The first Saturday of every September is observed as the ‘International Vulture Awareness Day’. The sharp decline in vulture population of South-Asia is often linked to Diclofenac, the non-steroidal anti-inflammatory drug used in animal treatment.
The studies found a near 99% drop in the population of ‘white-rumped’ vultures (Gyps Bengalensis), ‘Indian’ vultures (Gyps Indicus) and ‘slender-billed’ vultures (Gyps Tenuirostris) in the region since 1990 and are considered ‘critically endangered’.
The catastrophic decline was first noted in Keoladeo Natonal Park (formerly known as Bharatpur Bird sanctuary) and further studies led to the conclusion that the vultures fed on carcasses of cattle treated with ‘diclofenac’ suffered from poisoning, gout, hepatic & renal failure and finally death. While the decline was 97% among Indian and slender-billed vultures during 1990-2007 it was almost 99.99% among ‘white-rumped’ vultures. Studies revealed that even very low rates of diclofenac contamination—between 1:130 and 1:760—could cause the population crash.
Though the culprit was identified as ‘diclofenac’ as early as 2004 and the conservationists including Royal Society for the Protection of Birds (RSPB) worldwide demanded its ban, the Governments of India, Nepal and Pakistan banned it only in May 2006. ‘Meloxicam’ was suggested as an alternative to ‘diclofenac’ and was made available after the ban. It was considered to be safe to vultures. With the ban of ‘diclofenac’ from veterinary treatment and introduction of ‘meloxicam’ as a substitute, the rate of decline of vulture population was reportedly dropped by half. Since the drug, ‘meloxicam’ was comparatively more expensive and human pharma preparations containing ‘diclofenac’ are still available in the region, the threat still continues.
Is the decline in number of these birds alone the reason for conservation efforts? No. The sharp decline in the population of vultures had its own impacts in South Asia. Vultures provided a crucial ecosystem and were the natural scavengers in the region. With the decline in their population, animal carcasses often piled up posing a serious human health hazard. The carcasses left out in the open posed serious risks of contracting diseases to livestock too. And, in the absence of vultures, the number of feral dogs feeding on animal carcasses often doubled. Recent studies estimate an increase in the feral dog population by at least 5.5 million. An over 38.5 million additional dog bites and more than 47,300 extra deaths from rabies are reported in the region. According to media reports, the livelihoods of traditional tanners and craftsmen who worked with skin and bones of cattle picked clean by the vultures too were affected.
The interventions by the Government as banning of ‘diclofenac’ and the continued efforts and campaigning by conservationists, started yielding positive results. The vulture population in the region has slightly increased for the first time in two decades. The ‘Bombay Natural History Society’ reports a marginal increase in the population in 2011 and 2012. They also warn that though the stabilization figures are encouraging, the number of birds are very small and still vulnerable. The surveys indicated that there were only 1,000 slender-billed vultures (Gyps tenuirostris), 11,000 white-backed vultures (Gyps africanus) and 44,000 Long-billed vultures (Gyps indicus) remaining in the country.
And so, the conservation efforts should continue. Observing a day for ‘the critically endangered species’ will help creating awareness on the issue.