Thirty endangered vultures nursed back to health after poisoning due to feeding on pesticide-laced cattle carcass were released in the wild near eastern Assam’s Sivasagar town on April 9.

These vultures had undergone treatment at the Centre for Wildlife Rehabilitation and Conservation (CWRC) at Kaziranga, about 200 km east of Guwahati.

“These vultures were among 34 brought to our centre on the night of March 29 from a village near Demow where they had been poisoned. Three died during treatment, while one is still in a critical condition,” Rathin Barman, joint director of Wildlife Trust of India and head of CWRC, said.

Demow, in Sivasagar district, is about 180 km east of where CWRC is located.

The release of the vultures belonging to three species — Himalayan griffon, white-backed, and slender-billed — has enthused wildlife activists who have been facing hurdles in efforts to conserve the big scavenging birds crucial for maintaining the ecological balance.

A study by Bombay Natural History Society and other organisations in the 1990s found that the population of vultures found in India and Nepal declined by 99.9% from about 40 million in two decades.

“We carry out awareness campaigns on the importance of the vulture, a much-derided bird. But poisoning of the birds keep happening from time to time,” Sachin Ranade of the Vulture Conservation Breeding Centre at Rani near Guwahati said.

The 30 vultures revived at CWRC were among some 70 that were poisoned at Bam Rajabari village in Sivasagar district on March 29. These birds had fed on a cattle carcass that was apparently poisoned to kill feral dogs.

Mr. Ranade said 37 vultures died that day before members of a wildlife rescue team could reach them. Bam Rajabari is about 15 km from Udaipur village where 20 vultures died similarly in April last year.