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- Journal of East African Natural History
- OA African Journal Archive
- Volume 1970, Issue 119, 1970
Journal of East African Natural History - Volume 1970, Issue 119, 1970
Volume 1970, Issue 119, 1970
Author K.L. ModhaSource: Journal of East African Natural History 1970, pp 1 –6 (1970)More Less
Shallow-soil areas are here defined as those where up to 20 cm. of soil covers the underlying rocks (fig. I), and eleven such areas were studied in the Nairobi National Park. The vegetation of these shallow-soil areas is not much disturbed by human activities such as cultivation and road-making, and is very sensitive to drought; it only grows after the rains, remaining dormant during the dry months of the year. The present study was therefore started soon after the beginning of the short rains in October, 1967. Elongated areas of shallow soils are usually found on the side of a valley or the shoulder of a profile following the contour in the position of maximum slope. In the Nairobi National Park such areas are found mainly in the western wooded part which has many river valleys, but some occur near the Observation Point and near Hippo Pool. Shallow-soil areas are bordered by grassland and woody vegetation on one side or on both upper and lower edges.
Author M.E. TaylorSource: Journal of East African Natural History 1970, pp 7 –9 (1970)More Less
There are three species of genet in Kenya: Genetta genetta (Matschie), G. servalina (Thomas) and G. tigrina (Matschie). Of these G. tigrina is by far the commonest and is composed of two indistinct subspecies, G. tigrina erlangeri (Matschie) and G. tigrina stuhlmanni (Matschie). In this account the genets are treated at species level. G. genetta is a light coloured animal, the background colour being a dirty white, while G. tigrina has a much darker coloration; G. servalina has a yellowish-brown background colour with far more numerous markings. It is rare in Kenya, living in the remaining thick forests of western Kenya. The most recent record is from the Kakamega forest, collected in 1955. It is commoner in the forests of Uganda, several animals being caught in the Budongo forest in western Uganda in the last three years.
Author M.E.** Sale, J.B.* & TaylorSource: Journal of East African Natural History 1970, pp 10 –15 (1970)More Less
The four-toed mongooses belong to the African genus Bdeogale Peters. The genotype, Bdeogale crassicauda, was descriptionbed by Peters in 1852 and currently contains four sub-species. They are distributed through central Mozambique, Malawi and Zambia (B.c. crassicauda Peters 1852); northern Mozambique and southern Tanzania (B.c. puisa Peters 1852); Zanzibar Island (B.c. tenuis Thomas & Wroughton 1908); and northern coastal Tanzania and Kenya (B.c. omnivora Heller 1913), according to Coetzee (1967). In addition, most recent authorities (Walker, 1964; Coetzee, 1967) regard Galeriscus Thomas as a sub-genus of Bdeogale, containing the species B. nigripes Pucheran (1855) and B. jacksoni Thomas (1894). A new sub-species of B. crassicauda is descriptionbed in this paper and the sub-specific name nigrescens proposed.
Author G.C. BackhurstSource: Journal of East African Natural History 1970, pp 16 –26 (1970)More Less
This report covers the period 1 July, 1968 to 30 June, 1969. It is pleasant to report that, once again, the number of birds ringed is higher than ever before. As was hinted in last year's report (Backhurst, 1969b) some experienced ringers joined the scheme towards the end of 1968 while another came out early in 1969. The full list of birds ringed is given in Table I; the birds which are palearctic migrants are printed in bold type, others which are included in the palearctic fauna but which are also ethiopian are not so distinguished. The nomenclature used follows White (1960,1961,1962,1963,1965), a departure from previous reports but one that is considered desirable since White's lists reflect modern ideas more accurately than do the north-eastern parts of Mackworth-Praed & Grant's Handbook; moreover White's lists are to be the basis of the forthcoming AFRING list of birds (C. C. H. Elliott, pers. comm.). The number of recoveries, Table 2, shows a satisfying increase. Birds ringed in previous seasons and retrapped at or near their original ringing sites are listed in Table 3.
Migration of the butterflies Glycesthia aurota, Catopsilia florella and Crenis occidentalum in East Africa in 1967-68Author J.E.C. FluxSource: Journal of East African Natural History 1970, pp 27 –29 (1970)More Less
The complex patterns of insect migration in Africa are not well understood for even the two commonest pierid migrants Glycesthia aurota Fab. and Catopsilia florella L. For a review of existing records and illustrations of these two species see Williams (1958), and for the most recent discussion of the problems involved, Johnson (1969). From July, 1967 to July, 1968 all butterflies which appeared to be migrating (most fly below 20 ft. and are very conspicuous) were counted for five minutes (Table I) as they crossed an open area 50 yards wide in front of my office at the Botany Department, University College, Nairobi. Field trips away from Nairobi generally took less than one week and, as major migrations usually take longer than this, probably few were missed during the year. No attempt was made to select days or times of day of special abundance for the counts, which were made whenever butterflies were sufficiently numerous to be noticed. Wind direction varied and did not seem to affect orientation at all, but most movement occurred in sunshine. The butterflies were identified from collections in the National Museum, Nairobi.
Author S.D.K. SempalaSource: Journal of East African Natural History 1970, pp 30 –34 (1970)More Less
Bird migration has been recognized as a to-and-fro movement for a long time, but this type of movement is recorded for relatively few species of butterflies. The best known of these are the Monarch (Danaus plexippus L.) of North America and the Red Admiral (Vanessa atalanta L.) and Painted Lady (V. cardui L.) of the Old World. Records of migratory movements in these and many others, amounting to a total of 214 species, are summarized by Williams (1930) who defines insect migration as follows: ""It is a periodic, more or less unidirectional continued movement assisted by the efforts of the animal and in a direction over which it exerts a control, which results in the animal passing away from its previous daily field of activity.""
An analysis of the features of Sardinella gibbosa (Bleeker) Scales, with special reference to the problem of age determinationAuthor W. OkeraSource: Journal of East African Natural History 1970, pp 35 –46 (1970)More Less
Five species of Sardinella have been recorded in East African waters (Losse, 1968), S. gibbosa and S. albella (Valenciennes) being the most common in inshore waters of the Tanzanian coast. This investigation on the scales of S. gibbosa was a product of an attempt to find out whether there was any possibility of reading from the scale of the age of this species of sardine from its scales. In temperate waters where the seasons are well marked, many of the piscine structures, e.g. scales, otoliths, vertebrae, dorsal spines, pectoral spines and opercular bone, show well defined differences in their growth. The seasonal growth zones in scales and otoliths have provided a relatively easy and quick way of assessing the absolute ages of commercially important fishes such as herring, cod, plaice, and salmon with a satisfactory degree of accuracy. Beside these growth rings which are formed as a result of the accelerated and retarded growth processes during spring and winter respectively, ""the scales of many fishes show spawning rings and marks which are the result of the cessation of feeding and exhaustion during the spawning period"", (Nikolsky, 1963, page 194). Therefore if the fish spawns once a year and at the same time leaves a spawning ring on its scales, the number of these rings can be used to read the age of the fish since it first started spawning.
Author S.A. MoorjaniSource: Journal of East African Natural History 1970, pp 47 –52 (1970)More Less
Acetabularia is a pan-tropical genus with extra-tropical extensions. It comprises about twenty species which are all marine. The mature thallus is calcified (in varying degrees according to the species) and has an erect, unbranched siphonous stipe terminating in one or more whorls of gametangial rays. The rays may be free or fused along their lateral margins and contain numerous spherical cysts at maturity. On the upper surface and near the base, each ray bears a coronal knob, which knobs jointly comprise the corona superior. Some species also have a corona inferior below the gametangial rays. The corona superior bears delicate, decidous hairs, which in certain species are rudimentary. On the east coast of Africa, Acetabularia has been recorded in South Africa (Levring, 1938; Papenfuss & Egerod, 1957) and in Mozambique at Inhaca Island and Peninsula (Isaac & Chamberlain, 1958). As far as the author has been able to ascertain from the records available to her, the genus Acetabularia has not been previously recorded for the Kenya coast.
Source: Journal of East African Natural History 1970, pp 53 –55 (1970)More Less
In 1930-31, Major E. J. Lugard came on a long visit to his son and daughter-in-law, Cyril and Kitty, who had a farm on the south-eastern slopes of Elgon at about 2042m. (6,700 ft.) The map reference for this farm is GAM 560.050 on sheet 88/11 of series SKI II (1958), 1:50000. Major Lugard was an experienced collector for Kew and he and Kitty (Mrs. C. E.) Lugard proceeded to make a thorough collection, on and around the farm and up the slopes of Elgon to the top. He it was who first encouraged one of us (E.M.T.) to take up collecting with the special aim of completing his collection, which was made only between October and May. The collection numbered over 700, and was made, where possible, with much material from each plant. The best material was sent to Kew which deposited duplicates of many specimens in the East African Herbarium, and one incomplete set of plants was retained by the Lugards for their use and reference.
Source: Journal of East African Natural History 1970, pp 56 –61 (1970)More Less
The observations reported here were carried out near Kampala between 1962 and 1966. The species involved, the Black-headed Weaver Ploceus cucullatus bohndorffi (Reichenow) and Vieillot's Black Weaver Melanopteryx nigerrimus nigerrimus (Vieillot), are the commonest weaver birds in that area. General descriptionptions may be found in Jackson (1938), Bannerman (1949), Chapin (1954) and Mackworth-Praed & Grant (1955). One of the most striking features of their biology is the frequent occurrence of colonies of both species in the same site. Questions as to why this happens lead to a consideration of the advantages of colonial breeding, which are uncertain. At the same time, since these weavers appear to be closely similar in habits and ecology, problems of inter-specific competition are raised. The data descriptionbed throw some light on these problems.
Source: Journal of East African Natural History 1970, pp 62 –63 (1970)More Less
In September 1965 it became necessary to destroy a colony of Black Weavers on the school compound at King's College, Budo, near Kampala. The writer was present and was able to remove approximately half of the nests individually and so obtain a record of their contents and a number of specimens of young for analysis of gut contents. The resulting data throw light on the sex ratio in the colony, clutch size, spacing of hatchings and food of the nestlings. The total number of nests present was 59 and 30 of these were removed for examination. They represented an entire section of the colony and may be regarded as a representative sample of it.