PLUMAGES AND MEASUREMENTS OF THE BEARDED VULTURE IN SOUTHERN AFRICA

Abstract

Summary Brown, C. J. 1989. Plumages and measurements of the Bearded Vulture in southern Africa. Ostrich 60: 165–171. Four different age classes of the southern African Bearded Vulture Gypaetus barbatus are recognized and their plumages described: juvenile (3–24 months old), immature (24–45 months), subadult (45–60 months) and adult (60+ months). There was no significant difference in size between adult male and female birds. Adults were larger than juvenile birds in bill width, beard length, wingspan and mass, and had a higher aspect ratio and wing loading, while juvenile birds were larger than adults in the length of their outer rectrices, tail area, wing breadth and wing area. These features are considered to be adaptive to young birds inexperienced in flying. Immature and subadult birds were intermediate in size between juveniles and adults. Bearded Vultures differ from other large raptors in two sets of physical characteristics, (a) those adapted to cold, mountainous habitat, e.g. feathered head and f...