First evidence that populations of the critically endangered Long-billed Vulture Gyps indicus in Pakistan have increased following the ban of the toxic veterinary drug diclofenac in south Asia

Abstract

SummaryThe cliff-nesting Long-billed Vulture Gyps indicus is one of four critically endangered Asian Vultures. In India, this species has declined catastrophically, but in Pakistan only small population declines have been recorded. Mortality of this species has been linked to poisoning by veterinary diclofenac, which was banned throughout south Asia in 2006. Between 2003 and 2012 we measured abundance of adult, sub-adult, juvenile, and dead vultures, and nest occupancy and productivity at the largest known Long-billed Vulture colony in Pakistan. We compared population parameters from before (2003−2006) and after (2007−2012) the ban on veterinary diclofenac. Our data and models indicate that vulture abundance, nest occupancy, and nest productivity declined 61%, 73%, and 95%, respectively, in the three years before the diclofenac ban, and then increased 1–2 years after the ban by 55%, 52%, and 95%. Furthermore, we observed 87% of total vulture mortalities prior to the diclofenac ban. Our results demonstrate for the first time since the onset of the Asian vulture crisis that the ban on veterinary diclofenac is an effective management tool for reversing Long-billed Vulture population declines.