BREEDING BIOLOGY OF THE BEARDED VULTURE IN SOUTHERN AFRICA, PART III: THE POST-NESTLING DEPENDENCE PERIOD

Summary

Brown, C. J. 1990. Breeding biology of the Bearded Vulture in southern Africa, Part III: The post-nestling dependence period. Ostrich 6l: 43–49.

The post-nestling dependence period of the Bearded Vulture Gypaetus barbatus in southern Africa begins with the first flight of the young bird at 126 ± 2 days after latching (November-January) and ends during the pre-laying nod or the parent birds' next breeding attempt (April-June), a nod of about five months. For the first two weeks after first flit young bid remaine6 within about 200m of the nest, moving up to 800 m by the third week. By a month out of the nest young birds spent about 40% of the day in flight, moved up to 3 km from the nest, began bone-dropping and interacting with young birds from neighbouring nests. At six weeks they began to accompany their parents for part of some of their foraging trips, but returned to the nest alone, and by eight weeks they completed foraging forays with parents Pasting up to 3 h. At 2–3 months out of the nest young birds covered an area of about 42 km², excluding the foraging trips with parents, by 3–4 months, 78km² and 4–6 months, 168 km². Parent birds delivered food for at least five months after the young bird's first flight. Young birds left their natal areas of their own accord, usually during the first month of their parents' next breeding attempt.