsk Alatau, eastward to the north to the 56th - 58th parallels, southward to the Middle Afgan Mountains, the southern slope of Himalayans, and the Yunan Uplands. It is absent in the vast spaces of deserts within the Middle Asian - Central Asian portion of the range concerned. The vast range and discrete distribution determine the vast geographical variability of the species. Also, all the populations are characterized by a considerable individual variability range. Morphism is characteristic of the populations of the northeastern portion of the range and is not found in other sites. The polymorphous population inhabits the area from the Sa¬ lair Ridge, Western Altai and Saur and southeastward to the Aldan-Uchur Ridge, the valley of Arguni, Khentai and northward to the Kuznetsk Alatau, in the aiisei basin to the 56 h parallel and eastward to the north roughly to the 58 parallel; southward to Saur, Mongolian Altai, Khangai, Khentei. Within the area concerned, morphism manifests itself to a variable extent fluctuation geographically. But before discussing this problem a brief description of the types of coloration should be given. There are six of them (Stepanyan, 19775 : 1) The lower side of the body (throat, lower side of neck, chest, belly) is white. 2, The lower side of body (throat, lower side of neck, chest, belly) is white, with a brownish tinge on the belly. 3) The throat, lower neck and chest are white, belly light brown, the boundaiy between the zones of white and brown coloration not being veiy distinct. 4) The throat, lower neck and chest are white (occasionally chest is darkened by brownish specks or a touch of brown); the belly is brown, the boundaiy between the zones of white and brown coloration shaip; 5) The throat, lower side of neck and chest are light-brown, belly dark-brown, the boundaiy between these two zones being sharp enough. 65 The throat, lower side of neck, chest ancj belly are brown, coloration of the throat, lower neck and chest, only somewhat lighter than the stomach, the boundaiy between these two coloration zones not being pro¬ nounced (the morph represents the most melanistic coloration type). As can be seen from the above descriptions, the phenotypic pattern of the polymorphous population is exceptionally complex. The birds of all' the coloration types occur within a single region (one should bear in mind that the population is largely sedentaxy). That has led to a good deal of taxono¬ mic an nomenclature confusion, since practically for all the types of colo¬ ration, nomenclature units for . geograpnical strains or even species were 1246 proposed (biedermanni , bilkevitchi, middendorfii , bianchii, baicalensis, ki- borti, saturatus, leucogaster) . The taxonomical aspect of the problem is not considered here, but dealt with in a special paper (Stepanyan, 1977). There is no distinct alternation in the manifestation of the described types of coloration. Generally speaking, the discreteness of morphism in this case is less distinct than in the two previous cases. Nevertheless, in the local populations, birds of all the coloration patterns are invariably found, suggesting that the situation concerned can be .described as a balan¬ ced genetic polymorphism. As noted above, the spatial dispersal of morphs within the northeastern portion of the range varies geographically. The maximum diversity of colo¬ ration types and concurrent maximum relative and absolute numbers of the darkest melanistic morph (coloration type 6) is recorded in Saur, Altai, Mongolian Altai, Khangai and Khentei. Here, birds with purely white lower side of the body (coloration type 1) are rare, while melanistic individuals (coloration types 2-6) . prevail. Notably, both westward (Central Asia) and eastward (Trans-Baikal Territory) and farther to the east of this region, the variability of populations sharply declines, and in both cases, there white- bellied individuals of coloration type 1 are either dominants or are ex¬ clusively represented (Central Asia). The above complex geographically-phenotypical pattern clearly displays the association of the darkest melanistic morph with the above geographical centre of the Asian Mainland. As has been mentioned above, both absolute and relative incidence of this morph are highest in this region. On the whole, the range of melanistic morph, has almost not extended beyond the mountain regions of Saur, Altai, Mongolian Altai, Khangai and Khentei. Turdus atro- gularis ranges from the upper reaches of Kama and western piedmont of the Ural Ridge eastward to the upper reaches of the lower Tunguska and Baikal, northward to the 62n<* to 67^ parallels, southward in the Ural Ridge to the 59th parallel to the regions of Tyumen and Barnaul, Tarbagatai, Saura, southern and southeastern edges of Altai and the ridge of Tannu-Ola. Despite the rather vast range, the species is not characterized by con¬ siderable geographical variability. Irrespective of the fact whether this form is assigned to an independent species or a geographical strain of the complex Turdus ruficollls (as is done by some authors), no taxonomic popu¬ lations can be distinguished within it. Here, Turdus atrogularis is accepted as a monotypic species. Except for some age and seasonal variation of co¬ loration, the individual variability is not distinctly pronounced in the species in question. That makes the discovery of morphism in this species all the more inter¬ esting. In addition to birds with a common coloration type, there occur in¬ dividuals in which the entire head, the posterior neck, anterior back, throat and upper chest are coloured black as a single colour field. The degree of manifestation of this type of coloration ("relict*") varies with regard to the general space occupied by the black colour. But in all these cases, the birds thus coloured differ considerably from individuals with common (most widely dispersed coloration). The numbers of such melanisti 1247 individuals are low, they constituting only a small percentage of polymor¬ phic populations. The absolute numbers and percentage of the melanistic morph are the highest in the region of Altai and Sayany (Portenko, 1981). Actually, the population of this region alone can be considered truly polymorphous. The above data are indicative of spatial coincidence of morphism mani¬ festation in the above-considered species. It is noteworthy, that in all cases, a dark melanistic morph is recorded within a polymorphous population. The fact that the polymorphous species considered belong to two different orders (Palconifomes , Passeriformes) does not change the general pattern. Compared with the situation in the northeastern Asia, one can speak more definitely here of the reaction of polymorphous species to the- local complex of conditions. The lack of close affiliation among the species considered and a similar pattern of the manifestation of morphism are indicative that a factor of great impact is operating. True, in this case, the local popu¬ lations of polytypic species which do not show coloration morphism do not provide a complementary pattern as was observed in the extreme northeastern Asia. Nevertheless, the fact of spatial co-existence of melanistic forms in the four above-considered species is a phenomenon which is undoubtedly worthy of attention. The region concerned is the geographical centre of Asian Mainland. Thus, while the extreme northeast of Asia is an area of correlated manifestation of morphism and the region where the white morphs are localized, the centre of Asia is the region of correlated morphism where melanistic nlorphs are found. Naturally, the problem of the factors determining the above phenomena and of the adaptive significance is of great interest. No definite inferen¬ ces in this respebt can be made so far. To conclude, another problem should be touched upon. As was mentioned above, the ranges of species characterized by coloration morphism do not always coincide spatially. But one should not think that if they do coincide, the above correlation is bound to develop toward the above correlations. Dif¬ ferent situations may arise. In Primorye, for example, the ranges of Acclpi- ter gentilis and Terpslphone paradlsi overlap. Both these species are charac¬ terized by morphism and in both the manifestations of morphism vai^y geogra¬ phically. The population of Terpsiphone paradisi in Primorye is dimorphic: in addition to the dark-coloured morph (i.e. common in tei*ms of coloration type) there is also a white morph present here, whose incidence is relative¬ ly low. Accipiter gentilis is represented in this region by a non-monomorphic populations with absolutely no incidence of coloration morphism. The local populations of Accipiter gentilis are the darkest within the Bpecies. The same applies to Terpsiphone paradisi with respect to the dark morph. Thus, the conformity of geographical variability of coloration of the Gloger rule only partially applies to the manifestation of morphism. Some specific mechanisms are active here, which are still largely obscure. Mor¬ phism in avian plumage is one of the most vivid forms of discrete balanced genetic polymorphism, representing an independent problem. If morphism of ecological properties readily lends itself to interpretat¬ ion from the angle of adaptive significance .coloration morphism does not al- 1248 low of any definite interpretation although such attempts are frequently made. In addition, one should not rule out the possibility of the manifestation of morphism as a side product of the polymorphism of physiological properties. And beyond doubt, of particular interest is the genetic aspect of morphism. SUMMARY The most conspicuous form of balanced genetic polymorphism in birds is interrupted morphism (see Huxley, 1955) of plumage coloration. It is often characteristic only for a part of population of polymorphic species and is located only in some parts of its range. Cases of spatial sympatry of mor¬ phism among polymorphic species with overlapping ranges are of particular interest. Within the limits of nontropical Eurasia one example of the kind is well known, i.e. maximum development of morphism and the highest numbers of white morphism among Acciplter gentilis and Falco rusticoluB in the ex¬ treme north-east of Asia. Another region where such phenomenon is observed ha s been also located. It is the northern part of Central Asia (Dzhungarsky Alatau, the Altai, the Sayans, the Khangai, the Khentei). Here the pronoun¬ ced development of morphism is characteristic for four species, namely: Buteo buteo, Palco cherrug, Cinclus cinclus. Turdus atrogularia. Their local polymorphic populations include melanistic phenotypes which have maximum absolute numbers and rate here. North-east Asia is the area of correlated expression of morphism and the region of localization of white morphs, while northern part of Central Asia (i.e. the geographical centre of the continent) is the area of correlated expression of morphism and the region of localizat¬ ion of melanistic morphs. The regularities of spatial distribution of colour morphs coincide in some cases with general subordination of geographical changes of coloration to Gloger' rule, though in some other cases Buch coin¬ cidence is unronounced. The adaptive significance of interrupted balanced ge¬ netic polymorphism in bird coloration remains vague. References Dementiev G.P. Ptitzy Sovetskogo Soyuza. Moscow: Nauka, 1951, 2- Huxley J. - In-. Acta XI Congr. Intern. Omithol. Basel, '*955, p. 309. Kaschenko N.P. Results of the Altai zoological expendition of 1899. Vertebra¬ tes. Tomsk, Kononov and Skulimsky Publ., 1899. Portenko L.A. - In: Trudy zoologicheskogo Instituts. Leningrad, 1981, 102, p. 72. Stepanyan L.S. - Zool. zhum., 1977, 5£, N 12, p. 1834. Sushkin P.P. Materialy k poznaniyu' fauny i floiy Rossiyskoi Imperii. Otd. zoologii. Moscow, 1914, vyp. 13. Sushkin P.P. The birds of Soviet Altai and adjacent parts of northwestern Mongolia, v. 1, Moscow; Leningrad: USSR Acad. Sei. Publ., 1938. 43.3aK.981 1249 TYPES OP COLON IALITY IN THE FAMILY LARIDAE V.A.Zubakin Institute of Evolutionary Morphology and Ecology of Animals of the USSR Academy of Sciences, Moscow, USSR In 1973-78 the colonial nesting of 18 species of gulls and terms was studied in different regions of the USSR. Colonial! ty was found to differ in structure and ecology amongst these species of Laridae. On the basis of both this field data and data in the literature on other species of Laridae it was concluded that two types of coloniality exist in this family. There is obligatory coloniality (OC) and facultative (optional) coloniality (PC). The PC-species can be further divided into dense-nesting and diffuse-nesting species (Pig. 1). LARIDAE (Larinae + Steminae) 87 Bpecies ^PC^PECIES^^ DIFFUSE-NESTING DENSE-NESTING SPECIES SPECIES (about 65 species) - - - — - - about 6 species (min. 3 sp. ) ? L.heermanni ? L.delawarensis L.brunnicephalus L.melanocephalus H.caspia ? S.fuscata Pig. 1. Species of Laridae with different types of coloniality - ÖC -SPECIES about 16 species (min. 7 sp.) L.ichthyaetus L. relictus L.genei L. (belcheri ) atlanticus R.tridactyla R. brevirostris S. sandvicensis S. maxima S.bergii S.bengalensis S.eurygnatha S.elegans S.zimmermanni A.stolidus A .minutus A.tenuirostris The characteristic features of OC-species: - very high nest density (nests often contact one another); - lack of nesting in solitary pairs; - nesting only in places where terrestrial predators are absent; - lack of defended nest territory; - defecation by the incubating bird on the edge of its nest; _ absence of egg shell removal; - decrease of the cryptical properties of egg colour and, sometimes, chick colour; - the existence of special nestling "creches" and "herds" at the appearan¬ ce of a predator (in species that nest on flat islands); - absence of cannibalism in most species (as a rule); - the existence of ichthyophagia or trophic bonds with aquatic systems. 1250 The characteristic features of diffuse-nesting FC-species: variety of nest density; nesting in solitary pairs is not unusual; - nesting in places accessible to terrestrial predators; - defended nest territory in all species; - camouflaged nests (defecation on the nest does not occur, egg shells are removed); - cryptic egg and chick colour; chick scattering and hiding with the appearence of predator; - euryphagia and cannibalism in most species. The characteristic features of denso-nesting FC-species: - nest density is greater than in the diffuse-nesting FC-species but less than in OC-species; - the occurrence of nesting in solitary pairs in some species; - nesting in places where terrestrial predators are absent; - defended nest territory in all species; - absence of defecation on the nest; - egg shell removal by most species; - cryptic coloration of eggs and chicks evident but not so pronounced as in the diffuse-nesting FC-species; - the existence of special chicks "creches" and "herds" in some specieB; - cannibalism in some species. The reason for the variety in colonial structure lies in the different strategies of offspring defence. Larids use two strategies: A. Protection of eggs and chicks using the "effect of density", l.e. the compact packing of birds frightens away avian predators (ED-etrategy ) , ED- strategy lead to a very high nest density. In this case camouflage of nests and chicks is not necessary. The OC and partly dense-nesting FC are the result of this strategy. B. Protection of offspring based on the combination of active attack and diffuse distribution of cryptically coloured eggs and chicks (AD-strategy). Diffuse-nesting facultative coloniality is the result of this strategy. The ED-strategy is effective only against nonspecialized avian predators, that are mainly dangerous for eggs and chicks. If predators are dangerous for adult birds (as in the case of terrestrial predators or in the case of small colonial species) the AD-strategy becomes more effective. The evolutionary influence of the first type of avian predator has re¬ sulted in compaction of colonies of prey species, whereas the evolutionary influence of terrestrial predators has tended to disperse the nests in a colony. The influence of cannibalism of eggs and chicks is intermediate: it condenses the colony but only to the certain limit (Fig. 2). The following factors influence the choice of evolutionary strategies of offspring defence (Fig. 3): - resence or absence of terrestrial predators in the places of nesting; - body size of the colonial species; - type of feeding (euriphagia in large-bodied and medium-sized species often lead to the cannibalism). 1251 Fig. 2. Influence of predators and cannibals on the nest density Fig. 3. Influence of the main forming factors on the evolution of colonia lity in the family Larldae 1252 ROUND-TABLE DISCUSSIONS V.M. GAVRILOV SEASONAL AND CIRCADIAN CHANGES OF THERMOREGULATION AND NON-PASSERINE BIRDS; WHICH IS MORE IMPORTANT? IN PASSERINE I.H.J. LYSTER, D.T. LEES-SMITH HOLARCTIC AVIAN SPECIATION ATLAS G. Th. de ROOS TOURISM AND BIRDS S.D. MATVEYEV SEMISPECIES IN THE AVIAN FAUNA OF THE BALKAN PENINSULA O.L. SILAJEWA FOLK AND ONOMATOPOEIC NAMES OF BIRDS S.M. SMIRENSKY WORKING GROUP ON CRANES OF THE USSR E.D. MORENKOV MORPHOFUNCTIONAL ORGANISATION OF THE VISUAL SYSTEM IN BIRDS SEASONAL AND' CIRCADIAN CHANGES OP THERMOREGULATION IN PASSERINE AND NON-PASSERINE BIRDS; WHICH IS MORE IMPORTANT? V.M. Gavrilov Department of Vertebrate Zoology, Moscow State University, Moscow, USSR Accumulation of laboratory data on energy expenditure by animals under standard conditions have proved valuable in field ecological studies too, particularly in calculating energy budgets in free-living birds. But their correct use requires correct ecological interpretation and evaluation. In 1970 Ashoff and Pohl(1970) selected from a relatively large body of evidence on basal metabolism in different species of passerine and non-pas- serine birds, a relatively small number of measurements where basal metabo¬ lism was measured in each species under study in standard conditions during the daytime and at night. They obtained differences in the level of basal metabolism as a function of the time of measurement. The nocturnal basal me¬ tabolism proved to be 25% lower than diurnal. S.C.Kendeigh, V.R.Dôlnik and I (1977) showed seasonal fluctuations of nocturnal values for basal and standard metabolism, heat conductivity and lower critical temperature in a relatively large number of passerine and non-passerine birds. In 1981, I showed (Gavrilov, 1981) in 18 passerine and 12 non-passerine species that circadian fluctuations are characteristic not only of basal me¬ tabolism, but also of heat conductivity, energy expenditure at rest at 0°C, as well as at upper and lower critical temperatures and that of the body within a single season (winter) (Gavrilov, 1979, I960, 1982). The purpose of the present communication is to estimate the circadian fluctuations of thermoregulation in the same species during two seasons (winter and summer). Analysis is deliberately based on my own data, since it was not my in¬ tention to obtain differences in nocturnal vs. diurnal measurements; and other special studies are not uniform in either reporting such differences, if it is the puipose of the investigator to reveal them, or else, in neglect¬ ing such differences, if considered immaterial. MATERIAL AND METHODS • We studied 18 passerine species covering almost the entire order's range and 12 non-passerine ones with a similar size range (33-1,132 g). The sample included almost equal proportions of north-distributed species and those distributed in the south despite the fact that their patteras of distribution in the size series differed. Among the small species, which are mostly non¬ passerine, there is a greater proportion of .southern species, while large¬ sized birds are mostly northera. All the bioenergetic indices were obtained by measuring oxygen consumption in birds captured mostly on the Baltic shore ' or from the Moscow Zoo col¬ lection. The birds had been maintained in open aviaries for at least 4 weeks prior to the experiments. Tropical, subtropical and migratory birds were maintained at 10-22°C during winter. In winter (from December to February), only non-moulting birds were used in the extieriments, and in summer, measure- 1254 respondence of Scholander model ments were made in late June through early July, i.e. between the terminat¬ ion of breeding activity and onset of moult. Oxygen consumption was measured at different phases of the circadian cycle only in starved birds, which comp¬ leted assimilation of food; in some specially documented cases, birds, which did not complete assimilation, were measured as well. Large birds were made to fast 12 hours and the small ones - 3 to 4 hours prior to their measure¬ ments. The birds (one at a time) were placed first in special cages, then in air-tight chambers of acrylic plastic for measuring oxygen consumption in the dark. The chambers varied in size from 3 to 25 t depending on the size of birds. The chambers were installed in refrigerators or thermostats, where the needed temperature was pre-set. Before measurements, the air was pumped through the chambers for two hours in order to stabilize the temperature. Oxygen consumption was measured with a modified Kalabukhov instrument (Kala- bukhov, 1951); each measurement at the same temperature lasted 1-4 hours, with intervals between measurements from 1.5 to 2 hours. Within a single tem¬ perature cycle, oxygen consumption was only registered with 5°C elevations of ambient temperature in a step-like manner. The number of individuals stu¬ died per species was 2—4 in some hard— to— get at species, and 8—10 and more in others. The correlation of thermoregulation indices was in agreement with 1255 the Newton model as modified by- Scholander et al. (1950) and as shown in Pig. 1. in some cases in large birds, especially in the daytime, measurements deviated from that model. Data on oxygen consumption were transformed into energy terms: 1 cm^ Qg = 20.1 J. Body temperature was measured with a thermistor introduced into the cloaca and attached to the tall . Registration was long-range, using a direct cur¬ rent bridge. The relationship between thermoregulation values and body weight was es¬ timated separately for passerine and for non-passerine birds, for winter vs. summer and daytime vs. nighttime measurements. The relationship between ther¬ moregulation values and body weight was estimated according to the method of least squares, assuming that all the dependences are expressed by a power function M = a mb, where M is a thermoregulation index, m - body mass, a and b, empirically obtained constants, with a setting the regression level, and b - the slope. RESULTS AND DISCUSSION Circadian fluctuations of thermoregulations within a single season (winter). % Let us first consider fluctuations of thermoregulation as shown in Fig.1 within the same season but at different times of the day , under different illumination and depending on the gut content. In winter a normal diumal cycle of energy expenditure at rest is a weak¬ ly expressed two-peak rhythm with maxima at the beginning and at the end of the day (Fig. 2). Higher metabolism during the daytime persists when the birds are maintained in the dark for more than 24 hours. This is indicative of the fact that changes in the metabolic level are circadian. During the day and without food the level of diumal metabolism may be only 10-15% higher than that of nocturnal. The presence of food in the digestive tract changes the level of metabo¬ lism (Table 1). Immediately after feeding, metabolism is found to increase. In this case the energy of a specific dynamic action augments oxygen con¬ sumption and may promote maintaining heat balance under low temperatures of the ambient medium. In smeller species, the after-feeding energy expenditure following feeding in the thermoneutral zone approaches the basal level more rapidly, presumably due to a lesser capacity of the digestive tract. The spe¬ cies fed with meat or hen eggs prior to the experiments (Corvidae and Turdi- dae) exhibited higher oxygen consumption than those fed with grain mixtures (Galliformes, Ploceidae, finches and parrots). This reflects a higher degree of energy of the specific dynamic action effect of animal food compared with grain. In insectivorous birds, energy costs approach the basal level quicker than in granivorous ones of the same size, presumably due to the different rate of food passage through the digestive tract in these groups, and also due to the different rate of digesting these foods. Body temperature shows a similar circadian cycle, changes in body tempera¬ ture being closely correlated with metabolic changes (Fig. 2). It should be 1256 P 1 g. 2. Changes of oxygen consumption (points) and body temperature (cross) as a function of time in some species in winter. White abscissa - light, black abscissa - dark Table 1. Changes of resting metabolic rate in darkness after feeding Resting metaboli c rate in darkness at ambient temperature 22° 3, ml 02 hour-' Species at once in 2 in 4 in 6 in 12 in 1 2 hours after hours hours hours , hours, in the feeding in night in night, day-time, NBM DBM Excalfactoria chiner¬ ais 131.7 127.9 122.5 109.6 105.0 125.0 Cotumix cotumix 184.2 186.9 180.8 179.8 148.3 177.1 Legopus lagopus 812.5 751.7 771.0 713.3 514.8 681.5 Melopsittacus undu- latus 111.5 109.0 85.4 65.0 59.0 65.0 Nymphicu8 hollandicus 199.6 196.5 189.8 185.0 154.6 183.1 Estrilda troglodytes 65.4 32.9 31 .0 30/4 27.7 30.4 Parus ater 67.7 60.0 59.0 50.2 48.5 57.3 Taeniopygia castanotis 59.2 53.3 44.8 43.8 41.7 46.9 Erittiacus rubecula 91.2 66.3 54.2 55.4 50.4 54.6 Fringilla coelebs 96.9 91.0 91.7 85.0 79.0 85.8 Turdus iliacus 225.0 198.3 158.5 131.9 128.8 151.0 Turdus philomelos 522.9 264.6 160.8 135.8 135.4 155.8 Turdus merula 475.0 258.3 225.0 210.4 185.4 218.7 Corvus corone comix 1170.8 941.7 850.0 837.5 685.4 802.1 Corvus corax 2139.6 1950.0 1339.6 1335.4 1075.0 1281.3 1257 noted that the circadian ihythrn of body temperature is better retained in the dark compared with the rhythm of metabolism. "Energy coat at rest - ambient temperature" species regressions were ob¬ tained for all the species under study both in the daytime and nighttime measurements (Pig. 3, 4! Table 2). The energy costs at rest at 0°, which are beyond the thermoneutrality zone in all the species studied were higher during the day than at night. Presumably, this is explained by the higher body temperature during the day. The energy expenditure at any ambient tem¬ perature beyond the thermoneutrality zone is described by the equation SMR = h(Tb - Ta). Apparently, if Tb increases, the difference Tb - TA, and, hence, SMH in¬ crease. In addition, as shown by measurement results, in most cases heat con¬ ductivity increases during the day, which i3 presumably due to spontaneous optomotoric reaction. During the day, the feathers are pressed against the body closer, the vo¬ lume of air contained in the plumage is decreased, and heat conductivity is higher. There is practically no difference associated with plumage properties that would increase br decrease the ratio of the diurnal and nocturnal heat conductivity in species under study. Larger birds show a tendency to a some¬ what greater increase during the day time compared with the smaller ones (Table 3). This may be associated with greater thickness of the heat-insulat¬ ing layer in large birds, and secondly, oxygen consumption measurements may be more disturbing to larger birds. The lower critical temperature shows different fluctuation patterns in nocturnal and diurnal measurements in passerine vs. non-passerine species (Table 2, 3). In non-passerine birds, the diurnal T^c is lower than nocturn¬ al, whereas passerine birds show a reverse tendency except the largest ones. It* appears that ideally Tec is to have similar values both during the day and at nighttime, since during the day the values of heat conductivity, body tem¬ perature and basal metabolism augment. Although the above indices may in¬ crease independently, the joint impact of these parameters is not to change the lower critical temperature position on the temperature scale. The upper critical temperature is 1-2° lower in the majority of species compared with nighttime, which is due to an increase in basal metabolism (Table 2, 3)* During the day basal metabolism augments in all the species, but in the non-passerines under investigation, this increase is greater (Table 2, 3). Larger passerines augment their metabolism during the day time to a somewhat greater extent than smaller birds. Presumably, this is explained by the measurements being more disturbing to the larger birds. On the whole, the circadian basal metabolism in non-passerine birds is 23% higher than at night, and in passerines - by 12% higher (Table 3). These values are .some¬ what lower than those obtained byAschaffand Pohl (1970). The relationship between thermoregulation indices and body weight (Table 4 ) demonstrate that in passerines SMR, h, TU(J, BMR as measured diur- nally and noctumally, fluctuate with a similar regression slope, and it is the regression level that is changing. Tuc in them decreases during the day- 1258 O jq t •H OJ O *3 a o •H 00 O O O s K Perdix perdit: 400 - Coturnix ooturnix H00 200 J- 0 E.xcalfactoria chinensis p i g. 3. Dependence of energy expenditure at rest on ambient temperatures ( ?A , ° C ) in winter in Hon-Faaserlformes: daytime (white circles}, nighttime (black circles) time with a greater increase in size than at night. In non-passerines, SMR, h and T change in a similar way as in passerines, but in nocturnal measure- ments, BMH increases with an increase in size to a greater extent than in nocturnal. This results in a change in the power index of the respective de¬ pendence (Table 4). The diurnal BMR of non-passerines is approximately equal to the nocturnal one of passerines, but it increases with an increase of the bird size to a greater extent. Analysis of the relationship between and SMR and body weight for diurnal vs. nocturnal measurements in passerines and non-passerines demonstrates that the respective diurnal and nocturnal indices in these avian groups do hot differ significantly. The diurnal lower critical temperature in non-pas¬ serines (the lowest one) is higher than the diurnal or nocturnal Tlc of pas¬ serines (bird size being equal). The upper critical temperature in non-pas¬ serines is higher than the respective T’uc (diurnal or nocturnal) of passer¬ ines. Thus, the difference in the level of basal metabolism between these two groups manifests itself not in different energy expenditure under lower Corvus corax ji i g. 4. Dependence of energy expenditure at rest on in winter in Passeriformes : daytime (white circles); n ambient ighttime temperatures (black circles) temperature or heat conductivity, but in the upper and lower critical tem¬ peratures. 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O o O O O O O O r~ en VO vo LA vo r- VO LA en en » — rA ov o LA *4 LA VO O T— VX1) LA CM en O O O en en O O en ov en O ov O vO OV en m 4 sh en 4 CA -4 CA 'M 4 4 CA CA 4 •4 CA CO t— CM rA CA CM » — O O O CM o CD (A CM A VO IA vo rA f"* icv U"' en vo (O r— r’ r~ r— r- K — CM CM CM CM ^4 LA LTV f— C0 CO CA 4 VO O x~ LA o> CM LA n- 4 en CA rA CA co r— LA O t" CA rA x— VO CM r— 4 CA 4 o , — 4 vo 4 4 en O vO LA CA LA O O en en LA ‘M.1 ■4’ LA t“ T - tr 4 f- v0 .o '0 O o o O O O o o O O o o •4 • . « • m CÜ CM • CM «M- « -J- « (M * CM • ca CA • en • m '• LfV • IA co • CO • O • o « C’A C’A a) co 04 ION i , , 14V IA VO VO VO vO CÜ (0 UJ en o O r~ r X” -■i- •4 O O CD C3 CM CM CM (M LA IA Lf A IA CM CM (M CM -J TJ h o . * •V ,1h Pi •:S U Ö» ti Tl fi û.J r\ 'J TJ* û> O C: V) 07 r-J O O •H H Q> £ O rs s O K c U O O Jh O <■_> 44. 3uk. ‘>S | 1265 Table 3. Relation between day-time and hight-time measurements of thermoregulatoiy energetics in birds Species Season SM hl T1 *lc T uc BM tb 1 uc Llo SM-BM 1 2 3 4 5 6 7 8 9 10 11 Non-Passeriformes Aix sponsa S 1.11 2.22 0.99 0.89 0.97 1.14 1.03 1.05 1.07 W 1.13 1. 28 1.00 0.71 0.94 1.33 1.01 1.16 0.85 Anas plathyrhynchos S 1.14 1.24 0.98 0.86 0.97 1.18 1 .01 1.04 1.06 1ST 1.12 1.08 0.97 0.38 0.94 1.30 1.02 1.11 0.40 Exalfactoria chinem- S 1.C2 1.19 0.58 0.86 0.92 1.01 1.01 1.00 1.03 sis w 1.06 0.96 0.95 0.95 0.97 1.19 1.01 1.00 0.92 Cotumix cotumis s 0.98 0.93 0.72 0.50 0.95 1.08 1.01 1.44 0.88 v7 1.09 1.02 0.95 0.95 0.97 1.19 1.01 1.00 0.97 Perdix perdix s 1.10 1.25 0.48 0. 89 0.95 1.09 1.01 1.00 1.11 w 1.20 1.03 0.90 1.00 0.95 1.26 1.04 0.91 1.09 Lagonus lagopus s 1-. 1 1 1.39 0.65 0.86 0.92 1.14 1.02 0.96 1.05 V? 1.19 1. 30 0.95 0. 60 0.95 1.32 1.03 1.07 0.78 larus canus s 1.03 1.04 0.61 0.93 0.92 1.07 1.01 0.91 0.98 w 1.07 0.92 0.86 0.69 0.95 1.29 1.03 1.08 1.05 Laru s ri d i bun du s s 1.04 1.05 0.67 0.88 0.95 1.12 1.01 1.00 0.92 ’.7 1.06 0.95 0.80 0.87 0.95 1.20 1.02 1.00 0.82 Columba livia 3 1.11 1.33 0.84 * 0.87 0.97 1.08 1.03 1.13 1.16 7 / 1.05 1.02 0.74 0.94 0.97 1.11 1.04 0.96 0.97 Meloosittacus 3 1.02 1.07 0.81 0.93 0.97 1.08 1.02 1.08 0.99 undulatue w 1.04 1.09 0.86 0.92 0.97 1.10 1.02 1.08 1.01 Agaoomi3 roseicollis S 1.03 1.06 0.32 0.92 0.97 1.09 1.03 1.03 0.98 1.32 1.50 0.79 0.92 0.95 1.32 1.03 0.79 1.33 Nvmchicus hollandicus S 1.03 0.98 0. 66 1.00 0.95 1.10 1.03 0.87 0.99 ;v 1.05 1 . 03 0.71 0.91 0.95 1.18 1.02 1.13 0.94 Mean 3 1.06 1.15 0.73 0.87 0.95 1.10 1.02 1.05 1.02 V/ 1.11 1.10 0.87 0.82 0.95 1.18 1.02 1.02 0.93 Passeriformes Estrilda troglodytes 3 1.08 1.16 0.86 0.93 0.97 1.08 1.02 1.13 1.09 7/ 1.18 1.14 0.87 1.07 0.97 1.09 1.03 0.63 1.22 Parus ater s 1.03 1.06 0.93 0.91 0.97 1.11 1.03 1.07 0.97 w 1.17 1.10 1.18 1.05 C. 95 1.18 1.02 0.94 1.15 1266 Table 3 (end) 2 3 4 5 6 7 00 9 10 Taeniopygia casta- S 1.06 1.13 0.90 0.95 0.97 1.08 1.01 1.13 1.05 notls w 1.01 0.99 1.12 0. 96 1.00 1.12 1.01 1.11 0.96 Carduelis spinus s 1.06 1.14 a. 92 0.90 1.03 1.10 1.02 1.06 1.03 w 1.10 1.05 0.95 1.06 0.97 1.10 1.01 0.89 1.11 Acanthi s flammea s 1.08 1.14 0.77 0.95 0.95 1.08 1.03 0.94 1.08 w 1.15 1.09 0.97 1.12 0.97 1.13 1.03 0.84 1.17 Parus major s 1.08 1.15 0.83 0.91 0.94 1.11 1.04 1.00 1.06 w 1.07 1.03 0.95 1.00 0.97 1.10 1.03 0.94 1.30 Erithacus rubecula s 1.06 1.21 0.93 0.92 0.97 1.12 1.03 1.08 1.03 w 1.04 1.03 0.91 1.00 0.97 1.09 1.03 0.92 1.16 Pringllla coelebs s 1.07 1.09 1.21 0.89 1.00 1.21 1.01 1.19 0.96 w 1.14 1.09 0.93 1.10 0.97 1.09 1.05 0.81 1.19 Carpodacus erythrinus s 1-11 1.17 Ö.92 0.92 0.97 1.15 1.03 1.08 1.08 w 1 .04 1.01 0.71 1.00 0.97 1.07 1.03 0.86 1.02 Turdus iliacua s 1.06 1.15 0.90 0.91 0.97 1.08 1.03 1.07 1.04 ff 1.12 1.07 1 .00 1.00 0.97 1.17 1.02 0.94 0.93 Passer domesticus o »-> 1.05 1.08 0.96 0.89 0.97 1.15 1.01 1.10 0.S6 w 1.05 1.00 0.91 1.05 0.97 1.06 1.02 0.87 1.04 Smberiza citrinella s 1.07 1.07 0.96 0.93 0.97 1.15 1.01 1.03 0.99 IV 1.22 1.26 0.98 1.06 0.97 1.15 1.02 0.90 1.34 Chloris chloris s 1.09' 1.29 0.97 0.80 0.97 1.13 1.02. 1.19 1.05 w 1.11 1.10 0.92 1.06 0.97 1.08 1.03 0.90 1.08 Turdus philomelos s 1.03 1.04 0.94 0.90 0.97 1.13 1.03 1.06 0.94 w 1.09 1.01 0.98 1.03 0.97 1.15 1.°4 0.91 1.03 Turdus meiula s 1.07 1.06 0.87 0.88 0.94 1.16 1.03 1.00 0.94 w 1.07 1.04 1.18 0.86 1.00 1.18 1.01 1.09 0.87 Coleus monedula s 1.03 1.01 0.96 0.89 0.97 1.15 1.01 1.05 0.87 V 1.08 1.16 0.89 1.00 0.97 1.04 1.01 0.96 1.19 Corvus corone s 1.07 1.05 0.99 0.82 0.97 1.15 1.02 1.04 0.86 w 1.09 1.05 1 .00 0.63 0.97 1.16 1.01 1.03 0.63 Corvus co rax c u 1.09 1.09 0.93 1.00 0.97 1.09 1.03 0.96 1.09 w 1.12 1.10 1.02 0.50 0.97 1.19 1.01 1.03 0.43 Mean s 1.07 1.12 0.93 0.90 0.97 1.12 -.02 1.07 1.01 w 1.10 1.07 0.97 0.98 0.97 1.12 1 .02 0.92 1.05 Non-Passeriformes+Pas sert formes Mean s 1.07 1.13 0.85 0.89 0.96 1.11 1.02 1.06 1.01 'V 1.10 1.08 0.93 0.92 0.96 1.14 1.02 0.96 1.00 1267 G cd •H Tl CO' Pt O -P O •H -P aï rH <1) Pt £ •H 03 03 >> TJ O 4> a) 43 «H O 03 Pt Q) ä p< cd O •H -P <13 bO Pt <13 <13 O •H rO «M O 03 Ü Pi 03 TJ PÎ 03 PU 03 P m I • -p 03 rH H g 4* O 03 cd cd 0) eh ro bO CO O C\J o s •H rH U (U •> 03 C0 03 T- cd il PH PÎ bO CM A 03 «- 03 I o a «H CM •H h B a> 03 ß 03 -H CÖ rH PH ÖCM*“ O T- a z-'. 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O C0 t- in H m O O O O B S S S cd o •H -P 03 03 Pt bû a) ■ -P 03 Pt CD x — /•■s A VO «r-N o A A T~ H* A CM X — vO CM rj- O o T— O r— A O T- 00 CM • O o t- A r- CM CD O O q A A A A VO A • O O o 1 — A c- C*~ A CM • • • • • « • • O 1 • • • • • • « • o o O O O O o o 1 fi O o o G> o O O O » i P CT» H- O a O /-> vo /«■•> >-* A O in r- OJ IA vo vo • • • • o o O O I I B B fi fi co o v£> CM a LTv a a VO A A a in CM 8 2 • O O f o B S a O o \ H” CM r- 00 (A f- 00 • « VO O O O B B B vo O c*- vo - oo VÛ ^ ITS A a a en CM CD CM H* LH a LA CD CM « O B LA co o o (M o o o fi o o I I B B CM vo en CA O H- B B B B fi B B B A A A CO C0 O x — VO CM co A H- A «- vo O ■H r- A A CM % — VO CM vo A A A À 00 vo A O co CM x— r— A A T— A A CM CM A A O T— H- A A •w _ _ • v-z A H- CM r- vo h- A o O co O co vo CM CM T— ■ VO t— A ■>3- *— x — o r- H* n- A V}- o o C*~ A CM x — A r— A x— t*— x — o O A o A CO t- x~~ A O O vo CM O r— n- o • • A A A A A A • • O o T— A t— c*— A CM o o A • ■ • • • O O • « • • • • • • 1 1 • O O O O o 1 B *S o o O O O o O O B E D 0 fi fi fi H fi 0 fi s fi a s fi 0 CM A CO O H- A CM T— vo CM co VO A (O vo tr H* ■ CM A T— X— H- A A A CM co CM T— A co A O A r- T— r- c*- VO T— A A CM CM VO A o A A A A r- t- co co co co co CO \W v‘V o o r— T— tJ 'd tJ & I TJ Ph •H rO A) M I Tl Pt •H ZÛ h) Al I TJ Pt ^ 3 EH !>> cd cd Tl Tl T” k O 1 T3 1 Tl rH Pi *> H EH •h a •rH •* 1 « P O o 0* i O 3 O 3 O S s o E-t o Eh o P rfi co M P O Eh o 1268 (39.9 SEASONAL CHANGES IN THERMOREGULATION AT NIGHTTIME Calculated according to the method of least squares, the relationship between bioenergetio values and weight is given in Table 5 separately in pas¬ serines and non-passerines for two seasons. Below are considered the proper¬ ties of passerine vs. non-passerine adaptations to different seasons. The following bioenergetio indices are compared: energy expenditure during rest- standard metabolism, temperature coefficient of metabolic changes with am¬ bient changes by 1° - heat conductivity (separately for lower and higher tem¬ peratures) the threshold of thermoneutrality, the limit of thermoneutrality, energy expenditure in the zone of thermoneutrality - basal metabolism, the width of the zone of thermoneutrality, body temperature and energy costs of thermoregulation at 0°. Energy expenditure during rest at 0°C or standard metabolism SMR (Fig.5). Both passerines and non-passerines expend a similar amount of energy during rest at 0°C (Table 2, Fig. 6). The principle of seasonal fluctuation mani¬ fests itself in equal expenditure, hence, Fig. 5 shows the relationship bet¬ ween energy cost and body weight only for passerines, for which there are more data available. In summer, energy expenditure is 10-12% higher than in winter. The relationship between standard metabolism and body weight in non¬ passerines has a higher power index 0.54-0.55 (Table 5) due to the fact that the terminal part of the size series in non-passerines is formed by larger birds. The amplitude of seasonal fluctuations of standard metabolism is si¬ milar in terms of the absolute value both in passerines and non-passerines. Heat conductivity at low temperatures (h^). Heat conductivity at low tem¬ pe ratures- ri-TTi^iritüri—cöerTTcTin:E—ö7-mi:Fabo lie rate increase with a temperature decrease by 1°C. Measurements are made under ambient temperatu¬ res lower than the threshold of theimoneutrality zone. Since energy expen¬ diture during rest at 0°C is, in the size range under investigation, similar to both passerines and non-passerines, and there is no difference in body temperature, mean heat conductivity estimated for these species shows no dif¬ ferences (Table 2, 3). Seasonal fluctuations of heat conductivity at low tem¬ peratures are pronounced in non-passerines (Fig. 6)» Ih summer, their heat conductivity is higher throughout the entire size range and differences in¬ crease with an increase in bird size only to a small extent. Passerines Bhow insignificant seasonal deviations from the mean level of heat conductivity, and they have a tendency to exhibiting higher heat conductivity in summer (Fig. 7 ).The slopes of the regression lines concerned are similar to those of the relationship of standard metabolism and body weight. Analysis of spe¬ cies regressions used for the calculation of the respective equations re¬ veals that birds inhabiting higher latitudes exhibit a higher seasonal fluc¬ tuation of heat conductivity, which particularly holds for large non-passer¬ ines (Table 2). On theoretical grounds, energy costs of rest at a definite ambient tempe¬ rature beyond the thermoneutrality zone, particularly at 0°C, vary with body weight, proportionately to body weight in the power 1/2 (Kendeigh, Dolnik, Gavrilov, 1977). It is only passerines that rigidly conform to this rule, while in non-passerines, the equation slope is somewhat steeper. The slope is increased at the expense of larger birds' data, and the larger the birds 1269 Pig. 5. Regressions SMR on body mass in Passeriformes in summer and in winter P i g. 6. Regressions on body mass in Non-Paaaerl formes in summer and in winter 1270 the steeper the curve. Presumably, the change in heat conductivity and ener¬ gy expenditure during rest at 0°C exhibit two opposite trends related to dif¬ ferences in adaptations of large and small birds to the climate and its se¬ asonal variations. The major adaptations of non-passerine northern species is a drop in heat conductivity in winter; hence, northern birds' data at the extreme portion of the size series render the regression slope steeper. Heat conductivity at high ambient temperatures (hu). The presence of the zone of thennoneutraiity and ability of birds to purposely alter heat irra¬ diation indicate that there is more than one type of heat conductivity. In addition to heat conductivity at lower temperatures, which is minimal, there is another kind of heat conductivity at high temperatures (close to the limit of thermoneutrality zone). Heat conductivity at high ambient temperatures is determined by a deliberate increase in body temperature and evaporative cool- ing, which is not associated with increased metabolism. Thus, heat conducti¬ vity at higher ambient temperatures is heat production at the limit of ther¬ moneutrality zone (which is equal to basal metabolism) divided by the dif¬ ference between body temperature and that of the environment, i.e. the higher critical t emp e ra tu re ; . Because the body temperature in the zone ib-1uc of thermoneutrality increases for all the species concerned, the temperature at the upper border of the thermoncutrality zone was assumed to be equal to 42°C. Under such conditions, about half of the heat is dissipated through irradiation, convection and conduction, and the other half - through water evaporation (Gavrilov, 1979). Heat conductivity at high ambient temperatures is two times as high in small species and 6 to 7 times as high in larger species compared with that at lower temperatures (Table 2). This indicates the greater ability of large birds to alter heat irradiation, and, hence, their possession of a broader zone of thermoneutrality. Seasonal variation of H^ is less pronounced than H.|. In Gallif ormes, heat conductivity at high ambient temperatures is higher in winter than in summer; conversely, in Anserif ornes the winter hy is higher than the summer 1^, In other studies of the order concerned, either both situations are recorded, or heat conductivity at high ambient tempera¬ tures is not changed seasonally. Ho difference between average heat conductivity between passerines and non-passerines is recorded (Table 4). The slope of the equations of the re¬ lationship between and body weight is steeper than for h^. The lower limit of the zone of thennoneutrality(Tle ) .There are three re¬ latively idependent factors which determine the position of the limit of thermoneutrality zone: heat oonductivity of the integuments, metabolism rate and body temperature. Hence, the lower limit of the zone of thermoneut— rality is to be most variable, and this. feature can be widely used in adap¬ tations to the body size, climate and season. The principle of seasonal va¬ riation is similar both in passerines and non-passerines (Pig. 8, 9). In summer the threshold of the thermoneutrality zone is higher and it varies with variation of body size to a smaller extent. In birds weighing 1 kg, the winter T-^ is 4° lower than in summer, both in passerines and non-passerines. Passeriformes have a lower Tlc, in summer it being similar to that of non- passerif ormes in winter. The winter T. in passerines 1 kg in weight is 4°C 1271 Non Passeriformes n-tS - 1 — l— I - LLLJ - 1 I I I I II II I ii 30 HO 50 BO WO 200 H 00 600 1000 2000 HOOO ™,9 P i g. 8. Regressions T^c on body mass in Non-Passeriformes in summer and in winter ter lower than in non-passerines of similar weight. Seasonal fluctuations of T^c are more pronounced and show a more stable trend, compared with fluc¬ tuations of heat conductivity and standard metabolism. The upper limit of the zone of thermoneutrality or the upper critical tempera¬ ture (Tue)» The position of the limit of thermoneutrality on the temperature scale is determined by the limit of increase in the heat conductivity of in¬ teguments, the limit of adaptive body temperature, the level of water evapo¬ ration, which does not involve any special energy expenditure. We have not found any fluctiation of the threshold of thermoneutrality zofte as a function of body weight. Seasonal variations of Tuc indicate some small and insignificant tendency to lower Tuc in winter compared with summer time. It is also more pronounced in northern birds, both passerine and non- passerine. These variations do not go beyond one degree; hence, there is a reason to believe that does not depend on body size and does not vaiy seasonally (Table 2, 4). The lenght of zone of thermoneutrality (Tuc - Tlc). The zone of thermo¬ neutrality is a range of ambient temperatures within which heat production is at an unchanged (basal) level , and changes in heat irradiation with chan¬ ged ambient temperature are provided by a purposeful elevation of the body 1272 Pig. 10. Regressions BMR on body mass in Non-Passeriformes in summer and winter temperature and changes in evaporative heat irradiation. The zone of thermo- neutrality is a phenomenon characteristic of homoio thermal animals only. The existence of the thermoneutral zone does not follow from the Newton model or from any other model. The length of the zone of thermoneutrality depends on the ability of birds to alter heat irradiation, maintaining the level of heat production unchanged. Because with changes of body size, it is only the thereshold of the zone of thermoneutrality that is shifted, its limit remain¬ ing virtually unchanged, the equations for the relationship between the breadth of thermoneutrality zone and body weight will be in principe the re¬ verse of the equations for the relationship between the lower critical temperature and body weight. In winter, both passerines and non— passe¬ rines increase their thermoneutrality zone by 4°C, with body weight being equal to 1 kg. In passerines, the zone of thennoneutrality is invariably broader than in non-passerines, suggesting that Passeriformes have a greater possibility of changing the level of heat irradiation without changing heat production. In winter, both passerines and non-passerines retain the level of heat production unchanged at lower ambient temperatures (Pig. 3,4, Table 2). With temperature fluctuating within a wide range, expansion of the zone of thermoneutrality is expedient, particularly in winter. Basal metabolism (BMR). The Passeriformes and non-passeriformes exhibited different patterns of seasonal BMR rates. On the whole, BMR in passerines is higher in winter and in summer (Table 2, 4). Non -pas serines (Fig. 10 show partically no seasonal fluctuations of basal metabolism. In summer, BMR is only 6% higher than in winter. Conversely, the winter BMR in passe¬ rines (Pig. 11) is 10-12% higher than in the summer one, the power indices in the equations being similar to those of non-passerines. Thus in summer the basal metabolism of Passeriformes is, on the average, 27» ê : er that in non-passerines, while in winter this difference attains 48% .An 1 - crease in basal metabolism in winter lowers the threshold of themoneutra- ^ Pig. winter lity zone, expanding this zone. Since heat conductivity of the integuments in passerines and non-passerines is similar, but shows different fluctuat¬ ion patterns, ft is exactly the high basal metabolic rate in Passeriformes that ensures their broader zone of thermoneutrality which covers a broader boundaries of lower temperatures. Thus, an increase in the level of basal metabolism offers an advantage for life under cold conditions, particularly, for small birds, in which heat production - heat irradiation/ratio is un¬ favourable. Body temperature (Tb). For maintaining the heat balance, birds not only rely on heat production and heat irradiation changes, but also on chan¬ ges in body temperature. With elecation or lowering the body temperature the birds can respectively develop or not develop hypothermy or hyperthermy .both depending not only on the ambient temperature, but as a function of the season, (see Tb changes in Table 2). Analysis of data on the relationship of body temperature in species under study and body size reveals a very slight tendency to lowering body temperature with an increase in size both m passerines and non-passerines. Passeriformes exhibit an insignificantly lower mean body temperature (Table 2,4 >. Seasonal variations of T. are somewhat more pronounced and show a more stable trend in passerines under study in which in winter Tb increases on an average by 0.5 degree. In non¬ passerines a weak tendency is revealed to lowering body temperature in win¬ ter, particularly at low temperatures (in Table 2, the value of T. is mean body temperature in terms of all the measurements in different body tempe¬ rature ranges for all the species studied). Seasonal variations of body tem¬ perature are presumably not quite adaptive but associated with heat product¬ ion level, in particular, with the level of basal metabolism. Energy expenditure on thermoregulation at 0°C (SMB -BMP). One of the in¬ dices of seasonal re-adjustment of metabolism is energy expenditure thermo¬ regulation at a definite ambient temperature, which is beyond the zone of 1274 Pig. 12. Hegressions SMN-BMR on body mass in Hon-Passerlf ormes in summer and in winter Pig. 13. Regressions SMR-BMR on body mass in Passeriformes in summer and in winter thermoneutrality in all the species under study. We have calculated energy costs of thermoregulation at rest at 0°C, which is equal to standard meta¬ bolism at 0°C minus basal metabolism. Tn terms of this index, passerine and non-passerine birds differ only in the level of energy expenditure on thermo¬ regulation, the underlying pattern of seasonal changes being the same (Pig. 12, 13). In summer energy expenditure for thermoregulation is considerably higher than in winter, the difference increasing with an increase in bird size. In Passeriformes, the slopes of regression lines are steep, due to higher level of basal metabolism, on the one hand, and to the lower threshold of thermoneutrality zone, on the other. The level of energy expenditure on the iroo regulation in non-passerines in winter is the same as in passerines in summer. In winter, average energy costs of thermoregulation are 25/. lower in passerines compared with non-passerines. This indicates that on the who e the species under study are better adapted to lower ambient temperatures compared with non-passerines. 1275 Of all the bioenergetic parameters characterizing the metabolism of a resting bird, i.e. standard metabolism, heat conductivity, body temperature, the boundaries of thermoneutralilTy zone, breadth of therrooneutrality zone, basal metabolism, energy costs of thermoregulation, body temperature is the most stable index, which is not (almost or entirely) dependent on body size and ambient temperature. The fluctuation of all the other indices are aimed at maintaining a stable temperature of the body at different ambient tempe¬ ratures in different seasons and with different body sizes. Heat irradiation in standard conditions (i.e. standard metabolism or heat conductivity) of the body devoid of heat-insulation integuments is to in¬ crease with an increase in body size, i.e. proportionately to the body size value in the power 2/3. In bodies with heat-insulating integuments, heat irradiation should increase proportionately to the product of body surface by specific heat conductivity of the integuments. Apparently, every species can, adjusting to given ecological conditions, change the specific conducti¬ vity of the integuments, breadth of the heat-insulating layer, and hence, change heat conductivity and heat irradiation. Non-passerines gain an advan¬ tage by reducing heat— conductivity in winter. In some orders adaptation through seasonal heat conductivity changes are more common, for instance, in Gallif ormes, presumably due to some features of plumage. Birds with long and mobile feathers are, in addition to seasonal changes of heat conductivity during moult, capable of instantaneous heat conductivity changes through fluffing up the feathers or pressing them against the body. This permits to considerably change the heat conductivity with appreciable fluctuations of ambient temperature. Another adaptation type is changing the heat production level, and not heat irradiation, in response to temperature fluctuations, which is mostly characteristic of the passerines under study. The optimal zone of ambient temperature is known to be somewhat lower than the threshold of themoneutral zone. Hence, the threshold of thermo¬ neutral zone exhibits the greatest adaptive seasonal variation. The lowe— ing of the thermoneutral zone threshold in winter is accomplished by non- passerines through reducing heat conductivity of the integuments, and by passerines — through enhancing the basal metabolism rate. With the same mean heat conductivity, passerines, whose basal metabolism rate is 1.3-1. 5 times as high as in non— passerines, increase the breadth of thermoneutrality zone by 1.3 to 1.5 times too. Under such conditions, if the thermoneutral zone threshold in a non-passerine bird is equal to 25°C, it will be 19°C in a passerine one. This reduces considerably the optimal range of ambient tempe¬ ratures, giving an advantage to existence under colder conditions. Homoiothermal animals are known to maintain adequate energy equilibrium with the environment in every season of the year through two substantially different mechanisms, i.e. seasonal acclimatization and adaptation. Seasonal acclimatization is a seasonal change in the level of adjustment of homeosta¬ tic systems developed as a result of natural selection. Acclimatization emer¬ ges in response to the impact of environmental cues, or as a result of an endogenous ihythm. Adaptations are a complex of adaptive reactions which originate in response to the impact of primary (selective) factors of the 1276 environmentJVdaptationB have no seasonal fluctuations and is aimed at main¬ taining homeostasis at a pre-set acclimatization level. It can be assumed that seasonal acclimatization in passerines and non- passerines, which manifests Itself in lowering the threshold of thermoneut¬ ral zone and expanding the theimoneutral zone, is accomplished in pas¬ serines via changes of the rate of basal metabolism; and in non-passerines - via changes in heat conductivity. The latter strategy is associated with changes in plumage quality; hence it does not respond so fast to environmen¬ tal changes in comparison with the basal metabolism rate. A higher level of basal metabolism in passerine birds presumably results in another trend of adaptation to climate seasonality, i.e, the one which falls back upon heat production change, rather than heat irradiation change. COMPARISON OP LEVELS IN DAILY CHANGES OP THERMORE GU LA T I ON INDICES IN DIFFERENT SEASONS It follows from the above that there are seasonal differences in the level of adjustment of homeostatic systems, which manifest themselves at different thermoregulation indices. On the other hand, each season Is characterized by circadian rhythms of metabolism too, which also affect avian thermoregulation. Comparisons of the magnitude of such indices are given in Table 3,4 . Analy¬ sis reveals that thermoregulation varies in a wider range seasonally , while its circadian fluctuations are more uniform irrespective of the season. Cir¬ cadian variation manifests itself in an increase in some parameter or a decrease in others in relation to the level pre-set by seasonal acclimatizat¬ ion. Daily fluctuations are practically similar in passerine and non-passe¬ rine species, while the principle of seasonal acclimatization in these two groups may differ. Hence, it is seasonal fluctuations of thermoregulation that should be pri¬ marily taken into account, with subsequent corrections for circadian changes. References Aschoff J., Pohl H. - Joum. für Ornithologie, 1970, VM, N 1 , S. 38-47. Gavrilov V.M. - Zool. Zum., 1979, 5§, N 4, 5, p. 530-541 , 693-704. Gavrilov V.M. - In: Ecologia, geographia i okhrana ptitc, 1980, Leningrad, p. 73-97. Gavrilov V.M. - Omitologia, 1981, N 16. Moscow, p. 42-50. Gavrilov V.M. - in: Ornithological studies in the USSR, 1982. Moscow, "Nauka", p. 377-402. Kendeigh S.C.,Dolnik V.R. .Gavrilov V.M. - In; Oranivorous birds in ecosys terns. Eds. J.Pinowski and S.C.Kendegh. Cambridge University Press, p. 127-204. *1 I - - 1-277 ■ BIBÜÔÎHÈôÆ j HOLARCTIC AVIAN SPECIATION ATLAS I.HiJ.Lyster, D.T. Lees-Smith Royal Scottish Museum, Chambers Street, Edinburgh EH1 1 JF, Scotland; 134 The Avenue, Starbeck, Harrogate, North Yorkshire HG1 4QP, England The purpose of this atlas is to map, with commentaries, the breeding distributions of the 2014 biological bird species of different biogeographi- cal elements and origins which breed regularly entirely or partly within the Holarctic faunal area (the Palaearctic and Nearctic Regions of classical zoogeographers combined) from the arctic regions south to mid-Sahara, Arabia, Himalayas, west China, south Mexico with the Atlantic Islands and the eoolo- gical "islands" of the high montane areas of Taiwan and Chiapas/Guatemala. The atlas is intended as a contribution to better understanding of species evolution and the conservation of environments and gene "pools". The model for HASA is the two-volumed atlas of spéciation in African birds (Hall, Moreau, 1970; Snow (edw), 1978) published by the British Museum (Nat¬ ura 1 History ) . Whilst the various "national", "state" and "provincial" bird atlases of western Europe and North America are pure "gridded" distribution¬ al atlases without reference to relationships and evolutions of the taxa dealt with, HASA will not only map species by shading and symbols, but will also comment upon the ecologies and relationships of the species included and consider these in context of current understanding of the climatic and vegetational changes known to have been caused by the advances and retreats of the several Pleistocene glaciations. Morphologically distinct isolated populations are of paramount importance as these could represent stages in the spéciation process. As it is intended that this atlas should incorporate, as far as possible, the most recent data from museum and field studies with these obtained as efficiently as possioie, the preparation work is split between data gather¬ ing- from museum material, field records and published literature on the one hand and the actual map preparation with commentaries on the other hand. To faciliate data gathering, the entire Holarctic avifaunal area is divided into 306 areas grouped into three categories based upon the extent of or¬ nithological knowledge available for each area. The data so gathered is pas¬ sed on to specialists in different taxonomic groups who prepare the maps and write the accompanying commentaries. Whilst the ."master" map showing the whole Holarctic avifaunal area (see example attached to report) is based upon the Modified Gall Projection with Equatorial Scale of 1: 110, 000,000, all "subsidiary" maps (outlined upon the example of the "master") will be Equal Area Projection maps with one ex¬ ception. That exception is the North Polar centered map down to 60N for show¬ ing arctic and circumpolar taxa, for which the selected projection is the Zenith Equidistant with scale of 1; 24,000,000 (see map). Recruitment, on a voluntary basis, of area data collection organizers for areas and of taxonomic group specialists is now in progress; ten years work is envisaged to complete the maps and commentaries ready for publication by 1278 £ s • o Jz; 00 • O P CM P cd O d d CD T— d 3 O 3 H P P CD O (D p o p P o P p ? EH 3 cd P d O d 0 O d O bO 0 h cd rH O PM 43 -P O S3 CM d o P bû d ü H a> O •rD CÜ O S - d> “ O P O •P M O O MO O P P 03 cd CD cd O P *H 4 o P cd en p 'd O co 03 ft p d cd cd cd d 43 a S S3 0 *~D 3 p P 0 0 fl en T* O "d •* s o en d v£> d ed p CD en 2 cd 0 3 a> H bO aJ o S3 O fl o M U O cd in P O H p c O d m h JM O p » o M a> bd p 0 en 'd o P en O g P S 43 • P O » 3 O o z P aS d H — 0 p bO d Ü 0 ir> M en a o P B 0 c— o a> W p en JM p O O 0 T3 (D en d 0 m g o fl £5 0 cd p o (d en P a < P o o as p •H CD P S O d H ft rH Cfl cd 0 O z P d a> cd Es W I • t -2 cd en 4 g +» 5 m 6 2 p H d H CD < O § p cd o bO a> # p 03 •H CD JM o « CT) I «H O d ,o 09 >? t> fl en p o 3 m ed aJ o p o ,o p • P d Ph d d aS p p en M d a> d ft <î ü ed Bfl i p •> P 03 p 3 *) •5 eo en en 0) p p d K P P en d U as cd p • p d d p 3 m p o 3 CD P rH 09 » fl i — i 43 d P as 43 P d o 3 43 03 p p d p +■ d p O p P P d o 43 o 3 a) p d p aî 3 PQ p •w cd o a> S ° p B 03 d Eh en eo 3 o •5 • as fl aS p eo p U d •*■ P P p O v. p CD as o d en VD o o 0) » fl p p p » b£ en p 1 O ft. 43 en •* 3 0$ o aS p p CO en U p - fl en fl a> fl P kd S t 5 ta fl p rd p CD w 43 o o U p « p o P d O *ra p S U fl o p en p fl o d p 5 Ö en § 1 p P ÉH d 09 Ü d w CL) W * CD o d d o en d p • bO S3 0 en a> a) p p p (1 p »■ o d p CO O ü o U p d CD W Q S3 02 cd d O 03 ft P d • CD S3 g O CD O P m **”* - ‘i.rr zrs™ x. — «». °Krivonosov G.A. , ur. ABiroiau. Astrakhan 416605, USSR pAJJ 80_630 Gdansk 40, Poland Krôl A., Dr. Omitho og ca ^ ^ 80_680 Gdansk 40, Poland Kro'l W. , Dr. Omitho og ca ^ University of Massachusetts, Jjf, “ , »of. foologlo.l laboretonf. *>« »• "50 A* »«» Or.. The Netherlands "" ' Acad. USoR 36, Tomsk 634010, USSR iKrushinsky h. T7J( Dr., Prof., Corr. Memb. Kaenz A.S., Dr. Tomsk State University, Lenin pr . . . Kuchin A.P. , Dr. Gorno-Altaisk State Pedagogical Institute, Departmen o Zoology, Sotsialisticheskaya, 28, Gorno-Altaisk 659700. USSR Küdryavtsev S.M. , Dr. Moscow Zoo, B.Gruzinskaya ul. , 1, Moscow Prioksko-Terrasny Reserve, P.0. Danki, Moscow reg. Vilsandi Reserve, Vilsandi, Kingisepp dist. , Estonia 7, PRG Kuligin S.D. , Dr. USSR Kullapere A. , Dr. 203334, USSR iKumary B.V.I, Dr., Prof., USSR Kumerloeve H. , Dr. 8032 MÜnchen-Gräf elfing, Hubert-Reissner-Str. ♦Kumerloeve G. , Mrs. . . . . _ _ Kunichenko A.A., Dr. Institute of Zoology and Physiology, Akademichesk y Ul. , 1, Kishinev 277028, USSR Kurashvili B.E., Dr., Prof. Institute of Zoology, Chavchavadze pr. , 31, Tbilisi 380030, USSR “Kuresoo A.U. , Dr. Institute of Zoology and Botany, Vanemuise, 21, Tart 202400, USSR , Kurganova F.N. , Dr. Institute of Zoology and Physiology, Akademicheskaya u 1 , Kishinev 277028, USSR 1306 T™'? “inl8tl7 °f A7latlon Indus^. Ulansky per., 16, Moscow i Ul {iff USSR °Kurlavioius A.X., Dr. Academy 0f Agriculture, Noreikiskea -, Kaunas 234324, USSR Kurlavicius P.I., Dr. Institute of Zoology and Parasitology, Laysves al. , 53, Kaunas 233000, USSR Kurochkin E.N., Dr. Institute of Paleontology, Prof soyuznaya ul. , 113, Mos¬ cow 117321, USSR Kurochkin M.L., Dr. Odessa State University, Biological Department, Sham- pansky per., 2, Odessa 270015, USSR Kuznetsov A. A., Dr. Zoological Museum, Hérzen ul. , 6, Moscow 103009, USSR Kuznetsov B.A., Dr. Simpheropol State University, Yaltinskaya ul. , 4, Simpheropol 333036, USSR Kuznetsov G.A. , Dr. All-Union Ornithological Society, 1 Kotelnichesky per., 10, Moscow 109240, USSR Kwon K.-Ch. , Dr. Department of Biology, Dong-A University, Pusan 600, S. Korea Kydyraliev A.K. , Dr.Institute of Biology, Lenlnsky pr. , 265, Frunze 720071, USSR L Labutin Yu.V. , Dr. Institute of Biology, Petrovsky ul. , 35, Yakutsk, USSR Laidna A. A., Dr. Institute of Zoology and Botany, Vanemuise, 21, Tartu 202400, USSR “Lantbruks S., Sweden Lapshin H.V. , Dr. Institute of Biology, Pushkinskaya ul. , 11, Petrozavodsk 185610, USSR Larionov G.P., Dr. Yakutsk State University, Lenin pr. , 33, Yakutsk 677007, USSR Larsson B. , Mr. Meteorology Office, Krigsflygskolan, Box 501 , S-26070 Ljungbyhed, Sweden ^Laty M. , Mr. CRFASE 21 Avenue J. Isaac, 13617 Aix en Provence, France Lauersdorf I. B., Mrs. Unir. München, HDO-Poliklinlk, Pettenkoferstr. 8a, D-8000 München, 7RG Laybourne R.C. , Mrs. US Fish and Wildlife Service Smithsonian, 10006 Evans Ford Road Manassas, Virginia 22111, USA bedeva M.I. , Dr. Institute of Evolutionary Morphology and Ecology of Animals, Leninsky pr. , 33, Moscow 117071, USSR Lebedinsky V.I. , Mr. Ministry of Aviation Industry, Ulansky per., 16, Moscow 101717, USSR Lebedkina E.V. , Dr. Management of International Relations, Leninsky pr. , 14, Moscow 117901, USSR Lederer R. , Dr., Prof .Department of Biological Sciences, California State University, Chico, California 95929, USA Ledin Yu.Ya. , Mr. All-Union Ornithological Society, 1 Kotelnichesky per., 10, Moscow 109240, USSR Lee K.-S. , Dr.Institute of Ornithology, Kyung Hee University, Seoul 131, S. Korea Learning O.H. , Mr. RAF Inspectorate of Flight Safety FS 2e (RAF) Room 414, Adastrac House Theobalds Road, London, UK Lees-Smith D.T. , Dr. 134 The Avenue, Starbeck, Harrogate, Forth Yorkshire HGL 4QF, UK °Leht R. , Dr. Institute of Zoology and Botany Vanemuise 21, 202400 Tarty, USSR Leipe T. , Mr. 2200 Greifswald, Thälmann Ring 9/27, GDR Leisler B. , Dr. Vogelwarte Radolfzell 1 6, D-7760 Radolfzell’, FRG 1307 L.i,0 ..... ». inti««.. °< RSätaf«, R. .t” “"lTn».-r-. s*» «it. «ra«2. Lai vit s A.T.. Dr. Nigula Raaerve Kiling Turku, SP_20500 Lemraetyinen R. , Dr. Department of Biolog,, Onivera jzzzx — - — «■• oi- r“i trrsrs ssriTi.— j.ïïT'rsr.«“ Austria ., „„-a-i tät PSF 302, 4020 Halle, QDR Liedei K. , Dr. Anatomisches Institut, 226098. usgR Liepa A. E. , Dr. Latvian State W ,3,324. USSR Liepaïu., Dr. Academy of Agricuitu«. « g’alBBpiiB 229021, USSR s;:^r:r.rr;rrrw^,, — - 3,««. LilïT, Dr. zoological Department, Monash University . Clayton, Victoria —«. - — - — — ■ "• ““ Game and Kft.. Inatltut. Gam. Mvlelea. :i“Ä =:ä- — - , c DR-2100 Copenhagen, Denmark u.‘^T.i ” ». I».«!«« e< s”iu‘i™ ;"Sï10EI °f S;«S;. "“".ion «d Gall »!—•. 01 Litvinen o * * ' ,59 Vladivostok 690022, USSR »• «-*- »*»<■. ». jz r,r»!“i.». «... «. «“«■ ^ USSR „ Pvprton Rd. Kimherley 8300, Liver eidge R. . Dr. «oOr.gorla.eum, Dorn 3<6. g South Airi i Zoa Hexing Road, Harbin, China S. - — Aviation. Leningrad.« ,«• . 3,. »- „ÏÏ?;.Ï%. — — “»*-'»• I““' L0b"‘- »r.;«S..rve, „.hikov .1. . ,3. — . — Lo^nLs6v!v.!’^v!lnius State Pedagogical Institute, Studentu, 39, Vilnius 232034, USSR _ rinn Eichen 5, D-7271 Egenhausen, BRD ££ ti. » ,,ra4' "sæ Loparev S. A., Mr. All-Union Ornithological Society, 1 Kotelnichesky per., 10, Moscow 109240, USSR Loskot V.M. , Dr. Institute of Zoology, Universitetskaya nab., 1, Leningrad 199164, USSR Louette M. , Dr. Koninklijk Museum voor Midden Afrika, B-1980 Tervuren, Belgium “Lovejoy Th.E. , Dr. World Wildlife Fund, Washington, DC, USA Lubcke U. , Dr. Oevelgönne 66, D2000 Hamburg 52, FRG Lubrano A., Dr. Institute and Museum of Zoology, via Mezzacannone 8, 80134 Napoli, Italy “Lucca de E. J, , Dr. Departamento de Genética, Instituto Basico de Biologie Màdica e Agricola, Universidate Estadual Paulista "Julio de Mesquita Filho", Botucatu, Sao Paulo, Brazil Lucci V. , Mr. Servizio Sicurezza Operativa Société Aeroporti di Roma, Roma, Italy Luethi M. , Mr. Swiss Air Force and Anti-Aircraft Logistics Command CH-8600 Duebendorf , Switzeland Luleeva D.S., Dr. Institute of Zoology, Universitetskaya nab., 1, Leningrad 199164, USSR Lundberg A., Dr. Department of Zoology Uppsala University, Bom 561, 75122 Uppsala, Sweden Luniak M. , Dr. Institute of Zoology, Wilcza, 64 00-950 Warszawa, Bom 1007, Poland Luthin Ch. , Dr. Vogelpark Walsrode, Am Rieselbach, 303 Walsrode, FRG Luzzatti C. , Mr. Aeroporto Civile Alghero (Sassari) 079/930192, Italy Lysenko V.I. , Dr. Melitopol State Pedagogical Institute, Lenin ul. , 20, Melitopol 332315, USSR Lyster I., Mr. Royal Scottish Museum, Chambers St., Edinburgh, EH1 IJf, Scotland, UK Lyubushenko S.Y. , Mr. All-Union Ornithological Society, 1 Kotelnichesky per., 10. Moscow 109240. USSR m Maher W.J. , Dr. Biological Department, University of Saskatchewan, Saska¬ toon, S7N CWO, Canada Mayakov A. A., Dr. Perm State University, Department of Zoology , Bukerev ul. , 15, Perm 614000, USSR Makarov V.V. , Dr. Kursk State Pedagogical Institute, Radistchev ul. , 33, Kursk 305416, USSR |Makatsch W. , Diu| Maksimova A.P., Dr. Institute of Zoology, Akademgorodok, Alma-Ata 480032, USSR [iflalchevaky A.S. , Dr. ProTJ Manez Rodriguez M. , Dr. Museum Nacional de Ciencias Nat., Castellana, 80, Madrid-6, Spain Mantorov O.G. , Dr. School, Ungry, Oknitzky dist. Moldavia 279511, USSR “Marian M. , Dr. Ungarische Omithologische Gesellschaft, H-6720 Szeged, Kelemen u. 4, Hungary Marisova I.V. , Dr.Nezhin State Pedagogical Institute, Krapivnyansky ul. , 2, Nezhin, Chernigovskaya reg. 251200, USSR Markin Yu.M. , Dr. Oka Reserve, P.0. Lakash, Spassky dist., Ryazan reg. 391072, USSR Marr N.C. , Mrs. 1/160 North beach Dr. Tuart Hill, 6060 West Australia “Marten J. A. , Dr. Museum of Vertebrate Zoology, University of California, Berkeley, California, 94720, USA 1309 „ . „ j Dr Px0f. Institute für Zoologie, Saastr. 21, D-65 Mainz, FRG Inez Mr. Comission Investigacion de Accidentes Aereos, Avd. T*?" College Ïtnshu 1... Masatomi •. Tel-Aviv University, Israel „ “Maalaton S. , Dr. Zoologies ep . vanvitelli 32. 20129 Milano, Massa R. , Dr.. Prof. Institute Faxmacologia. via Vanvi “Mastronardi D. . Dr. Institute and Museum of Zoolog,, via Mezzacanone 8. uZ-nt °« »*• °”1U" Mv*8lrt’ C‘U‘ ».,« Te. ®««T ».«»• *“ *»• 40235 05,rt"rS' den oMatf^sü Dr! Department of Zoology, University of Washington, Seattle, «ÄT. ZZl». — — . s“‘“- ä r™ - — - »— «-• Tashkent 700095» USSR _ tïr Milcinskega 14, Ljubljana 61000, Jugoslavija ZZ4« i * ■ —, 404 >— • — - «' Pool«'---*’- *•«*"*. 51..JC. Pnl».r.;t,, »Uw». 012 »«■ Scottlana.UZ „„.«rc«., BpU »«.a, BAU, Chib. rrr» ; — ■ «—• » - »-• a»2»-« — - —■ - 2"k ”502; °“ c„t„ d, MB, Zoolog«... « «onttéal. »I«'- McNeil R., Dr., Prof. aoO Box 6128, Succursale „it* de Montréal, 5858 cSte-des-Neiges, suite 400, hills, Moscow 117234, USSR Salaspils 229021, USSR “Üf »riÏÏÎÏ ~ Naturli jke Historie, Raamsteeg 2, 2311 PL "r‘orÏ.°Î»Sl..h. Institut «a I0.l00.0h.. B— Vl.ai«nl.. ht. a»«*“*- °' “°1— w“*"k s'*** V“" „iS: Z’. S“*.l“°.l V.“, — i...W.A» -5, «1» “ah--““ „ '■ DcT"L «,««—. o. Zoolog, i «.Z. um.«.!«,. Barola »0002 Ml. ZZZZl ». Institut. Ion Zoological »...«oh, K.np.nt.ng.-.S 61. 6816 RM Arnhem, The Netherlands Moscow 123820, USSR „oahlv V.A., Dr. Moscow Zoo, B. Gruzinskaya ul. , 1, Mmmw 1«, M -D tt TVr Bockumer Str, 289, D-4000 Dusseldorf 31. FRG Meylmrg B.-U*, Ur. , . * Milano and Society °Minali G. , Dr. Department of Pharmacology, University of Milano »A. Chigi" f or Vertebrate Biol. , Italy 1310 “Michev T.M. , Dr. Reaearoh Institute of Nature Conservation, 113 Sophia, Gagarin 2, Bulgaria ihlhelaon H. A4, Dr. Mikheev A. V. , Dr., Prof. Moscow State Pedagogical Institute, Department of Zoology, KIbalohioh ul. , 6, koiT?. 5, Moscow 129243, USSR “Mikhalevich O.A. , Dr. Kiev State University, Vladimirskaya ul. , 60, Kiev 25 2017, USSR Miller D.B. , Dr. Department of Psychology, U-20 University of Connecticut, St orra, CT 06268, USA Milone M. , Dr., Prof. Institute of Zoology, via Mezzacannone 8, 80134 Napoli, Italy Mlneyev Yu.N. , Dr. Institute of Biology, Kommunistioheskaya ul. , 24, Siktivkar 167610, USSR Mirzobakhaburov R. A., Dr. Leninabad State Pedagogical Institute, Voykov ul. , 216, Leninabad USSR Mironov S.V. , Mr. All-Union Ornithological Society, 1 Kotelnichesky per., 10, Moscow 109240, USSR Mistchenko N.G. , Mr. Ministry of Civil Aviation, Leningradsky pr. , 37, Moscow 125167, USSR Mistchenko A.L. , Dr. Moscow State University, Biological Department, Lenin- hills, Moscow 117234, USSR Missbach D. , Dr. Medizinische Academie Magdeburg, 3090 Magdeburg, Leipziger Str. 44, GDR Mityaj I.S. , Dr. Cherkassy State Pedagogical Institute, K.Marx ul. , 24, Cherkassy 257000, USSR Mlikoveky J. , Dr. ÎSAV, Department of Evolutionary Biology Na Folimance 5, 12000 Praga., ÎSSR °Mocci-Demartis A., Dr. Institute of Zoology Viale Poetto, 1-09100 Cagliari, Italy °Moermond T.C. , Dr., Prof. Department of Zoology, University of Wisconsin, Madison, WI 53706 USA Mokhov V.F. ,Mr. Ministry of Aviation Industry, Ulansky per., 16, Moscow 101717, USSR Molodan G.N. , Dr. Donetzk State University, Biological Department, Univer- sitetskaya ul. , 24, Donetzk 340065, USSR Molodovsky A.V. , Dr. Gorky State University, Biological Department, Gaga¬ rin pr. , 23, korp. 1, Gorky 603091, USSR Monaghan P. ,Dr. Department of Zoology, University of Glasgow, Glasgow G12 8QQ, Scotland, UK °Mongini E. , Dr. Zoological Department , Parma University, Parma 43100, Italy °Moore M. ,Dr. Department of Zoology, University of Washington, Seattle, WA 98195, USA Mordvinov Yu.E. , Dr. Institute of Biology of the South Sees, Nakhimov ul. , 2, Sevastopol 335000, USSR Morenkov E.D. , Dr. Moscow State University, Biological Department, Lenin- hills, Moscow 117234, USSR Morgan R.A. , Dr. British Trust for Ornithology, Beech Grove, Tring, Hert¬ fordshire, UK Morgan P.J. , Dr. National Museum of Wales Cardiff, Wales, CFI 3NP, UK Morioka H. , Dr. National Science Museum, Department of Zoology Hyakunin-cho 3-23-1, Shinjuku-ku, Tokyo 160, Japan Moroshenko N.B. ,Dr. P.0. 48, Baykalsk 665914,Sludyansky distlrkutsk reg. .USSR Mortensen A., Dr. Department of Arctic Biology, University of Tromss*, Norway 1311 Moskwitin S.S., Dr. Tomsk State University, Zoological Museum, Lenin pr. , 36, Tomsk 634010, USSR Mourer-Chauvire C. , Drs. Department des Sciences de la Terre, 27-43 BD DU 11 Novembre, 69622 Vileurbanne Cedex, Prance Mundinger P. , Dr. Department of Biology Queen s College, CUNY Flushing, New York 11367, USA ^ Murphy M. ,Dr . Department of Zoology, Washington State University Pullman, Musaev^A-M* , Dr. Institute of Zoology, Kiylov ul. , 5. Baku 370073, USSR oMustafaev K.T. ,Dr. Baku State University, Biological Department, P.Lumumbu ul. , 23. Baku 370073, USSR Myand R.A. , Dr. Institute of Zoology and Botany, Vanemuine ul. , 21, Tartu, 202400, USSR »iyasoedova 0. M. , Dr. Dnepropetrovsk State University, Biological Department, Gagarin ul. ,72, Dnepropetrovsk, USSR “Nachtigall W. , Dr. , Prof. Zoologisches Institut der Universität des Saarlan¬ des 6600, Saarbrücken, FRG Nadler T. , Mr. Institut für Luft- und Kältetechnik, 8047 Dresden, Langobar- denstr. 98, QDR Nadtochy A.S. , Dr. Kharkov State Pedagogical Institute .Biological Departmen Artem ul., 29, Kharkov 310078, USSR °Naik R.M. ,Dr. Department of Biosciences, Saurashtra University, Rajkot 360005, India Nakamura Ts., Dr., Prof,. Department of Biology, Yamanashi University, Kofu 4 400, Japan Nankinov D.N. , Dr. Institute of Zoology, Russky bul. , 1, Sofia, 10000, Bulgaria Nastro S. , Mr. Alitalia Servizio Navigazione NRG/FCO Finmicino L. da Vinci, Rome, Italy Nazarenko A. A., Dr. Institute of Biology and Soil Sciences, Stoletya Vla- divostoka pr. , 159» Vladivostok 690022, USSR Nazarenko L.F. , Dr. Odessa State University, Biological Department, Sham- pansky per. » 2, Odessa 270015» USSR Navasaitis A.Z., Dr. Akademy of Agriculture Department of Forestry, Norei- kiskes, Kaunas 234324» USSR Nechaev V.A., Dr. Institute of Biology and Soil Sciences, Stoletya Vladi- vostoka pr. , 159.» Vladivostok 690022, UoSR Nechay G. , Mr. •> Hungary Necker R. , Dr. Ruhr-Universität Bochum, P. f. 102148, 4630 Bochum 1, FRO Nedoseckin V.Yu. ,Dr. "Galichya Gora" Reserve, P.0. Donskoye Zadonsky diet., Lipetz reg. 399020, USSR Nedzinskas V.S., Dr. "Zhuvintas" Reserve, Alitussky dist. Lithuania 234583, USSR Nehls H.W. , Dr. Zoologischer Garten, Rennbahnalle 21 , Rostock 2500, GDR Neifeld I. A., Dr. Institute of Zoology, Universitetskaya nab. ,1, Leningrad 199164, USSR Nekhoroshkov S.A. , Dr. Frunze State University, Biological Department, Frunze ul. , 32, Ufa 450074, USSR Nekrasov A.V. , Dr. Institute of Biology, Fabrichnaya ul. , 6, Ulan-Ude 670042, USSR Nerlich R. , Dr. Astfelder Str. 41, 3380 Goslar, FRG “Nettleship D.N. , Dr. Canadian Wildlife Service, Bedford Institute of Oceano¬ graphy, Box 1006, Dartmouth, N.S., B2Y 4A2, Canada 1312 0Neu7°n(in V. , Mr. Oy Gleisradio Ab, Helsinki, Finland ÏZhinaI;'MDr‘ï0nkS W°0d 3X1,131 Statl0n Abb0ts RiPton, Huntingdon 215, HK ’Nichollsw Z M-Plr°80Vakaya ttl" ’> ”9435. USSR bolls T. J., Dr. Department of Zoology, University, Woodland Rd, Bristol, Nicholson B.M. , Dr. 13, Upper Cheyne Row, London SW 3 5JW, UK NieWr l’ ’ Z' ’ Pr°f’ In8titut f"r Togelforsohung, 2940 Wilhelmshaven, FRG ■’ r’ Biol°6ical Laboratoiy Vrije University, De Boelelaan 1087 Amsterdam, The Netherlands Nikolskaya V. I., Dr. Pern State Pedagogical Institute, Department of Zoo- logy , K.Marx ul. , 24, Perm 614000, USSR Nikolsky I.D., Dr. Moscow State University, Biological Department, Lenin- hills, Moscow 117234, USSR INitecki C., Dr. University Gdynia 81-378, ul. Czolgistow 46, Poland or erg U. , Dr. Department of Zoology, University of Göteborg, Box 25059, S-40031 Goteborg, Sweden Nordstrom 1.0. , Mr. Skandia Insurance CO ltd Internationale Marine and Aviation Division, S-10350 Stockholm, Sweden "°r^’eI)r’ 31 ’ 051,51,1111 de Corgnac, F-87100 limoges, Université de Limoges, °NoselW., Dr. Institute of Virology, Slovak Academy of Sciences, Bratislava, ov G-A. , Dr. Leningrad State University, Department of Zoology, Univer- s etskaya nab., 7/9, Leningrad 199164, USSR Novikov B.G., Dr., Prof. Kiev State University, Biological Department, Vla¬ dimirskaya ul. , 60, Kiev 252017, USSR Nowak F. , Dr. Institut für Naturschutz und Tierökologie (BFANl), Konstan- tinstr. 110, D-5300 Bonn 2, FRG Numero v A.D. , Dr. Oka Reserve, P.0. Lakash, Spassky dist. , Ryazan reg. 391072, USSR 0 Oehme G. , Dr. Pädagogische Hochschule, Sektion B/C, 4020 Halle /S. , Kröll- witzer Str. 44, G DR Oehme H. , Dr., Prof. 1136 Berlin, Am Tierpark 125, GDR Oelke H. , Dr., Prof. 1 Zoologisches Institut, Berliner Str. 28, D-3400 Böttingen, FRG O'Meara M. , Dr. C/o Irish Wildlife Conservancy, Southview, Church Road, Breystones, Co. Wicklow, Irland Orians G.H. , Dr., Prof. Department of Zoology, University of Washington, Seattle, WA 98195, USA Orth G. , Dr. Zoologisches Institut Universität Frankfurt, Siesmayerstr. 70. D-6000 Frankfurt 1 , FRG Oshmarin P.G. , Dr. Yaroslavl State University .Helminthological Laboratory, Sovetskaya ul. , 19 Yaroslavl 150000, USSR Ostapenko M.M. , Dr. Institute of Zoology and Parasitology, Niyazov ul. , 1, Tashkent 700095, USSR Ostapenko V. A. , Dr.Moscow Zoo, B. Gruzinskaya ul. ,1, Moscow 123820, USSR Otsuki Sh. , Dr. 20, Omiya-yakuahiyama-higashi , Kitaku, Kyoto, Japan Ouellet H. , Dr. National Museum of Natural Sciences, National Museum of Canada, Ottawa, Ontario, KIA 0M8, Canada P Paakspuu V.M. ,Dr. Matsalu Reserve, Haapsalu dist. Lihula 203190, USSR Panov E.N. , Dr. Institute of Evolutionary Morphology and Ecology of Animals, Leninsky pr. , 33, Moscow 117071, USSR 1313 Panchenko 7.0. . Br. Oka Reserve.P.O. Lakash. Spassky diet.. Ryazan reg. 391072, USSR 6 plea 1.561OO, »Papi »., Dr. Inatituto di Biologin Generale, ria A, Vol •Pto.2,. ».«-.»■ •« Bio..»»«.. S.™..»«. 1— Rajkot 360005, India . university of Tromsçf, Norway »Parker H. , Dr. Department of Arctic Bio gy. University of Parmelée D.F., Dr. Field Biology Program, 349 f ’ 55455) USA Minnesota. 10 Church Street S.i , Minneapolis, «inn-ot ” PatapaviciusR. E. , Dr. Zoological Museum, Laysves’ al.,106, Kauna USSR , . “Paton D.M. Dr. Australian Museum, Sydney, Australia T t Dr Culterty Field Station, Newhurgh, Aberdeenshire, UK Patterson I.J., Dr. Cuitervy Q „ -iooo Leuven. »Paulussen J. , Mr. ZoSlogisch Institut, Naamse str. 59, B-3000 Leuven, p ::îf7 Dr 42 rue Emile Collard, B-4030, Grivegnée (Liège). Belgium p:;::;; ;:a./dt. institute Of Zoology. Univ.rsit.tskaya nab., 1. Lenin- U»».b.,., «•«“• “» “ .0— «•« I“1"- xr;.rs: ïst “ ^ ”• .,.^1 P- ». >““* r- - w— — «~î S». ■*- S. BO, B3 B~. XoOT3 „ „ t nr Psncevacka 28, 23000 Zrenjanin, Yugoslavia plrerva'v. I.", Dr. Institute of Nature Ooneervation and Reserves, Znsmen- , o.jn p o VILAR, Moscow reg. 142790, USSR »“•b*1* ”mi* -i* - 0°1“I',o 00100 Roma Eur, Italy OB* • Pet!r ;.!7ri.°"emon 7ologie WB Ökologie, 69 dena. Praunhof erstr. 6, +GB! fs g a Dr. Institute of Biology, Miera, 3, Salaspils 229021, USSR llZTZ It'. ». Institute or Oo.lo* „0 Beitel.*, «.,.„0. 2, PetrinêhT.a.TS.' Si tut. ei Molen, «1er*. S.l.*pll. 229021, USSR Petrovskikh A.I., Dr. Pem State University, Department of Zoology, Bukerev ul. , 15, Perm 614000, USSR Petryanov L.V., Mr. Ministry of Civil Aviation, Leningradsky pr. , 37, Moscow 125167 ■ USSR Pilper J. , Dr. Prof. Max-Planck-Institut , für Experimentelle Medizin, Hermann-Rein-Str. 3, 400 Göttingen, FRG „ , Pikula J. ,Dr. Institute of Vertebrate Zoology, 60365 Brno, Kvetna 8, CSSR » Pimenov V.N. , Dr. Institute of Game and Fur-Farming, Engels ul., 79, Kirov 610600, USSR . Pinowski J.K., Dr. Institut Ekologii PAN, 05-150 Lomianki, Dziekanow Lesny, Poland Pinowska B., Dr. Institut Ekologii PAU, 05-150 Lomianki, Dziekanow Lesny, Poland Plotnikov, Mr. All-Union Ornithological Society, 1 Kotelnichesky per., 10, Moscow 109240, USSR Podolsky A.L., Dr. Saratov State University, Biological Department, Astra- khanskaya ul. , 83, Saratov 410601, USSR Pohl H. , Dr. Max-Planck- Institut für Verhaltensphysiologie, D-8138 Andechs, FRG Pokrovskaya I.V. , Dr. Leningrad State Pedagogical Institute, Department of Natural Sciences, Moika nab., 48, Leningrad 191186, USSR Polivanov V.M. , Dr. Teberda Reserve, Karachaevo-Cherkesskaya A.O. , Stavro- polsky kray 357192, USSR Polo zo v S.A. , Dr. Moscow State Pedagogical Institute, Department of Zoology, Kibalchich ul. , 6, korp. 5, Moscow 129243, USSR Poltavetz S.A. , Dr. Donetzk State University, Biological Department, Univer- sitetskaya ul. , 24, Donetzk 340065, USSR Poluda A.M. , Dr. Institute of Zoology, Lenin ul. , 15, Kiev 252650, USSR Ponomareva T.S. , Dr. Research Institute of Nature Conservation and Reserves, Znamenskoye-Sadki, P.0. VILAfi , Moscow reg. 142790, USSR Popenko V.M. , Dr. "Bielovezhskaya Pustcha" Reserve, P. 0. Kamenyuky , Kame¬ netsky dist. Brest reg. 225063, USSR Popova— Bondarenko E.D. , Dr. Institute of Evolutionary Morphology and Ecology of Animals, Leninsky pr. , 33, Moscow 117071, USSR “Porkert J. , Dr. NA Slupi 12, 12800 Praha, 2, ÖSSB Poslavsky A.N. , Dr. Amu-Darya Reserve, Chardzhou Reg. Far ab, 746070, USSR PoBtnikov S.N. , Dr. Institute of Plant and Animal Ecology, 8 March ul. , 202, Sverdlovsk 620008, USSR Potapov R.L. , Dr. Institute of Zoology, Universitetskaya nab., 1, Leningrad 199164, USSR Powell P.L. , Dr. Department of Medicine, M-028, University of California, San Diego, La Jolla, Ca 92093, USA Power J.B. , Dr. 838 Northampton Drive, Palo Alto, California 94303, USA ♦Power M.L. , Mrs. Pozdnyakov V.I. , Dr. Institute of Biology, Petrovsky ul. , 2, Yakutsk 677891, USSR Poznanin L.P. , Dr.Institute of Evolutionary Morphology and Ecology of Ani¬ mals, Leninsky pr. , 33, Moscow 117071, USSR Priednieks Ya.Ya.,Dr. Latvian State University, Biological Department, Pr.Gaylya, 10, Riga 226098 , USSR Prlgioni A., Dr. Institute of Zoology, Pz. Botta 9, 27100 Pavia, Italy Priklonsky S.G. , Dr. Oka Reserve, P.0. Lakash, Spassky dist., Ryazan reg. 391072, USSR “Prince P.A. , Mr. British Antarctic Survey, Madingley Rd. , Cambridge CB3 OET, UK “Profirov L.An. , Dr. Research Institute of Nature Conservation, 1113 Sophia, Gagarin 2, Bulgaria Profus P. , Dr. Research Centre for Protection of Nature and Natural Re¬ sources, Polish Academy of Sciences, 31—512 Krakow, ul. Lubicz 46, Poland Pronin N.M. , Dr. Institute of Biology, Fabrichnaya ul. , 6, Ulan-Ude 670042, USSR “Pronina S. V. , Dr. Institute of Biology, Fabrichnaya ul. , 6, Ulan-Ude Prove E. , Dr. Universität Bielefeld, Fakultät für Biologie, P7 8640, D-4800 Bielefeld 1, BRD 1315 .K„..n. A., ». I«-«»»*. »' “1" 2 , Vilnius 232021 , USSR >■ — * _ T Mr Ministrv of Radio-indUBtry , Kitalsky pr. , 7, Moscow Rabinovich G.L. , Mr. Ministry 103074, USSR ,m,s 15, sigulda 229050, USSR Rainberg A.,». Rational Park ^auya, state university, Las oRaitt R.J., Dr. Department of Biology, jr“:». S- A «-.1». 3A, SP-0OM0. •< »«« W-1«' "1" ’■ Kishinev 277028, USSR v,1T.iBtiku 7, Tallinn 200010, USSR Randla «..Mr. 3o£** V^n Aviation, Leningradsky pr. , 37, Rasputikov A.S., Mr. Ministry JZTS'tuZ o, Zoology «0 .ot„„ — • *• •JSL, ... »• — * — ' —*■ M65 Bochum, PRG ul 11, Movosibirsk 630091, Ravkinïu.S. , Dr.Institute of Biology, Prunze , USSR „ _ . _ nri stol University, UK th' pI" JJZtX ««. — rr. S: -■£— s°“01 °* **iIcln*’ s‘"' Dnl' varsity „o Bot soy , T— *- Tartu 202ACO, Renno 0.1. , Dr. i* , . Dr. «- *—» «“ • ' IV/S3 »»fV f5l terhaltenspbyaioloSlO' Reyer H.U. , Dr. mail Seewiesen^ PRO tment of Zoology, Box H, 9750 AA toria oigö Australia -Kn?pr IliKh Cross) Madinglsy Rd- » =1.. ». »»*•■> *"'“rtl4 S™ • „„„rids.. UK „In, Laboratory , D.ir.r.i.y •< sl”:3:rr £ ä ’lie »ur.i, - » Tbaï D., Mr. ^ricuiture, Box 1671, Adelaide 5001, Robertson D.G. , nr. w S0U„ Australia Department «»..«.'» Robertson R. , Dr" * rru Ontario, K7L 3H6 Cana a weat Australia Bobiueo. B. . DU- *« »; ^.tor, ^ Ro chard ^ DuilH.ra. Surr«. « Ie tM„ D.tur.l... «r». >»-> oRodriquez M.M. , Dr. mus 1316 Rogaohev A.I., Mr. Ministry of Civil Aviation, Leningradsky pr. , 37, Moscow 125167, USSR Romaneev N.S., Dr. Dnepropetrovsk State University, Department of Zoology, K.Marx pr. , 36, Dniepropetrovsk, 44, USSR "Romanov A.N. ,Dr. Research Institute of Game and Fur-Farming, Engels ul. , 79, Kirov 610601, USSR Romanyuk G.P. , Dr. Zhiguly Reserve, P.0. Bakhilova Polyana, Zhigulyovsk 446351, USSR Roos de G.Th., Dr. Agricultural University, Natural Conservation Department, Dorpsstraat 198, 8899 AP Vlieland, The Netherlands Roselaar C.S. , Dr. Institute of Taxonomic Zoology, Department Aves, Plantage Middenlaal 53, Box 20125, 1000HC Amsterdam, The Netherlands Rostchevsky Yu. K. , Dr. Kuibyshev State University, Department of Zoology, Ak Pavlov ul. , 1, Kuibyshev 443086, USSR °Rothe H.-J. , Dr. Zoologisches Institut der Universität des Saarlandes Saar¬ brücken, FRG °Rothstein St.I. , Dr. Department of Biological Sciences, University of Ca¬ lifornia, Santa Barbara, Ca 93106, USA Rootsmäe I.E. , Mrs. Tartu house-intemat, Liiva, 32, Tartu 202400, USSR Rowley I. , Dr. C/o CSIRO Division of Wildlife Research, Clayton Rd. , Hellene Valley, 6056 West Australia, Australia Rubinstein N.A. , Dr. Moscow Zoo, B. Gruzinskaya ul. , 1, Moscow 123820, USSR “Rudneva L.M. ,Dr. Kiev State University, Vladimirskaya ul. , 60, Kiev 252017, USSR °RÜppel G., Dr. Kleikamp 5, 3301 Lagesbüttel, Braunschweig, FRG Rustamov A.K. , Dr., Prof. Institute of Agriculture, Pervomayskaya ul. , 62, Ashkhabad 744012, USSR Rustamov E. A. , Dr. Turkmen State University, Department of Zoology, Lenin pr. , 31, Ashkhabad 744014, USSR Rute Yu. Ya. , Dr. Latvian State University, Zoological Museum, Fr.Gaylya, 10, Riga 226010, USSR Rutschke E. , Dr., Prof. Pädagogische Hochschule "Karl Liebknecht", Potsdam, GDR “Ryabitsev V.K. , Dr. Institute of Plant and Animals Ecology, 8 March ul., 202, Sverdlovsk 620008, USSR “Rymkevich T.A. , Dr. Leningrad State University, Department of Zoology, Universitetskaya nab., 7/9, Leningrad 199164, USSR Ryzhanovsky V.N. , Dr. Institute of Plant and Animals Ecology, 8 March ul., 202, Sverdlovsk 620219, USSR Rysavy B. , Dr. Department of Natural Sciences Kargov University 12844 Brag 2, Vinicna ul., 7, ÎSSR I Hyzhlkov K.M.|, Dr. , Prof. , Corr. Memb. Acad. S "Sadykov O.F. , Dr. Institute of Plant and Animals Ecology, 8 March ul. , 202, Sverdlovsk 620008, USSR Safriel U. , Dr. Department of Zoology, Hebrew University, Ierusalem, Israel Saiff E. , Dr., Prof. Ramapo College, 505 Ramapo, Valley Rd. , Mahwah, N.J. 07430,. USA Sakaguchi S. , Dr. Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA Sakalauskas G.Z., Mr. Society of .Photoarts, Pionieriu, 8, Vilnius 232000, USSR Silomonsen fJ, Prof. 1317 ... ». c«rtr. « 01-i- • ™I3n,0a’ °*11* 2,5 • q^OOO Sao Leopoldo, Rio Grande do Sul, Brasil S.p.,in ». I-«“'* »' 7namenskoy e-Sadky , P.0. VILAR, Moscow reg. 142790, USS Sapetina I.».. Dr. Central Research Moratory of Game ^ 18, Losinoostrovskaya Lesnaya Dacha, Moscow 12934 , Saevari L. , Dr. Department of Systematic Zoology an co s. “» ss~ — - - *«— - ,rr;: ™r.; ----- — • — - jrrr»««— . — — — ■ 6om Norrkoping , Sweden Technical Universität Darmstadt. FRG irr: c . — » - St. Oswald, FRG Schifter H. , Dr. Naturhistorisches Museum, P.f. 417, A-1014 Wien, Austria »Schifter Th. , Mrs. “Schleicher A. , Dr. Anatomisches Institut der Universität* Köln, PRO Schmidt K., Mr. 6204Barchf ield/Werra Liebensteiner Str, 118, GDR Schmidt R. , Dr. Vogelwarte Hiddensee, 2346 Kloster/Hidd, GDR Schneider D. , Dr. Department of Ecology and Evolutionary Biology .Univer¬ sity of California, Irvine, 92717 USA Schneider W. , Mr. 7030 Leipzig, August-Behel-Str. 45, GDR Schonn S., Dr. 7260 Oschatz, H-Mann-Str. 11b, GDR Schreiber R.W. , Dr. Natural History Museum, 900 Exposition Blvd, Los Angeles, CA 90007» USA “Schultz J.C., Dr. Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA Scott P. , Sir Dr. Wildfowl Trust, Slimbridge, Glos. The New Grounds, Gloucester, GL2 7BT, UK •Scott D. , Dr. ♦Scott Ph. , Dr. Searcy W.A. , Dr. Field Research Center, Rockfeller University, N.7. , USA “Seki M.P. , Dr. 2089 Akaikai Loop, Pearl City, HJ 96782, USA Seliverstov N.M^pr.School No. S^hesteryntzy Lysyansky dist. , Cherkassy reg. 258690, USSR Sema A.M. , Dr. Institute of Zoology, Akademgorodok, Alma-Ata 480032, USSR Semin P. , Dr. Department of Zoology Goethe-University P.W. , Frankfurt, FRG Serebryakov V.V. , Dr. Kiev State University, Department of Zoology, Vladi¬ mirskaya ul. , 60, Kiev 252017, USSR Seymour N. , Dr. St. Francis Xavier University Antagonish, Nova Scotia, B2GIC0, Canada Seymour R.S., Dr. University of Adelaide, Zoological Department, Adelaide 5001 , South Australia “Shah R.V. , Dr., Prof. Department of Zoology Faculty of Science, M.S. Univer¬ sity of Baroda, Baroda-390002, India 1578 Sharonov A. Yu. , Mr. Academy of Civil Aviation, Leningradaky pr. , 37, Moscow 125167,' USSR “Sharrock J.T. , Dr. "British Birds", Fountains, Park Lane, Blunham, Bedford MK44 3NJ, UK Shedden C.B. , Dr. Department of Zoology, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK Shepel A. I., Dr. Perm State University, Department of Zoology, Bukiveva ul. , 15, Perm 614000, USSR Shevyakov V.S., Dr. Institute of Zoology and Parasitology, Akademyos ul. ,2, Vilnius 232021, USSR Shibaev Yu. V., Dr. Institute of Biology and Soil Sciences, Stoletya Vladi— vostokapr., 159, Vladivostok 690022, USSR Shihnev Yu. B. , Dr. "Kedrovaya Pad" Reserve, Primprskays , Khasansky dist. , Primorsky Kray 692710, USSR Shields G.P. , Dr., Prof. Institute of Arctic Biology, University of Alaska, Fairbanks Alaska 99701, USA ♦Shields G.F. , Mrs. Shlnkarenko A.V. , Dr. Irkutsk State University, Institute of Biology, Lenin, ul. , 3, Irkutsk 664003, USSR Shishkin V.S. , Dr. Institute of Evolutionary Morphology and Ecology of Animals, Leninsky pr. , 33, Moscow 117071, USSR Shkarin V.S., Dr. Novokuznetsk State Pedagogical Institute, Department of Zoology, Pionersky pr. , 7, Kemerovo reg. 654019, USSR Shkatulova A. P. , Dr . Altai Medical Institute, Barnaul, USSR Short L.L. , Dr., Prof. American Museum of Natural History, New York, N.Y. , 10024, USA Shteinbakh M.V. , Dr. Moscow State University, Biological Department, Le¬ ninhills, Moscow 117234, USSR Shukurov E.D. , Dr. Institute of Biology, Leninsky pr.-, 265, Frunze 720071, USSR Shumakov M.E. , Dr. Institute of Zoology, Universitetskaya nab., 1, Lenin¬ grad 199164, USSR Shurakov A. I., Dr. Perm State Pedagogical Institute, Department of Zoology, K.Marn ul. , 24, Perm 614000, USSR Sibley C.G. , Dr,, Prof. Peabody Museum of Natural History, Yale University, New Haven, Conn. 06520, USA Sick H. , Dr., Prof. Bor 229, Academia Brasileira de Ciências, 20000 Rio de Janeiro, RJ, Brasil Siefke A. , Dr. Vogelwarte Hiddensee, 2346 Kloster/Hiddensee, GDR “Siegfried W.R., Dr. Percy Fitzpatrick Institute of African Ornithology, Cape Town, South Africa Silajewa O.L. , Dr. Institute of Evolutionary Morphology and Eoology of Animals, Leninsky pr. , 33, Moscow 117071, USSR “Slmeonov P.St., Dr. Research Institute of Nature Conservation, 1113 Sophia, Gagarin 2, Bulgaria Simkin G.N. , Dr. Moscow State University, Biological Department, Leninhills Moscow 117234, USSR “Singh S., Dr. Department of Zoology, Banares Hindu University Varanasi 221005, India Sindem C. , Mr. Flughafen München, GmbH, ‘8 München 87, Postfach 870220, FRG Siokhin V.D., Dr. Melitopol State Pedagogical- Institute, Biological Depart¬ ment, Lenin ul. , 20, Melitopol 332315, USSR Sitnik O.E. Mr. Ministry of Civil Aviation, Moscow, USSR Skarlato O.A. , Dr., Prof., Corr. Mamb. Acad. Institute of Zoology, Univer- sitetskaya nab., 1, Leningrad 199164, USSR Skokova N.N., Dr. Institute of Evolutionary Morphology and Ecology of Ani¬ mals, Leninsky pr., 33, Moscow 117071, USSR Skryabin N. G. , Dr. Irkutsk State University, Institute of Biology, Lenin ul. , 3, Irkutsk 664003, USSR Skryleva L.F. , Dr. Michurinsk State Pedagogical Institute, Gogolevekaya ul. , 274, Michurinsk 393740, Tambov reg. , USSR Skuja V., Dr. Slitere Reserve, Mazirbe, Talsin diet. 229573, USSR Skuodis V.K., Dr. Institute of Zoology and Parasitology, Laysvea al. , 53, Kaunas 233000, USSR Slagsvold T. , Dr. Zoological Department, University of Trondheim, Norway Smirensky S.M. , Dr. Moscow State University, Biological Department, Lenin- hills, Moscow 117234, USSR Smirin Yu.M. , Dr. Moscow State University, Biological Department, Leninhills, Moscow 117234, USSR Smolin A. A., Mr. Ministry of Civil Aviation, Leningradsky pr. , 37, Moscow 125167, USSR Soikkeli M.T. , Mr. Department of Biology, University of Turku, S. P-20500 Turku 50, Finland Sokolov V.E., Dr., Prof., Memb. Acad. Institute of Evolutionary Morphology and Ecology of Animals, ' Leninsky pr. , 33, Moscow 117071, USSR Sokolov V.S., Mr. Ministry of Civil Aviation, Leningradsky pr. , 37, Moscow 125167, USSR “Sokolov L.V., Dr. Institute of Zoology, Universltetskaya nab., 1, Leningrad 199164, USSR Sokolova S.M. , Dr. Botanical Garden, Botanicheskaya ul. , 4, Moscow 12727b, USSR Solinov V.F., Mr. Ministry of Aviation Industry, Ulansky per., 16, Moscow 101717, USSR „ „ , . , Solomonov N.G., Dr., Prof. Institute of Biology, Petrovsky ul. , 2, Yakutsk 677891 , USSR Sonin M.D., Dr. Helminthological Laboratory, Leninsky pr. , 33, Moscow 117071, USSR Sonin V.D. , Dr. Irkutsk State University, Lenin ul. , 3, Irkutsk 664003, USSR Sonina M.V., Mrs. Regional Department of Popular Education, K.Marx ul. , 19, Irkutsk, USSR Sonnette J. , Mr. COMETEC-SNPL Orly-sud N 213, 94396 Orly Aérogare Cedex, Prance Sopyiev- O.S., Dr. Institute of Agriculture, Pervomayskaya ul. , 62, Ashkhabad 744012, USSR Sorokin A.G. , Dr. Research Institute of Nature Conservation and Reserves, Znamenskoye-Sadky, P.0. VILAR, Moscow reg. 142790, USSR “Spassky A. A., Dr., Prof. Institute of Zoology and Physiology, Akademiches- kaya ul. , 1 , Kishinev 277028, USSR Speek B.J. , Dr. Vogel trekstation Institute of Ecological Research, Kemper- bergerweg, 67, Arnhem, The Netherlands Spitzer P. ,Dr. Section of Ecology and Systematica, Cornell University, Ithaoa, N.Y. 14850, USA “Springer A.M. , Dr. Bodega Bay Institute, 2711 Piedmont Avenue, Berkeley, 94705, USA Springer H. , Dr. Alaska Department of Transportation, P.0. Box 80-375 Fairbanks, Alaska 99708, USA 1320 |srebrodolskaya M.I. , Dr.| Stalidzans Yu. I.., Dr. "Teygy" Reserve, P.O. Atashiene, Ekabailsky dist. , Latvian 228247, USSR Stannard J. , Dr. Box 99, Port Edward 4295, South Africa Staskewicz A. , Mrs. 3624 E. 6th St. Long Beach University California, 90814, USA Stasthy K. , Dr. Institute of Landscape Ecology, ?SAV Bezrucova 927, 2510L îîicany, CsSR Stawarczyk T. , Dr. Zoological Institute of Wroclaw University, Wroclaw, Sienkiewicza, 21, Poland “Steen J.B. , Dr. Institute of Zoophysiology, University of Oslo, Norway “Stempniewicz L. , Dr. Department of Animal Ecology, Gdansk University, SI- 378 Gdynia, Czolgistow 46, Poland Stenman 0. , Mr. Finnish Game and Fisheries Research Institute, Pikänsillan- ranta 3A, 00530 Helsinki 53, Finland Stepanyan L. S. , Dr. Institute of Evolutionary Morphology and Ecology of Animals, Leninsky pr. ,33, Moscow 117071, USSR Stephan B. , Dr. 1040 Berlin, Invalidenstr. 43, Museum f. Naturkunde, GDR Sternberg H. , Dr. Im Schapenkampe 1 1 , 3300 Braunschweig, FRG Stetney Ph. , Dr. Natural History Provincial Museum of Alberta, 12845-102 are, Edmonton, Canada Stettenheim P. , Dr. Meriden Rd. , Lebanon, N.H. 03766, USA Stevens J. , Mr. Zoologisch Institut, Naamsestraat 59, B-3000 Leuven, Belgium Stjemberg T.G. , Dr. Zoological Museum, University of Helsinki, N. Jamväg- sgatan 13, SF-00100 Helsingfors 10, Finland “Stokkan K.-A. , Dr. Department of Arctic Biology and Institute of Medical Bio¬ logy, Box 635, 9001 Tromsjf, Norway Stolbov I. A., Dr.Museum of Nature, Kr. Baron ul. , 4, Riga 226050, USSR Stotskaya E. E. , Dr. Research Institute of Nature Conservation and Reserves, Znamenskoye-Sadki , P.0. Vilar, Moscow reg. 142790, USSR Strand A., Mrs. Kruthomsvägen 17, 19153 Sollentuna, Sweden “Strawinski S. , Dr., Prof. Gdansk University, ul. Czoïgistôw 46, 81-378 Gdynia, Poland Strazds A.D. , Dr. Museum of Nature, Kr. Barou ul. , 4, Riga 226050, USSR Strazds M. D. , Dr. Latvian State University, Fr. Gaylya, 10, Riga 226098, USSR Strigunov V.I. , Dr. Kryvoy Rog State Pedagogical Institute, Department of Zoology, Gagarin pr. , Dnepropetrovskaya reg. 324086, USSR |Strokov v.v. , Pr7| Stubbe M. , Dr. Martin-Luther-Universität , Sektion Biowissenschaften, Zoology, 40? Halle (Saale), Domplatz 4, GDR Stubs J. , Dr. Universität, 2200 Greifswald, Uhlenhuthstr . 4, GDR Stuksa P. , Dr. Presidium of the Czechoslovak Academy of Sciences, Norodny tr. , 3, Staroje Mjasto, Praha 1, SsSR “Stulova O.P. ,Dr. , Prof. Bashkir State University, Biological Department, Frunze ul. , 34, Ufa 450074, USSR Suarez Sh.H. , Dr. Nature Reserves Authority Yermiyahu 78, Jerusalem 94-467, Israel Sugawa H. , Dr. Department of Zoology, Faculty of Science, Kyoto University, Sakyo, Kyoto 606, Japan Sunkel M. , Mrs. 6413 Tann Rhön, Am Galgenberg 15, FRO Survilo A. V. , Dr. Institute "Microb", Universitetskaya 46, Saratov 410002, USSR Sutter E. , Dr. Naturhistorisches Museum, Augustinergasse 2, CH-4001 Basel, Switzerland 48. 3aK. 981 1321 ♦Sutter ß. , Mrs. Sushkina A.P. , Mrs. All-Union Ornithological Society, 1 Kotelnichesky per., 10, Moscow 109240, USSR §vec P. , Dr. V Ondrejove 4, 14700 Praha 4, 5sSR Svensson S.B., Dr. Department of Animal Ecology, University of Lund, Ecology Bld., S-223 62 Sweden Swanson G.A. , Dr., Prof. 1404 W. Lake, Pt Collins, Colo 80521, USA ♦Swanson, Mrs* Sych V.P. , Dr. Institute of Zoology, Lenin ul. , 15, Kiev 252030, USSR Syroetchkovsky E.E., Dr., Prof. Institute of Evolutionary Mo^hology and Ecology of Animals, Leninsky pr. , 33, Moscow 117071 , USSR Syroetchkovsky E.V. , Dr. Institute of Evolutional? Morphology and Ecology of Animals, Leninsky pr. , 33, Moscow 117071, USSR T o Tahon J. ,Dr. Station Zoologie appliquée de l’Etat, Centre de Recherches Agro¬ nomiques, Chemin de Liroux 8, B-5800 Gembloux, Belgium “Tarkhutin V.D. , Dr.Institute of Biology of the South Sees, Nakhimov pr. , 2, Sevastopol 335000, USSR Tashliev A.O. , Dr., Prof. Institute of Zoology, Engels ul. , 6, Ashkhabad 744000, USSR °Tatarinkova I.P. , Dr. Kandalaksha Reserve, Rechnaya ul. , 18, Murmansk reg. , Kandalaksha 1 84040 , USSR Tatarinov L.P. , Dr., Prof., Memb. Acad. Paleontological Institute, Prof- soyuznaya ul* » 113? Moscow 117321, USSR Tembrock G. ,Dr. ,Prof. Humbold-Universität>1040 Berlin, Invalidenstr. 43.GDR Temchin A.N. , Dr. Moscow State University, Biological Department, Lenin- hills, Moscow 117234, USSR “Temple St. A., Dr. Department of Wildlife Ecology, 226 Russel Laboratoi?, University of Wisconsin, Madison, Wisconsin 53706, USA “Terschuren A., Dr. 11, At. de l’Oiseau Bleu, 1150 Bïuxelles, Belgium orjets van G.P. . Dr. Musée National d’Histoire Naturelle, Institut Paléonto¬ logie, Paris, Prance Thaler E. , Dr. Alpenzoo, A-6020 Innsbruck, Weiherburg, Austria Thiede W., Dr. 5000 Köln 40 (Lövenich), An der Rönne 184, PRG ♦ Thiede U. , Mrs. Thielcke G. , Dr. Am Obstberg D-7760 Radolf zell-M'oggingen, PRG Thimra P. , Dr. Physiologisches Institut der DSHS, Carl-Diem Weg, D-5000 Köln 41, PRG “Thomas C. , Dr. Department of Zoology, University of Durham, UK Thomas D.H. , Dr. Zoological Department, University College, Cardiff CPI 1XL, UK Thompson E. , Dr. Earth Sciences Department, Monash University Clayton, Vic¬ toria 3168, Australia “Thomson D. , Dr. LGL Ltd, Environmental Research Associates, 44 Eglinton Ave, W, Toronto, U4R 1AL, Canada Thorpe J. , Mr. Civil Aviation Authority, Safety Data Unit, Brabazon House, rh6 9JH Redhill, Surrey, UK Thrane E. , Mr. Plight Operation Mgr. SAS Copenhagen, Kjlbenhaus Lufthvn. DK 2770, Kastrup, Denmark Tikhonov A.V., Dr. Moscow State University, Biological Department, Lenin- hills, Moscow 117234, USSR Tilba p.A . , Dr. Caucasus State Blospher Reserve, Sukhumskoye shosse 7-a, Krasnodar reg., Sochi 354067, USSR 1522 Tindle L.E., Dr. 26, Lammermuir GardenB, Bearsden, Glasgow G61 4QZ, UK Todt D, , Dr., Prof. Zoologisches Institut der Universität Haderslebenerstr. 9, D-1000 Berlin-West 41, West Berlin Tolchin V.A., Dr. Museum of Regional Studies, K. Marx ul. ,1 .Irkutsk 664003, USSR Tomialojc L., Dr. Museum of Wroclaw University, ul. Sienkiewicza 21, 50-335 Wroclaw, Poland Tomkovich P.S., Dr. Zoological Museum, Herzen ul., 6, Moscow 103009, USSR Torôk J,, Dr. University of Eötvös, Department of Ecology, H-1088 Budapest, Pu skin u. 3, Hungary Tschemitschko I.I., Dr. Odessa State University, Biological Department, Shampansky per., 2, Odessa 270015, USSR Tselminysh A. ,Dr. Academy of Agriculture, NoreykiBhkes Department of Forest¬ ry, Kaunas 234324, USSR Tsokolaev V.A., Dr. Lvov State University, Biological Department, Stcherba- kov ul., 4, Lvov 29000, USSR Tuchin A.V. , Dr. Saratov State Pedagogical Institute, Saratov 410600, USSR Turchanlnova V.A., Dr. Institute of Evolutionary Morphology and Ecology of Animals, Leninsky pr., 33, Mosoow 117071, USSR Turesson L.O. , Mr. Board of Civil Aviation, 60-1 79 Norrkoeping, Sweden U '“Udvardy M.D.F., Dr. Prof. Department of Biological Sciences, California State University, Sacramento, CA 95819, USA Ugarkin S.M., Mr. Ministry of Civil Aviation, Leningradsky pr. , 37, Moscow 125167, USSR Ulf strand A., Mr. Department of Zoology, University of Lund, S-22362 Lund, Sweden Umrikhina G.S., Dr. Institute of Biology, Leninsky pr., 265, Frunze 720071, USSR “Unander S., Dr. Department of Arctic Biology, University of Troms^, Norway Unanyan A.K., Dr. Khosrov Reserve, Yerevan, USSR V Vai einen R.A., Dr. Department of Zoology, University of Helsinki, P.Rauta- tiekatu 13, SF-00100 Helsinki 10, Finland ValiUB M.I., Dr. Institute of Zoology and Parasitology, Laysves al., 53, Kaunas 233000, USSR Varshavsky S.N.,Dr. Institute "Microb", Universitetskaya ul., 46, Saratov 410002, USSR Vasilchenko A.A., Dr. Sokhonda Reserve, Gorky ul., 48, Kyra, Chita reg. 674250, USSR Vasilenko V.A., Mr. Ministry of Civil Aviation, Leningradsky pr., 37, Mosoow 125167, USSR Vaslliev Yu. E. , Mr. Ministry of Aviation Industry, Ulansky per., 16, Moscow 101717 USSR Vasin I.f! , Mr. Ministry of Civil Aviation, Leningradsky pr. , 37. Moscow 1 ?R1 67 USSR Vakhromeeva M.G., Dr. Moscow State University, Biological Department, Lenin- hilla, Moscow 117234, USSR u„_„nw rec Veprintsev B.N., Dr., Pxuf. Institute of Biophysics, Pustchino, Moscow reg. oveZrLp!rDr. Department of Biology, U.I.A.-Universiteisplein 1. B-2610 - *>“»• 21 • 202400, USSR 1323 Vetrova I.B., Mrs. Publishing House "Nauka" , Prof soytiznaya ul., 90, Moscow Vie t inghof f -Scheel E. , Dr. Museum für Naturkunde, Omithologische Abteilung Vi lorit^V^DrTvia Vanvitelli, 32 Iatituto Farmacologia Milano, Italy E A ‘;r. Research Institute of Forestry, RSSmu te 2, Tartu 202400, USSR Institute of Biology, Miera ul 3 Salaspils 22902t OK Viksne A.. Mrs. Latvian State University, Fr.Gaylya.IO, Riga 226 10. USSR Vilbaste H.O. , Dr. Nigula Reserve, Kilingi-Kon«. , Parnt > diet 2036 , vilka E K Dr. institute of Biology, Miera, 3, Salaspils 229021, USSR Vinokurov 'À . A . , Dr. Research Institute of Nature Conservation and Reserves, Znameoskoye-Sadky, P.0. VILAR, Moscow reg. 142790, USSR Visconti S., Mr. ATI Italian Domestic Airlines Fiumicino Rome, Italy Vitkauskas N. , Dr. Institute of Zoology and Parasitology, Akademyos, 2. i - Via institute of Forest and Wood, Akademgorodok, Krasno- ovier^r^'C-nt of Biology, University of Arizona. Losen, Arizona ovieck7^’, S! Department of Eoology, University of Arizona, Tucson, Arizona »=•• ««t. or rooi.CT, °Volkov F.M. , Dr., Prof. Moscow State University, Leninh VoousSK.H., Dr., Prof. v.d. Duyn van Maasdamlaan 28, 1272 EM, Huizen, The Netherlands *Voou3 Mrs. f T,lolorv university of Hanoi, Viet Nam ~r«oio51c.1 ..U, , P- - or Evolutional? «o^olog? «.d Eool.d, or Ini- mais Leninsky pr. , 33, Moscow 117071, USSR Vorobyeva T.D., Dr. Kyzyl-Agaoh Reserve, Narimanabad-2 , Lenkoran dist. , Azerbaijan 373722, USSR Voronin R.N. , Dr. Institute of Biology, Kommunisticheskaya ul. , 26, Syktyv¬ kar 167610, USSR Voronina P.A. , Mrs. Executive Commitee of Regional Soviet, Gorky ul. , i, Moscow 103009, USSR Voronkova K.A. , Mrs. All-Union Ornithological Society, 1 Kotelnichesky per., 10, Moscow 109240, USSR ovoronov A.G., Dr., Prof. Moscow State University, Geography Department, Leninhills, Moscow 117234, USSR Voronov B.A., Dr. Complex Research Center, Kym-Yu-Chen ul. , 65, Khabarovsk 680063, USSR Voronov V.G. , Dr. Research Institute, Novo-Aleksandrovsk, Sakhalinsk reg. 694050, USSR °Vos de G.J., Dr. Department of Zoology University of Groningen, Box 14, 9750 AA Haren (Gn) , The Netherlands Vronskaya E.V. , Dr. Institute of Evolutionary Morphology and Ecology of Animals, Leninsky pr. , 33, Moscow 117071, USSR Vuilleumier P. , Dr. American Museum of Natural History, General Park al 79th Street, N.Y. 10024, USA 1324 Vyazovich Yu. A. , Dr. Institute of Zoology, Akademicheskaya ul. , 27, Minsk 220072, USSR W Wada M. , Dr. 2-3-10 Kanda-Surugadai , Chiyodaku, Tokyo 101, Japan Y/aite R.K. , Dr. University of Nottingham, Department of Psychology, Univer¬ sity Park, Nottingham NG7 2RD, UK Walasz K. , Dr. Instytut Biologii Srodowiskowej Universytetu Jagielonskiego, ul. Karasia 6, 30-060 Krakow, Poland- Wallraf H.G., Dr. Max-Planck-Institut, D-8131 Seewiesen, PRO Wallschläger D. , Dr. Sektion Biologie der Humbolt-Universität 1040 Berlin, Invalidenstr. 43, GDR Walton B.J., Dr. Prebatory Bird Research Group , 231 Clark Kerr Hall, Univer¬ sity of California, Santa Cruz, 95064, USA, Wattei J. , Dr. Zoological Museum Box 20125, 1000HC, Amsterdam.The Netherlands Wawrzyniak H. , Mr. Institut für Forstwissenschaften, 1300 Eberswalde-Finow 1, A. -Möller Str. , GDR Weathers W.W. ,Dr. Agricultural Experimental Station, University of Califor¬ nia, Davis, 95616 , USA Wesolowski T. , Dr. Department of Avian Ecology, Wroclaw University 50-335 Wroclaw, Sienkiewicza 21, Poland Wessum van H.J.D. , Mr. Department of Civil Aviation P.O. Box 20903 2500 EX the Hague, The Netherlands Westall M. , Dr. 289 Southwinds Dr. Sanibel Is. , Florida, USA Westerterp K. , Dr. Zoological Laboratory Haran (Gr), The Netherlands “Wickler W. , Dr. Max-Planck-Institut für Verhaltensphysiologie D-8131, Andechs, FRG Widström E. , Mr. Flight Safety Department, Tlight Operation Office S-601 79 Norköping, Sweden “Wieloch M. , Dr. Ornithological Station PAS 80-680. Gdansk 40, Poland “Wiens J. , Dr., Prof. University of New Mexico, Department of Biology Al¬ buquerque, New Mexico 87131, USA Wiley J.,Dr. Puerto Rico, U.S. Department of the Interior Fish and Wildlife Service, Box 21, Palmer, Puerto Rico 00721, USA *Wiley B. , Mrs. “Williams A.J., Dr. Percy FitzPatricfc Institute of African Ornithology, University of Cape Town, Rondebosch, 7700, South Africa “Willis Ed.O. , Dr. University of Rio Claro, Department of Zoology, Rua 2 no 2272, 13500 Claro, SP, Brazil “Wilson M., Dr. West Palearctic Birds LTD., Oxford (E.G.I.) 8 Green Street, 0X4 1YB, UK . Wiltschko W. , Dr., Prof. FB Biologie der Universität, Zoologie, Siesmayers 70, D 6000 Frankfurt a. M. , FRG Wiltschko R. , Dr. FB Biologie der Universität, Zoologie, Siesmayers r. D 6000 Frankfurt a. M. , FRG Wingfield J. ,Dr. Rockfeller University, Field Research Center, Tyrrel Road, Millbrook, New York 12545, USA “Wink M. , Dr. Institut für Pharmazeutische Biologie , Technischen Universität, 3300 Braunschweig, FRG Winkel W. , Dr. Institut für Vogelforschung Bauemstr. 14, D-3302 Gremblingen 1, FRG ♦Winkel D. , Mrs. Winkler R. , Dr. Naturhistorisches Museum, Augustinergasse 2, CH-4001 Basel, Switzerland Wittenberg J. , Dr. Maienstr. 13, 3300 Braunschweig, FRG 1325 Woldhek 3., Dr. Dutch Society for the Protection of Birds 3708 JB Zeist. Driebergseweg 16 B,The Netherlands Wolffgramm J. , Dr. Institute of Physiologie, Hufelandstr. 55, D 43 Essen 1, FRG Won P.-O., Dr., Prof. Institute of Ornithology, Kyimg Hee University, Seoul JZZZ Carnegie Museum of Natural History, Pittsburgh, PA 15213, USA Woolf enden G., Dr. Department of Biology, University of South Florida, Tampa, FI 33620, USA »Wunderlich K. , Dr. 1136 Berlin, Am Tierpark 155, GDR Y Yakoby V.E., Dr. Institute of Evolutionary Morphology and Ecology of Animals, Leninsky pr. , 33, Moscow 117071, USSR Yamalova G.B. , Dr.. Ufa State Pedagogical Institute, Department of Zoology, Oktyabrskaya Revolutziya ul. , 3A, Ufa 450025, USSR Yapp W.B., Dr. Church End House, Twyning, Tewkesbury, Gloucestershire, GL20 6 UA, UK „ ... Yaremchenko O.A., Dr. Polessky State Reserve Selesovka, Ovruchsky Zhitomir reg. , 260025, USSR Yesilevskaya M.A. , Dr. Kharkov State University, Biological Department, Dzerzhinsky ul. , 4, Kharkov 310077, USSR Yokota Y., Dr. "Association of Wild Geese Protection", 1-2-31 Haranomachi Sendai Japan 983, Japan - J., ». Dep.rtm.at o, Zoolog,. DBie.r.lt,. I.ra.l ï..hll Dr. V»..hin„ iB.tltute ter Omlttolog,. 8-20 Shlbu,^ I!Ï° »!'i™.“«t. »I Biolog, , KOB.« «1-. Bo.oaiMrak 6)009,. JToT...., Dr. I».«it«>0 ot Blolog,. i™.. «1-. ». «ok.Bo-.Lt», R.o.rve, P.O. D»k,. «o.oow reg. Dr. Department Zoolog,. ... Joeeph. Coll.ge. De.agiri. Calicut 673008, Kerala, India , „ »Zagorodnyuk I.V. , Dr. Kiev State University, Vladimirskaya ul. , 60, Zahavi'^fu^Dr! 'wise^ Faculty of Life Sciences.Institute for Nature Conser¬ vation Research, Tel-Aviv, Israel Zajicek P. , Mr. 1089 Shell Basket Lane Sanibel Is. Fla. Florida, USA Zalakeviciùs M.M. , Dr. Institute of Zoology and Parasitology, Akademyos 2, Vilnius 232021, USSR »Zaletaev V.S., Dr. Institute of Water Problems, Sadovaya-Chemogryadskaya ul. , 13/3, Moscow 103064, USSR Zaianckauskas P.A. , Dr. Institute of Zoology and Parasitology, Akademyos 2, Vilnius 232021, USSR Zhordania R.G. , Dr. Tbilisi State University Biological Department, Chavcha- vadze pr. , 1 , Tbilisi 380028, USSR »Zilles K. ,Dr. , Prof. Anatomisches Institut der Universität Kiel, Olshausenstr. 40-60, D-2300 Kiel, FRG Zimdahl W. , Dr. "Der Falke" 1080 Berlin, Otto-Nuschke-Str. 28, GDR Zimina R.P. , Dr. Institute of Geography, Staromonetny per. 29, Moscow 109017, USSR »Zink G., Dr. Vogelwarte Radolfzell, Schloss Moeggingen, D-7760 Radolfzell, GDR 1326 Zinoviev V. I. , Dr. Kalinin State University, Department of Zoology, Chaykovsky pr. , 70/1, korp. 5, Kalinin 170002, USSR Ziomenko Mr. All-Union Ornithological Society, 1 Kotelnichesky per., 10, Moscow 109240, USSR Zlotin R.I. , Dr. Institute of Geography, Staromonetny per., 29, Moscow 109017, USSR Zorina Z.A. , Dr. Moscow State University, Biological Department, Leninhills, Moscow 117234, USSR Zubakin V. A. , Dr. Institute of Evolutionary Morphology and Ecology of Animals, Leninsky pr. , 33, Moscow 117071, USSR Zubkov H.I., Dr. Institute of Zoology and Physiology, Akademicheskaya ul. , 1, Kishinev 277028, USSR Zusi R.L. , Dr. National Museum, Smithsonian Institution of Natural History, Washington, D.C. 20560, USA Zvonov B.M. ,Dr. Institute of Evolutionary Morphology and Ecology of Animals, LeninBky pr. , 33, Moscow 117071, USSR Zweers G. , Dr. Department of Morphology, Zoological Laboratory, Kaiseretr. 63, Leiden, The Netherlands *Zweers Mrs. 1327 INDEX OF AUTHORS Able K.P. 293 Abrams R.W. 1023 Abuladze A.V. 1072 Ahlen I. 1032 Ahlquist J.E. 83 Alatalo R.V. 1072 Albuquerque J.L.B. 1008 Amanova M.B. 1061 Amellchev V.N. 1073 Ananin A. A. 1073 Ananlna T.L. 1073 Andreev A.V. 409 Anleimow W. 1074 Appert 0. 1074 Ar A. 1075 Ardamazkaya T.B. 1075 Aslanova S.M. 1076 As8enmaeher I. 935 Auesov E.M. 1111 Avery Gr. 1065 Avilova K.V. 1076 Babaryka V. 1024 Babenko V.G. 1132 Baèyens G. 1022 Bairlein Fr. 1077 Baida R.P. 1037 Baldaccini N.E. 1077 Balouet J.C. 200, 1078 Baptiste L.F. 1056 Barbiéri F. 1078, 1084 Bardin A.V. 1078 Barsowa L, 1079 Barus V. 1016 Bech G. 970 Becker P.H. 1059, 1198,1206 Bednorz J. 1080, 1084 Beintema A.J. 1033 Bejcek V. 1080 Belopolskii L. 1024 Bergmann H.-H. 1081, 1118 Bemdt R. 1081 Berthold P. 922 Bewolskaja M. 1082 Bianki V.V. 1014 Biebach H. 1053 Bibikov D. I. 1082 Bingman V.P. 1202 Black C.P. 984 Blagosklonov K.N. 1083 Blix À.S. 1155 Blondel J. 373, 594, 1040 Blums P. 797, 1090 Bochenski 338 Boer de, L. 1046 Boglianl G. 1084 Bogoslovskaya L.S. 818 Bogucki Zd. 1084 Bolotnikov A.M. 873, 1052 Bont de, A. F. 1155, 1178 Bossema I. 1029 Bostrom U. 1032 Boswall J. 1085 Brodkorb P. 174 Brown E.D. 1086 Brown J.L. 774, 1036 Brown R.G. 559 Bruderer B. 1086 Brulnsma 0. 1029 Brunov V.V. 1086 Brush A.H. 1044 Bruyn de, K. 1085 Buchuchanu L.S. 1111 Bulakhov V.L, 1088 Bulatova N. 1046 Buldakova A.N. 953 Burchak-Abramovitch If. I. Burger J. 905 Burke Ch.J. 1117 Burnham W.H. 328 Burtt E.H. 1044 Busse Pr. 122 Butler P.J. 995 Buttemer W.A. 388 Butterfield J.E. 1071 Cadbury C.J. 754 Cade T.J. 329 Capo M.L. 1151 Carey C. 845 Semy V. 1018 Chakravorty K. 768 Chandola A. 768 Cherny akin R.G. 1088 Cho K. 1203 Collias N.E. 1041 Cooch F.Gr. 1030 Cooper J. 1065 Coppola D. 1101 Coulson J.C. 783, 892 Coulter M.C. 1089 Crick Q.P. 1041 Croxall I.P. 1065 Csörgo T. 1089 Cvelych A.N. 1090 Czikeli H. 1090 Danilenko A.K. 1091 Danilenko E.A. 1091 Danilov N.N. 1091 Danilova O.V. 64 D'Anselmo R. 1092 Dau Ch.P. 1092 Davies S.J. 1060 Dawson W.R. 106l Delius J.D. 804, 1093 Demartis A.M. 1154 Denslow J.S. 1154 DeBpin B. 1093 Deviche P. 1093 Dhondt A. A. 792, 1039 Dittami G. 501 Dmitrieva L.P. 1094 Dobrokhotova L.P. 1095 Dobrovolskaya E.V. 1095 1076 Dobrynina I.N. 488, 1212 Dobrynsky L.N. 1094 Dolnik V.R. 416, 421 Donham R.S. 946 Dornbusch M. 1096 Dorofeev A.M. 679 Drent R. 392 Drewien R.C. 1051 Drozdov N.N. 1063 Dshabbarow A. 1096 Dyachenko V.P. 1097 Dyck J. 1045 Dyrcz A. 615 Dzerzhinsky F. Ye. 1098 Edelstem C. 1053 Eichler W. 1018 Ellis D.H. 1098 Elzanowski A. 178 Erdelen M.1206 1328 Faaola M. 1078, 1098 Faraci F.M. 928 Parner D.S. 946 Fedde H.R. 978 Fedotova I, B. 1099 Feduocia A. 184 Filippo de, G. 1101, 1117 Fireova L.V. 1100 Fitzpatrick J.W. 1031,1036 Flint V.E. 1050 Fokin Ju.S. 1100 Foster M.S. 1038, 1101 Fraiaainet M. 1101, 1117 Fretwell S.D. 630 Frugis S. 1077 Fry C.H. 1041 Fujimaki 7. 1101 Fuller R.J. 1033 Pumese B.L. 1102 Fume aa R.W. 1065, 1070 Gabrielsen G.W. 1102 Ganahirt G. 501 Gaidar A. A. 1103 Galushin V.M. 662, 1103 Gan ja I,M. 1104 Garmatina S.M. 953 Gatter W. 115 Gauthreaux S. 620 Gavrilov A.e. 1122 Gavrilov E.I. 1104, 1106 Gavrilov V.M. 421,488,' 1220, 1254 Gepp B.Ch. 1105 Geraesimov N.N. 1105, 1188 Giataov A.P. 1106 Glen D.M. 1006 Glowacinski Z. 1106 Goo M. 1114 Gochfeld M. 882 Golovatin M.G. 1167 Golovkin A.N. 1063 Golubeva T.B. 259 Gordienko N.S. 1107 Graf R. 1114 Graphodataky A. 1046 Greenberg R. 648 Gromadska J. 1108 Grotta M. 1144 Gubin B.M. 1109 Gubkin A. A. 1088 Guean G.Z. 1162 Gvozdev E.V. 1097 Gwinner E. 501 Haartman L. von 34 Haaa V.1109 Haffer J. 1031 Haftom S. 137 Haila Ï. 1032 Hallet C. 1117 Hammeratrom Fred. 1110 Hammeratrom Fran. 1117 Hardy J.W. 1042 Harria M.P. 1168 Harriaon C.S, 1066 Helb H.-W. 1081, 1111 Heller H.C. 1107 Heuwinkel H. 1111 Hida Th.S. 1066 Hilbom R. 1192 Hildén 0. 716 Holmes R.T. 1007 Holz R. 1112 Hornberger D.G. 1010 Home J.F.M. 1040 Home R.S.C. 1112 Hou L.H. 1164 Houston D.Ch. 1113 Hoyt D.F. 832, 864 Hultsch H. 1113 Hummel D. 1067 Hunt G.L. 1025, 1064 Idzelis R. 1114 Ilyichev V.D. 8, 318 Ilyina T.A. 416 Ilia8chenco V.Yu. 1114 Imboden Ch. 336 Immelman K. 156 Ingel a J. 1114 Isakov Yu. A. 654 Isenmann P. 1040 Ito M. 1196 Ivanitsky V.V. 900 Ivanov G.K. 1128 Ivanova L.S. 953 Ivanovsky V.V. 679, 1116 Jallageas M. 935 James F.C. 1030 Janaus M. 1115, 1188 Jenni L. 1116 Jermakov A. A. 1189 Jestafyev A. A. 1189 Johansen K. 970 Johnson Ned.K. 1028 Johnson St.R. 530 Johnstone G.W. 1112, 1126 Joiris C.R.E. 1025 Jones D.R. 990 Kalby M. 11 17 Kalchreuter H. 1015 Kamil A.C. 811 Kania W. 1118 Kataevsky V.H. 1118 Katz Y. 300, 1119 Kenward R.E. 666 Kerry K.R. 1112 Kespaik J. 1119 Kettle R. 1085 Kharchenko V.J. 1120 Kharin V.L. 1073 Kharitonov S.P. 1228 Khayutin S.N. 247, 1094 Khodkow G.J. 1120 Khrabry V.M. 1121 Khrokov V.V. 1121, 1122 Kiley J.P. 978 King J.R. 404 Klaus S. 1122 Kneis P. 1112 Knystautaa A. 1123 Kocian L. 1123 Kokshaysky N.V. 1067 Kolatad M. 1148 Kondratyev A.Y. 1124 Konstantinov V.M. 1125 Konyayev A.V. 1103 Korshunova E.N. 1125 Koryakin A.S. 1126 Korzjukow A. 1128 Korzun I.P. 1011 Kotjukov J.V. 1177 Koshelev A. I. 1015, 1127 Kostin 1.0. 1127, 1128 Koviasyn V.I. 1103 Kovshar A.F. 567, 1109 Kretchmar A.V. 570 Krivenko V.G. 1129 Krivonoaov G.A. 1129 Krôl A. 1129 Krol W. 1129 Kroodsma D.E. 1013 Kruijt J.P. 1029 Krushinsky L.V, 821 Ksenz A. 1149 Kuchin A.P. 1130 Kuligin S.D. H 31 Kullapere A. 1130 Kumari E. 61 Kurashvill B.E. 1132 Kurganova T.N. 1104 Kurlavicius A. 1132 Kurlavicius P. 1132 Kurochkin E.N. 19 1 Kydyralyev A.K. 1137 1529 Laidna A. 1163 Lapshin N.V. 1133 Lebedeva M.I. 1133 Lees-Smith D.T. 1178 Lederer R.J. 1010 Leht R. 1119 Leito A. 1133 Lemmetyinen R. 1071 Leonovitch W.W. 1134 Leppelsack H.-J. 1012 Leuven K.U. 1155, 1178 Lewis J.C. 1051 Li Zhong-zhou 1140 Liepa V. 300, 1134 Lill A. 1026 Lilleleht V. 1163 Lindén H. 1016 Li tun V.I. 1103 Litvinenko N.M. 1173 Liversidge R. 1034 Lobanov V.A. 1107 Lobkov E.G. 1135 Lohrl H. 1038 Lomov A. A. 1135 Loakot V.L.1031 Lovejoy Th.E. 324 Lubrano A. 1092 Lucca de, Ed.J. 1047 Lundberg A. 1072 Lyuleeva D.S. 1137 Lycenko V.I. 1136 Lyster I.H. 1136, 1278 Maksimova A.P. 1138 Malchevsky A.C. 1289 Marten J.A. 1028 Martens J. 358 Masatomi H. 1049 Maslaton Z.. 1075 Massa R. 1142 Mastronardi D. 1092 Mathew N. 1193 Matt K.S. 946 Mattocks P.W. 64 Matvejev S.D.‘ 763, 1281 Mauersberger G. 757 Mayhew P.W. 1138 Ma Yi-Ching 1048, 1139, 1140 McCabe R.A. 1034 Mednikov B.1135 Mednis A. 797, 1083 Melnichuk V.A. 1141 Melnikov J.I. 1140 Mertens J.A. 1051,1141 Meyburg B.-U. 683 1350 Miasojedova O.M. 1142 Micali G. 1142 Michev T.W. 1143 Mihelson H. 797, 1143 Mikhalevich O.A. 1090 Miller I).B. 1144 Mishenko A.L. 1232 Milone M. 1092, 1101, 1144 Mineyev J.M. 1189 Mlikovsky J. 1145, 1146 Moennond T.C. 1157 Molodovsky A.V. 1158 •Monagham P. 1070 Mongini E. 1077 Moore M.C. 946 Morenkov E.D. 1288 Morgan R. 588 Mortensen A. 1148 Moskwitin S. 1149 Mourer-Chauviré C. 234 Mundinger P.C. 1057 Musaew A. 1150 Nachtigall W. 1069 Nadler T. 1150 Nagy K.A.388 Naik R.M. 1151 Nakamura T. 1196 Nankinov D. 1151 Nazarenko A. A. 1152 Nechaev V.A. 1135 Necker R. 1152 Nedzinskas V.S. 1153 Neifeldt I. A. 1050 Nekrasov A.V. 1 1 6 1 Newton I. 694 Nicholls T.J. 27 Nicolai J. 1042 Nitecki Cz. 1153 Noskov G.A. 930 Novikov B.G. 953 Nowak E. 1154 Numerov A.D. 1289 Oehme G. 1154 Oehme H. 1068 O'Meara M. 754 Orians G.H. 1022 08hmarin P.G. 1017* Otsuki Sh. 1181 Parasharya B.M. 1151 Parker H. 1155 Pannelée D.P. 520 Patterson I.J. 770 PaulBsen J.A. 11 55 Payevsky V.A. 1154 Payne R.B. 1027 Pechenev S.I. 1156 Pelgunov A.N. 1018 Pererva V.I. 1157 Perrins C.M. 1021 Peter H.-U. 1157 Petrins A. 1083 Piiper J. 840, 958 Pimenov V.N. 1103 Podolsky A.L. 1073, 1157 Polozov S.A. 1158 Poluda A.M. 1159 Ponomareva T.S. 1159 Poole A.P. 705 Porkert J. 11 60 Fostnikov S.N. 1160 Potapov R.L. 409 Powell Pr.L. 963 Prince P.A. 1065 Prigioni C. 1078 Profus P. 1162 Profirov L. 1150 Pronin N.M. 1161 Pronina S.V. 11 61 Prove E. 11 62 Putramantene A. 1172 Raitt R.J. 1042 Rajala P. 1016 Rakul A. I. 1162 Rattiste K. 1163 Rautenberg W. 1107 Ravkin Yu. S. 580 Reeves R.B. 1 12 Reyer H.-U. 1037 Rhijn van, J.G. 1028, 1045 Rich P.V. 200, 1078,1164 Ricketts Ch. 1065 Risebrough R.W. 1008 Robbins Ch.S. 737 Robertson R.J. 11 64 Rodriguez M.M. 1165 Roman eev N.S. 1088 Romanov A.N. 1103 Roos G.T. 1280 Roselaar C.S. 1054 Roshchevsky Y.K. 1165 Rothe H.-J. 1069 Rudneva L.M. 953 Rustamov A.K. 584 Rustamov E.A. 1166 Rute J. 1166 Ryabltsev V.K. 1167 Rymkevich T.A. 930 Rysavy B. 1019 Ryzhanovsky V.N. 1167 Ryzhikov K.M. 1017 Sadykov O.P. 1073 Safriel O.N. 1168 Sakaguchi S. 1107 Salomonsen P. 541 Sander M. 1008 Saevari L. 1168 Scott P. 1170 Searcy W.A. 1020 Seki M.P. 1066 Sema A.M. 1104 Semm P. 312 Serebryakov V.V. 1170 Seymour N.R. 1178 Seymour R.S. 854 Scheibel M. 705 Scheich H. 118 Scheid P. 958, 976 Schleicher A. 117 Schmidt R. 1169 Schneider D. 1064 Schonn S, 1169 Schultz J.C. 1007 Scott D.K. 1170 Sharrock J.T. 716 Sheddew C.B. 1171 Shepel A, I. 1172 Sheviakov V. 1172 Shibaev Yu.V. 1178 Shields G.P. 1047 Shishkin V.S. 1138 Shkatulova A.P. 1173 Short L.L. 1040 Shumakov M.E. 1174 ShurakovA.I, 1052 Sibley C.G. 83 Siefke A. 1112, 1169, 1174 Siegfried W.R. 1065 Silajewa O.L. 1230, 1283 Simeonov P.s. 1143 Singh S. 468 Siokhin V.D. 1175 Skryabin N.G. 1175 Slagsvold T. 638 Smirensky S.H. 1046, 1232, Sokolov L.V. 1176 Sonin M.D. 1018 Sopyiev 0. 1060 Sorokin A.G. 1177 Spassky A. A. 1177 Spitzer P.R. 705, 1009 Springer A.M, 1008 STastny K. 1080 Steen j.B. 1052 Stempniewicz L. 1178 Stepanyan L.S. 1242 Sternberg H. 1191 Stevens J. 1178 Stjemberg T. 743 Strawinski S.T. 1179 Stubbe M. 1179 Sugawa H. 1181 Sutter E. 1055 Svec P. 1180 Syroetchkovsky E.V. 570 Tahon J. 1181 Tatarinkova I.P. 1181 Tembrock G. 242 Temchin A.N. 275 Temple St. A. 336 Tets van, G.P. 200, 1078 Thielcke G. 1057 Thomas D.H. 1062, 1182 Thomas C. 1071 Tikhonov A. 259, 1082 Tilba P. A. 1183 Todt D. 1184 Tomialojc 608 Tomkovich P.S. 1184 Torök J. 1185 Tschemitschko 1. 1. 1185 Unander S. 1148 Verheyen R. 1087 Veromann H. 1176 Vietinghoff-Scheel E. 1186 Vigorita V. 1142 Viksne X. 1187, 1188 Vilks E. 300 1285 Vladishevsky D.V. 1006 Vleck C.M. 399, 864 Vleck D., 864 Vo Quy 1178 Volkov E.N. 1104 Vorobyeva E.I. 227 Vorobyeva T.D. 413 Voronin R.N. 1189 Vos de, G. J, 1007, 1029 Vuilleumier Fr. 348 Wada M. 516 Waite R.K. 1189 Wallraff H. 284 Wallschläger D. 253 Walton Br.J. 1007 Wattei J. 1055 Weathers W.W. 388 Weselovsky T. 1197 Westerterp K. 392 Wieloch M. 1190 Wiens J. 1064 Wiley J.W. 1035 Wiltschko R. 304 Wiltschko W. 304, 312 Williams A.J. 1190 Wingfield J.C. 478 Wink M. 1182 Winkel W. 1081 Wittenberg J. 1191 Woolfenden G.E. 1036 Wunderlich K. 1193 Yesilevskaya M.A. 1192 Yom-Tov Y. 1192 Yurlov K.T. 1015 Zablotskaya M.M. 1013 Zacharias V.J. 1200 Zagorodnyuk I.V. 1090 Zahavi A. 919, 1043 Zalakevicius M. 1194 Zhordania 1194 Zinovjev V.I. 1193 Zorina Z.A. 1099 Zubakin V.A. 1250 Zvonov B.M. 1195 CONTENTS Symposium ADAPTATIONS OF BIRDS TO MAN-MADE ENVIRONMENTS Ravkin Yu. S. Anthropogenic Transformations of Avian Communities in the USSR Forest Zone . . . RustamovA.K. Birds and Man-Induced Environmental Changes in the Arid Zone of the USSR . • . . . . Morgan R. Changes in the Breeding Avifauna of Agricultural Land in Lowland Britain . . . Blondel J. Mediterranean Bird Faunas in the Light of Anthropic Pressure Since the Neolithic . . . . . . Tomialo je L. Urbanization as a Test of Adaptive Potentials in Birds . Dyrcz A. Breeding Ecology of the Two Populations of Turdus grayi at Localities of Different Human Influence in Panama Lowland ... 580 584 588 594 608 615 Symposium ECOLOGICAL ASPECTS OF BIRDS MIGRATION Gauthreaux S.A., Jr. The Temporal and Spatial Scales of Migration in Relation to Environmental Changes in Time and Space . Fretwell S.D. Why Do Birds Migrate? Inter and Intraspecific Competition in the Evolution of Bird Migration Contributions from Population Ecology . . Slagsvold T. Habitat Phenology and Spring Migration Schedules . Greenberg R. Social Behavior and Foraging Ecology of Neotropical Migrants . . . Isakov Yu. A. The Role of Heredity and of Collective and Individual Experiences in Seasonal Distribution and Migration of Birds .... 620 630 638 648 654 Symposium ECOLOGY OF RAPTORS Galushin V.N. Adaptation of Predatory Birds to Altered Environmental Conditions . . . Kenward R. Problems of Goshawk Predation on Pigeons and Other Game . . . . . . Dorofeev A.M. , Ivanovsky V.V. The Role of Predatory Birds in the Ecosystems of the Byelorussian Lake Region . Meyburg B.U. Management zur Anhebung des Greifvogelbestandes . Newton I. Recent Developments in the Study of Raptor Populations .. Spitzer P. R. , A. F. Poole, M.Scheibel. Initial Population Recovery of Breeding Ospreys (Pandion haliaetus) in the Region between New York City and Boston . . * . 662 666 679 683 694 705 1332 Symposium DYNAMICS OP BIRDS RANGES Hilden 0. , Sharrock J.T.R.A. Summary of Recent Avian Range Changes in Europe . . 716 Robbins C.S. Recent Changes in the Ranges of North American Birds . . . . . . 737 Stjernberg T. Recent Expansion of the •Scarlet Rosefinch (Carpodacus erythrlnus) in Europe . . . 743 Cadbury J .C . ,0 'Meara M The Decline of the Corncrake (Crex crex) in Europe . . . 754 Mauersberger G. Analysis of Different Factors Causing Dynamics of Birds Ranges.. . . 757 Matvejev S.D. Expansion of Areas by 15 Bird Species in Balkan Peninsula . . . 763 Symposium DENSITY REGULATION IN BIRD POPULATIONS Patterson I.J. Territorial Behaviour and the Limitation of Bird Populations . . . . . . 770 Brown J.L. Cooperative Breeding and the Regulation of Numbers ...... 774 Coulson J.C. Density Regulation in Colonial Sea-Bird Populations ... 783 Dhondt A. A. The Effect of Interspecific Competition on Numbers in Bird Populations . . . . . . . 792 Mihelsons H., Mednis A., Blums P. Regulatory Mechanisms of Numbers in Breeding Population of Migratory Ducks . 797 Symposium ONTOGENY AND PHYLOGENY OP COGNITIVE PROCESS Delius J. Complex Visual Information Processing in the Pigeon . 804 KamilA.C.The Evolution of Higher Learning Abilities in Birds . 811 Bogoslovskaya L.S. Homologous Relationships in the Central Nervous System of Birds and Mammals . 818 Krushinsky L.V. Study of Conscious Activity and Its Morphological Basis in Birds . . . 821 Symposium PHYSIOLOGY OP THE AVIAN EGG Hoyt D.P. Introduction to the Diffusive Exchanges and Water Relations of Avian Eggs . . 882 Piiper J. Respiratory Gas Exchange of Avian Eggs . *••* 8^° Carey C. Adaptation of Avian Eggs to Extreme Environments . Seymour R. Physiology of Megapode Eggs and Incubation Mounds . 854 Vleck D., Vleck C.M., Hoyt D.P. Physiological Correlates of Synchronous Hatching in Rhea Eggs (Rhea americana) . 864 Bolotnikov A.M. Haterogeneity of Eggs and Heterochrony of Avian Embryos Development under Incubation in Nature . . ®^3 1555 Symposium ADAPTIVE SIGNIFICANCE OF COLONIES AND FLOCKS Gochfeld M. Predation and Coloniality in Seabirds . 882 Coulson J.C. A New Hypothesis for the Adaptive Significance of Colonial Breeding in the Kittiwake Rissa tridactyla and Other Seabirds . . . 892 Ivanitsky V.V. Evolution of Sociability, Formation and Structure of Monospecific and Mixed Colonies of Sparrows from the Subfamily Passerinae . 900 Burger J. Advantages and Disadvantages of Mixed-Species Colonies of Seabirds . . 905 Zahavi A. Some Further Comments on the Gatherings of Birds . . 919 Symposium PHYSIOLOGY OF REPRODUCTION, MOULT AND MIGRATION Berthold P. Endogenous Components of Annual Cycles of Migration and Molt . 922 Noskov G.A., Rymkevich T.A. Photoperlodic Control of Post juvenile and Postnuptial Molts in Passeriformes ......................... 930 Jallageas M., Assenmacher I. Endocrine Correlates of Molt and Reproductive Function in Birds . . . . . 935 Moore M.C., Famer D.S. , Donham R.S., Matt K.S. Endocrine and Photoperiodic Relationships during Photoref ractoriness , Postnuptial Molt, and Onset of Migration in Zonotrichia leucophrys gambelii . . . * 946 Novikov B.G., Rudneva L.M., Buldakova A.N., Ivanova L.S., Garmatina S.M. The Role of the Hypothalamo-Hypophysial System in the Annual Cycle of Molt and Gonadal Function . 953 Symposium AVIAN RESPIRATION Piiper J., Scheid P. Anatomy and Physiology of the Avian Respiratory System . . 958 Powell F.L. Inert Gas Transfer and Functional Inhomogeneities in Avian Lungs . . 963 Bech C. , Johansen K. Avian Respiration in the Service of Body Temperature Regulation . 970 Scheid P. Significance of Lung Structure for Performance at High Altitude . . 976 Fedde M.R. , Kiley J.P., Faraci F.M. Recent Advances in Understanding the Control of Breathing in Birds . 978 Black C.P. Respiratory Adaptations to High Altitude in Birds . . 984 Jones D.R. Physiology and Metabolism in Breath-Hold Diving . 990 Butler P.J. New Techniques for Studying Respiration in Free Flying Birds . 995 1354 ABSTRACTS OP APTERNOON SYMPOSIA . . luu= ABSTRACTS OP POSTER PRESENTATIONS . 1072 POSTER PRESENTATION Becker P.N. Common Tem Breeding Success and Nesting Ecology under Predation Pressure of Herring Gulls . 1198 Becker P.N. , Erdelen M. Distribution of Herring Gull Egg Size and Nest Density in the Mellum-Colony in Relation to Vegetation Height . 1206 Dobrynina I.N. Characteristics of Some Bird Species Migrations According to the Ringing Data . 1212 Gavrilov V.M. Energy of Existence at 0° and 30° and Basal Metabolism of Insectivorous and Granivorous Passeriformes ! Their Seasonal Change and Dependence on Body Mass . 1220 Kharitonov S.P. On Structure of Black-Headed Gulls (Parus ridlbundus ) Colonies . 1228 Silajewa O.L. Sound Imitation in the Formation of Communication Be Ween man and Birds . . . . .. 1230 Smirensky S.M., Mishchenko A.L. Taxonomic Status and Historical Formation of the Area of Common Swallows (Hirundo rustics) in the Amur region . 1232 Stepanyan L.S. The Geographical Correlation of Morphism Phenomena in Birds in Central Asia . 1242 Zubakin V.A. Types of Coloniality in the Family Laridae . 1250 ROUND-TABLE DISCUSSIONS Gavrilov V.M. Seasonal and Circadian Changes of Thermoregulation in Passerine and Non-Passerine Birds; Which is More Important? . 1254 Lyster I.H.J., Lees-Smith D.T. Holarctic Aviao Spéciation Atlas .... 1278 Roos G. Th.de. Tourism and Birds . . . . . 1280 Matveyev J.D. Son,ispocios ' in the Avian Fauns of the Balkan Peninsula 12si oilcj ewe O.L. Polk and Onomatopoeic Names of Birds , 1283 Smirensky S.M. Working Group on Cranes of USSR . . . 1285 Morenkov E.D. Morphofunctional Organisation of the Visual System in Birds . . Malchevsky A.S., Numerov A.D. Interrelations between the Common Cuckoo and its Hosts in the Territory of the USSR . . 1289 MEMBERS OP THE CONGRESS . 1290 INDEX OP AUTHORS . 1328 MsflaHHe ocymecroneHo c opHniHana, noflroTOBneHHoro k ne^ara BcecoiosHbiM opHHTononwecKHM oômecTBOM AH CCCP Tpyflbi XVIII MEîKflyHAPOaHOrO OPHHTOJIOrHHECKOrO KOHrPECCA Tom II ( Ha aHrn. H3.) yreepxdeHO k neiaru MncTUTyTOM -jeojiKmuOHHoü Moptpo/weuu u 3 Ko/ioeuu MueoTHbix um. A.H. Ceeepuoea AH CCCP H/K rionnucaHO k newara 22.1 1.8S. OopMaT 70x 100 1/16 ByMara pjm rny60K0ü ite«iaTn. IIe>iaTb o^JceTHaa. ycJi.neB. ji. 61,8 ycji.Kp.-OTT. 61,8. y«i.-H3H. n. 64,S THpa* 1600 3K3. Thti. aaK. 981 IJeiia 5 py6. 3aKB3Hoe OpueHa TpyaoBoro Kpacnoro 3HaMeHH H3flaTejibCTBO ’’HayKa” 117864 TCn-7, MocKBa B-485, npo4>coio3HaJi yji., a. 90 Opnewa TpyaoBoro KpaCHoro 3HaMeHH 1-H Tnnorpa4>HH H3jaaTejibCTBa ’’HayKa” 199034, JleHHHrpaA B-34, 9-h hhhhb, 12 * iBIBLDU (muséum/ lPARIS> cSmj Bt f s*.:S£ BlßUOTHrQUf