BREEDING BIOLOGY OF THE BEARDED VULTURE IN SOUTHERN AFRICA,PART II: THE NESTLING PERIOD

Brown, C. J. 1990. Breeding biology of the Bearded Vulture in southern Africa, Part I: The nestling period. Ostrich 61: 24–32.

The nestling period of the Bearded Vulture Gypaetus barbatus in southern Africa was 124–128 days. The hatching interval between the normal two-egg. clutch was usually 3–6 days (range 2–9 days Only one nestling per clutch survived to the third day. Tittle sibling aggression and no infanticide took place, but the older nestling dominated the younger which obtained no food. For the first 40 days the nestling was closely brooded. The nest duties were evenly shared by both parents, but females brooded at night. Food was brought to the nest usually once or twice per day by both parents, and was stored behind the nest. During days 41–90 parental attendance steadily decreased. Dunng this stage the female spent more time in the nesting area (57%) and on the nest (91%) than the male. Towards the end of this stage the nestlin started to feed itself but preferred to be fed by a parent. From da 91 to first flight the nestling was left unattended and was visited by its parents only to provide food, which it fed from itself. All pars monitored (40 pair-years) attempted to breed every year. The breeding success (n = 18 pair-years) was 0,89 young fledged per pair per year.