Avian Use of Habitat Patches Dominated by Exotic Leucaena leucocephala or Native Tree Species in Urban Dar es Salaam, Tanzania

Abstract

There has been an incursion of an exotic Leucaena leucocephala in disturbed areas and into habitat patches of native tree species in some areas in Tanzania. However, the impacts of this exotic tree on native biodiversity are not well understood. We assessed bird use of habitat patches dominated by L. leucocephala in comparison to patches of native tree species  at the University of Dar es Salaam main campus, Tanzania, by comparing bird species richness, abundance and diversity using mist netting. Based on the same mist netting efforts in each habitat patch type, patches of native trees had significantly higher overall diversity (t = 1.999, df = 293.64, p < 0.05) and abundance (χ² = 40.525, df = 1, p < 0.001) of birds than those dominated by the exotic L. leucocephala and significantly greater abundance of forest-dependent species (χ² = 10.938, df = 1, p < 0.001) and forest visitors (χ² = 15.258, df = 1, p < 0.001). The similarity in bird species between the two habitats was 0.658 indicating that many bird species occurred in both habitat types. The lower diversity and overall abundance of  birds in the patches dominated by the exotic plant suggest that it does not provide appropriate habitat for many bird species, and further spread of this exotic will be detrimental to the local avifauna.

Keywords: Birds, diversity, native tree species, exotic tree species, Leucaena leucocephala