BEARDED VULTURE POPULATION AND HABITAT VIABILITY ...

Population and Habitat Viability Assessment: Bearded Vulture (Gypaetus barbatus)
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Sub-adult: (45-60 months). Like 2 nd immature, but head paler, clearly separated from more
rufous chest and belly by dark chestnut neck ring. Eye-ring is deep red, not opaque, as in
adult.
Immature: (24-45 months) Eyes change to clear yellow by 36 months, though still darker than
adults, eye-ring deep red and slightly opaque though becoming less so with age. Beard 37
mm at 36 months (n=1). Transition to complete adult plumage takes 6 years with pale feathers
first appearing on the upper wing coverts and under-body and only later on the head so
highlighting the black facial mask. After the first moult flight feathers are rounded and greyer.
Juvenile: (3-24 months, n=2), Very dark brown all over, feathered mane is blackish. Beard
short, ca 10 mm. Eyes slightly opaque pale yellow-brown, eye-ring changes from opaque
brown-red at 8 months to opaque dull red. Rectrices and remiges are plain dark brown, paler
along shafts and tipped buff. In flight the tail is more wedge-shaped and longer than that of
adults, the wings are more pointed. Upper wing coverts and contour feathers are not as
conspicuously streaked as in adults, making upper wing appear dappled.
Confusing species: Large size, long pointed wings and long wedge-shaped tail are
distinctive. On the ground, the long folded wings give a hunched appearance and it stands
with body almost horizontal and gives the impression of being elongated with short legs, unlike
the larger Cape Griffon Vulture (Gyps coprotheres), the only other sympatric vulture in
southern Africa, which holds its body almost upright. All age classes are darker than the Cape
Griffon Vulture and its neck is much shorter. In the air, the Bearded Vulture has longer and
more pointed wings and tail (Brown 1989; Mundy, Butchart, Ledger and Piper 1992: 202ff).
Confusion between Bearded Vultures and other species should be unlikely in southern Africa
(Brown 1997a).
Individual recognition: Based on a small sample size in a three week study of birds visiting
the hide at Giant’s Castle (Magdel Combrink, in litt.) it was possible to identify nine different
adult Bearded Vultures flying past, based on their under-wing patterns (i.e. ‘armpits’).
Other: The rufous or orange stain on the feathers of the underbelly is from an accumulation of
iron oxide on the feather barbs, acquired from a passive and incidental contact (C.J. Brown in
Mundy et al. 1992: 206) though, in captivity, they may actively seek out dust-bathing in iron
oxide rich soils (see photograph and caption in Frey, Schaden and Bijleveld van Lexmond
2000: inside back cover.
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