The Sigur plateau in the Mudumalai Tiger Reserve (MTR) in the Nilgiris is one of the last remaining regions where a sizeable breeding vulture population is clinging on in Southern India. At least four species of India’s vultures are seen in the region, and at least three are believed to be using the plateau to breed and nest.
The region could potentially help critically endangered vulture species recolonise the surrounding landscapes from where they have become locally extinct over the last few decades because of the use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) to treat cattle. Due to the use of drugs like diclofenac since the early 1990s, vulture populations across India have plummeted as they died after feeding on the carcasses of cattle treated with the drugs. Four of India’s nine vulture species have been listed as “critically endangered” by the International Union for the Conservation of Nature (IUCN). Three of the four species seen regularly in the Sigur are on the “critically endangered” list, while the other, the Egyptian vulture, is classified as being “endangered”.
H. Byju, a researcher who has studied vultures in the Sigur plateau and the Moyar Valley, says the future of vultures remains precarious in the Sigur. “For a population of vultures to be considered stable requires at least 800 pairs, while Sigur, which has the largest population of vultures in southern India, hardly has 300 individuals,” said the author of Valley of Hope–Vultures and Moyar.
According to S. Manigandan, a research scholar with Arulagam, a conservation NGO working on protecting vultures in the landscape, the latest surveys in the MTR buffer zone indicate that there are between 110 and 120 white-rumped vultures (Gyps bengalensis), 11 and 15 Indian or long-billed vultures (Gyps indicus) and maybe up to 5 Asian king vultures (Sarcogyps calvus) in Sigur.
Mr. Manigandan says that during the most recent breeding season, only 14 nests of the white-rumped vulture have seen successful hatching of vulture chicks, while three nests of the long-billed vulture are also believed to have hatchlings. Despite the best efforts of researchers for more than a decade, the nesting site of the Asian king vulture, among the rarest of the vultures in India, remains yet to be recorded in the Sigur.
Meanwhile, the Egyptian vulture (Neophron percnopterus), once widely seen in the Nilgiris, is not believed to have any nesting sites in the region, but is still occasionally spotted.
“Though the vulture population is comparatively much higher than in other parts of southern India, it is still very small. The breeding population is even smaller and the success rate for breeding pairs remains at only 70%,” says Mr. Byju. This highlights one of the reasons the population is yet to see any sizeable increase despite strict protections being enforced in the MTR and the surrounding areas against the use of NSAIDs.
For Chris Bowden, Globally Threatened Species Officer and Programme Manager for Saving Asia’s Vultures from Extinction (SAVE), it is of paramount importance to secure regular monitoring of vultures. “Only when this is done will we have a handle on the population trends in the region,” he says. He is “fairly confident” that the population in the Sigur was probably stable. Mr. Bowden, who is also the co-chair of the IUCN vulture specialist group, reiterates the need to ensure NSAIDs, such as diclofenac, nimesulide, ketoprofen and others, are not used to treat cattle in the region to ensure continued protection of the vultures.
“Tamil Nadu is also taking much needed steps, setting examples both nationally and internationally, by prosecuting manufacturers, distributors and suppliers of NSAIDs for treatment of cattle,” he says, referring to the recent announcement by Tamil Nadu’s Director of Drugs Control that his office has initiated 104 prosecutions across the State for the sale of diclofenac for veterinary use in the last two years.
Conservationists and researchers have also outlined steps that can be taken to help vulture populations. “For a start, cattle that die of natural causes and are certified by a veterinarian to be free from poison and NSAIDs can be left out in the open for vultures to scavenge on,” says M. Bharathidasan of Arulagam.
“Invasive species such as Lantana camara and Eupatorium have taken over large parts of the vultures’ habitat, limiting their ability to scavenge for food. One way to help the vultures could be to undertake large-scale removal of invasive species, opening up more grassland where they could scavenge carcasses of both wild animals as well as cattle,” says Mr. Byju.
Deputy Director of MTR (Buffer Zone) P. Arunkumar says the Sigur plateau is home to the largest nesting colony of vultures south of the Vindhya Mountain Range. “This makes conservation of this population extremely important. We have sensitised our field staff to the need for monitoring the vultures, their breeding cycles and the success of their nesting seasons. By doing this, we are also able to ensure that the threats they face are minimised, and our efforts are aimed at creating conditions for the vulture population to increase in the coming years and recolonise the surrounding areas,” he says.