Forest bird diversity and edge effects on three glade types at Mount Meru Game Reserve, Tanzania

This study examined the edge effects on forest bird diversity in five man-made, five upper natural and 15 lower natural glades in the Mount Meru Game Reserve, Tanzania from September 2005 to November 2005. Bird species composition differed significantly between the three glade types. Mountain Greenbul and Common Bulbul were indicators of forest edge habitat for upper natural and man-made glades, respectively. Bird total abundance, species richness and species diversity differed significantly with distance into the forest for all glade types, and decreased significantly with distance from the edge to the forest interior for man-made glades only. For upper natural glades, bird total abundance correlated positively with plant species richness and percentage basal cover for forbs. Most bird species strongly selected man-made glades over upper and lower natural glades, and strongly avoided upper natural glades. Habitat guilds in man-made glades were associated with foraging. Edge effects for all three glade types influenced bird total abundance and bird species composition, richness and diversity in the forest. In summary, forest glades and their edges have high conservation value for edge bird species. Therefore, clearing of the forest edges for man-made glades should continue in order to maintain these habitats for conservation purposes. Key words: Edge effects, forest birds, forest edge, forest glades, indicator species.