This study examined the ecological distribution and abundance of the small mammal fauna in the Kora National Reserve, Kenya. Over a period of eight weeks, 3300 trap-nights yielded 11 species and a total of 298 small mammals. All 11 species were trapped in the diverse nyika habitat, whereas in the riverine habitat five species were trapped and the rock outcrops had only two species. However, the catch per trap-night was the highest on the rock outcrops compared with the riverine and nyika habitats. The duration of prebaiting had a marked effect on both diversity and abundance. With one exception, males of all species were in breeding condition whereas females tended to be more erratic. The biology of small mammal species in Kora in the dry season is discussed.

Animals inhabiting environments with low productivity and food availability commonly have reduced energy demands and increased digestive efficiencies. The dry matter intake (DMI), apparent digestible dry matter (ADDM), digestible efficiency (DE) and digestible energy intake (DEI) of two populations of common spiny mouse Acomys cahirinus were compared during both winter and summer under conditions of simulated water stress. Mice were captured from the north- and south-facing slopes (NFS and SFS) of the same canyon that represent mesic and xeric habitats, respectively. Measured variables were also compared between F1 mice that had been born to either NFS or SFS mice, and raised in the laboratory. SFS mice were able to assimilate energy more efficiently than NFS mice during the summer. By comparison, NFS mice were able to assimilate more energy during the winter. During winter, NFS mice assimilated more energy at low levels of water stress, whereas SFS mice assimilated more energy at higher levels. Differences were also apparent in F1 mice. It is therefore suggested that local climatic conditions can impose physiological adaptations that are retained in succeeding generations, creating unique meta-populations.