Bird Conservation International



Articles

Vulture restaurants and their role in reducing diclofenac exposure in Asian vultures


MARTIN GILBERT a1c1, RICHARD T. WATSON a1, SHAKEEL AHMED a1, MUHAMMAD ASIM a1 and JEFF A. JOHNSON a1a2
a1 The Peregrine Fund, 5668 West Flying Hawk Lane Boise, ID 83709, USA
a2 University of Michigan Museum of Zoology, 1109 Geddes Avenue, Ann Arbor, MI 48109, USA

Article author query
gilbert m   [PubMed][Google Scholar] 
watson rt   [PubMed][Google Scholar] 
ahmed s   [PubMed][Google Scholar] 
asim m   [PubMed][Google Scholar] 
johnson ja   [PubMed][Google Scholar] 

Abstract

The provision of supplementary food at vulture restaurants is a well-established tool in the conservation of vulture species. Among their many applications, vulture restaurants are used to provide a safe food source in areas where carcasses are commonly baited with poisons. Rapid and extensive declines of vultures in the Indian subcontinent have been attributed to the toxic effects of diclofenac, a pharmaceutical used in the treatment of livestock, to which vultures are exposed while feeding on the carcasses of treated animals. A vulture restaurant was established at the Oriental White-backed Vulture Gyps bengalensis colony at Toawala, in Punjab province Pakistan, to test the effectiveness of the technique in modifying ranging behaviour and mortality at the colony. Six male vultures were fitted with satellite transmitters to describe variation in movement and home-range during periods when safe food was alternately available and withheld at the vulture restaurant. There was considerable variation in individual home-range size (minimum convex polygons, MCP, of 1,824 km2 to 68,930 km2), with birds occupying smaller home-ranges centred closer to the restaurant being more successful in locating the reliable source of food. Fixes showed that 3 of the tagged vultures fed at the vulture restaurant and the home-range of each bird declined following their initial visit, with a 23–59% reduction in MCP. Mean daily mortality during provisioning was 0.072 birds per day (8 birds in 111 days), compared with 0.387 birds per day (41 birds in 106 days) during non-provisioning control periods. Vultures tended to occupy greater home-ranges, cover greater distances each day and spend proportionately more time in the air during the late brooding and post-breeding seasons. Attendance at the vulture restaurant also declined during this period with fewer birds visiting less often and no tagged vultures visiting the vulture restaurant at all. These findings indicate that vulture restaurants can reduce, but not eliminate, vulture mortality through diclofenac exposure and represent a valuable interim measure in slowing vulture population decline locally until diclofenac can be withdrawn from veterinary use.

(Published Online March 13 2007)
(Received June 7 2005)
(Accepted April 2 2006)


Correspondence:
c1 Author for correspondence. Current address: Wildlife Conservation Society, 2300 Southern Boulevard, Bronx, NY 10460, USA; e-mail: mgilbert@wcs.org