Trends in waterbird diversity at Banzi, Shokwe and Nyamithi pans, Ndumo Game Reserve, South Africa

Abstract

Our understanding of the timeous changes to pan-associated bird diversity is very important for the conservation of these wetlands. At Ndumo Game Reserve, a Ramsar site located in northern KwaZulu-Natal, seasonal (from March 2005 to January 2006 at Nyamithi Pan) and long-term (1993 to 2008 at Banzi, Shokwe and Nyamithi pans) changes in the composition of waterbird assemblages were investigated. The numbers of waterbirds were determined and their relationship to water level and diet investigated for winter and summer. Banzi Pan was dominated by piscivorous species that used shallow water and the waterbird assemblage of this pan was stable in the long term. At Shokwe Pan, species richness and the overall abundance of waterbirds showed a long-term increase in winter. At this pan, decreasing water levels may have benefited insect-eating, shoreline users, resulting in an increased waterbird population. At Nyamithi Pan, over the short-term, in shallower water the insectivorous shoreline and mudflat users dominated, and in deeper water the larger piscivorous species. Over the long-term, in both summer and winter, variability of bird abundance decreased, although numbers still showed considerable fluctuation. The species composition of waterbirds is different at each of the pans and all are valuable for waterbird conservation.