| Forest fragmentation leads to loss of area and the quality of the forest. In Kenya, Kakamega Forest, the only rainforest, is under intense pressure from rapidly growing human population, and rising economic aspirations of the local communities. Only about 20% of the forest remains, divided into 9 fragments. I examined the effects of fragmentation on microenvironment, vegetation structure, food availability and nest predation. I assessed how these factors may directly or indirectly, singly or in concert affect bird communities in six fragments: two highly disturbed, two relatively undisturbed, and two moderately disturbed. I measured temperature, humidity, vegetation variables, and insect abundance at seven distances from the edge. I placed and monitored artificial nests baited with artificial eggs, sampled birds (via mistnet and point-count), and observed feeding and social behavior of Cabanis and Joyful Greenbul.; Temperatures and humidity were higher and lower respectively, at forest edges and in highly disturbed fragments. Vegetation cover was higher at edges and in undisturbed fragments. Moderately disturbed fragments had highest tree density. Rates of nest predation were higher at the edge. Surprisingly, nest predation was highest in undisturbed fragments, possibly because of “mesopredator release effect”. In highly disturbed fragments, there are higher number of domestic dogs that might be “surrogate” top predators.; The number of bird species was similar among and within fragments. Forest interior had higher forest specialists of understory birds. Undisturbed fragment had high canopy forest specialists but higher abundance of understory birds. Among the insectivore feeding guild, frugivore, sallying and nectarivore were in higher abundance in highly disturbed fragments and, though not significant, at the edges. Leaf-gleaning insectivores had higher abundance in undisturbed fragments and at the interior. Both greenbuls foraged at a lower height. The foraging flock size of Cabanis Greenbul was higher in the interior forest site than in the other fragments. The response of bird to fragmentation suggested that each species is affected by a unique set of factors.; Natural forests had higher diversity of plants and birds. Restored forests had higher tree densities. However, both natural and restored forests and similar bird species richness and foraging guild abundance. |
