Avifaunal Responses to Landscape-Scale Habitat Fragmentation in the Littoral Forests of South-Eastern Madagascar

Abstract

Madagascar's lowland littoral forests are rich in endemic taxa and considered to be seriously threatened by deforestation and habitat fragmentation. In this study I examined how littoral forest bird communities have been affected by fragmentation at the landscape scale. Bird species composition within 30 littoral forest remnants of differing size and isolation was determined using point counts conducted in October - December in 2001 and 2002. Each remnant was characterised by measures of remnant area, remnant shape, and isolation. Step-wise regression, nestedness analysis, and binomial logistic regression modelling was used to test the relationship between bird species and landscape variables. Bird species richness in remnants was significantly (p < 0.01) explained by remnant area but not by any measure of isolation or landscape complexity. The bird communities in the littoral forests were significantly (p < 0.01) nested. The majority of forest-dependent species had significant (p < 0.01) relationships with remnant area. As deforestation and fragmentation are still significant issues in Madagascar, I recommend that large (> 200 ha) blocks of littoral forest are awarded protected status to preserve what remains of their unique bird community.