From page 10 of Birds of Southern Africa:
Southern Africa encompasses Namibia, Botswana, South Africa, Lesotho, Swaziland, and southern and central Mozambique, as well as oceanic waters within 200 nautical miles of the coast. In total it covers a land area of approximately 3.5 million square kilometers and has incredible diversity in its bird life. More birds breed in Southern Africa than in the United States and Canada combined. Currently, there are 951 known species, 144 of which are endemic or near-endemic. One of the reasons for this high bird diversity is the region’s climatic and topographical diversity. The climate ranges from cool-temperate in the southwest to hot and tropical in the north.
Birds of Southern Africa Fourth Edition
Ian Sinclair, Phil Hockey, Warwick Tarboton & Peter Ryan
Birds of Southern Africa continues to be the best and most authoritative guide to the bird species of this remarkable region. This fully revised edition covers all birds found in South Africa, Lesotho, Swaziland, Namibia, Botswana, Zimbabwe, and southern Mozambique. The 213 dazzling color plates depict more than 950 species and are accompanied by more than 950 color maps and detailed facing text.
This edition includes new identification information on behavior and habitat, updated taxonomy, additional artwork, improved raptor and wader plates with flight images for each species, up-to-date distribution maps reflecting resident and migrant species, and calendar bars indicating occurrence throughout the year and breeding months.