Are Afrotropical Protected Areas Effective in Increasing Waterbird Richness and Diversity? A Case Study from South Sudan (East Africa)

Abstract

In many tropical areas of high conservation concern there is still no evidence on the effectiveness of protected areas in protecting specific components of biodiversity. Here, to assess the management effectiveness of protected areas, we carried out a field sampling design for collecting data on waterbird communities within the Nibule National Park (South Sudan), a poorly-known hot-spot of biodiversity, and in the surrounding buffer zone. All the metrics of richness (absolute species richness, Margalef index, Chao-1) and diversity were significantly higher for bird communities inhabiting the national park, when compared to the buffer zone. Evenness was predictably lower in the national park when compared to the buffer zone, probably due to the large numbers of rare species that were observed in the park’s richer communities, thus increasing the differences in relative frequencies between species. The diversity profiles highlighted this pattern, with more sloping curves in the park sites, evidencing a role of protected area management in positively affecting the bird community structure. Our data provide the first evidence for a poorly-known area of high conservation concern on the effective role played by a National Park in maintaining high values of richness and diversity, at least for wetland-related birds.