Tigers moving to higher altitude in Bhutan

May 2008.  Evidence from Bhutan shows that tigers have expanded their range to higher altitudes than ever before, and their territories now overlap with Snow leopards. Pictures and pugmarks from the Jigme Dorji National Park show that royal Bengal tigers in Bhutan are being found at altitudes never seen before.

"We've realized that Bhutan is now officially the only country in the world to have tigers at such high altitudes and also the only country where the habitat of the snow leopard and the tiger are overlapping," said Tiger Sangay of the Nature Conservation Division. Sources say that pugmarks and pictures have been spotted at between 3,700 to 4,300 metres in the latest study.

Infrared cameras

The study, which started in April 2008, is using 38 strategically placed GPS-marked and infrared-trigger cameras to find out the total number of tigers in the country. At the moment, the study is focused in Jigme Dorji National Park and will move to other parks. According to Tiger Sangay, each tiger has a unique stripe.

The study hopes to get a photographic record and a clear idea of the total number of snow leopards in the country. The previous estimate was around 100 animals and there is now confirmed data that can support this guesstimate. These cats have been found at heights of up to 5,500 metres, migrating down to 2,000 metres in winter.

Implications

The implications and reasons for tigers being found at such high altitudes will hopefully emerge from the study. "We may also get data on how the overlapping of territory of these two big cats may be affecting each other, if at all," said Sangay.

"Global warming with warmer temperatures in the higher reaches is a logical but as yet unconfirmed explanation," said animal specialist Dr. Sangay Wangchuk of the Nature Conservation Division.

Another possible explanation could also be habitat pressure on tigers forcing them to extend their hunting area upwards with growing habitat disruption at the lower reaches. The data may be an indication of the good health of Bhutan's forests because they allow the tiger to reach high places due to continuous forest cover in a diverse landscape.

Subspecies?

Another possible explanation could be that Bhutan's tigers have always roamed at high altitudes, but, until now, have not been recorded there.

"We're also hoping to see if tigers at these altitudes have developed any extra features by which we can classify them as being different from their cousins in the plains," said Sangay. "We're looking for features like if they're bigger than the plains version or if they have more fur to deal with the cold."