Scientists marvel at tiger sightings in higher reachesUpdated: Jan 11, 2019 07:48 IST
Researchers found a promising tiger population between 2015 and 2017 in the upper reaches of the Dibang Valley in Arunachal Pradesh, the highest range in the Indian part of the eastern Himalayas at almost 12,000 feet, surprising wildlife biologists and researchers.
And on January 6, a Bengal tiger was spotted on a camera trap set by the forest department in the Pangolakha Wildlife Sanctuary, East Sikkim at an altitude of 9,500 feet, the first ever tiger sighting in the state. A snow leopard was also captured on camera near the same spot on January 2.
Wildlife biologists and the National Tiger Conservation Authority (NTCA) are pleasantly surprised by these sightings in high altitude areas, far away from the known tiger range in India, but it’s too early to say what could be causing the beasts to trek up to these areas. One theory is that tigers may have always migrated to high-altitude regions in the Himalayas, but are only now being documented through the installation of camera traps.
“Tigers do cover long distances. The first tiger sighting at a very high altitude happened in Bhutan almost a decade ago. Then there was another sighting in Nepal. We cannot say that they are being seen in Arunachal Pradesh and Sikkim because their range has expanded or that they are being driven out of their habitat. It could be just that camera traps are there so they are being photographed now,” said tiger expert and wildlife biologist Ullas Karanth.
“Private institutions and government bodies are setting up camera traps so monitoring has improved. Of course, it’s interesting that they are seen moving so high up. But we have known that they move through mountain passes and even breed at about 7,000 to 8,000 feet in the Nilgiris and other parts of the Western Ghats. There is case of a tiger walking 300 km. So moving large distances is not surprising.” Karanth added.
Dipankar Ghose, director, species and landscapes programme, WWF-India, also cautioned against making any inferences based on these two cases in Arunachal Pradesh and Sikkim. “There is historical data to show there were tigers in Sikkim. In fact there is a rock carving very close to the Pangolakha Sanctuary by a labourer who spotted a tiger in the early 90s. Tigers were in Neora Valley also in Kalimpong. They may be looking for new territory but it’s too early to say why.”
Ghose recommends protection of the area from intrusions by external elements like tourists and matching the photograph of the tiger captured in Sikkim with the tiger database at NTCA.
NTCA has started documenting tiger landscapes outside known tiger areas and wildlife sanctuaries. “We have started monitoring tigers at a landscape level which includes high-altitude areas. We will document and study the case in Sikkim,” said Amit Mallick, inspector general of NTCA.
According to Sanjay Gubbi, wildlife biologist and author of Second Nature: Saving Tiger Landscapes in the Twenty-First Century, it’s always heartening to find new records of wildlife species, including the tiger, in locations where they had not been documented by visual evidence.
“From the camera trap picture the individual looks like a large adult male, hence it may not be a transient animal but possibly a resident with its home range that includes Pangolakha Wildlife Sanctuary,” he added. “Since it’s also close to the Bhutanese border this individual tiger may have its territory across the two countries. This depicts the importance of cross-border cooperation for conservation.”
“Finding tigers in cold regions is not surprising as they are habitat generalists and live in subzero temperatures in the Russian Far East to the hot tropical forests of Rajasthan.”
Tigers in India were known to be limited to the tropical deciduous forests. In forests with high prey density, the range of an adult male tiger is usually 20 to 25 sq km but in the Russian far-east an adult male can have a range of as much as 500 sq km. Experts said the larger ranges in high-altitude areas makes documentation difficult.
In Uttarakhand, researchers have earlier documented a tiger at 12,500 ft. The spatio-temporal overlap of tigers and snow leopards is interesting and possibly recorded for the first time in India, Gubbi said.
The last National Tiger Census in 2014 had estimated that India had about 2,226 tigers; another census started in 2018 and the results are likely to be published this year. Compared to 9, 700 cameras used in the 2014 Census, the 2018 estimation will use nearly 15, 000.
First Published: Jan 11, 2019 07:48 IST