In species-rich ecosystems such as the tropical rainforests, understanding and identifying factors affecting the patterns of diversity and distribution of birds is a very important issue for conservation biologists. Rainforests hold a high proportion of Asia''s critically endangered bird species. Considering the extent to which lowland forests have been degraded or lost, isolated and fragmented forest patches may well represent the last refuge for regional biodiversity. Thus, to guide conservation initiatives for these ecosystems, secondary lowland rainforest understorey avian communities were studied to determine their responses along an edge-interior gradient with the aim of identifying the key factors influencing their composition, distribution, and diversity. In this study, the way in which understorey bird assemblages are dependent on the local environmental variables, along an edge-interior gradient, was determined. In addition, species-specific responses, composition and species richness were also evaluated. This study allows managers, planners and policy makers to better mitigate the effects of forest edge on the understorey avian community.