Bird communities in logged and unlogged compartments in Budongo Forest, Uganda

We made 2200 point counts of birds in five compartments of the Budongo Forest Reserve in western Uganda. Two compartments had not been logged and the others had been selectively logged in 1947–52, 1965, and 1982–86. We recorded 104 forest bird species out of a total count for the forest of 197. Species overlap of the bird communities was about 78% between the compartments, with a lower overlap between the two unlogged compartments than between several logged and unlogged combinations. Of the 22 species for which densities could be calculated 8 showed significant differences between logged and unlogged forest. Not all species at low density in logged forest were forest specialists. Higher numbers of frugivores, bark-gleaning insectivores, nectarivores and omnivores and fewer sallying insectivores and leaf-gleaning insectivores were found in logged forest. Supporting evidence that these differences could be attributed to logging was obtained from correlations of bird abundances with measures of forest structure or composition. Changes in forest structure are probably particularly important for sallying insectivores; these species will be one of the groups most at risk from logging and consequently will be useful indicators of logging impacts.