A publication of the East Africa Natural History Society, Box 44486, Nairobi, Kenya. Price 4 shillings NOTES FOR CONTRIBUTORS Members of the Society (and non-members) are asked to follow these simple instructions when writing articles or letters for submission to the Bulletin. The Bulletin is presented six times a year in a duplicated format: the paper size is 20.5x23 cm (10x8 inches), line drawings can be reproduced but the area should not be more than 17.5x23 cm. Lettering on figures should preferably be in ‘Letraset’, neatly done in Indian ink or left blank: if the last method is followed, the lettering should be indicated on an overlaying sheet and should not be done on the figure. Figures should be prepared on good quality white writing paper and not on Bristol Board or other thick material. Whenever plants or animals are mentioned the scientific name should also be given but not in parenthesis. Trinomials should not be used unless there is good reason to do so. 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EAITHS BULIETIII SEPTEKBER/OCTOBEE 1977 COHTEITTS A ITote on the Flora and Fauna of two Seasonal Sv/anips in theRiftValley. c . » . . . . . , . . . . , . . . e 96 A G-ras sliopp er-\7arbler from Rguruman Escarpment 5 Kenya , , IO4 A Definite Sighting of the Taita Falcon , » , . o . . » . 105 I'lotes on Birds seen in Diani Forest, Kanya 106 Great Spotted Cuckoo 0 .. ...... o«..» . 108 East African Rest Record Scheme ............. 108 Ringing hews .. 110 Cov/ries on the South Kenya Coast 112 Hints on Collecting, Fluid Preservation of Reptiles, Amphibians and Fish ... , ........ 113 Mammal .Notes 115 Late News from the Rift Valley Swamp 116 Letter oo u h cnditor . . . . . . . « . . . . . . . . . . 117 Scopus ..... ....... 118 Requests .. ...... 118 Annual Orchid Show , . ........... 119 Special Film Show 119 Socieuy Notes . . . . . . . . . . . . . . . . . » « . . 120 Nev/ Members 121 Society Functions 122 A ¥OTE OE THE ELORA AHD EAUHA OE TWO SEAS ORAL SWAMPS II THE RIET VALLEY The fauna and flora of local temporary or seasonal s¥/amps have not received much attention but to a naturalist they should be fascinatingo Unf ortunat ely j all too often, time does not allow a proper study. This note reports on v\rhat we have been able to undertake over a series of visits to a seasonal swamp area in the Rift Valley, to the West of the Ngong Hills, Kenya, The main sv/amp and lake, which is nameless, lies at about 1800m above sea level, belov/ the Hgong Hills at 1 23.5 ’S and 36 35 'E, They are shov/n on the 1; 50, 000 map as being some 2866m long by 758m wide. There is a smaller swamp area to the West, on -slightly higher ground. To our knowledge and on ques- tioning the loaal people, no appreciable water has accumulated in these hollows since 19.6 2., the last period of heavy and susta- ined rainfall. Throughout 1970 - 1977 this area has been more or less arid, almost a desert, v/ith little in the way of green vegetation other than Acacia sp,, Eicus sp. on„t.he J.scarp’ walls and a few hardy, drought-resistant shrubs and small trees, including Dr ac aena ellenbeckiana. This year, 1977, we have experienced almost unprecedented rainfall, particularly during Eebruary - May, The nearest recording point comparable to the swamp area is Ololkisaili to the South which has recorded the follov/ing; January 48,4mm, Eebruary 1 6 0 . 9m.m, • March 9.1mm, April 311»6miii5 May- 135.6mm, June 26,2mm and July nil, .This total of 691,8mm fell on 44 days. during the period. In 1976 Ololkisaili recorded a total of only 266,3inm which fell 'on 27 days, mostly during April and May, As there are no rainfall reco'rds on the immediate vicinity of these -swamps, these rainfall figures can be taken as reasona- baly representative of the area. It is sufficient to say that the swamps, with up to 2m of water, have been more or less dry for at least 10' years and probably more, CvS visited these swamps for duck shooting during 1938, 1939 and 1951 | all years of high rainfall, LKR , this year, during the course of his duties, had flown repeatedly over the area and noted the flooding of the low lying areas. On 26th June he v/as able to visit the large swamp and lake (Swamp l) by travelling over appalling tracks but was able to confirm his aerial observations that there ?/ere a great number of v/ater fowl and that the Great Crested Grebes, Podiceps cr ist atus , were displaying. 96 It would appear that the first rains flooded the lov/er areas and certain vegetation responded to it. Further flooding resulted in this early growth being drov;ned and left under extremely turbid water. On our first visit the water was slowly but cleai-ly receding. There was no grass or sedge such as Cyperaceae around the shore as v;ould have been expected. Little green could be seen in the lake except at one point where there was a thin cover of sedge. One species of aquatic plant, Aponogetum abyss inicus , was only represented by dead and decom- posing foliage. This was probably due to the turbidity of the water preventing sufficient light getting to the plants, which, however, responded when the lake level fell tov/ards the end of the month by sending out new green shoots. The dead leaves were extensively used by the Grebes for their floating nests. The lake contained a considerable number of Acacia trees particularly at the southern end', all standing in water. Most of these were one or two metres above water level with a few taller ones which formed the nesting sites for a number of species of birds. Some of these Acacia nilo t ica had died, while others were covered in yellow pompom flowers. On our earlier visits the water was 'alive' v/ith countless miriads of all sorts of swimming organisms. Crustacea of many kinds were everywhere and could be scooped out with a fine mesh net. There v/ere at least two species of Branchipoda and Ostrac- oda of various sizes from pin-head and less to creatures over a centimetre in length. These, of course, formed a rich food for the Y/ater birds. Their life span is short but they leave a mass of desiccation-resistant eggs in the mud. Their millions of scintillating microscopic 'shells' v/ere seen trapped on the cattle footprints where they had died as the v/ater level receded. On 24th July the edges of the upper sv/amp had been v/ell trampled by cattle and the footprints v/ere found to be full of mosquito larvae, both Anophaline and Culicine, Of particular interest was the presence of vast numbers of the fresh water snail, Bulinus sp,, a known intermediate host of various flukes, Trematodes, including the human Schist as oma (Silharzia), Lither birds had introduced these snails or they had survived the years of desiccation buried deep in the dried mud. This species and others are known to be able to lie dormant for some yea.rs but 10 years or more appears to be an excessively long time I Plants may have also been introduced by birds or their seeds lain dormant all those years. One plant found was the submerged v/ater weed, Utricularia g i b b a , with its filmy foliage and emergent racemes of yellov/ flowers. We did not, however. 97 find this species 5 nor the snails, in the upper sv/aiap (Swamp 2) which suggests that those in the main swamp had managed to with- stand the desiccation, for surely both the snails and the plant would also have been introduced into Swamp 2 by birds ? A few clusters of together with a very int Slat in e sp. which awaits the first record of the Sahara (Mr Gillett & Dr arrive at the swamp ? C come from ? the water f ern Mars ell ,ia e r e s ting s mall wat e r plan det erminat ion . Th is spe f ami ly in E as t Af ri ca and Ball j per s . c 0 mm. ) 0 How ar ri ed by b irds 9 If so , sp« v/ere seen t, the aquatic cies is probably South of the did this plant where did it Progs, of course, were numerous, mostly juveniles and five species were collected (det, A» Duf f-MacKay ) . These were metam- orphosing Kassina senegalensis ; a species v/ith black spots on a white belly, Carcost ernum boett zeri ; a tree frog, Hyperolius viridif lavus f enr i gue and a stout toad, Pyxic ephalus delalandi . In the smaller upper sv/amp tadpoles of the Clawed Toad, Xenopus sp, v/ere seen in their thousands in all stages of development. A single example was collected from the larger swamp and doubt- less these formed the main food of the Grebes and other v/ater birds . Several Terrapins, Pelomedusa subruf a were noted, some small and others v/ith a carapace at least 30cm across. The question arises as to how they survive the years of drought or where had they come from and how had they found the swamp ? Insect life was represented by small clusters of '\7hirligig Beetles, Gyrinidae , and by hundreds of gaudy Dragonflies, part- icularly the bright blue bodied Orthet rum sp., banded-winged Brachy themis sp. and the marbled-winged Palpopleura sp. The scarlet Tri themis and the broad-bodie dj scarlet Croc o themis sp. were plentiful, as was a species of Pant ala. Hov/ever, these species were virtually absent from the upper swamp and v/ere replaced by the slender-bodied Demoiselle Dragonflies, the blue-green Pseudagrion sp. , a Le s t e s sp. and the orange-red Cereagrion sp. These smaller dragonflies v/ere absent from the lower swamp until 24th July when a few v/ere seen. Butterflies were a feature along the muddy shoreline where groups of the bright yellov/ Pieridae , Bur ema brigitta gathered to feed on the v/hite liquid bird droppings in the wet mud. These were joined by the white Pierid, Belenois au rota and the Liar oon- 1 ip , C 0 1 0 1 i s danae . Also present is what is probably the world’s best known butterfly, the Painted Lady, ¥ an e s s a cardui . These were in large numbers, some feeding at the bird droppings. The common Yellow Pansy, Pr e c i s hiert a , v/ith its 98 large yellow patches on the hindwings and its relative the Blue Pansy, Precis oenone , v/ith blue patches on the hindwing, were everywhere in the grass or feeding on the mud. On 10th July, at mid-day, while we were at lunch, we witnessed a mass migration of the two latter species. They flew past, between the car and the lake edge in their hundreds per minute, flying low and moving steadily southwards. Mammals in the area and around the lake were not plentiful but we did see a fine herd of Eland, Tauro tragus oryx , on two visits and on each trip a few Grant's Gazelle, Gazella grant! v/ith the occasional Giraffe, Giraf f a Camelopardalis . A pair of Bat-eared Poxes, Oc t o c yon megalot is sat at an earth near the upper swamp v/hich clearly at one time had been flooded. This earth appeared to be a disused burrow of an Aardvark, Or yc t er opus af er , and all around the shore there were many such burrows which made driving somev/hat hazardous. In the mud we recognised tracks of Jackal, Can is sp, and Lion, P an t h e r a 1 e o , but we were confused by the many tracks and small prints of small carnivora which doubtless prey on the nesting birds. On 24th July prints of Leopard, P an t h e r a p ardus and the Ratel or Honey Badger, Mellivora capensis were found, those of the Ratel clearly show- ing the very long digging claws on the front feet, Birdlife was remarkable and one could only ask how did all these birds find the swamps and what induced them to stay and breed ? Breeding must have started soon after the onset of the rains in February, The following notes will give some idea of the attractivness of these very important seasonal v/etlands. On 17th July we had the use of a small boat which made exploration of the lake more comfortable than slogging through the mud or wading in deep water which prevented us from closely examining many potential nest sites. Outstanding and suprising was the nesting colony of Spoon- bills, Plat alea alba intermingled \7ith Sacred Ibis, Thre skornis aethiopica, and Long-tailed Cormorants, Phalacrocorax af r ic anus . The largest tree held nests of all tiiree species plus a pair of Yellovz-billed Egret, Egr e 1 1 a intermedia which had tv70 well grov/n youngsters. In this same tree we found five Ibis still sitting on eggs plus 2S juvenile birds almost ready to fly. On another tree 'were three pairs of Spoonbills each with three juveniles at an advanced stage, thcagh not ready to fly. Cormorant juveniles and adults numbered some 20+, In another tree there were tv/o nests and seven juvenile Spoonbills and a fourth tree held only one Spoonbill nest, again with three large youngsters. On 24th July there were four late Spoonbills sitting on eggs while three more Yellovz-billed Egrets were nesting and had clut- ches of 1 , 2 and 5 blue eggs vvhile a fourth was nest building. 99 A fifth tree had many nests but all were empty except for an oldeggofaSpoonbill, On 7th August a further check was made and it was found that all the young Spoonbills 5 Ibis and Cormorants had left the colony and that there were nine new nests of Spoonbillj nine of Cormorants and a Yellow-billed Egret 5 all with eggs. V/hile we v/ere investigating a large juvenile Ibis fell from its nest into the water and appeared to commence s?/imming so v/e turned back to rescue it. Our efforts were unnecessary as the bird swam directly to an Ac ac ia and climbed up into the branches with remarkable agility. Ve had no idea that an Ibis could sv^im, however another youngster must have fallen into the v/ater as vre recovered its body near the shore ?/here it had been blown, A single Fish Eagle 5 Haliae tus vo c if er had found it but had not yet started to feed when v/e disturbed it. The Eagle had been standing in at least 23cm of water by the carcass. At Swamp 2 5 v/hich contained far more half-drowned Acacia trees j we found another nesting colony of Ibis and Cormorant, The nests v/ere in a thicket of Acacia , v/hich made close examin- ation difficult j however Y'le counted 17 juvenile Ibis and seven Cormorant. Parents came readily to the nests to feed the young unperturbed by our presence a fev/ metres away. Crebes of three species \?ere present in numbers 5 one of these 5 the Great Crested Grebe we had seen displaying earlier in June and July. On 17th July, having a boat, we were ablevto examine any collection of weed that might have been a Grebe's nest. In all we located the following numbers t Great Crested Grebe v?ith nests containing clutches of 1, 4, 6, 1, 2, 2, 6, 4? I5 4j 4, and on 24th July a further clutch 1 and 2. On 7th August Y'fe located a further nine nests of this bird with clutches 1, 2, 3? 2, 3j 3s 2, 3s and 1, Many of these were still white, indicating that they v/ere nev/ly lo.id. Black-necked Grebes, P o d i c e p s caspicus had clutch 1 and 3 and the Little Grebe or Babchick, Tachybapyus ruf icollis , had clutch 2, 4, 6, 3s and 1, On 7bh August, two further nests were found containing clutch 1 and 1, Some nests contained very fresh eggs almost immaculate pale blue-white but other eggs were very brown stained from the v/ater weeds with v/hich the birds cover their eggs v/hen they leave the nest. On 24th July we located two further .Black-necked Grebe nests with clutches 6 and 4o There v/ere many pairs with chicks at various stages which we found more difficult to count. Many of the Grebe nests were supported on submerged branches of the Acacia trees, making it a 'prickly’ business to get close enough to count the clutches. 1 00 At one point, though nests could be seen, we just penetrate the thicket. could not Other nesting waterfowl were duck islands as nest sites. These islands 3 v/hich used the little were formed of old termite mounds. On such places, on 10th July v/e found tv/o nests of the African Pochard 22, the second with a minature iT e 1 1 a erythrophthalma , egg were checked on 17th July 19, again v/ith a minature ( taken ) we found that the egg (again taken) with clutches 9 and When these nests clutch 22 was now liormal eggs measured 58 x 43i'iim while the minatures were 4-2 x 33mm. The clutch nine had been reduced to six a.nd a third nest had appeared with four eggs plus a fourth empty nest. All these nests were within about 30cm of each other. On 7th August we found another Pochard with clutch 13. On a second small island we found a Pochard v/ith clutch 12 with one egg out of the nest. This nest was within a metre of that of a Black-v/inge d Stilt, Himant opus himant opus v/hich contained tvvo normal pyriform khaki eggs with black blotches together with a small abnormal egg of pale blue with feint blotched markings (taken). The normal egg measured 43 ~ 44 x 31kuh while the abnormal one v/as 41.5 x 31mm. On 17th July this clutch had two normal eggs. An Egyptian Goose, Alopo on v\rhat was probably a nest On 17th July we located a Re in a flotilla of nine newly one of these had been lost, Pendrocygna bicolor was seen on the lithe Moccoa Pucks, bill and stiff upright tails vfe could not locate a nest, insufficient cover of grass nesting condition. Many nes in another swamp further up Moccoa is said to often use Crested Grebe. On 18th Augu find a nest of the Moccoa wi was of dry grass well hidden Acacia branch which had fall down lining to the nest and chen aegyptiaca was seen sitting but we ommited to inspect it, d-billed Puck, Anas erythrorhynchos hatched ducklings but by 14th July A single Pulvous Tree Puck, on 9th July and it v/as still there Oxyura moccoa with their bright blue were present in small numbers but It is possible that there was or Cyperus as this is their preferred ts were found in 1938 - 39 by CvS the valley. In South Africa the the floating nests of the Great st we were fortunate enough to th a clutch of four eggs. The nest amongst grass growing over an en into the water. There was a the eggs were very fresh. Other breeding birds seen were Stilts and the Blacksmith Plover, Vanellus armatus and we located the follov/ing nests: three of the Stilt, each with four eggs and another found on 24th July with four eggs. There were three Plovers nests of four eggs. On 10th July we located one Stilt with a clutch of two on a tiny island but left this to examine another tree and returned some ten minutes later and found a newly hatched chick floating in the water. It was lying ’doggo' , feining dead. 101 V/e persuaded it to swim to shore where it climbed out on rather wobbly legs 5 and to our suprise v/e found that the nest had only one eggo The youngster had hatched in the fev/ minutes we were away. V/e found several other young Stilts and many of these were swiniming„ V/e remarked on the close resemblance of a two week old Stilt to the Marsh Sandpiper 5 Tr inga st agnat alls , both in general colour pattern and sizoo V/e presume the Stilts must have come from Lake Magadij the near- est place where the indigenous birds occurj for we knov/'that the Magadi water level has been very high and possibly unsuit- able for them to feed or breedc 'They went through various distraction acrobatics and aerobatics when we approached the nests. Some birds appeared to deliberatly fall into the water and then proceed v/ith the ’ br oken-wing ' behaviour. The Black- smith Plovers v/ere just as noisy in their protests at the invasion of their nest territory. Coots 5 Pu 1 i c a cr is t at a , v/ere present but no nests were found. Moorhens, Gallinula chloropus v/ere numerous and we located a number of nests up in the flooded Ac ac ias . Many youngsters v/ere seen of all ages, often without parents in attendance. Bests found contained clutches of 6, 3 5 and there were 2, 2, 2, 2, 2, and 3 juveniles in nests. We found the Common Sandpiper, Tringa hyp o leu c a at both sv/amps but no evidence of nesting. These v/ere either over- summering birds or very early migrant arrivals. On 17 th July v/e noted Crowned Cranes, Balearica re gulp rum, behaving in an odd manner, one of the birds running ahead of the car along the grassy track. V/e discovered it was being follov/ed by a small fluffy brown and cream coloured chick which we were able to catch up with and examine v/hen it hid in the grass. This chick v/as again seen on 24th July. Other breeding birds were a pair of Cut-throat Pinches, Ama.dina f as c iat a in an abandoned nest of the Chestnut Weaver, Plo c eus rubiginosus , in a small Acacia tree less than 2m high. Another Weaver nest had been taken over and adapted by a Superb Starling, S p r e o sup er bus and contained two newly fledged young- sters. Another nest was that of the Grey Plycatcher, Bradornis michr orhyn chus , v/hich had two young, one considerably bigger than the other. On 24th July at Swamp 2, a nest of the Kenya Rufous Sparrow, Passer iagoensis , was found v/ith two eggs. Other birds noted at the Swamp were Hottentot Teal, Anas hott ent o t a and Knob-billed Goose, Sarkidiornls me 1 an o t a . A single European Stork, Cic onia c ic onia v/as present on the 10th and 17th July, with a Great White Pelican, Pel ecanus on ocro talus . 102 Possibly the most interesting bird was a single fine Osprey^ Pan d ion halisetus , which flew over us on 1?th July, This bird must have strayed a considerable distance 5 for Naivasha must surely be the nearest locality for the species. Squacco Herons Arde ola rail o ides were present and at the smaller swamp tv'fo sub- adult light Herons 5 Hyc t ic orax nyo t icorax in their speckled plumage. Grey Heron j Ardea c inerea and Black-headed Heron, Arde a me lano c ephala Y