Diversity and distribution patterns of non-volant smallmammals along different elevation gradients on Mt. Kenya,Kenya

The distribution of small mammals in mountainous environments across different elevations can provide important information on the effects of climate change on the dispersal of species. However, few studies conducted on Afromontane ecosystems have compared the altitudinal patterns of small mammal diversity. We investigated the species diversity and abundance of non-volant small mammals(hereafter ‘small mammals')on Mt. Kenya, the second tallest mountain in Africa,using a standard sampling scheme. Nine sampling transects were established at intervals of 200 m on the eastern(Chogoria) and western(Sirimon) slopes.A total of 1 905 individuals representing 25 species of small mammals were trapped after 12 240 trap-nights.Abundance was highest at mid-elevations on both slopes.However, species richness and their distribution patterns differed between the two slopes. More species were recorded on Chogoria(24) than on Sirimon(17). On Chogoria, species richness was higher at mid-high elevations, with a peak at mid-elevation(2 800 m a.s.l.),whereas species richness showed little variation on the Sirimon slope. These results indicate that patterns of species diversity can differ between slopes on the same mountain. In addition, we extensively reviewed literature on Mt. Kenya's mammals and compiled a comprehensive checklist of 76 mammalian species. However, additional research is required to improve our understanding of smal mammal diversity in mountain habitats in Africa.

Small mammal diversity of Mt. Kenya based oncarnivore fecal and surface bone remains

Ecological dynamics and faunal diversity documentation is normally conducted by direct observation and trapping of live animals. However,surveys of carnivore scat prey and surface bone remains, which are relatively inexpensive, can provide complementary data that expand carnivore diet breadth and may improve accuracy regarding inferences of the ecological dynamics of a given ecosystem. We used this inexpensive method to document species diversity variation with elevation on the leeward(Sirimon) and windward(Chogoria)areas of Mt. Kenya. Bone and fecal specimens were opportunistically collected by walking 2 km in opposite directions from transect points selected at 200-m intervals along the elevational gradient of the study areas. We collected a total of 220 carnivore fecal and owl pellet specimens from both study sites, which were mainly deposited by the spotted hyena(Crocuta crocuta), leopard(Panthera pardus),serval(Leptailurus serval), genet(Genetta sp.), and Mackinder's Cape owl(Bubo capensis mackinderi).Serval scats were the most common, followed by those of the spotted hyena. Scats and bones were found at the lowest density at the lowest elevations,peaked at mid-higher elevations, and then declined at the highest elevations. Based on skeletal analysis only, there were more species in Sirimon(19) than in Chogoria(12). Small fauna(rodents to duiker size bovids) formed the bulk of the identified remains,representing 87.9% of the Sirimon fauna and 90.9% of the Chogoria fauna. The genus Otomys was the dominant prey of the owl and serval in both sites. Three giraffe teeth were found at 3 500 m a.s.l. in Chogoria on the edge of Lake El is, suggesting that it is an occasional visitor to such high elevations. This study underscores the value of fecal and bone surveys in understanding the diet and diversity of mammals in ecological ecosystems,but such surveys should be complemented with analysis of hairs found in scats to obtain a more complete list of carnivore prey at Mt. Kenya.

Glacier variations and rising temperature in the Mt.Kenya since the Last Glacial Maximum

High-resolution imagery can be used to reconstruct former glacier boundaries through the identification of glacial erosional and sedimentary geomorphology. We employed moraine mapping and the accumulation–area ratio method(AAR), in conjunction with Landsat, Google Earth, and SRTM imagery, to reconstruct glacier boundaries and equilibrium-line altitudes(ELAs) for Mt. Kenya in the Last Glacial Maximum(LGM), the Little Ice Age(LIA), and at present. Our results show that the areas of Lewis Glacier and the Tyndall-I glacier system were 0.678 km^2 and 0.390 km^2, respectively, during the maximum of LIA. Those mean that the both glaciers have shrunken by 87.0% and 88.7%, respectively since the LIA. Area change ratios for each glacier were significantly larger in the period of 2000 through 2015 than the former periods, indicating that glacier recession has accelerated. Continuous ice loss in this region has been driven by rising temperature and fluctuating precipitation. Linear regression data for Lewis glacier show that mass balance sensitivity to dry season temperature was –315 mm w.e./℃, whereas the sensitivity to dry season precipitation was 5.2 mm w.e./mm. Our data also show that the ELA on the western slope of Mt. Kenya rose by 716-816 m from the LGM to the modern era, corresponding to that temperature rose by 5.2℃-6.5℃.