Edge effects on the understory bird community in a logged forest in Uganda

Understanding how the fauna of logged tropical rainforests responds to frag mentation and the creation of edges is vital to ensure conservation of biod iversity. We studied the composition of the understory bird community from the edge of a 15-ha clearing toward the interior of the forest in a part of Budongo Forest Reserve, Uganda, that was selectivity logged about 45 years ago. Mist netting was conducted along five transects from the edge, but th ere was a significant increase in the number of species. We sampled fewer, but more common species near the edge, whereas the interior of the forest h ad more, and less common species. Guild composition also changed with dista nce from the edge. Frugivore-insectivores and nectarivores were most common close to the edge. Among insectivores, ground foragers, bark-gleaners, and leaf-gleaners were most common in the interior of the forest, whereas sall ying insectivores favored the edge. Graminivores were unaffected by the edg e. Analysis of common species showed that Ispidina picta, Andropadus curvir ostris, A. latirostris, Camaroptera brachyura, Terpsiphone rufiventer, and Nectarinia olivacea were associated with the edge, but no species showed si gnificant avoidance of the edge. This finding may be explained by the gener ally low sample sizes of interior species. Our results show that even bird communities in logged forests respond to edges. Estimates of edge effects s uggested that changes in bird densities may have occurred several hundred m eters from the edge. In conclusion, logged forests provide habitat for bird species avoiding forest edges, and this should be considered in the manage ment of such forests for conservation.