The altitudinal and seasonal use of riverine forests by birds in the uluguru mountains, Tanzania

Seasonal and altitudinal distribution of birds was studied between May - 2005 to July 2006 at five altitudes (300, 600, 900, 1200 and 1500 m above sea level) along a riverine forest in Uluguru Mountains, Tanzania. The study aimed at examining the influence of seasons on bird abundant and diversity, and on the relative abundance of birds in different feeding guilds in the riverine vegetation, along the elevation gradient. Furthemiore, the study examined whether forest dependent species were using the riverine forest in both seasons.With the use of mist netting and ringing (a total of 73,440 metre-net hrs), 150 one- hour Timed Species Counts and general field observations, 128 species in 42 families and 11 Orders were identified in this study- of these 58.9% were forest dependent species which at each altitude sampled, were more numerous than non- forest species. Species richnns decreased with increasing elevation. Some bird species, particularly forest dependent ones, moved down to lower altitudes along the riverine forestt during the cold season and during the hot season they migrated to higher altitude forest. The seasonal and altitudinal movements were revealed by ringing recaptures at different altitudes. Due to the presence of seasonal migrants and threatened species during the cold season at low elevations, and the intra-African migrants in the Ulugurus, the study recommends the need for a strict protection and maintenance of the forest along the entire altitudinal gradient, not only in the Ulugurus but also elsewhere. It further stresses the importance of designing wildlife corridors between forest reserves to permit seasonal vertical altitudinal movements of wildlife as well as dispersal into areas of similar altitude.