S5Y-3 Seeoe AE em Ta ZF det oatyts es Bis ee etre a ote Hi a) The Reading Naturalist No. 23 Published by the Reading and District Natural History Society 1971 Price to Non-Members Three Shillings and Sixpence THE READING NATURALIST No. 23 for the year 1969-70 The. Journal of The Reading and District Natural History Society President: Miss L. E. Cobb, B.A. Hon. General Secretary: Hone Editors Mrs. K. F. Rhodes Miss E. M. Neimes 65 Tilehurst Road 27 Westbourne Avenue Reading ACO, Wed RG3Z 2dC 6JL Editorial Sub-Committee: Theshaator,7B.wR. Baker, Missel:zeh.Cobb, A. Price, Miss J. M. V. Housden, Miss S. Y. Townend Honorary Recorders: Botany: Mrs. B. M. Newman, Earley Cottage, 25 Beech Lane, Harley, Reading Entomology: Me, os (h> Baker, 5 Dovedale Close, The Mount, 'Caversham, Reading Vertebrates: Mr. H. H. Carter, 82 Kennylands Road, Sonning Common, Reading Berkshire, Buckinghamshire and Oxfordshire Naturalists' Trust: Hon. County Secretary (Berks.): Mr. B. R. Baker, The Museum, Reading CONTENTS Meetings and Excursions, 1969-70 Presidential Address: Our fish ancestors The successful mating of two full albino frogs (Rana_temporaria L.) A study of some beetles (Coleoptera-Polyphaga) found in cow dung (Abstract) A letter from Canada The natives in my garden Cothill and Dry Sandford Pits An account of the Society's excursion on June 13th 1970. Grasses Report on Aston Uptnorpe Reserve - 1970 Honorary Recorders! Reports: Botany Entomology Vertebrates List of Members J. Leeke Price J. Weston . Leatherdale F. Rhodes R. W. Sell V. Fletcher R. W. Sell M. Newman R. Baker . Hi-Carter Page ue 18 ce 25 28 30 ae 37 4h 52 — Meetings and Excursions 1969-70 Mr. C. J. Leeke delivered his Presidential Address entitled "Our Fish Ancestors" at the Annual General Meeting (attendance 44). Two evenings were devoted to members' exhibits, talks and slides (29 and 31). The lectures delivered at the remaining indoor meetings were "A Look at Flowers of the South African Cape Region", by Mr. R. T. Pearl (38); "Trees in Towns", by Mr. W. J. Dulborough (33); "The Work of the Nature Conservancy", by Mr. H. J. Williams (49); "Bees", by Mr. G. R. Hawthorne (44); "Micro-organisms and the Leaf Surface", by Dr. H. Owen (32); "Bird Art and Illustration" by Mr. R. Gillmor (31); “Geology and Landscape in Britain with particular reference to Berkshire", by Mr. R. Jessup (49) and "Jungle on the Doorstep, or Wildlife in Trinidad", by Mr. M. Hardy (42). Winter walks were held on lst November, Aston Upthorpe Down (attendance 9); 6th December, Dunsden Chalk Pit (3); 3rd January, Emmer Green (8); 7th Febrvary, Theale and Burghfield for birds (11); 7th March, Englefield for lichens (4). The summer field meetings were: 18th April, Mongewell Wood area (12); 2nd May, Clayfield Copse, Emmer Green (18); 14th May, Reading Corporation Nurseries; 16th May, Sulham Woods (135); 30th May, Chiltern Escarpment near Chinnor(c. 12); 7th June, coach excursion to Middlebere Heath and the Isle of Purbeck (28); 13th June, Sonning, Peppard and Gatehampton to study grasses (25); 24th June, Thames-side from Reading to Sonning (4); 27th June, Whitehorse Hill (16); 8th July, Horticultural Research Laboratory Gardens and Historical Rose Garden at Shinfield Grange; llth July, Stanford Dingley, Blue Pool, and River Pang; 25th July, Pamber Forest, afternoon walk (15) and entomological evening (6); 29th July, ditch near Pangbourne (4); Sth August, Thames-side from Wargrave to Reading (15); 22nd August, Heath Pool, Finchampstead (fresh-water biology) (15); 5th September, Ashley Hill (14); 19th September, Theale, Kingsclere, Inkpen Beacon (Geology and land forms) (c. 25); and 3rd October, fungus foray at Kingwood (26). The leth Young Naturalists' Evening was held in the Large Town Hall on Wednesday, llth February 1970. The Panel, consisting of Dr. Reed. 1) Bowen,’ Dri Ja" Rie Le Alien ,~Mr.“W.- De Campbell and’Mr. C.J. Leeke, faced an audience of about 500 Reading schoolchildren. Mr. Jd. F. Newman was Questionmaster and about 30 of the 662 questions sub- mitted were answered. Prizes for the 8 best questions were presented by the Right Worshipful the Mayor of Reading, Alderman Mrs. E, E. Lovett, who then joined the chiidren to watch the Lincdnshire Natur- alists' Trust film "Nature in Trust". Prizewinners were:- Elizabeth Brown, Abbey Junior School: (10 yrs.), Geoffrey Crosson, Cintra Secondary School (14 yrs.), Teresa Flowers, Redlands Primary School (7 yrs.), Joanne Horwood, Norcot Primary School (10 yrs.), Paul Keep, E. P. Collier Primary School (11 yrs.), J. Matthews, Reading School (12 yrs.), Roger Thorne, Grovelands Primary School (10 yrs.) and Jane Woolford, Alfred Sutton Secondary Girls' School (12 yrs.). me OUR FISH ANCESTORS The Presidential Address to the Reading and District Natural Histor Societ 16th October 1969 I suppose my interest in fish began soon after my intro- duction to their natural habitat, when, as a small boy, I fell into the paddling pond at Christchurch meadows; since then I have been fascinated by water and the organisms that live in it. If you have ‘not lain down to gaze into the clear water of a flowing ditch, with its clumps of brilliant green starwort and its iridescent stickle- backs, then you have not lived. Fishes were the ancestral vertebrates, having their origins more than 500,000,000 years ago. They have experienced several great adaptive radiations following the appearance of structural novelties. Since 1920 it has been thought necessary by eminent systematists to classify the group into several distinct classes. Jordan suggested six classes, Romer suggested four and Berg suggested twelve. That there has been such disagreement is indicative of the diversity of the group. However, for the purpose of this address I have chosen to discuss some of the more important of the structural novelties which have been instrumental in producing the nigher vertebrate classes. Tne following scheme shows the relationships of the classes of vertebrates to each other, after Romer. CHONDRICHTHYES AGNATHA “ACTINOPTERYGII MAMMALIA “SN. CHOANICHTHYES wm AMPHIBIA —REPTILIAZ = AVES Garstang's theory has been generally accepted that pre- vertebrates developed from echinoderm larvae probably in the Cambrian period. These larvae, like the pre-vertebrates, must have been very small and delicate and left no known fossils. The Ordovician fish fossils however were several inches long, with bony dermal plates and skeletons. The development of bone has been of fundamental importance to vertebrates, particularly in the attain- ment of large size and in conquering the land. Bone is a mixture of calcium phosphate and calcium carbonate, forty parts to sixty, it is consistent and peculiar to the vertebrates. Since all the echinoderms have been and are marine it follows that the pre-vertebrates originated in the seas probably in some shallow coastal regions such as the long narrow seas which géol- ogists tell us divided the N. American continent running from North to South. and fed by rivers slowly flowing from East or West. The oF ee gentle flow would enable the less dense freshwater to float over the more dense seawater for some time before mixing. The new little pre-vertebrates were not good swimmers and could be carried into estuaries by tides where they would find a rich manna falling as from heaven, from the freshwater above. As they increased their size and swimming power they would be able to penetrate further into the estuaries but they would then encounter an osmotic press- ure which would cause them to absorb water and they would have to retreat or die. Many of those who went too far probably did die, but it has been shown in a marine worm, Gunda, thet the membranes become less permeable in the presence of divalent ions such as calcium and it is likely that such ions were available in and around the estuaries. In small creatures with a high surface-to-bulk ratio and isotonic with an aquatic medium, there is no need for sophisticated organs of excretion or of osmoregulation, therefore if some of them could absorb divalent ions they would tend to retain them and slowly build up a concentration which would decrease the permeability of their membranes. Such creatures could venture into increasingly fresh water for longer periods of time. So far this is fine, our pre-vertebrates can now swim into rivers where there would be none of their marine predators and a plentiful supply of food, they being cetritus feeders filtering small particles from the water by ciliated tracts. Their inability to excrete calcium ions would eventually however become an embarr-= assment, but calcium carbonate and phosphate can be precipitated and the thesis is that this happened in many of the body membranes or epithelia, particularly in the ectoderm in the less mobile head region and internally in membranes, where growing musculature exerted stresses. This would account for the bony skeletons and armour of the early fish fossils. Further advantages would accrue from these structures. The surface would become much less permeable to water and increased skeletal strength wovld allow an increase in size and therefore better swimming power, which would buy time for the developing kidneys to cope with osmoregulation and to.take over the increasing excretion of nitrogenous compounds and excesses of otherwise useful substances. Modifications in the nature of the nitrogenous com- pounds and in the structure of the kidney tubules is a story in itself. It may be worth saying that pre-adaptation is probably the rule in all important structural innovations; they have to be available when the need arises, they cannot develop in time to be of use in response to a situaticn. which creates a need. Thus the early pre-vertebrates could not live in freshwater nor even move into it for long without some protection from the osmotic pressure. Similarly it will be obvious that the subsequent developments a a described here, occurred without prompting and stayed because they proved useful. In a wide range of Ordovician fossils there was a mouth with no jaws or teeth and ten pairs of gill slits supported by bony gill arches. These animals were filter feeders as their forbears had been and the larvae of :their descendants, the lampreys, still are. They belong to the class Agnatha and have several primitive features that distinguish them from all other fish. The more advanced fish have jaws but none have more than seven pairs of gill arches. In the Gnathostomes, as all jawed verte- brates are called, the first two gill slits have disappeared completely, the mouth has moved back to occupy the position of gill slit number three and its pre- and post-trematic arches have become the upper and lower jaws respectively. There is good palaeontological and embryological evidence for this. The attainment of jaws and teeth immediately allowed their possessors to turn their attention to different sources of food. They could now eat large pieces of plant or animal matter not available to filter feeders and they could obtain nourishment mcre quickly. Therefore this development was important in increasing their size. An increase in size has far reaching results. It improves the individual's survival chances whether in interspecific or intraspecific competition and obviously improves the survival chances of the species as a whole. Further, the larger an animal - is, the more cells it will have, not only for muscular power, but for more complex mental processes and the substitution of reason ‘for instinct, thus allowing more varied responses to given stimuli. So successful was the acquisition of jaws that there was a great radiation of types and the waters became crowded. Several groups of fish moved back into the seas where they gave rise to the sharks, rays and chimaeras of today. The remainder spread further into the lakes and rivers where another novelty arose. With a further loss o* the two posterior pairs of gill slits, one of these became a pair of closed pouches retaining its connection with the pharynx and its blood vascular system. Immed- iately, a new organ had arisen called a lung, which could be filled with air gulped from the surface and which enabled its possessors to survive in the Silurian and Devonian waters when generally warm climates reduced the oxygen content and evaporated the watei to dangerously low levels. Once an organ is initiated and it confers a benefit under existing conditions, there is selection pressure which brings about improvement of efficiency In “ts LUE baer « Again a successful novelty produced a great radiation of types, some returning to the sea while others like the Dipnoi ag IR = (lung fishes) and the Crossopterygii (coelacanths and an important extinct group called Rhipidistia) stayed in freshwater. Event- ually, by the end of the Cretaceous period, the coelacanths too had moved to the sea and simply enlarged from about a foot to upwards of five feet in length. To go back to the other groups, those that moved to the sea had no real use for lungs in a medium so vast and with so much wave action that there was never a shortage of oxygen. Further changes occurred and the lungs became sealed air chambers which could be inflated or deflated, within limits, to adjust the density of the fish and therefore, acting as a hydrostatic organ, enabling the animal to remain suspended effortlessly at any reasonable depth. Some of their descendants again entered the rivers and lakes to become the ancestors of such modern fish as pike, eels, minnows and sticklebacks. The lungfishes. once widespread and numerous and now rep- resented by only three species, one each from South America, Africa and Australia, are suffering a severe decline in face of competition from the more active hydrostatic teleosts and possibly changes in the habitat. In the Dipnoi and Coelacanthini are found peculiar fins Supporved on short limbs which have, unlike any other living fish groups, a bony skeleton. Here now is an interesting situation. Certainly by the Devcnian, and possibly in the Silurigtr , were creatures with bony skeletons, with jaws and teeth, with lungs and the rudiments of limbs, poised for the step onto land. However, it was neither the Dipnoi nor the coelacanths who took that step but some unknown member of the Rhipidistia. Comparison of modern tetrapod, limb skeletons show them to have a common form, whether they be amphibian, reptilian, avian or mammalian. In all of these there is a single bone joined to two bones which then connect to a group of small bones and finally thereon depends no more than five digits. This wonderfully adapt- able pentadactyl limb can be shown to be basically like the skeleton found in the proximal region of the rhipidistian fin. This group of fishes became extinct over 250,000,000 years ago, but what earth-shattering descendants they left. The mighty dinosaurs who ruled the earth for over 100,000,000 years and man, who has only just arrived on the scene but has already made changes more far-reaching than were made by the whole of the dinosaur dynasty,are examples as also are the giant whales who rule the seas. For 300,000,000 years our fish ancestors, moving between seas and rivers several times, diversified and innovated and collected together more important structural novelties than any = ON other vertebrate group has done. Perhaps the only novelty comparable to those diseussed here is the development of the cerebral hemispheres in the primates, culminating in Homo sapiens who is able to consider his history as we have, but we must remember that these structures had their origin in the neopallium of an ancestral fish brain. C.J. Leeke Members will be sorry to learn that Mr. Moon, who for many years now has provided and commented on our meteorological data, is this year unable to do so because of illness. We hope that he will soon be quite recovered and will produce our weather reports for many years to come. an = The Successful Mating of two Full Albino Frogs (Rana temporaria Ts oh. by Arthur Price The two 1967 double recessive frogs were taken out of hiber- nation on 22nd February 1970. The male was 62 mm. in length and 26.4 g. in weight, the female 66 mm. and 39g. Both were in good condition; the male's nuptial pads were black. In spite of the failure of the 1969 mating of these two frogs, it was decided to give them another chance. On lst March 1970 they were placed in the south enclosure of the froghouse and nine hours later they were in amplexus, remaining in this position for thirty-seven days. On 6th April 1970, 220 ml. of white spawn was laid. Later that day 90% of the eggs were seen to be dividing and by llth April the neural ridges could be seen. About 700 DR tadpoles hatched on 8th April but they were not very vigorous and swam with difficulty. By 5tn May all these tadpoles were dead. Again it seems that the sib relationship carried with it a lethal element. Following oviposition by the 1967 DR female, the 1967 DR male was placed in the north enclosure of the froghouse with one of the 1968 DR females. Individual identification of the 1968 DR's was not possible. The two frogs went into amplexus the same day and ten days later 125 mi. of white spawn was laid containing approx- imately 750 eggs. After oviposition the female was 54 mm. long and weighed 11.65 g. Immediately after disengaging, the 1967 DR male went into amplexus with another 1968 DR female but no spawn was laid. This adds up to fifty-four days of continuous amplexus for the male. Who can say that all albinos are weakly creatures? Of the 750 eggs, 90% were fertile and by 17th April 1970 the neural ridges were visible. The tadpoles which hatched were all double recessives and quite vigorous. Only 1% showed the kinked tail. To lessen the chance of total loss of this valuable stock the tadpoles were widely dispersed. Some were given to the local schools and some to interested naturalists. Twenty-four of these tadpoles were given to Pat Smallcombe who, in November 1970, still had five living DR frogs in an enclosure in her garden. Mr. B. Butcher, who took over his son's Stock, also has four living DR frogs. The majority of the tadpoles were kept in tanks on my study desk but later some were transferred to the froghouse where they made good progress. By 17th May 1970, I had 400 living tadpoles of this stock. This figure included the tadpoles which had been distributed. Nearly all of these DR tadpoles showed a progressive pigmentation of the gall bladder, ranging through pink, red, pale green, green, dark green to black. These were the stages in the development of the 'Black spot' reported earlier. In this case is PO the black spot did not persist and no tadpoles or frogs were lost as a result of it. During June/July some 200 DR frogs metamorphosed and again they were dispersed as a precaution against loss. The frogs were fed on aphids, spiders and insects and made very good progress. In November i970 I still had twenty-nine living DR frogs of this brood ranging in length from 25 to 37 mn. Three other 1968 DR females were successfully mated in the spring of 1970 and laid fertile, white spawn. One was mated with a normal male and all the tadpoles pigmented as expected: CC male X cc female ----- Co +. Ce + Ce 4 Ce The other two 1968 DR females were mated with Jim, 2? SR male, and 1968/10, ? SR males Both these pigmented males developed from white spawn which had been laid by a pigmented female and one could have expected cc female X Cc male ----- cC + cC + cc + cc That is to say, 50% DR tadpoles. This, however, was not the case, as both matings resulted in all the tadpoles pigmenting as they developed, suggesting that neither male was a simple single recess- ive. More than one gene could possibly be involved. There are now in the froghouse twenty-four 1970 pigmented frogs which had a DR mother and 1968/10 ? SR for a father. When these frogs breed in 1972 a few questions could be answered. Eight of the nine 1968 ? SR pigmented female frogs, which hatched from white spawn samples, laid black spawn. One clump was infertile whilst the other seven produced 100% pigmented tadpoles. This is not as expected if pigmented, white-spawn progeny are Single recessives. We should have had Ce male X Cc female ----- CC +. Ce +) cCos1ec These results suggest that frogs which develop from white spawn _ which was not laid by pink females are not all single recessives. The ninth female, 1968/4, laid a mixed batch of spawn; one- third of the eggs were dark grey, one-third speckled grey and one- third were white. The male was a presumed single recessive and ~ all the tadpoles pigmented. Pressure of work prevented detailed work on this mixed batch of eggs. The two pigmented males, 1968/10 and Jim, together with the female 1968/4 who laid the mixed clump of spawn, have been retained for further breeding. All the other pigmented female frogs and their tadpoles have been released in the lake in Whiteknights Park. A further attempt was made to mate Mickie, the DR male, with the Matriarch, who lays white spawn, but this was unsuccessful as they did not go into amplexus. The Matriarch was.later mated with Jim, a ? SR male, and on 3lst March 1970 laid 520 ml. of white spawn containing two black eggs. Only three eggs were fertile, two as, 1S xe hatched, none metamorphosed. An earlier mating of Mickie and the Matriarch produced 'Arfer'! who for obvious reasons was later renamed 'Marfer'. She is now 70 mm. long and weighs 37.5 g. and an attempt will be made in 1971 to cross her with the 1967 DR male. The result should be cc male X Cc female ----- cC. . eC. 4-4, #Gc Only time will tell. Frogs of the 1965 pigmented stock have now all been released with their tadpoles or have died. A further series of visits was made to the pond in Highmoor Road in the spring of 1970. Owing to the prolonged cold weather in the spring no frogs were seen in the pond until 22nd March when seventeen single frogs and six pairs in amplexus were seen. They again resembled the recessive stock with the black patterns; no albino or partial albinos were seen in the pond. Even in the early davs of the season there was a preponderance of males. A total of fifteen clumps of white spawn and twenty-six slumps of black were seen. Samples of the white spawn were taken just vefore a severe frost damaged the remaining white spawn in the pond. After this frost not one white tadpole was found in the pond. A total of 150 DR tadpoles were found in the 10,000 tadpoles which hatched from the samples. These tadpoles were typical textbook albinos, asym- metrical and swimming in cirsles. Not one. metamorphosed. Half the samples were returned to the pond while the others were placed in the lake in Whiteknights Park. Ten mature and twenty-nine immature DR frogs were still alive in November 1970. Thanks are due to many people who have assisted me in this work and to none more than my sister, Mrs. G. Beeching, whose interest and help is never failing. Summary. Ls Five female DR frogs laid fertile white spawn. Ze The tadpoles which hatched from spawn resulting from the mating of 1967 female and male DR's again failed to metamorphose. 3. The mating of 1967 DR male with 1968 DR female was successful. Twenty-nine 1970 DR frogs survived in November 1970. 4, The frogs which develop from white spawn laid by pigmented females are not all simple single recessives. References. Price, A. Reading Naturalist Nos. 19 (1967), 20 (1968), 21 (1969), 22 (1970). -12- A STUDY OF SOME BEETLES (COLEOPTERA - POLYPHAGA) FOUND IN COW DUNG. (ABSTRACT) by D. J. Weston Reading School, 1967 The objectives of this study were to try to find the optimum conditions for some of the species of beetle found in the dung of a herd of beef cattle, which was kept outside throughout the year near Sonning Common, Oxon., and to investigate the life history of one of them. The species recorded, following Joy's nomenclature, were:- Family Aphodiinae - Aphodius fossor (L.), Ae fimetarius CTeeDiy fi. dsurd dus { Pers A. depressus (Kug.) and_A. rufipes inde Family Aleochariinae - Aleochara villosa Mana., A. lanuginosa Gr. Family Sphaeridiinae- Sphaeridium scarabaeoides (L.), Cercyon haemorrhoidalis idalis (F.) and C. melanocephalus (L.). The study was centred on the Aphodiinae and it would seem that little is known about these beetles. Authoritative works, such as Fowler "Coleoptera of the British Isles", describe the adults but give little information about the larvae and none about the pupae. Yhe life history of Aphodius fossor, one of the larg- est of the beetles, was investigated. The habitat Dung pats are microhabitats, but their ecology is closely connected with the more general habitat in wthich they occur. The area of the study consisted of three fields grazed in rotation by a herd of about 20 beef cattle, so that either fields 1 and 2 or fields 2 and 3 were in use at any one time. The fields were on soil overlying chalk, which in the drier places came to within 3 ft. of the surface. Because of a gentle Slope towards the centre of the area from both the north and the south the central region tended to be damper and it was here that most pats were found, possibly because of lusher grass in this part. ' The cattle tended to walk along some boundaries that were either near where they were given supplementary foods or that kept them from adjacent fields. They also used a telephone pole as a rubbing post and sometimes sought the shelter of a large hedge along the east boundary. In these parts also the occurrence of dung pats was above average. =. Lae. Beetle populations were highest in the damper regions, perhaps because the desiccation of the pats was slower here. It was noticed that where larvae of the Tabanidae (Diptera) were found in dung, on the drier ground, the only beetles present were Staphylinids. So the different conditions may be important in reducing the competition between these various larvae for food. Finally, the composition of dung of a given age is fairly constant from animal to animal over short periods of time, vdut differs slightly over longer periods due to the seasonal changes in the composition of the herbage. Methods Dung pats were collected, weighed and dissected to remove the beetles, larvae and other animals which were then identified, counted and recorded with their position in the pat. The zones recognised were the outer crust, the centre and the bottom. The age of all pats taken for analysis was recorded. At first this wes found by marking the fresh pat with a stick in the ground beside it and recording the date. This proved to be accurate when the stick was not trampled by the cattle, but very time consuming. However, it was found possible to construct a colour scale, which, in conjunction with texture, enabled the pats to be dated with reasonable accuracy at first sight. In general dung pats lasted 30 days before beginning to disintegrate, by which time they were straw-colovred and dry. A suspension of lg. dung in 2 cc. of freshly distilled water was tested for its pH value, which was recorded. A 50g. sample of tne dung was then analysed for water, organic and mineral contents. The sample was weighed, then carefully heated to evaporate all the water, and the new weight was recorded. The sample was then ignited by fierce heating in a crucible to remove all organic matter. The residue is the ash or mineral content, which was weighed and recorded. The weights of water and organic matter were found by subtraction, and by doubling all these results the percentages were obtained. In all, 2257 beetles and larvae were counted from 85 pats. In order to try to discover the events in the life cycle of A. fossor a pat was selected in wnich this beetle predominated and a diary was compiled from observations taken over 7 weeks. eee = Results Chart. 1 Distribution of beetles and larvae in time and space. Aphodius fossor pert ss A. fimetarius A. luridus A. depressus A. rufipes Aleochara villosa j— eee = A. lanuginosa -— ee — —4 _C. haemorrhoidalis poe a | C. melarnocephalus -- S. scarabaeoides | ~ a ————} months J F M A M J J A s O N D position in pats t—-———H centre j- — - — -+ bottom -— —-