Capture and fitting of satellite- and radio-telemetry equipment onto Cape Griffon
Vulture Gyps coprotheres, African White-backed Vulture Gyps africanus vultures and
Lappet-faced Vulture Torgos tracheliotos in the Waterberg area, Namibia in 2004
*Maria Diekmann, Ann Scott, Mike Scott & Jörg Diekmann
Summary
The breeding population of Cape Griffon Vultures Gyps coprotheres (CGVs) on the cliffs of
the Waterberg Plateau has declined from an estimated 500 in 1939 to only eleven birds in
2004, and the species is now considered critically endangered in Namibia. In 2002, the Rare
and Endangered Species Trust (REST) initiated a supplementary feeding scheme on the farm
Uitsig, as part of a project to obtain and fit satellite-telemetry equipment onto some of the
remaining birds. Three capture operations were performed, in January, March and April 2004,
using a capture and release aviary designed by REST, and captive CGVs as decoy birds to
lure the wild birds. Each capture had 1-3 processing teams. REST is now the first
organization in the world to fit satellite “collars” or PTT harnesses onto CGVs. Radio-telemetry
devices have been fitted to a further five African White-backed Vultures Gyps africanus
(AWBVs) in the area. REST is also the first in the world to develop a capture aviary and
mechanism of this nature and the first in Africa to catch and process such a large number of
free-flying old-world vultures in one operation for extensive sampling. During the three
operations, a total of 291 birds were captured. These include two of the last remaining CGVs
from the Waterberg colony (one of which was recaptured during the third operation).
Altogether 259 of the captured birds were ringed. All vultures handled were documented
photographically, while a full set of mensural and other data was taken for 36 birds, and sex
estimations done for 164 birds. No losses were sustained, and marked birds returned to the
restaurant and into the capture aviary almost immediately after the captures. The success of
the operation is ascribed to painstaking organization and preparation, good team work, the
gradual habituation of the wild birds to the capture aviary, the practical design of the capture
mechanism and subsequent refinements, and the thorough testing of the harness devices on
captive birds.