The field survey, conducted by a five-member team from Bombay Natural History Society recently in the Nilgiri Biosphere Reserve and adjacent areas, found that vulture population had been declining at a dangerous pace.
The survey covered Wayanad Wildlife Sanctuary in Kerala, Muthumalai Tiger Reserve and Sathyamangalam Wildlife Sanctuary in Tamil Nadu and Bandipur Tiger Reserve and Rajeev Gandhi National Park, Nagarholai, in Karnataka.
C Sasikumar, ornithologist and chief investigator of the survey, said that the total population of Oriental White-backed Vultures (Gyps bengalensis) in the region could be 100-150.
A 1992 survey had sighted up to 300 birds of the species in Muthumalai sanctuary alone.
The region was considered a good habitat of the white-backed vultures, red-headed vultures and Indian long-billed vultures (Gyps indicus).
As many as 22 red-headed vultures and one long-billed vulture had been recorded during survey in Muthumalai then while the recent survey revealed that population of these species had fallen further.
The number of red-headed vultures could be around 20 and Indian long-billed vulture was extremely rare in the entire region now, Sasikumar said.
The red-headed and white-backed vultures were so common in Kerala during 1930s, CK Vishnudas, member of the team said.
"We could not see a single bird of the species in most parts of the state, except in Wayanad Wildlife Sanctuary, during a bird survey organised by Kerala Forest and Wildlife department a few months back," he said.