Population of three Gyps vultures in South Asia decreased by about 95% in 1990s. A major contributing factor in declining populations of vultures is believed to be the widespread use of drugs such as Diclofenac, once commonly-used as a livestock anti-inflammatory drug. Use of Diclofenac is now banned in India. During the last 3 years, vulture’s death cases are increasing not only in Rajasthan but also in other parts of the India. The IUCN Red Data Book has listed this bird as ‘critically endangered’.
In May 2009, 21 vultures have died after consuming poisoned carcasses in the northeast Indian state of Assam. In winter 2011 death of 80 vultures including Himalayan griffon, Eurasian griffon, Cinareous vulture and Egyptian vulture and also 17 steppe eagle was reported. The mortality was due to poisoning and happened at the Jorbeer dead animal dumping site.
In winter 2012, totally 56 vultures, including 3 species i.e. Eurasian griffon, Cinareous vulture and Egyptian vulture and 10 steppe eagle were found dead at Jorbeer dumping site. Additionally, 6 Eurasian griffon were found dead in May 2013 due to dehydration and wing injury. Jorbeer has been declared as conserved forest area, but dead animal dumping site is not part of the protected area.
The dramatic vulture decline observed across India presents a range of ecological threats, by influencing the numbers and distribution of other scavenging species. Increased feral dog populations have been reported all over in India posing many associated disease risks such as rabies to humans and wildlife. India already accounts for a very high incidence of rabies cases, and an absolute shortage of quality anti rabies vaccine in rural areas can aggravate the problem even further. Similarly increased crow populations at carcass site in vicinity of settlement areas pose a risk of infections to poultry, domesticated birds, avian & humans. Prevalence and concentration of diclofenac residues in ungulate carcasses is important for India’s threatened vulture populations. Only existence of small proportion (< 0.8%) of ungulate carcasses containing lethal levels of diclofenac is sufficient to cause the observed rapid decline of vultures population.
Further research is needed on ban of human usage of Diclofenac, to increase the efficiency of conservative activities for migratory vulture’s species.