Population densities and community structure of birds in Acacia savanna in the lowveld of Swaziland

Abstract

The community structure and population density of birds was studied at four sites in Acacia savanna in the lowveld of Swaziland. Birds were surveyed monthly between June 1998 and May 1999 using a standard point-count technique. A total of 128 species of birds was recorded in Acacia savanna (of these, population estimates were calculated for 107 species). Species richness was similar at the four sites, as was total bird population density (when the highly mobile finches and canaries were excluded from calculations). Bird densities increased from winter to summer and then declined in autumn. These seasonal changes in density are expected, and are due to an influx of migrants and newly-fledged offspring in late spring and summer. In contrast to species richness and population density, species composition varied between the four areas. This finding suggests that Acacia savanna is not as homogenous as commonly thought. The conservation implications of this are discussed.