The Bearded Vulture Gypaetus barbatus has experienced a substantial decrease in range in southern Africa during this century. The present population, numbering about 200 pairs, is confined mainly to the highlands of Lesotho and the Natal Drakensberg. In these areas the birds breed successfully (about 0,9 young/pair/year) and non-adult birds about 36% of the total population. constitute The food supply was found not to be responsible for the decline of Bearded Vultures on commercial farming areas in South Africa. The use of poisons by farmers for the control of mammalian predators is considered to be the most important factor leading to the extinction of Bearded Vultures and other scavenging species on farmlands. Adult Bearded Vultures forage over an area of about but were recorded up to 75 km from the nest. They feed exclusively on carrion, at least 75% of which is derived from domestic animals. Present conservation areas are not large enough to contain the entire ranges of any pairs of these birds or to supply sufficient food to support a viable population throughout the year. The birds therefore have to forage over commercial farmlands in South Africa and communal areas in Lesotho. This study, designed to be as broad-based as possible, covers in detail the following aspects of Bearded Vulture biology; age related characteristics, home range and movements, feeding ecology, breeding biology, behaviour away from the nest, energetics, distribution, status and population dynamics and their conservation. In conclusion, recommendations on the management and monitoring of the population are offered. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1988.