Impact of drought on the breeding of a subtropical South African bird community

Abstract

Drought is a common phenomenon in Africa. Its consequences for avian communities have been extensively documented in arid and semi-arid regions of the continent. The impacts in higher-rainfall areas, though, remain poorly-elucidated. Bird community data were assembled at a high-rainfall locality in KwaZulu-Natal Province, South Africa. The study coincided with a two-year drought (1991/92 and 1992/93) when annual precipitation dropped 32–45% below the site’s long-term median (990 mm/annum). Impacts on breeding birds were severe but time-lagged. Breeding indices more than halved during 1992/93 to 1993/94. Low breeding indices continued into the 1994/95 and 1995/96 seasons, despite a normalization of annual rainfall. Breeding indices returned to pre-drought levels by 1996/97. The results demonstrate that drought is potentially important for avian population dynamics not only in arid and semi-arid parts of Africa, but in high-rainfall areas too.