Species richness and seasonality of forest avifauna in three South African Afromontane forests

Abstract

Presence data were recorded and analysed for avian bird species in a study of three separate Afromontane Forests in the KwaZulu-Natal Midlands, South Africa. Levels of endemism for South Africa and forest-specificity were investigated. In total, 136 species were identified utilizing forest, yet not all species occurred in all three forests. Slight differences in species composition are attributable to latitudinal and altitudinal differences as well as differences in disturbance regime. However, the respective subsets of forest-specific, frugivorous or migrant birds were similar between forests. Almost all forest-specific species were found at all three study sites and the absence of particular species may be attributable to extinction or rarity. Subsets of endemic frugivores and endemic forest-specific species were also similar between forests. Relatively high levels, for South Africa, of forest-specificity (about 24%) and endemicity (about 17%) were recorded, showing little seasonal variation in species numbers whereas frugivorous and migrant species showed seasonality in their presence. The importance of these forests in conserving avifaunal biodiversity in the region is highlighted. Bird ringing was conducted at two forests to supplement observational data, and assisted in detecting rare and cryptic species. Recommendations are made for the conservation of the larger forest patches, within a naturally fragmented biome.