AN ECOLOGICAL PERSPECTIVE OF LARK (ALAUDIDAE) DISTRIBUTION AND DIVERSITY IN THE SOUTHWEST-ARID ZONE OF AFRICA

Summary

Dean, W. R. J. & Hockey, P. A. R. 1989. An ecological perspective of lark (Alaudidae) distribution and diversity in the southwest-arid zone of Africa. Ostrich 60:27-34.

The southwest-arid zone of Africa comprises the Succulent, Karoo, Nama Karoo and Desert. The region Has a wide diversity of climate, land form, soils and vegetation. Most of the southwest-arid zone receives less than 250 mm mean annual rainfall. The larks are well presented in the southwest-arid zone and 19 species occur in this region. On the basis of movement patterns, the arid-zone larksMaybe divided into resident (n = 9) and nomadic (n = 8) species. The residents are characterized by their larger body size, mainly insectivorous diets and limited movements: these species occur in pairs or small groups, Mayhold territories throughout the year and are characteristic of the southern and southwestern Karoo. The nomads are smaller, predominantly granivorous, and occur frequently in very large groups which make extensive movements. These species are characteristic of the northern and northwestern Karoo. The larksMayalso be differentiated on the basis of colour match with soil type, with “grey” species predominating in the southern Karoo, and “red” species in the Nama Karoo and on Kalahari Sands.