African Coastal forests

The various features determining species distributions remains enigmatic in ecology. This thesis deals with the spatial and temporal dynamics of land birds on the islands of the Dahlak archipelago, the Red Sea, and of mammals, birds and reptiles among the forest fragments of the archipelago-like east African coastal forest. The bird species richness on the islands of the Dahlak archipelago depended on area, isolation and extent of habitat. Similarly, species richness of the east African forest fragments was related to area, habitat diversity and isolation but the importance of each factor varied among taxa as well as among generalists and specialists. For example, area influenced species richness of most categories except specialist mammals and reptiles, habitat diversity was more important for forest specialists than generalists, and isolation was important only for birds. In both study areas, similarity in bird species composition decreased with increasing distances among isolates suggesting that dispersal from source pools and among isolates facilitate re-colonization. The nested community structure, i.e. species composition of species−poor communities are a subset of species−rich communities, of birds in the Dahlak archipelago depended on are