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A comprehensive checklist of dragonflies occurring in the Kakamega Forest, Kenya is given and shortly discussed. A total of 72 dragonfly species, representing 42 % of Kenya's dragonfly fauna, has been recorded from the forest. Three of these are based on literature records only. The habitat preference and affiliation with other African regions is listed for all species. Twenty species are of national importance for Kenya, since they are only found at this site within the country. For these species habitat affiliations in the Kakamega Forest are given more in detail. The dragonfly fauna of the Kakamega Forest is impoverished compared to more western Guineo-Congolian rain forest areas. The effects of forest fragmentation and isolation hindering any immigration from western rain forest patches is shortly addressed.
A list of the Tephritidae from Kakamega Forest and it environs was compiled from published records, Malaise trap, baited trap, and sweep-net collections, rearings from flowers and fruits, and examination of museum specimens. One hundred and thirty-five species are recorded, and collection information is provided for all of them. Twenty-five of these species are undescribed, or were so at the time our study began. Frugivorous Tephritidae were reared from 134 of 378 (35%) fruit collections made within the forest. Fruits of 17 of 47 plant families (36%), and 37 of the 123 plant species (30%) yielded Tephritidae. The plant families of greatest importance in the life histories of frugivorous species were the Sapotaceae, Rubiaceae, Flacourtiaceae, Rosaceae and Solanaceae, while the Asteraceae provided hosts for most of the flower-feeding species. The affinities of the Kakamega forest tephritid fauna with those of other regions, in particular the main central and western African rain forests and the East African coastal forests, are discussed.
Disa walteri, Satyrium aberrans, S. comptum and S. johnsonii are rare terrestrial orchids that co-occur and flower around the same time in southern Tanzania. We found the first three of these species on Mbeya Peak in March 2005, about 45 years after they were last recorded by botanists and present the first illustration of D. walteri in the form of pictures here. S. johnsonii could not be located and might be extinct on Mbeya Peak. Major habitat loss and the extraction of tubers for consumption or trade severely threaten these narrowly distributed species. Based on herbarium records and our field observations we provisionally assess D. walteri and S. johnsonii as Critically Endangered and S. aberrans and S. comptum as Endangered.
The aim of this study was to compile and analyse information on local use of plants in Ethiopia based on data obtained from labels of specimens stored at the National Herbarium and from published volumes of the Flora of Ethiopia and Eritrea. Two families were considered: Fabaceae and Euphorbiaceae. Analysis of the herbarium data yielded a total of 116 locally useful plant species in Ethiopia. The highest proportion of plants (52%) was used for medicinal purposes. The study also revealed Acacia nilotica, Croton macrostachyus and Ricinus communis as having the highest use diversity. Further analysis of the Euphorbiaceae herbarium data demonstrated an increasing trend, with time, for collectors to incorporate plant-use information on specimen labels even though much of the records were found too incomplete to be considered useful. The study also revealed that the majority of plant-use information on herbarium labels was absent from the relevant Flora volumes. We, therefore, recommend that more thorough ethnobotanical investigations are conducted in Ethiopia to obtain more complete and precise data on the local use of plants.
This is the first detailed report on the natural prey and the prey-capture tactics of Palpimanus sp. from Entebbe (Uganda). Although this species fed occasionally on insects, its dominant prey in the field was other spiders, especially jumping spiders (Salticidae) and their eggs. Encounters between Palpimanus sp. and salticids were staged in the laboratory under red light (to simulate nocturnal or dimly-lit conditions) and under white light (i.e. full light, to simulate daylight or brightly-lit conditions). Altering ambient lighting had no discernible effect on the palpimanid's predatory tactics, suggesting that eyesight has little, if any role, in governing the palpimanid's prey-capture behaviour. Reliance on stealth appeared to be critical in enabling the palpimanid to avoid detection and to succeed at capturing salticids. The prey-capture tactics of Palpimanus sp. are compared to the tactics used by other araneophagic spiders to capture salticids.
Mound-building termites were studied from 1976–1982 at Emali, Selengei and Ruaraka, three sites in semi-arid southern Kenya. The mounds, most of which were built by species of Macrotermes but some by Odontotermes species, contained 2–20 m3 of soil ha−1. Mound dispersion was regular to a significant degree (implying intra-specific competition) at Emali and Selengei, but not at Ruaraka, where instead there was a distinct vertical zonation of species up a valley slope. Mound-building termites show evidence of intra-specific competition in other ways—for example, large mounds are further apart. Inter-specific competition was also apparent at Emali and there is evidence of inter-generic competition at Ruaraka but of inter-generic associations at Selengei. Building activity increased during wetter periods, whilst feeding, as reflected by the extent of earth coverings, was negatively correlated with rainfall, especially for the Macrotermes species. Ventilation shafts are numerous on large, unshaded mounds of M. subhyalinus, confirming the main purpose of the shafts, which may however limit the maximum size of mounds. M. michaelseni, which has no external openings, uses a different system for ventilation. Flighting by Macrotermes alates shows interesting variations between and within species whose full explanation will require further research.
Of all the climatic variables in the environment of termites in southern Kenya, only rainfall shows marked seasonality and unpredictability. But despite the great variability in rainfall patterns, the populations of termite mounds of various species in three well-separated study areas remained remarkably constant over a period of 6½ years. This provides good evidence for the effectiveness of the termites' control of their nest environments, and suggests that their populations are close to their carrying capacities. New colonies appeared either as new mounds or as recolonisations of old ones, the latter being less frequently recorded but having higher survival rates. The appearance of new colonies of Macrotermes michaelseni followed years of higher rainfall; the opposite was true for M. subhyalinus. Numbers of old colonies dying were roughly equalled by new colonies surviving. For the largest mound population, that of M. subhyalinus at Selengei, colonies in larger mounds had higher survival rates, as did those which had no close neighbours. Few colony deaths were attributed to ants, but more to aardvarks Orycteropus afer, particularly in wetter years, and more in the apparently softer mounds of M. michaelseni. Mounds containing live populations usually increased in size but all mounds lost soil by erosion. However, the whole process was so slow that turnover of soil was less than 1.0 m3.ha−1.yr−1.
The age and growth of largemouth bass Micropterus salmoides in Lake Naivasha, Kenya, was determined using scales and otoliths collected in July 2002. Although validation could only reveal the likelihood of annual check formation on these structures, the subsequent growth outputs were valuable in revealing that M. salmoides were apparently growing at a rate in excess of those recorded from populations in more temperate regions. However, their life span appeared compromised, with no specimens recorded over the age of 4 . It was believed their limited life span was related to both their high exploitation in sport and commercial fisheries, and a trade-off between fast growth and longevity in individual fish.
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