- As many as 36 vultures in Assam reportedly fell prey to secondary poisoning after consuming a goat carcass laced with pesticides.
- Officials say the incident could be linked to illegal bait-poisoning and vultures were not the key target. Goats were poisoned with pesticide to bait livestock-depleting feral dogs.
- The dead vultures represent three different species: Himalayan griffon (Gyps himalayensis), Oriental white-backed (Gyps bengalensis) and slender-billed (Gyps tenuirostris) vulture. The last two are critically endangered.
- Exposure to diclofenac, a veterinary drug present in the livestock carcasses that they scavenge is implicated as the major cause of rapid decline of vulture population during the mid-1990s all over their ranges in the Indian subcontinent.
Thirty-six vultures, including those belonging to two critically endangered species, were killed in an alleged illegal bait-poisoning incident in Assam.
Thirty-six of the scavengers succumbed after consuming poison-laced goat carrion in the state’s Sivasagar district, while seven others were placed in veterinary care and are being attended to, by doctors of Bombay Natural History Society (BNHS) and the state veterinary hospital.
Vulture carcasses at Sivasagar. Video by Dilip Kumar Deka, Range Officer, Sivasagar and Bombay Natural History Society.
“This could be an incident of retaliatory killing or secondary killing where the vultures were not the key target. Villagers had poisoned a goat to bait dogs that were killing off the goats. Thirty-six vultures are dead. Seven were rescued and placed under treatment. Forensic analysis is being conducted. Our investigation into the matter is on so we can catch the culprits,” Bidya Bordoloi, divisional forest officer of Sivasagar division, told Mongabay-India.
Raunak Ghosh, a research biologist with BNHS that runs the vulture-breeding centre in Rani, near Guwahati, in collaboration with the Assam forest department, said four of the seven surviving vultures were released post-treatment.
“Drugs for pesticide poisoning such as atropine sulphate and dexamethasone were administered intravenously, after flushing out the crop content. The ones that died were not residents of our breeding centre,” Ghosh said.
Assam hosts six endangered vulture species. The dead vultures belonged to three different species: Himalayan griffon (Gyps himalayensis), Oriental white-backed (Gyps bengalensis) and slender-billed (Gyps tenuirostris) vulture. The majestic birds lay dead within half an hour of feasting off the goat carcass, officials informed.
“Of the dead, as many as 29 were Himalayan griffon vultures, four slender-billed and three white-backed. We managed to rescue three Himalayan griffons, one white-backed vulture and three slender-billed birds. The last two are critically endangered species,” elaborated Ghosh. The Himalayan griffons were sub-adults and the rest had attained adulthood, he said.
Echoing Bordoloi, Ghosh said, villagers often resort to poisoning goats to bait leopards, wolves and feral dogs that prey on their cattle and vultures face the brunt. Despite awareness generation drives such events recur, they said.
“Retaliatory killings via bait-poison are a very big problem for vultures. In the last five years, there have been over ten poisoning-related vulture death incidences in Sivasagar. The poisons used to kill the goats are organophosphates and carbamate pesticides,” Ghosh said.
Diclofenac remains the biggest threat
Linking the crash in vulture population to the marked increase in feral dogs, Vibhu Prakash, principal scientist of BNHS, contends NSAIDs (Nonsteroidal Anti-inflammatory Drugs) such as diclofenac are a “much bigger threat” than secondary poisoning.
“These incidents are like road accidents. They happen and they are bad, no doubt. They should be stopped. Education (for awareness) is very important but it’s a slow process. I would be very worried if the culprit was diclofenac.”
Exposure to diclofenac, a veterinary drug present in the livestock carcasses that they scavenge is implicated as the major cause of rapid decline of vulture population during the mid-1990s all over their ranges in the Indian subcontinent.
Prakash said populations of three resident vulture species (Indian white-backed vulture, long-billed, and slender-billed vulture) in India have decreased by more than 90 percent since mid-1990s, and they continue to decline. They are on the verge of extinction.
[Also read Declining vulture population can cause a health crisis].
“The white-backed vulture population is stabilising but I would not be complacent,” cautions Prakash. Studies have indicated that “diclofenac can continue to kill vultures” even after its ban in India for veterinary use.
Noted ornithologist Bikram Grewal termed the developments as “depressing.”
“There are many more such incidents that go unreported. The whole episode should be thoroughly investigated by stakeholders,” Grewal told Mongabay-India.