Bird Conservation International (2008) 18:S30-S48.
BirdLife International 2008
doi: 10.1017/S0959270908000324 Printed in the United Kingdom

The race to prevent the extinction of South
Asian vultures

DEBORAH J. PAIN, CHRISTOPHER G.R. BOWDEN, ANDREW A.
CUNNINGHAM, RICHARD CUTHBERT, DEVOJIT DAS, MARTIN GILBERT,
RAM D. JAKATI, YADVENDRADEV JHALA, ALEEM A. KHAN, VINNY
NAIDOO, J. LINDSAY OAKS, JEMIMA PARRY-JONES, VIBHU PRAKASH,
ASAD RAHMANI, SACHIN P. RANADE, HEM SAGAR BARAL, KALU RAM
SENACHA, S. SARAVANAN, NITA SHAH, GERRY SWAN, DEVENDRA
SWARUP, MARK A. TAGGART, RICHARD T. WATSON, MUNIR Z. VIRANI,
KERRI WOLTER and RHYS E. GREEN

Summary

Gyps vulture populations across the Indian subcontinent collapsed in the 1990s and continue to
decline. Repeated population surveys showed that the rate of decline was so rapid that elevated
mortality of adult birds must be a key demographic mechanism. Post mortem examination
showed that the majority of dead vultures had visceral gout, due to kidney damage. The
realisation that diclofenac, a non-steroidal anti-inflammatory drug potentially nephrotoxic to
birds, had become a widely used veterinary medicine led to the identification of diclofenac
poisoning as the cause of the decline. Surveys of diclofenac contamination of domestic ungulate
carcasses, combined with vulture population modelling, show that the level of contamination is
sufficient for it to be the sole cause of the decline. Testing on vultures of meloxicam, an
alternative NSAID for livestock treatment, showed that it did not harm them at concentrations
likely to be encountered by wild birds and would be a safe replacement for diclofenac. The
manufacture of diclofenac for veterinary use has been banned, but its sale has not. Consequently,
it may be some years before diclofenac is removed from the vultures' food supply. In the
meantime, captive populations of three vulture species have been established to provide sources
of birds for future reintroduction programmes.