RAPTOR RESEARCH Volume ii Number 3 Fall lf)77 fl _ NCHHL. US. FfSH & WI LD WOvswjjif,: Ru,,^ a BOISE, ILJAhu SSiyy Riiptm Research Found ji timi. liu\ Pruv o„ U cnli, U.5.A. ■ I'tv'.'Cfi Fall 1977 RAPTOR RESEARCH Volume 11, Number 3, Pages 48-80 CONTENTS SCIENTIFIC PAPERS The Status, Ppulation Structure, and Breeding Dates of the African Lammergeier— L. H. Brown ; 49 Diet Values and the Food Consumption of New Zealand Falcons— Nick Fox 59 A Roadside Raptor Census in the Eastern Great Basin— 1973-1974— Neil D. Woffinden and Joseph R. Murphy 62 Reversing Female Dominance in Breeding Raptors— John Campbell 66 Techniques Useful for Determing Raptor Prey- Species Abundance— R. E. Fitzner and L. E. Rogers 67 Barbed Wire Impales Another Great Horned Owl— H. Leroy Anderson 71 Reintroduction of Captive-Bred Prairie Falcons in California— 1976— Sue Elizabeth Granger 73 News Items 74, 75 Abstract of Theses.. 77 RAPTOR RESEARCH Published Quarterly by the Raptor Research Foundation, Inc. Editor Dr. Clayton M. White, Dept, of Zoology, 161 WIDB, Brigham Young University, Provo, Utah 84602 Editorial Staff Dr. Frederick N. Hamerstrom, Jr. (Principal Referee) Dr. Byron E. Harrell (Editor of Special Publications) Dr. Joseph R. Murphy (Printing Coordinator) The Raptor Research Foundation, Inc., welcomes original articles and short notes concerning both diurnal and nocturnal birds of prey. Send all papers and notes for publication and all books for review to the Editor. Most longer articles (20 or more typeset pages) will be considered for publication in Rap- tor Research Reports, a special series for lengthy and significant contributions containing new knowledge about birds or new interpretations of existing knowledge (e.g., review articles). However, authors who pay page costs (cur- rently $20.00 per page) will expedite publication of their papers, including lengthy articles, by ensuring their inclusion in the earliest possible issue of Raptor Research. 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THE STATUS, POPULATION STRUCTURE, AND BREEDING DATES OF THE AFRICAN LAMMERGEIER Gypaetus barbatus meridionalis by L. H. Brown P.O. Box 24916, Karen, Kenya Abstract The African Lammergeier ( Gypaetus barbatus meridionalis), occurring in mountain- ous country from Yemen south through Ethiopia and East Africa to Lesotho and adja- cent parts of South Africa, is listed as threatened in the ICBP Red Book (Fisher, Sim- on, and Vincent 1969). The authors state that the African Lammergeier is common only in the northern and southern parts of its range but is locally abundant only in Ethiopia. They imply that the nominate North African race G.b. barbatus is less threatened. This paper attempts to clarify the status and some other facts about the African Lammergeier and to demonstrate that the race is not at present threatened because of its abundance in Ethiopia. Methods Between 1963 and 1975 the number of Lammergeiers seen in Ethiopia (and wheth- er they were immature or adult) was recorded and summarized in my field notebooks and diaries. One can usually determine whether a Lammergeier is adult or immature at 400-500 m with the naked eye in good light and at up to 4-5 km with xl2 binocu- lars. The conspicuous white heads of adults show up clearly. In 1975 it also became clear that the immatures could be subdivided into different age groups, described lat- er; but since this was not done between 1965 and 1974, no adequate quantitative data on the various age groups are available for those years. Of 527 Lammergeiers recorded in Ethiopia, however, only 49, 9.3 percent, could not be identified as adult or immature. Most of them were seen at very long range or against the sky as I trav- eled fast in a car. Samples from mountain areas include fewer unidentified individuals (15/234 or 6.4 percent) because in these areas I was usually on foot or muleback and could take longer to identify distant individuals. Of the counts I made in towns where I spent several days, only the highest thor- ough count has been included, since observation shows that the same individuals visit the same areas daily. A good count in any town can usually be made between 0900 and 1000 h, when Lammergeiers are searching for food but have not yet soared to great height. Different individuals can be recognized by molt or minor plumage dif- ferences. In mountain areas, when several days were spent at one camp, I avoided counting birds in the same area twice. Although there is still some risk of double- counting, errors have thus been minimized. Data from Ethiopia were compared with a small sample from Spain for 1955 and one from Lesotho for 1973, giving a comparative sighting rate per day as a crude in- dex of relative abundance. These have been supplemented from published data, nu- merous personal observations in East Africa, correspondence with other observers, and the East African Natural History Society’s and the South African Ornithological Society’s nest record card schemes. 49 Raptor Research ll(3):49-80 50 RAPTOR RESEARCH Vol. 11, No. 3 Status and Numbers Good recent data from Yemen are lacking. Nothing is recorded in Meinertzhagen (1954) regarding this area. It seems likely that the Lammergeier may still be fairly common in mountainous parts of Yemen, since land-use methods have probably al- tered little, and accordingly there is no obvious reason why the status of the Lam- mergeier should have changed. In the rest of the race’s range numbers are assessed as follows: 1. Ethiopia: Common, locally abundant (more than 10 seen daily in preferred habi- tat). Most numerous around towns and villages, but also numerous in high mountains in northwest Ethiopia, e.g. Semien Mountains. Daily sightings varied from none to a maximum of 23 in one day at Gondar in 1965. In 150 days on which Lammergeiers could have been seen, 527 were recorded, an average of 3.5/day overall. The average sighting rate in towns and inhabited areas, 4.4/day, is higher than in thinly inhabited or uninhabited mountain areas, 2.8/day. However, the latter figure is biased by a long expedition through the Bale and Arussi mountains in southeast Ethiopia in 1966, where in a total of 54 recorded days only 87 were seen, an average of 1.6/day. The species is much less common there than in the Semien Mountains, where in 24 days 134 were seen, 5.6/day, an even higher average rate than in towns and villages in the same general region. The overall sighting rate of 3.5/day may be compared with 10 in 15 days in Spain, 1955, 0.66/day; and 8, perhaps 10, in 10 days in Lesotho in 1973, 0.8-1.0/day. There is thus no question that the Lammergeier is relatively common in Ethiopia, perhaps more so than anywhere else in the world except Tibet (Schaefer 1938). Total numbers cannot be estimated on present available evidence. However, it occurs over about three-fourths of the main Ethiopian highland massifs that total about 475,000 km 2 but is absent or scarce in the forested southwest. Normally it is common only above 1800 m in elevation but occasionally occurs lower (in the deserts of the Awash Valley down to 300 m), though it is not known to breed at these lower elevations. Four known nesting sites range from about 2500-3700 m, but it also probably nests below 2000 m. No thorough surveys have been possible to establish the home range of a pair. In one area, two known nest sites are approximately 3.5 km apart, suggesting a range per pair of 12-15 km 2 . However, Lammergeiers nesting relatively close together along cliffs in gorges probably travel many miles daily over flat plateaus lacking any nest- ing sites, so that average home ranges in practice would probably be much larger. Assuming however that the home range per adult pair averages 100 km 2 (a density certainly exceeded locally), there could then be about 4750 pairs in Ethiopia, and since 22.6 percent of the population is immature, perhaps 11-12,000 birds altogether. If this estimate is even approximately correct, the African Lammergeier is not a threatened race. 2. East Africa: In Kenya the African Lammergeier is widespread but uncommon or rare in high mountain ranges and on isolated peaks. Recorded from Mt. Marsabit (North, pers. comm.); Mt. Kulal, more than 3 birds (P. Saw, in litt.); Matthews and Ndotos ranges, certainly 4-6 pairs, and Muruanisigar, Turkana (G. H. H. Brown, in litt.); Ololokwi (Ol Donyo Sabachi) north of Archer’s Post (unpub. data and North, pers. comm.); north of Kapenguria in western Pokot District (T. Barnley, in litt.); Cherangani Hills, more than 1 pair; Mt. Elgon, at least 2 pairs; Mt. Kenya, possibly 5 Fall 1977 Brown — African Lammergeier 51 pairs; Ngobit (unpub. data and R. Hook, pers. comm.); along the Rift Valley from near Naivasha to near Ngong (North 1944, and unpub. data); Ol Donyo Orok and east of Chyulu Hills (Van Someren 1939); and even at Maungu, at only 800-900 m (Hopson, pers. comm.). These records suggest that although the species is much rarer in Kenya than in Ethiopia or even Lesotho, the Kenya population may be about 20- 30 pairs. In Tanzania it is recorded from Mt. Longido, Kilimanjaro, Mawenzi, and Mt. Meru, perhaps 10 pairs (G. H. H. Brown, and unpub. data); the Crater Highlands, at least 5 pairs (unpub. data, and Fuggles-Couchman and Elliott 1946). Its most south- erly outpost is probably Mt. Hanang (Fuggles-Couchman 1953). There may be anoth- er 20-25 pairs in the mountains of northern Tanzania. In Uganda it occurs on Mount Elgon; in northern Acholi; Karamoja (Mt. Moroto and probably Mt. Kadam); Ruwenzori; but not on Nyamlagira; in Zaire (Pitman, in litt., quoting Haddow, Bere, and personal records). There must be at least 5, possibly 10 pairs in Uganda. The total East African population therefore is probably at least 50-60 pairs. Although rare, it is apparently not threatened, as the population appears stable. 3. Southern Africa: There is a complete gap in the range from Mt. Hanang in northern Tanzania to the Orange Free State, Natal, and Lesotho. In Lesotho Rude- beck (1961) found Lammergeiers quite common, and there it has recently been stud- ied in detail at the nest (Guy and Tomlinson, in prep.). At least one breeding pair is known in the Golden Gate National Park in the Orange Free State (Newman 1969); and it occurs along the Drakensberg escarpment; in Natal in Giants Castle Game Re- serve; and almost certainly in east Griqualand, northern Cape Province, since I saw one within 1.5 km of the border between east Griqualand and Lesotho in November 1973. In Lesotho, in 10 days spent in suitable areas, I saw certainly 8, probably 10 differ- ent individuals, of which 7-9 were adults and 1 an immature. Rudebeck (1961) saw 21 including 17 identified adults and 2 immatures. My own sightings, averaging 0.8- 1.0/day (without making any special effort to find the birds), are about a quarter of the average sighting rate in Ethiopia, indicating that the Lammergeier is much less common in Lesotho than in Ethiopia. However, my average sighting rate per day is apparently at least as high as Rudebeck’s, suggesting no marked recent decrease. It is also about the same as the average sighting rate per day of the Golden Eagle Aquila chrysaetos in northwest Sutherland in 1967, in an area surveyed in detail on foot, where the known density of Golden Eagles is one pair per 4600 ha (11,400 acres) (Brown 1967). Even supposing that a pair of Lesotho Lammergeiers requires about three times the range of a pair of Golden Eagles (150 km 2 ), there could still be about 100 pairs in 15,000 km 2 of mountainous Lesotho suited to Lammergeiers. The total southern African population may thus be about 120 pairs, rather than the 20-25 pairs sometimes casually mentioned for South Africa as a whole. Thus, the total population of G.b. meridionalis might be about 12,000 birds in Af- rica, with an unknown, but probably large, population in Yemen. Most of the African birds live in Ethiopia, with small groups totaling not more than 200 pairs in East and South Africa. Even in East and South Africa the small populations appear stable and are not obviously threatened or declining (Brown 1977, Kemp & Kemp 1977). Although the African Lammergeier is thus not apparently threatened with extinction in any part of its range, it should nevertheless receive complete protection as a mag- nificent and completely harmless bird. 52 RAPTOR RESEARCH Vol. 11, No. 3 Population Structure Between 1965 and 1975, inclusive, I have recorded 527 Lammergeiers in Ethiopia, probably about 80 percent of those seen. After 1965 almost all have been recorded. Of the 478 identified individuals 370 (77.4 percent) were adults, and 108 (22.6 per- cent) were immatures. Forty-nine (9.3 percent of the total) could not be identified. These figures compare with 31 percent immatures in the Bateleur Terathopius ecaud- atus (Brown and Cade 1972) and 16-24 percent in the African Fish Eagle Haliaeetus vocifer (Brown and Cade 1972, Brown and Hopcraft 1973). The proportion of imma- tures in the Ethiopian population appears much higher than in Lesotho (3/27 or 11 percent) (my figures and Rudebeck 1961); and in the small sample from Spain (1/10 or 10 percent) in 1955. In Ethiopia high mountain areas with sparse or moderately dense populations of peasant farmers and graziers are mainly occupied by adult Lammergeiers, whereas immatures and subadults tend to congregate around village and town rubbish dumps. Table 1 shows that in 84 days spent in mountains, I saw 188 adults (85.8 percent of identified birds) and 31 immatures (14.2 percent). In towns and predominantly in- habited areas on the plateau 182 adults (70.4 percent) and 77 immatures (29.6 per- cent) were seen in 66 days. Counts made only in mountains or around towns and vil- lages would thus give a misleading picture of the population structure. The Ethiopian Lammergeier appears nearly twice as common in and near towns and villages as in mountain areas, but the mountain sample is biased by the results of one long expedition in Bale and Arussi, in which only 83, including 62 adults and 13 immatures, were seen in 52 days. In Bale and Arussi, in 54 days (some results stolen in 1973) 87 Lammergeiers were seen, averaging 1.6/day, whereas in four trips to Semien, totaling 24 days, 134 were seen, or 5.6/day. The proportion of immatures seen in the Bale Mountains, 13/78 or 16.67 percent, is also higher than in Semien, 13/128 or 10.16 percent. This might be because in Semien large towns and villages are closer to the main mountain massif than in Bale so that immatures could more easily move there. However, it seems likely that, as in some other large birds of prey (e.g., Gargett 1975), immature Lammergeiers are unable to remain in the breeding ranges and must subsist in areas not occupied by breeding adults. In Ethiopia, the fact that immatures can readily find scraps of meat, skin, and bones around any vil- lage rubbish dump or slaughterhouse may improve survival and help to explain the apparently higher proportion of immatures in the Ethiopian than in the Lesotho or Spanish populations. No detailed description of the molt from first immature to adult plumage in the Lammergeier seems to be available, while the visible plumage characters are com- plicated by the known cosmetic habits of the birds. However, according to Glutz von Blotzheim et al. (1971), the Lammergeier assumes adult plumage in about 5 years. The first immature plumage has the head blackish brown, and pale edges to the feathers of the back and wing coverts sometimes produce a pale patch on the upp^r back. In the later subadult plumages the pale edges disappear on the upper side, and pale or white feathers molt in on the breast and belly. The course of the plumage changes, presumably based on observation of captive birds, is, however, not described accurately. In wild Ethiopian birds at least three phases of immature plumage are dis- tinguishable: 1. Presumed juvenile; head and neck blackish brown, contrasting with a paler dull brown breast and belly; upper side dark brown with pale or whitish streaks some- Fall 1977 Brown — African Lammergeier 53 times coalescing; this probably would correspond to the first immature plumage as described by Glutz von Blotzheim et al. (1971). 2. Presumed immature; head and neck remain blackish brown, but the pale streaks disappear from the back and upper wing coverts, which are more uniform paler brown; breast and belly more rufous brown. 3. Subadult; in what is assumed to be an immediate subadult plumage approaching maturity, white feathers grow in on crown and cheeks; the head is now clearly sepa- rated from a still paler, more rufous, breast and belly by a dark chestnut neck-ring; sclerotic eye ring bright red, iris whitish, as in adult. Phases 1 and 2 look very similar from below; and as relatively few Lammergeiers can normally be viewed from above, they have been lumped in a small sample since 1974 when an attempt was made to separate age groups of immatures. Among 22 identified immatures, 20 were in phase 1 or 2 and only 2 in phase 3. This small sample suggests that only about 1 immature in 10 survives to adulthood. Certainly, very few individuals in the distinctive phase 3 are seen. If Lammergeiers assume adult plumage in about 5 years, like the African Fish Eagle, and as suggested by Glutz von Blotzheim et al. (1971), then, on the basis of theoretical mortality rates of 50 percent in the first year and 20 percent per year thereafter (Brown and Cade 1972) and a breeding rate of 0.55 young /pair /annum (see below), adult Lammergeiers must live 13.7 years as adults and 18.7 years alto- gether to maintain a stable population. However, Lammergeiers might actually take longer to reach maturity, as suggested by recent molt studies of Griffon Vultures Gyps spp. by Houston (1975). Griffons apparently take at least 7 years to attain adult plumage, completing a primary wing molt in 3 years. He quotes Menzbier (1894) to the effect that Lammergeiers take 2 years to complete a body molt but only 1 to cbmplete a wing molt; if so, they would perhaps mature more quickly than Griffons. If, however, their rate of assuming adult plumage is similar to that of Griffons and the Bateleur Terathopius ecaudatus (Brown and Cade 1972), then, again using the theoretical mortality rates for the Bateleur (50 percent in year 1 and 10 percent per annum thereafter), adults must live for 14.3 years as adults and 21 years altogether. Available figures for age-classes of immatures, which cannot in any case be correlated with good molt studies in captive birds, do not currently permit any better approx- imations. Adult plumage is normally rather rich pale rufous below, but the coloration is caused by a powdering of iron oxide (see e.g., Jackson & Sclater 1938, Berthold 1967). Adults are sometimes seen with pure white undersides, and zoo captives usual- ly become pure white. In the Crater Highlands, Tanzania, in October 1957, one of a pair seen in Olmoti Crater was pure white, the other rufous. At Makalle, Tigrai, Eth- iopia, in September 1975, several adults were pure white below; but by late October all adults seen had become rufous. Thiollay (1968) saw many individuals with pure white undersides in Corsica in July and August and, in April 1966, a pair of which one was white, the other rufous. These observations suggest that the rufous color of breast and belly can easily be lost or washed off, though normally maintained by cos- metic activities. The fact that all adults at Makalle in September 1975 were pure white, just after an unusually heavy rainy season, suggests that in a prolonged period of wet weather the rufous color may be more easily lost than at other times. Breeding Dates Yemen: There are apparently no published records (Meinertzhagen 1954). Ethiopia: 54 RAPTOR RESEARCH Vol. 11, No. 3 six good egg-date records (1,C1; 1,C2) include four in October and two in November. Laying thus occurs at the end of the main rainy season in north and west Ethiopia, but the single November record for the Bale Mountains in the southeast is during a subsidiary rainfall peak. In Kenya, R. Hook took an egg on May 8 (Meinertzhagen 1944), which may have been laid in April. A pair in the Njorowa Gorge at Naivasha has laid (in three defi- nite records) once in January, once in April, and once in early May; other observers' reports suggest that this pair has laid about April-May, at the height of the rains; young are flying by November. In Uganda Pitman records an egg from north Acholi in January (East Africa Nat. His. Soc. nest record cards). There appear no certain egg dates from Tanzania, but immatures have been seen on Kilimanjaro and Mt. Meru (G. H. H. Brown, in litt.). The few available records from East Africa and Ethiopia suggest that, in countries where the entire protracted breeding season (at least 180-200 days from nest building to independence of the young) can be completed in dry weather, egg laying occurs early in the dry season; but that in the intertropical convergence zone (where two three-month rainy and dry seasons alternately annually), the Lammergeier is as likely to lay in the rains. Two recent Lesotho records are for May (Guy, pers. comm.). A pair photographed by Barnes and others near Mokhotlong in Lesotho laid in June (Barnes, pers. comm., Pearse 1974). Two South African nest record cards for eggs are in July and August, and one for young in September (South African Orn. Soc. Nest record card scheme). A pair was incubating in Golden Gate National Park on 21 June (Newman 1969) and had a chick in the same nest in September (Steyn 1970). These records all suggest peak laying in South Africa about June, in the depths of winter, and are compatible with records of midwinter laying, in January or even December, in southern Spain (Glutz von Blotzheim et al. 1971). Breeding Frequency and Success The scanty data available on the subject of breeding frequency and success do not suggest that the Lammergeier is an unusually infrequent breeder or, consequently, un- usually long-lived. One Ethiopian pair observed for four consecutive years bred in two years and in two other years frequented the usual breeding site and apparently had no alternate. Another pair bred in 1973, but not in 1974 or 1975. The Naivasha pair in Kenya were reputed to have reared young annually from 1964-69, but not in 1970, though they again bred successfully in 1971. They certainly succeeded in 1964, 1969, and 1971, but definitely did not breed in 1970. After 1972 they were much dis- turbed by rock-climbers and did not breed but may have succeeded again in 1975. Thus, in 7 pair years in Ethiopia young were reared in 3, 0.43 /pair /annum; and in 4 years in Kenya one pair reared three young, 0.75/pair/annum. Combined, the breed- ing success of these three pairs is 0.55/pair/annum. This record is similar to that of a number of large eagles (e.g., Gargett 1970, Brown and Hopcraft 1973) and better than some large solitary vultures, e.g., the Lappet-faced Vulture Torgos tracheliotus (Pennycuick 1976), but is far lower than the breeding success of the strongly colonial Ruppell’s Griffon ( Gyps rueppellii ) in Serengeti (Houston 1976) in which success per occupied nest approaches 100 percent. In this case, however, the number of non- breeding pairs could not be assessed. Taken in conjunction with the proportion of im- matures in the total population, the rather inadequate data on breeding success do not suggest that the Lammergeier is exceptionally long-lived, but further data are needed. Fall 1977 Brown — African Lammergeier 55 In 1963 one Ethiopian egg was taken for electrophoretic analysis. In 1964 the same site was again used and had a downy chick; but Ethiopians threw burning brands into the nest and destroyed it. The site was never used again up to 1971, though the adults remained in the vicinity, suggesting that a catastrophe may inhibit breeding for several years. Reasons for Abundance or Relative Scarcity The Lammergeier is often apparently commensal with rather primitive pastoral cultures, where large populations of domestic stock are maintained under hard moun- tain-range conditions and consequently subject, with inadequate veterinary services or none at all, to high death rates. In Ethiopia, the Lammergeier is commensal with man, feeding on scraps of meat and carrion as well as bones, and, in Tibet, following the plough in spring to obtain grubs from the spread manure (Schaefer 1938). The Lammergeier disappears or becomes rare in areas where efficient stock-keeping and modem sanitation prevail, e.g., in Switzerland. Even in Ethiopia it is commoner in inhabited mountain ranges such as Semien than in the almost uninhabited Bale Moun- tains. In East Africa the Lammergeier must compete for bones with very much more powerful or numerous predators and scavengers such as the Griffon Vultures Gyps rueppellii, and Gyps africanus ; spotted hyenas Crocuta crocuta-, or jackals Canis spp. Lammergeiers cannot successfully contest prey with domestic dogs on rubbish dumps, or with Gyps rueppellii at a carcass. The Ethiopian highlands support about 15 million cattle, at least 25 million sheep and goats, and 3 million equines, all with high death rates from disease, accident, or starvation. Here too the Lammergeier must compete with jackals and spotted hyenas for the available bone supply but, being diurnal, often has the first chance after larger flesh-eating vultures have stripped a carcass. Moreover, it is not wholly depen- dent on bones. Near villages and towns adults and immatures readily obtain their re- quirements from discarded scraps of meat, skin, and bone. An adult has been seen to walk clumsily three times in succession into a patch of dense bush to feed on the body of a dead gelada baboon Theropithecus gelada, in each case taking a cropload about 1 km away to a nest containing a large young bird and returning for more soon after regurgitating the food on the nest edge. However, Lammergeiers do un- doubtedly feed on bones to a large extent and are often seen dropping them (Brown 1970). I have also seen the process in Spain in 1955, and there are several good re- cords from India (e.g., Lowther 1947). Occasionally, they may also kill their own prey (Newman 1969). In Ethiopia, religious beliefs forbidding good Christians and Muslims to eat animals not correctly slaughtered probably contribute to the abundance of food available to Lammergeiers and other scavenging birds. Probably similar beliefs would apply in Yemen. In Lesotho, on the other hand, no such religious taboos prevent hungry herd- boys from eating an animal which has died; this could be a contributory factor in the relative rarity of the Lammergeier in Lesotho compared to Ethiopia, though condi- tions are otherwise rather similar (Guy, pers. comm.). However, the difference could also be due to less favorable climatic conditions, notably a severe winter. Even in East Africa Lammergeiers seem commoner in mountain ranges inhabited by pastoral- ists such as the Maasai than in uninhabited massifs; but they are so uncommon that their members cannot be assessed quantitatively. Scavenging and carrion-eating birds commensal with man are considerably more abundant in Ethiopia than in East Africa. In counts summarized for thinly inhabited 56 RAPTOR RESEARCH Vol. 11, No. 3 East African grasslands (Brown 1970) scavengers and carrion-eating raptors made up 55.7 percent by numbers and 75.7 percent by biomass among 32 species of birds of prey; vultures (excluding very rare Lammergeiers) comprise 59.4 percent of the bio- mass. In densely inhabited Ethiopian highlands and lowlands scavengers and carrion- eaters generally make up more than 80 percent by number and more than 90 percent of the biomass, though roadside counts tend to become biased when the roads pass through frequent villages where such birds congregate. For instance in 6 days, 5-10 May 1970, between Addis Ababa and Dessie in northern Ethiopia, of 462 individuals of 16 species of birds of prey, 387 (83.8 percent) were scavengers or carrion-eaters, equivalent to 93.2 percent of the biomass. They included 18 Lammergeiers seen on 5 days (one spent in lowlands with no Lammergeiers), representative of the general av- erage sighting rate, 3.6/day. Lammergeiers made up 4.65 percent by number of scavengers, 7.0 percent of the whole biomass, and 7.52 percent of the scavenger bio- mass. About 15 percent of an average sheep consists of bones so that, allowing for some competition with other bone eaters and the fact that Lammergeiers do not eat all bones, such figures are not incompatible with the available bone supply. The ma- jor part of any carcass is made up of soft flesh and intestines, eaten by the large vul- tures. The large numbers of scavenging and carrion-eating birds commensal with man have also been noted by Galushin (1971) in New Delhi, and a similar predominance of scavengers and carrion eaters has been recorded in a variety of biotopes in South America (Reichholf 1974). The usefulness of such scavenging birds as sanitary squads in the tropics has recently been stressed by Pomeroy (1975). The main threat to the continued abundance of the African Lammergeier is not di- rect persecution, from which it suffers little in either Ethiopia or East Africa (though it is to some extent persecuted in Lesotho); nor is it, as suggested by Fisher, Simon, and Vincent (1969), indiscriminate poisoning, which seems to have little serious effect even in South Africa. Rather, it may in time be threatened by improvements in stock-keeping methods, disease control, better sanitation, and consequent reduction in the present readily available supply of food in its range. Such a situation is still re- mote in its main stronghold, Ethiopia. Literature Cited Berthold, P. 1967. Uber Haftfarben bei Vogeln; Rostfarbung durch Eisenoxid beim Bartgeier ( Gypaetus barbatus ) und bei anderen Arten. Zoo/. Jb. Syst. 93:507-595. Brown, L. H. 1969. Status and breeding success of Golden Eagles in northwest Suth- erland in 1967. Brit Birds 345-363. . 1970. African birds of prey. Collins, London. . 1977. The status of, and threats to, diurnal and nocturnal birds of prey in East Africa and Ethiopia. Pages 15-28 in R. D. Chancellor (ed.), ICBP World Conf. on Birds of Prey, Proc., Vienna, 1975. Brown, L. H., and T. J. Cade. 1972. Age-classes and population dynamics of the Ba- teleur and African Fish Eagle. Ostrich 43: 1-15. Brown, L. H., and J. B. D. Hopcraft. 1973. Population structure and dynamics on the African Fish Eagle Haliaeetus vocifer (Daudin) at Lake Naivasha, Kenya. E. Af- rica Wildl. Joum. 11: 255-269. Fall 1977 Brown — African Lammergeier 57 Fisher, J., N. Simon, and J. Vincent. 1969. The Red Book. Collins, London. Fuggles-Couchman, N. R. 1953. The ornithology of Mount Hanang, in northern cen- tral Tanganyika. Ibis 95:468-482. Fuggles-Couchman, N. R. and H. F. I. Elliott. 1946. Records and field notes from NE Tanganyika Territory. Ibis 88:327-347. Galushin, V. M. 1971. A huge urban population of birds of prey in Delhi, India. Ibis 113:522. Gargett, V. 1969. Black Eagle survey, Rhodes-Matopos National Park; a population study 1964-68. Ostrich Supplement 8:397-414. 1975. The spacing of Black Eagles in the Matopos, Rhodesia. Ostrich 46:1- 44. Glutz Von Blotzheim et al. 1971. Handbuch der vogel Mittel-Europas, vol. 4. Frank- furt. Houston, D. C. 1975. The moult of the White-backed and Ruppell’s Griffon Vultures, Gyps africanus and G. rueppellii. Ibis 117:474-488. 1976. Breeding of the White-backed and Ruppell’s Griffon vultures Gyps af- ricanus and G. rueppellii. Ibis 118:14-40. Jackson, F. J. and W. L. Sclater. 1938. The birds of Kenya Colony and Uganda Pro- tectorate. Vol. 1: p. 201. Gurney and Jackson, London. Kemp, A. C., and M. I. Kemp. 1977. The status of raptorial birds in the Transvaal Province of South Africa. Pages 28-34 in R. D. Chancellor (ed.), ICBP World Conf. on Birds of Prey, Proc., Vienna, 1975. Lowther, E. H. N. 1947. The Lammergeier. J. Bomb. Nat. Hist. Soc. 46:501-508. Meinertzhagen, R. 1944. The breeding of the Bearded Vulture in Kenya Colony. Ibis 86:549. 1954. The birds of Arabia. Oliver and Boyd, Edinburgh. Menzbier, M. A. 1894. Ornithologie du Turkestan et des pays adjacents. Newman, K. B. 1969. Some notes on the feeding habits of the Lammergeier Gypaetus barbatus. Bokmakkierie 21 (4): 84-87. North, M. E. W. 1944. Some East African birds of prey. Ibis 86:117-138. 1948. The Lammergeier in Kenya Colony. Ibis 90:138-141. Pearse, R. O. 1973. Barrier of spears. Howard Timmins, Cape Town, pp. 194-203. Pennycuick, C. J. 1976. Breeding of the Lappet-faced and White-headed Vultures (Torgos tracheliotus Forster and Trigonoceps occipitalis Burchell) on the Seren— geti Plains, Tanzania. E. Africa Wildl. Journ. 14: 67-84. Pomeroy, D. E. 1975. Birds as scavengers of refuse in Uganda. Ibis 117:69-81. Reichholf, J. 1974. Artenreichtum, Haufigkeit, und Diversitat der Greifvogel in eeni- gem Gebieten von Sud Amerika. J. Fur. Om. 115:381-396. Rudebeck, G. 1961. Observations on the Bearded Vulture ( Gypaetus barbatus) in South Africa, with notes on behaviour and field characters. South African Animal Life, pp. 406-414. Schaefer, E. 1938. Ornithologische Ergebnisse Zweier Forschungs reisen nach Tibet. /. Fur. Orn., vol. 86. Steyn, P. 1970. Letter in Bokmakkierie 22(1):23. Thiollay, J. M. 1968. Particularity de plumage chez les Gypaetes corse ( Gypaetus barbatus aureus) Alauda 36(3) :211. Van Someren, V. G. L. 1939. The birds of the Chyulu Hills. /. E. Africa and Uganda Nat. Hist. Soc. 14:15-129. Predominantly densely populated areas Predominantly mountain areas without with towns/villages towns /villages Year/Month Days obs. Adults Imms. Unid. Total Days obs. Adults Imms. Unid. Total 58 RAPTOR RESEARCH Vol. 11, No. 3 onw I | BHt- | CO 00 ' 1 co co co 1 cooo 0 l | co o O | h o « CO H | I ^ CO CO I O I I I w fflNSi | | Tf | CO jHco^-^ooosc^ioaicp IM 05 N CO 00 © a ® 5>5 1 1*5 >s ^ ji c -a a CC +-> aj os -a c ^ a 3 £ 3 c O U 5 §§ 3« O (J O 0 Ph n ■S s 131 a £ 3 s-, "O E <5 lO oq TrooiooincoTfcocM t-HTjHcqrH^oqcqoq OCDrHC^CDiAlO^cOcq 00 (M H <.'J NJ' I.-J >j'I I— i O O ^ cq cq cq cq cq cq OO^NOHiDfjqcooqoiH oo t> in i— i cq .in oo cq oo N . . . .CO o © t- CO oq rf CO ID O COin^OOCqCT)' W w3 g H3 ^2 3 5o PQ Ph O 8 J? sj ^ bJD «o £ 3 O 3 ® 3 t3 3~> 3 o _ 3 3 1 'S I e I 13 <* £-§ a,s 8| 3 "3 ^ .^4 O r? £ -3 ^^4 ffi > cS ^ ^4 s db I ifi.» .sa s § t* s.s II It h 2 w co £ I § PS p © 3 a -s H3 oj 2 Ph 2 rt Pd Ph o w ^ ^ bJD.3 2 M 3 <3 (Ss s 18 ? = .£ 58 i jj -£ 5 & h * ^ 66 RAPTOR RESEARCH Vol. 11, No. 3 Johnson, D., and J. H. Enderson. 1972. Roadside raptor census in Colorado— Winter 1971-72. Wilson Bulletin 84(4):489-490. Murphy, J. R. 1975. Status of a Golden Eagle population in central Utah, 1967-73. In J. R. Murphy, C. M. White, and B. E. Harrel, eds.. Population status of raptors. Raptor Research Report no. 3, pp. 91-96. Raptor Research Foundation, Vermil- lion, South Dakota. Overton, W. S. 1971. Estimating the numbers of animals in wildlife populations. In Robert H. Giles, ed., Wildlife management techniques. The Wildlife Society, Washington, D.C. Southern, W. E. 1963. Winter populations, behavior and seasonal dispersal of Bald Eagles in northwestern Illinois. Wilson Bulletin 75(l)::42-55. 1964. Additional observations on wintering Bald Eagle populations: Includ- ing remarks on biotelemetry techniques and immature plumages. Wilson Bulle- tin 76(2):: 121-137. Woffinden, N. D. 1975. Ecology of the Ferruginous Hawk ( Buteo regalis) in central Utah: Population dynamics and nest site selection. Ph.D. dissertation, Brigham Young University, Provo, Utah. REVERSING FEMALE DOMINANCE IN BREEDING RAPTORS by John Campbell Box 130 Black Diamond, Alberta, Canada In past years we have had trouble with female aggression in Merlins ( Falco columbariui). This aggression seems to occur only at certain times of year and becomes most pronounced (in our cases) around the equinoxes. The females become very aggressive and chase and attack their mates. In one of our cases the male was killed from a pair which had successfully raised four young the year before. Other cases of aggression with Merlins have come to our attention (Fyfe, Adamson pers. comm.). In all cases mentioned above the aggression did not appear to be due to imprinting, but rather to the birds’ high-strung temperament, and possibly because they were confined to pens where the male could not readily escape. The females seem to become highly territorial and do not even permit the presence of their mates in their territory. We discussed methods of reversing or repressing this aggression and finally decided to clip the wing tips of the females in the spring before putting them into the breeding chambers with the males. The males are kept in the breeding pens the year round, but the females are removed in September or October and are kept out until the following April. The wings were clipped to a rounded shape, like an accipiter’s wing, with a pair of scissors. The birds could fly and reach any part of the pen but were severely handicapped. We clipped one female this spring just prior to putting her in the breeding pen. She flew up to a perch and remained there in a frozen position for forty minutes. Meantime the male was flying round the pen. Finally he flew over near the female and caused her to duck to avoid being hit. After forty minutes the female moved, but there was no further aggression, and courtship and copulation followed shortly after. The male seemed to have asserted his dominance and seemed to court more aggressively thereafter. This method could possibly be used on imprinted birds with good results where im- printing could possibly be reversed. TECHNIQUES USEFUL FOR DETERMINING RAPTOR PREY-SPECIES ABUNDANCE* by R. E. Fitzner, L. E. Rogers, Battelle Northwest Laboratories Battelle Boulevard Richland, Washington 99352 and D. W. Uresk Campus Rapid City, South Dakota 57701 Rocky Mountain Forest and Range Experiment Station U.S. Forest Service South Dakota School of Mines Abstract A workshop was held by the Raptor Research Foundation on October 27 and 28, 1976, in Ithaca, New York, to develop standardized data collection and analytical methods for raptor studies. Applications of the methods will ensure compatibility and facilitate year-to-year and area-to-area comparisons valuable in environmental assess- ment and raptor population trend monitoring. We have focused on one of the workshop topics, that of methods appropriate for measuring prey-species abundance. Emphasis is on techniques used in western grass- lands. The selection and use of the particular techniques described in this paper will depend on the level of quantification desired, the habitat type, and the availability of research time and money. Long-term studies should include methods that will provide quantified data, i.e., density (number of individuals per unit area). Such data will en- able calculation of prey exploitation rates and prey densities, parameters important to our understanding of raptor population dynamics. Invertebrates Sample Counts Petrusewicz, K., and A. Macfadyen. 1970. Productivity of terrestrial animals, prin- ciples and methods. IBP Handbook 13. Blackwell Scientific Publications, Oxford. This technique is based on counts of all individuals of the species or group of species con- sidered in a sample from a small but representative area. The size of the sample plot depends on the mobility and abundance of the species. Sample plots 1 m 2 work well for Coleoptera and Orthoptera. Data obtainable: density. Catch-Mark-Recatch See above reference. Capture, mark, and release a number of individuals at the same site. Later capture again using the same method in the same area and find the marked individuals. The population can then be determined by the Lincoln Index: N = (b)a/a'. This technique is useful for large, easily captured insects, particularly beetles. Data obtainable: relative density. Quick Trap and Vacuum Sampler 1. Turnbull, A., and C. Nicholls. 1966. A “quick trap” for area sampling of arthro- pods in grassland communities. /. Econ. Entomol. 59:1100-1104. A trap that can be set down quickly over the sample area to contain the flying insects present is used. Material is removed by means of a D-Vac vacuum insect net. Berlese funnels are used to separate micro-invertebrates from the debris. Widely used in grassland stud- ies. Data obtainable: density. 'This work was done for the U.S. Energy Research and Development Administration under contract EY- 76C061830. 67 68 RAPTOR RESEARCH Vol. 11, No. 3 2. Ahearn, G. A. 1971. Ecological factors affecting sampling of desert Tenebrionid beetles. Amer. Midi. Natur. 86:385-406. Discusses the influence of climatic conditions, activity, population size, surface illumination, trap density, and trap spacing on the use of the pitfall trapping technique in evaluating population size of ground-dwelling beetles. Data obtainable: relative abundance. 3. Greenslade, P. J. M. 1964. Pitfall trapping as a method for studying populations of Carabidae. /. Anim. Ecol. 33:301-310. Reviews pitfall trapping as a sampling meth- od for Carabidae. Considers the effects of population size, locomotor activity, species’ susceptibility to trapping, and habitat on the total catch. Data obtainable: relative abundance. Malaise Trap 1. Mathews, R. W., and J. R. Matthews. 1971. The Malaise trap: its utility and po- tential for sampling insect populations. Mich. Entomol. 4:117-122. This method is based upon the observation that most flying insects that hit an obstacle respond by flying or crawling upward and thus into captivity. These traps are easy to use, can be placed in almost any habitat at any height, and are cheap to construct, or they can be purchased ready-made. Data obtainable: relative abundance. 2. Townes, H. 1972. A light-weight Malaise trap. Entomol. News 83:239-247. Ocular Census Method 1. Bhatnager, K. E., and R. E. Pfadt. 1973. Growth, density, and biomass of grass- hoppers in the shortgrass and mixed-grass association. U.S. IBP Grassland Biome Tech. Rept. No. 225. Colorado State Univ., Ft. Collins, CO. This method permits an esti- mate of the density of large-sized insects by traversing an area and counting the number of individuals in small sample areas (30.5 cm 2 ). A large number of sample points can be gathered in a short while, but the method applies only to large, easily recognized species (grasshoppers, beetles, etc.). Data obtainable: density. Vertebrates (Reptiles and Amphibians) Transect Lines Fitzgerald, G. J., and J. R. Rider. 1974. Seasonal activity of the toad Bufo ameri- canus in southern Quebec as revealed by a sand-transect technique. Can. J. Zool. 52(1): 1-5. A covered sand transect was used to collect data on toad movements. The transect was 225 m long and 46 cm wide. Tracks are recorded and then erased at least twice a day. This technique is useful to measure trends in reptile and amphibian populations. Data obtainable: trend data. Drift Fence Gibbons, J. W., and D. H. Bennett. 1974. Determination of anuran terrestrial activ- ity patterns by a drift fence method. Copeia No. 1, pp. 236-243. Hardware cloth, 0.64-cm mesh and 61 cm high, was used for fencing. “The fence was placed in an 8- 10-cm deep ditch, later filled with soil. Metal stakes alongside the fence added extra support. Metal buckets (diameter 35 cm; depth 41 cm) were placed at 20-m intervals in paired holes on opposite sides of the fence so the mouth of each can was at ground level flush with the fence.” Amphibians were directed along the fencing and became entrapped in sunken buckets. This technique is widely used for amphibians. Data obtainable: relative abundance. Mark-Recapture Rose, F. L., and D. Armentrout. 1974. Population estimates of Ambystoma tig- rinum inhabiting two playa lakes. J. Anim. Ecol. 43:671-679. Neotenic salamanders Fall 1977 Fitzner, Rogers & Uresk — Raptor Prey-Species Abundance 69 were collected with a 12.2 m x 1.8 m bag sein. Each animal was toe clipped, and its initial and subsequent dates of capture were determined. Population size was esti- mated by six different methods: Lincoln-Peterson (Southwood 1966); Bailey triple catch (Bailey 1952); Schnabel (Ricker 1958); Schumacher-Eschmeyer (1943); Jolly (Southwood 1966); and Leslie (1952). This technique was used on aquatic organisms, but the principles also apply to terrestrial organisms. Data obtainable: density. Grid Trapping 1. Beilis, E. D. 1964. A summer six-lined racerunner ( Cnemidophorus sexlineatus) population in South Carolina. Herpetologica 20(1):9-16. Wire-screen funnel traps (108 cm long; with a 15-cm diameter receiving cylinder at each end and a cone with a small opening at the apex with a 38-cm base resting on the ground) were used to capture lizards. Each cone was somewhat flattened where it contacted the ground, thus providing a broad receiver for the lizards. The cylinders were covered with veg- etation to protect lizards from excessive sunlight. Traps were systematically moved about within quadrants to assure that all habitats were well trapped. Traps were not baited; their success depended on movements of lizards in normal activity. Lizards were individually marked by toe amputation and small blotches of poster paint on their dorsa. Data obtainable: density. 2. Rickard, W. H. 1968. Field observations on the altitudinal distribution of the side-blotched lizard. Northwest Sci. 42(4): 161-164. Five can traps arranged in a line with 3-m spacing between were used to capture lizards and insects. Data obtainable: relative abundance; this method can also be used to determine density when coupled with a grid arrangement of traps, the mark-recapture technique, and assessment lines. Birds Line Transect Methods 1. Kendeigh, S. C. 1944. Measurement of bird populations. EcoL Monogr. 14:67- 106. A simple tally of individuals detected per unit of effort. Data obtainable: rela- tive abundance and species diversity. 2. Rickard, W. H. 1964. Bird surveys in cottonwood-willow communities in winter. Murrelet 45(2):22-25. A simple tally of individuals detected while walking along an established path. Data obtainable: relative abundance and species diversity. 3. Jarvinen, O., and R. A. Vaisanen. 1974. Estimating relative densities of breeding birds by the line transect method. Oikos 26(3):316-322. This method considers tran- sect belts of two different widths. “In the line transect censuses of breeding birds, all observations are registered. Observations made within 25 m of the transect, about 20% of total, constitute the main belt’ records while 'survey belt’ records refer to all observations. This study shows how observations outside the main belt can be utilized to estimate densities of different species.” Data obtainable: relative abundance and species diversity. 4. Emlen, J. T. 1971. Population densities of birds derived from transect counts. Auk 88:323-342. Field transect counts are conducted in which all detections of birds, visual and aural, out of the limit of detectability are tallied. The count of each spe- cies is then multiplied by a conversion factor (coefficient of detectability) representa- tive of the percent of the population that is normally detected by these procedures. This method is applicable for all seasons and is more efficient in terms of area cov- ered per unit of effort than nest- or territory-count methods. Data obtainable: abso- lute density, which can be used for determining biomass and energy functions. 70 RAPTOR RESEARCH Vol. 11, No. 3 Mammals Mark-Recapture Technique 1. Jolly, G. M. 1965. Explicit estimates from capture-recapture data with low death rates and immigration— Stochastic Model. Biometrika 52:315-337. A model is presented which gives an estimate of the total population for each trapping period. Data obtainable: total population estimate, movements, and biomass estimates. 2. Smith, M. H., et al. 1971. Determining density for small mammal populations using a grid and assessment lines. Acta Theriologica 16(8): 105-125. A 16-X-16 grid was used to obtain density estimates. Eight assessment lines were used to evaluate the area of effect around the grid. Data obtainable: total population, biomass. 3. Kaufman, D. W., et al. 1971. Use of assessment lines to estimate density of small mammals. Acta Theriologica 16(9): 127-147. Uses an octagon census line plus primary and secondary assessment lines. Linear regression equations were fitted to accumula- tive captures over distance for primary and secondary assessment lines to determine the area of effect around the octagon census lines and a selected portion of the pri- mary assessment lines. Data obtainable: density. 4. Smith, H. D., C. D. Jorgensen, and H. D. Tolley. 1972. Estimation of small mammal using recapture methods: Partitioning of estimator variables. Acta Theriolo- gica 17(5):57-66. A model using a grid design surrounded by a dense line of traps to detect movement of animals into and out of the grid. Useful where permanent and semipermanent grids are established in populations that cannot be disturbed by re- moval or killing. Data obtainable: density. Area Estimate Flinders, J. T., and R. M. Hansen. 1973. Abundance and dispersion of Leporids within a shortgrass ecosystem. /. Mammalogy 54(1):287-291. Modified belt or strip method using a line transect which was developed for grasslands. The number of Leporids sighted within the transect area divided by the transect area yielded a meas- urement of population density. Data obtainable: density for hares and rabbits, coy- otes, raccoons, skunks, badgers, and other medium-sized night-active mammals; move- ments. Mound and Earth Plug Census Reid, V. H., R. M. Hanson, and A. L. Ward. 1966. Counting mounds and earth plugs to census mountain gophers. J. Wildlife Manage. 30:327-334. Count mounds and earth plugs which can be related to intensive trap out of study area. Data obtainable: density. Other Useful References Avery, T. E. 1975. Natural resources measurements. McGraw-Hill, New York. 339 pp. Bailey, N. T. J. 1952. Improvements in the interpretation of recapture data. /. Anim. Ecol. 21:120-127. Cochran, W. T. 1963. Sampling techniques. Wiley, New York. 451 pp. Dixon, W. J., and F. J. Massey, Jr. 1969. Introduction to statistical analysis. McGraw- Hill, New York. 638 pp. Fitzner, R. E., and J. N. Fitzner. 1975. Winter food habits of short-eared Owls in the Palouse Prairie. Murrelet 56(2):2-4. Giles, R. H., Jr. (ed). 1971. Wildlife management techniques. The Wildlife Society, Washington, D.C. 633 pp. Golly, F. B., K. Petrusewicz, and L. Ryszkowski. 1975. Small mammals: their produc- tivity and population dynamics. Cambridge University Press, New York. 451 pp. Fall 1977 Fitzner, Rogers & Uresk — Raptor Prey-Species Abundance 71 Guenther, W. C. 1964. Analysis of variance. Prentice Hall, Englewood Cliffs, N.J. 199 pp. Kovner, J. L., and S. A. Patil. 1974. Properties of estimators of wildlife population density for the line transect method. Biometrics 30(2):225-230. Leslie, P. H. 1952. The estimation of population parameters from data obtained by means of the capture-recapture method. II. The estimation of total numbers. Bio- metrika 39:363-388. Ricker, W. E. 1958. Handbook of computations for biological statistics of fish popu- lations. Bull. Fish. Res. Bd. Can. 119:1-300. Rogers, L. E., W. T. Hinds, and R. Buschbom. 1976. A general weight vs. length rela- tionship for insects. Annals Entomol. Soc. Amer. 69(2):387-389. Rogers, L. E., R. L. Buschbom, and C. R. Watson. 1977. Length-weight relationships of shrub-steppe invertebrates. Annals Entomol. Soc. Amer. 70:51-53. Rotenberry, J. T., and J. A. Wiens. 1976. A method for estimating species dispersion from transect data. Amer. Midi. Natur. 95(l):64-78. Schumacher, F. X., and R. W. Eschmeyer. 1943. The estimate of fish population in lakes or ponds. J. Tenn. Acad. Sci. 18:228-249. Snedecor, G. W., and W. G. Cochran. 1972. Statistical methods. Iowa State Univ. Press, Ames, Iowa. 593 pp. Southwood, T. R. E. 1966. Ecological methods: with particular reference to the study of insects. Methuen, London. 391 pp. Woodbury, A. M. 1953. Methods of field study in reptiles. Herpetologica 9:87-92. BARBED WIRE IMPALES ANOTHER GREAT HORNED OWL by H. Leroy Anderson U.S. Fish and Wildlife Service 813 “D” Street Anchorage, Alaska 99501 At 0900 on 24 May 1976, accompanied by K. Quackenbush, I found an adult Great Horned Owl ( Bubo virginianus) impaled by both wings on the top wire of a five- strand, barbed-wire fence (fig. 1). The fence was on semiarid rangeland, pre- dominantly mesquite ( Prosopis glandulesa) and retama ( Parkinsonia aculeata ), near a small water tank, approximately 20 km NNE of Laredo, Texas. The bird was alert and active when found. A set of barbs was entangled in the skin of each wing. Closer examination showed that the bird had injured its right eye, probably on a barb, during its attempt to get free. A small patch of skin was lost on each wing when the barbs were removed, but no bleeding occurred. Because the owl was active and did not appear seriously injured, we released it, whereupon it hopped along the ground for 18 m, perched briefly on a small tree, and then flew 90 m to a mesquite tree. We did not observe it further. The owl was apparently flying with wings extended when it hit the barbed wire with enough force that it made two complete turns around the wire and became firmly entangled on the barbs. 72 RAPTOR RESEARCH Vol. 11, No. 3 Edebum ( Wilson Bull 85:478, 1973) found a Great Homed Owl impaled by one wing on a barbed-wire fence in Pennsylvania, and McCarthy ( Wilson Bull. 85:477- 478, 1973) found one impaled by one eye on a barbed-wire fence in Missouri. Fitzner (Raptor Research 9:55-57, 1975) found a Great Homed Owl and a Short-eared Owl (Asio flammeus ) impaled, each by one wing, on a barbed-wire fence in Washington. In all instances the impaled owls appeared to have hit the wire forcefully as if they either did not see it or did not perceive it as a hazard to their flight. Figure 1. Great Homed Owl impaled on barbed wire fence. REINTRODUCTION OF CAPTIVE-BRED PRAIRIE FALCONS IN CALIFORNIA- 1976 by Sue Elizabeth Granger Wildlife and Fisheries Biology University of California, Davis Davis, California 95616 In recent years there has been an increase in raptor captive-breeding programs throughout the country. However, there have been very few attempts to reintroduce captive-bred birds of prey into the wild (Olendorff and Stoddart 1974). Fyfe (Olendorff and Stoddart 1974) and Cade et al. (1974, 1975) have successfully reintro- duced captive-bred Prairie Falcon (Falco mexicanus) nestlings in Canada and Colo- rado, respectively. The successful reintroduction of two captive-bred female Prairie Falcons during the summer of 1976 reported herein is the first such project in the State of California. During the spring of 1976, Gary A. Beeman of LaFayette, California, raised twelve Prairie Falcons in captivity. Two were donated to Robert Malette of the California Department of Fish and Game for release. On 9 June 1976 Carl Thelander and Brian Walton of that Department placed the two female falcons in an eyrie located near Newell, California. The birds were approximately 13-14 days of age. Each was band- ed on the right leg with a Fish and Wildlife Service band. I was assigned by the Cal- ifornia Department of Fish and Game to observe them. The eyrie was occupied at that time by one naturally bred female nestling of ap- proximately the same age. Both adult falcons were also present. The nest cliff has in the past supported two pairs of Prairie Falcons (Wenzel pers. comm.), but only one adult pair occupied the site in 1976. Other raptors nesting on the surrounding cliffs included a pair of Red-tailed Hawks (Buteo jamaicensis) and a pair of Golden Eagles (Aquila chrysaetos). Follow-up observations showed that the reintroduced nestlings were accepted by the parent falcons. Direct and indirect feeding of the young by the adults was noted on several occasions. The wild-bred female and one of the female captive-bred nest- lings fledged on 1 July 1796. The other captive-bred female fledged two days later. After fledging the young falcons stayed close to the nest cliff for two week as their flying and hunting abilities improved. At my last observation, two of the young fal- cons were observed foraging for themselves. Literature Cited Olendorff, R. R., and J. W. Stoddart, Jr. 1974. The potential for management of rap- tor populations in western grasslands. In Management of Raptors, Proc. Conf. Raptor Conserv., Tech. Raptor Res. Rep. No. 2 pp 44-88. Cade, T. J., et al. 1974. Introductions to wild begin. Peregrine Fund Newslett. 2:1-3. Cade, T. J., et al. 1975. Prairie Falcon release. Peregrine Fund Newslett. 3:4. 73 74 RAPTOR RESEARCH Vol. 11, No. 3 BOOK REVIEW British Birds of Prey. 1976. Leslie Brown Collins New Naturalist Series £6. Leslie Brown will be best known to American ornithologists as the coauthor of Eagles, Hawks, and Falcons of the World in which he shared the honors with Dean Amadon. This new book concentrates on the species that breed within the British Isles. It is not just another book, but the definitive work on the subject. Mr. Brown has amassed a vast wealth of data from a wide variety of sources, much of it hitherto unpublished. Typical of his many interesting observations is that a buz- zard is able to see a grasshopper— against a background of its own color— at a dis- tance of 110 yards, a visual acuity four times greater than that of man. The book runs to nearly four hundred pages, all crammed with absorbing informa- tion. There are chapters on all the British breeding species, classification, food habits, territory, conservation, pesticides (Mr. Brown, agriculturalist, is able to make a more accurate assessment than most), and one headed “Some burning issues.” No punches are pulled; the facts are dealt with fairly and squarely! Fortunately for us, he takes a remarkably tolerant view of falconry. The real enemy is not so much pesticides, but greed and stupidity; the wilful destruction of raptors by gamekeepers, often with the connivance of their masters; pigeon fanciers; and the wanton desires of phoney fal- coners and ‘hawkkeepers,’ plus the unwitting thoughtlessness of man, “twitchers” in particular. A twitcher is Mr. Brown’s word for a tally-hunter. The discriminative reader will spot a slight discrepancy between the age given for the Sun Life Peregrine of Montreal, the figure quoted is 12 years, not 17 (as in Hick- ey), but this is a trivial matter in a book of such magnitude. Anyone studying the birds of prey will find it an indispensable source of reference and an extremly good value at £6. R. B. Treleaven. INFORMATION ON ACCIPITERS REQUESTED At present I am preparing a manuscript on the biology and current popu- lation status of the three North America accipiters, the Sharp-shinned Hawk, Cooper’s Hawk, and Goshawk. Upon completion this paper will be published through the Bureau of Land Management as a technical note in the Habitat Management Series. I am requesting information about current research projects on accipiters in North America. Data on the regional status of the three species is also needed. Any information which you could provide would be greatly appreciated. All communications and data will be acknowledged appropriately in the paper. Thank you very much. Address all correspondences to Stephen Jones, Depart- ment of Zoology, Brigham Young University, Provo, Utah 84602. Fall 1977 BOOK REVIEW 75 BOOK REVIEW Collected Papers in Avian Paleontology Honoring the 90th Birthday of Alexander Wetmore. 1976. Storrs L. Olson, ed. Smithsonian Contr. to Paleontology, no. 27, 211 pp. There is considerable of interest in this volume for the student of raptors. Most ex- citing is a paper by O. Arredondo on “The great predatory birds of the Pleistocene of Cuba.” Giant fossil Barn Owls ( Tytonidae ) have been known for some time from various West Indian islands. Now we learn that in Cuba at that time there were two such Barn Owls, a vulture as large as the Andean Condor ( Vultur ), an eagle bigger than a Golden Eagle, and, perhaps most remarkable, a strigine owl bigger than any living species; it is thought to have stood about a meter tall! It is most remarkable because the wing bones show that it must have been flightless or nearly so. Appar- ently some of the mammals that swarmed in the West Indies at that time must have been as clumsy as today’s “guinea pigs,” a relative of some of them. Another paper describes the oldest known fossil owl. From the Paleocene of Colo- rado, it seems to have been somewhat intermediate between the present families Stri- gidae and Tytonidae. An osprey from the Miocene of California is assigned to a sepa- rate species but may have been ancestral to the living one. Dean Amadon BALD EAGLE LITERATURE WANTED The National Wildlife Federation’s Raptor Information Center is creating a com- puter-based, working (i.e., keyworded) bibliography on the Bald Eagle. An attempt is being made to include all existing literature, both published and unpublished. Infor- mation on extant bibliographies and sources of unpublished literature (reports, theses, disserations, etc.) is especially being sought. If you have pertinent articles that you wish to be included, please send them to: Mr. Bill Clark, Director, Raptor Informa- tion Center, National Wildlife Federation, 1412-16th Street, N.W., Washington, D.C., 20036. Thank you. PEREGRINES BEAT ALL ODDS IN MORRO ROCK STRUGGLE (News Release, Department of Fish and Game, 9 July 1977) Somewhere in the air surrounding Morro Rock, a fledgling Peregrine Falcon is learning the “tricks of the trade” from its foster mother. It may not seem like much, but for biologists at the Department of Fish and Game it is cause for celebration. It is the culmination of an intense but troubled effort to salvage one of only ten active peregrine nesting sites known in the state. The Per- egrine Falcon is an endangered species. “I consider it a great success, because without man’s efforts that young peregrine would not be there today,” said Robert D. Mallette, associate wildlife manager-biolo- gist and the department’s expert on raptors. “And the information we’ve learned from this operation will help us in our future efforts to increase the peregrine population in California.” Morro Rock in San Luis Obispo County is an ecological reserve, because for years a single pair of Peregrine Falcons has nested on its rocky ledges. The site is so criti- cal that in recent years a human guard has been hired to protect the nesting site 76 RAPTOR RESEARCH Vol. 11, No. 3 from other human intrusion. The guard was paid with funds from the California Non- game Wildlife Conservation Program. It was the guard, a young biologist named Merlyn Felton, who first noticed the troubles which would plague this year’s nesting attempt. The female peregrine at Morro Rock stopped incubating the egg early in May. No one knew why, but it was assumed the egg had gone bad, and it appeared doubtful a new Peregrine Falcon would fly off Morro Rock this year. But Mallette decided to try something never attempted on the West Coast before, to plant in the nest peregrine chicks hatched in captivity and allow the adult per- egrines to raise them. The young peregrines were from eggs hatched at captive breeding facilities at Cornell University in Ithaca, New York. While arrangements were being made to bring the chicks to California, the per- egrine nest on Morro Rock was filled with a pair of young Prairie Falcons, which were incubated and fed almost at once by the adult peregrines. The Prairie Falcon is a close relative of the peregrine. “We put the Prairie Falcons in the nest to try to keep the nesting instincts alive in the adults,” Mallette said. When the peregrines were placed in the nest a few days later, the Prairie Falcons were removed and placed with their own kind. The adult peregrines also readily assumed the care of the two foster peregrine chicks, Mallette said. As is the custom, the female would sit at the nest while the male, also called a tiercel, captured food on the wing and brought it to the nest. The agile peregrine has been clocked at 180 miles per hour while diving on prey. For about a week it appeared the bird transplant project would be an unqualified success. But within a matter of days two events took place which would once again alter the scope of the attempt to salvage the Morro Rock nesting operation. First, the adult male disappeared. Then one of the chicks died in the nest. The cause of the death is unknown, but the loss of a chick is not unusual among raptors. Later, the tiercel was found dead on Morro Rock. Pellets were found in its wings, but the body was so decomposed laboratory technicians have been unable to deter- mine an exact cause of death. The death of the male Peregrine Falcon presented a difficult problem to Mallette and Felton. If the female had to leave the nest for food, it would leave the remaining chick unprotected at the nest. So a scheme was devised which allowed Felton to as- sume the role of the food gatherer. In a blind not far away from the peregrine nest, Felton did his best to imitate the call of the male peregrine coming in with food. The call alerted the female, which customarily meets the male in mid-air for a food exchange. But in this case, Felton merely released a pigeon or other prey species from the blind. It flew by the nest and was quickly snared by the female falcon. The unorthodox feeding method worked, and the surviving foster chick fledged on schedule about a month after it was hatched more than 3,000 miles away. Felton re- ports it keeps a close eye on its mother and is learning how to catch prey on its own. It also appears Felton has been relieved of his duty of providing food for the Per- egrine Falcons. On his last visit to the nest, he discovered a new tiercel had somehow found the nesting territory and had taken over the role of the provider. “We don’t have any idea what turned him on to taking the place of the first tier- cel, but we’re sure happy to see him,” Mallette smiled. “We’ve got a complete fam- ily group once again. Next year there will, in all probability, be a mated pair on Morro Rock.” ABSTRACTS OF THESES As previously indicated {Raptor Res. 10 [2] ; 49), we will publish abstracts of theses and dissertations, retroactive to 1974. Be sure to include the complete citation (author’s full name, year, title, university, pages). A SURVEY AND ANALYSIS OF BALD EAGLE NESTING IN WESTERN WASHINGTON Through extensive aerial surveys of the western Washington marine coastline, 218 Bald Eagle nests were located in 1975; 114 (52 percent) were occupied. Of 100 active nests, 63 percent were successful, producing 86 young for an average of 1.37 young per successful nest. One hundred forty-four nesting territories were defined, of which the 114 occupied represented 79 percent. Territories are felt to provide a more accurate measurement of habitat utilization and population status than nest numbers alone. Only 54 territories (38 percent) contained alternate nests. Analysis of 40 nest-site parameters showed proximity to open water, large nest trees with sturdy branching at sufficient height, and stand hetero- geneity, both vertically (crown dominance) and horizontally (crown cover), to be the most important factors in site selection. General characteristics associated with most nests are privately owned land within 200 yards of shore, open but irregular salt water coast, pre- dominantly coniferous stands, greater than 40 percent crown density, continuous stands often near openings, Douglas fir nest trees with Sitka spruce common on the Olympic Peninsula, nest trees usually codominant with other large trees in uneven stands, live trees less than 25 percent dead and often with broken tops, moderate to dense foliage over nests, moderate to light foliage surrounding nests, nests within top 20 feet of nest trees, and disc-shaped nests 5 feet across and 2 feet deep. Of the nests, 89 percent had at least one of ten categories of human activity within 1 mile and 74 percent within .5 mile. A tabulation of field observations on nests with a disturbance less than .25 mile away resulted in an average distance from productive nests of 130 yards and from unproductive nests an average of 80 yards. The Forest Service 5-chain (110-yard) protection zone was substantiated. Stepwise discriminant analyses were used with nest -site parameters to test their value in discriminating between occupied and inactive sites, and successful and unsuccessful nests. The technique showed promise for future evaluations of potential Bald Eagle nesting habitat. Grubb, Teryl G. 1976. A survey and analysis of Bald Eagle nesting in western Washington. M.S. thesis. University of Washington, Seattle. 86 pp. Present address: Teryl G. Grubb, Research Wildlife Biologist U.S. Forest Service Rocky Mountain Forest & Range Expt. Sta. Forest Hydrology Laboratory Arizona State University Tempe, Arizona 85281 77 78 RAPTOR RESEARCH Vol. 11, No. 3 BREEDING ECOLOGY OF THE FERRUGINOUS HAWK IN NORTH- ERN UTAH AND SOUTHERN IDAHO Forty-three and 54 Ferruginous Hawk (Buteo regalis ) pairs were found occupying territories in northern Utah and southeastern Idaho during 1972 and 1973, respective- ly. Of these, 38 and 27 nesting pairs laid eggs. Nesting success was 77.1 percent in 1972 and 74.6 percent in 1973. For successful nests, an average of 2.9 and 2.6 young hatched and 2.7 and 2.3 young fledged during the respective years. This population is reproductively comparable to others in Utah and Colorado. Analysis of prey items collected from the nests indicated that black-tailed jackrabbits ( Lepus californicus ) constitute 86 percent of the biomass (by weight) of three major prey species con- sumed by Ferruginous Hawks in this area. Jackrabbit density may be a major de- terminant of the number of young produced in a given year. Weight gained by nest- lings showed a marked sexual dimorphism. Female fledglings weighed up to 1.43 times as much as males. Criteria were developed for sexing Ferruginous Hawks by measuring the diameter of the hallux. Mortality of 17 birds from the study area was recorded, of which 47 percent were immature birds. A total of 108 fledglings were banded and marked with color-coded patagial wing markers. Band reports of five (10 percent) of these birds were received. Utah juniper (, Juniperus osteosperma) provided nest sites for 96.0 percent of the nests, and 3 percent were built on the ground. Plant community types were determined at 63 nesting sites from aerial photographs. Domi- nant vegetation around nest sites were desert shrub types and crested wheatgrass ( Agropyron cristatum) seedings. The possible impact of land management practices on Ferruginous Hawks is discussed. Howard, Richard P. 1975. Breeding ecology of the Ferruginous Hawk in northern Utah and southern Idaho. M.S. thesis, Utah State University, Logan, 70 pp. THE BIOENERGETICS OF THE BARN OWL (TYTO ALBA ) The bioenergetics of the Bam Owl ( Tyto alba ) was investigated to gain information on a larger raptor and a representative of family Tytonidae. Measurements of oxygen consump- tion from 0°C to 37° C, body temperature, insulation, and existence energy are presented. The relationship between standard metabolic rate and body weight in owls was re- evaluated. Results show that the SMR for the Barn Owl is slightly lower than for other strigiform species and much lower than predicted values based on weight for other non- passerines. Insulation values were lower than those for other owls. It is suggested that T. alba has apparently made up for this inability to conserve energy over a broad temperature spectrum by the use of man-made and natural shelters. Metabolized energy of wild Barn Owls was estimated to be 7.3 times greater than exis- tence energy of captives, and 1 1.2 times greater than SMR. Johnson, Wayne Douglas. 1974. The bioenergetics of the Barn Owl ( Tyto alba). M.A. thesis. California State University, Long Beach. 55 pp. Fall 1977 Abstract Theses 79 WINTER ECOLOGY AND EFFECTS OF HUMAN BEHAVIOR ON BALD EAGLES IN THE NOOKSACK RIVER VALLEY, WASHINGTON An ecological and behavioral study was conducted during the autumns and winters of 1974-75 and 1975-76 on a population of Bald Eagles ( Haliaeetus leucocephalus ) on the Nooksack River, Washington. Eagles congregate on the Nooksack during win- ter to feed on spawned-out salmon ( Oncorphynchus spp.). The largest aggregations were observed along gravel bars and sloughs where salmon carcasses were most abun- dant. Peak numbers of 91 and 105 were recorded for two seasons. Subadult eagles ar- rived on the Nooksack later than adults, but departure patterns were similar. Sub- adults comprised 35 percent of the population. Preferred perch trees were characteristically tall and close to the feeding grounds, providing unobstructed pan- oramas of the river. Deciduous trees were used primarily as perching sites; whereas coniferous trees were used for roosting. Four roosting sites were located. Human ac- tivity was found to adversely affect eagle distribution and behavior. A significant dis- placement of eagles to areas low in human activity was observed. Human activity was especially prevalent and disturbing on the feeding grounds. Human activities confine the population to a smaller area which may increase intraspecific strife for food resources. Sensitivity to disturbance increases with age. The mean flight (flush- ing) distance of adults was 196 meters, but 99 meters for subadults (n = 300). This dif- ferential tolerance to disturbances may affect the accuracy of ground censuses. The effects of disturbance are lessened by the presence of vegetation buffer zones which conceal activities. Habituation of eagles to human activity seems to occur. Manage- ment recommendations for wintering grounds are presented. Stalmaster, Mark Victor. 1976. Winter ecology and effects of human activity on Bald Eagles in the Nooksack River valley, Washington. M.S. Thesis. Western Wash- ington State College, Bellingham. 100 pp. BEHAVIORAL ECOLOGY OF COASTAL PEREGRINES (Falco peregrinus Pealei) A long-term study, 1968-75, of Peregrine Falcons at Langara Island, British Colum- bia, produced much information on the behavior and ecology of this population. An ethogram summarizes descriptions and functions of 43 behavior patterns in courtship, 32 in territorial advertisement and defense, and 15 in self, nest, and food defense. Males are more active in courtship, territorial advertisement, and defense. Mainly same-sex intruders are chased, but males also evict females. Nine hypotheses of sex- ual-size dimorphism are considered. I conclude that aerial combat with dangerous weapons selects for smaller males, better combatants; the proportion of aerial to ground fighting sets the lower limit to the size of males. The annual schedule of courtship, incubation, nestling, fledgling, and dispersal phases is described. Seasonal changes in courtship are not proximate causes of egg laying. Photoperiod is an early timer for laying. Ambient temperature is a “final” timer initiating rapid follicle growth ca. two weeks before egg 1 is laid. Early egg laying gives juveniles more experience before autumn-winter hardships. 80 RAPTOR RESEARCH Vol. 11, No. 3 Productivity over eight years averaged 1.76 fledglings per territorial pair, and 2.32 per successful pair. Average breeding spans were: males, 6.0 years; females, 3.5 years (survival rates: 0.85, 0.75). A first-year survival rate of ca. 0.45-0.55 and a floating population at least 50 percent of the size of the breeding population were estimated. The Langara falcons declined from ca. 21-23 pairs in the early 1950s to 5-6 pairs in 1968-75. This decline paralleled a seabird decline, apparently throughout the Queen Charlotte Islands. Falcons amalgamate territories by means of pseudopo- lyandry; an orderly population decline results, toward a new “equilibrium” with the prey base. Peregrines occupy type A, B-A, and B territories, from 0.3-0.5 km to ca. 15 km in diameter. Individuals establish and adjust territory size in relation to available food. They harvest on a conservative sustained-yield basis. The result is the “natural con- servation” of V. C. Wynne-Edwards, but the cause is individual selection. Peregrines demonstrate Bergmann’s Rule. Larger birds live in cooler climates and have higher mortality rates and larger clutch sizes. Clutch size offsets natural morta- lity and provides a floating population of optimum size. Peregrines evolve a strategy which does not produce the most fledglings at inde- pendence (e.g., D. Lack), but which balances the survival of parents and the number and quality of fledglings. Smaller broods will produce young with better survival rates and competitive abilities. When balanced with quantity and combined with philopatry, this strategy tends to increase genetic fitness. Nelson, R. W. 1977. Behavioral Ecology of Coastal Peregrines ( Falco peregrinus pealei ). Ph.D. dissertation. University of Calgary, Calgary, Alberta, xxi + 490 pp. May. UTILIZATION OF NEST BOXES BY BIRDS IN THREE VEGETA- TIONAL COMMUNITIES WITH SPECIAL REFERENCE TO THE AMERICAN KESTREL (FALCO SPARVERIUS ) This study was designed to determine if, by providing artificial nest sites, a rapto- rial predator could be attracted into an area where suitable sites are limited. The American Kestrel ( Falco sparverius ) was a common species in the area and nest boxes designed for their use were placed in three vegetational types in western Utah and eastern Nevada. Seventy boxes were available in 1975 and 110 in 1976. Kestrels nest- ed both years in the salt-desert shrub community but were absent from ■ the pinyon- juniper and riparian areas. Four other bird species nested in the latter two areas, however. In 1975 the nesting success was affected by severe weather including unseasonable cold and snow. In 1976 interaction with and predation by rodents affected utilization and success. Other factors such as existing hole-nesting populations, size, construction, and placement of the box also affect the rate of occupancy and number of boxes used. Laurence B. McArthur. 1977. Utilization of Nest Boxes by Birds in Three Vegeta- tional Communities with Special Reference to the American Kestrel (Falco Spar- verius). M.S. thesis. Brigham Young University, Provo, Utah. 42 pp. April. THE RAPTOR RESEARCH FOUNDATION, INC OFFICERS President Dr. Joseph R. Murphy, Department of Zoology, 167 WIDB, Brigham Young University, Provo, Utah 84602 Vice-President Richard W. Fyfe, Canadian Wildlife Service, Room 1110, 10025 Jasper Avenue, Edmonton, Alberta T5J 1S6 Canada Secretary Dr. Donald R. Johnson, Department of Biological Sciences, University of Idaho, Moscow ID 83843 Treasurer Dr. Gary E. Duke, Department of Veterinary Biology, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota 55101 Address all matters dealing with membership status, dues, publication sales, or other financial transactions to the Treasurer. Send changes of address to the Treasurer. Address all general inquiries to the Secretary. See inside front cover for suggestions to contributors of manuscripts for Raptor Research, Raptor Research Reports, and special Raptor Research Founda- tion publications. BOARD OF DIRECTORS Eastern Dr. James A. Mosher, University of Maryland, Appalachian Envi- ronmental Laboratory, Frostburg State College Campus, Gunter Hall, Frostburg, Maryland 21532 Central Dr. James Grier, Department of Zoology, North Dakota State Uni- versity, Fargo, North Dakota 58102 Pacific and Mountain Dr. Joseph R. Murphy (address above) Canadian Eastern: David Bird, Macdonald Raptor Research Center, Macdo- nald College, Quebec, HOA1CO, Canada Western: Dr. Wayne Nelson, 620 Harris Place Northwest, Cal- gary, Alberta, T3B ZV4, Canada At Large Dr. Dean Amadon, Department of Ornithology, American Mu- seum of Natural History, Central Park West at 79th Street, New York, New York 10024 At Large Dr. Stanley Temple, Department of Wildlife Ecology, Russell Laboratory, University of Wisconsin, Madison, Wisconsin 53706 At Large Dr. Thomas Dunstan, 3500 Morris Hill Road, Boise, Idaho 83704