Conservation status of birds in Botswana in relation to land use

Differences in reporting rates of birds on atlas checklists from major land-use categories (protected, unprotected, wildlife management area (WMA)) in Botswana were investigated to evaluate the conservation status of 12 ecological assemblages of birds. Large grassland birds and birds of prey were more frequently reported from protected than unprotected land or WMAs. Birds of canopy woodland, and the larger, resident insectivores were particularly frequently reported in WMAs and least frequent on unprotected land. Except for some intensely hunted species, waterbirds were indifferent to land use. The most dramatic difference between land use categories was for thornveld birds, which were much more frequent on unprotected land. Migrants also preferred unprotected land. Most differences between land uses can be ascribed to the widespread effects of intensive grazing by livestock, which results in a reduction of the herbaceous stratum and ultimately in bush encroachment. About half of the species typical of the Kalahari basin are thornveld species, and this group, which includes 18 regional endemics, benefits from this change. No regional endemic bird species typical for the Kalahari basin seems yet to have a critically poor conservation status in Botswana, but some species of open grasslands and the more intensely hunted species require monitoring. The shortclawed lark, a near-threatened restricted-range species, occurs only in unprotected areas. Only one of the globally threatened Cape vulture's breeding colonies in Botswana is within a (small) formally protected area. (C) 1998 Elsevier Science Ltd. All rights reserved.