Abstract:
Habitat loss and fragmentation are major threats to biodiversity worldwide, and little is known
about their effects on bats in Africa. We investigated effects of forest fragmentation on bat
assemblages at Kakamega Forest, western Kenya, examining captures at edge and interior locations in three forest fragments (Buyangu, 3950 ha; Kisere, 400 ha; and Malava, 100 ha) varying
in forest area and human-use regimes. Basal area, canopy cover, tree density and intensity of
human use were used as predictors of bat abundance and species richness. A total of 3456 mistnet hours and 3168 harp-trap hours resulted in the capture of 4983 bats representing 26 species,
eight families and four foraging ensembles (frugivores, forest-interior insectivores, forest-edge
insectivores and open-space insectivores). Frugivores were frequently captured at the edges of
the larger, better-protected forests, but also in the interior of the smaller, more open fragment.
Forest-interior insectivores and narrow-space foragers predominated in the interiors of larger
fragments but avoided the smallest one. Forest specialists showed positive associations with
forest variables (canopy cover, basal area and tree density), whereas frugivores responded positively to the human-use indicators. On these bases, specialist species appear to be especially
vulnerable to forest fragmentation.
