GUWAHATI: A three-year camera trap study has reported the presence of tigers in the snow-clad Dibang Valley of Arunachal Pradesh at the height of 3,630 metres. It might be the highest spot at which the big cats have been sighted, but Aisho Sharma Adhikarimayum — a Wildlife Institute of India (WII) scientist — believes that they may be present in even higher reaches of the mountains.Adhikarimayum of the WII's department of endangered species management said there was a possibility that the predators were present beyond 3,630 metres in the valley, like in Bhutan, where a tiger was photographed at 4,200 metres in 2012. He was backed by conservationist Anwaruddin Choudhury, the author of several reports on the wildlife of Dibang Valley. Choudhury told TOI there was a distinct chance of tigers being present in the landscape up to a height of 4,000 metres.Tiger sightings above 4,000 metres have also been reported in Uttarakhand but no conclusive evidence to back the claim has been found so far. If, according to Adhikarimayum and Chowdhury, tigers do exist above 3,630 metres in the Indian part of the Eastern Himalayas, it would significantly add to conservationists' knowledge about the species.The camera trap exercise of which Adhikarimayum was a part, along with WII scientist GV Gopi, was carried out in 2015-17 across 336 square kilometre of the total 4,149 square kilometre area of the Dibang Wildlife Sanctuary (DWS).The study, which was published in the Journal of Threatened Taxa on November 26, not only gave photographic evidence of tigers at 3,630 metres, it also found 11 individual tigers, including two cubs, in the DWS. As per the study, "A total of 108 camera traps were deployed in 336 square kilometre area, with 13,761 trap nights inside and outside the protected area."