Wildlife experts believe there could be more tigers living in hill areasAfter tiger sightings in Dadeldhura and Ilam, wildlife experts say there could be more tigers living in or migrating to the hill areas due to improved green cover and prey abundance.
Last year, two Royal Bengal Tigers were spotted strolling in the mid-hill region of the country. Wildlife conservationists were left questioning what was encouraging tigers to move upwards.
They suspect there could be more tigers dwelling in the country's hilly region, which has not been a typical tiger habitat at least in the last several decades.
During a virtual discussion organised by Environmental Graduates in Himalaya and Resources Himalaya Foundation on Monday, conservationists discussed the possibility of tigers living in the hill region of the country.
“Tiger sightings in Dadeldhura in the west and Ilam in the east have shown that tigers can be found at such altitudes of the country as well,” said Jhamak Bahadur Karki, associate professor with Kathmandu Forestry College. “Not only Ilam, if we deploy camera traps focusing to study the presence of tigers along the north-south corridor, tigers may be found anywhere at that elevation. I am not asserting that tigers will be found, but there can be tigers at that elevation if we look at its possibility.”
Last year in April, a tiger was captured on a camera trap at an altitude of 2,500 metres in a Dadeldhura forest—the highest ever recorded sighting of the big cat in the country. In December, another tiger was photographed in the eastern part of the country. The spotting of the tiger at an elevation of 3,165 metres beat the previous record of the tiger sighting in western Nepal.
The government authorities had confirmed that never before had a tiger been spotted and captured on camera at such an altitude in the country’s documented history.
Wildlife experts had attributed improved green cover in the country's mid-hill region, providing north-south connectivity, less disturbance in upper regions compared to the low-lying Tarai districts where they are facing habitat loss and decline in prey as possible factors behind tigers migrating upwards lately.
According to Karki, who is also a wildlife biologist specialising in tiger conservation, a tiger can dwell in the area which has 20 percent forest cover, with corridor connectivity and adequate prey.
Rising numbers of tiger population, which is also prompting tigers to stray outside their habitats, will cause tigers to move further up in the future, according to wildlife experts.
“When tiger population sees an increase, sub-adult tigers will have only two options—either fight with another competitor to claim their territory or make a journey upwards, which depends on forest connectivity,” Karki said at the virtual event.
The latest tiger census, in 2018, detected signs of tiger presence in 12 districts—Bara, Parsa, Makwanpur, Chitwan, Nawalparasi, Dang, Salyan, Banke, Bardiya, Surkhet, Kailali and Kanchanpur—of the 18 districts surveyed across all potential tiger habitats in the Tarai Arc Landscape (TAL).
Before tigers were captured on camera in Dadeldhura and Ilam last year, there were several anecdotal reports of tiger sightings in the hill region. Royal Bengal tigers have been spotted at even higher altitudes in India and Bhutan. In India, the big cat has been sighted at an altitude of 3,630 metres and in Bhutan at above 4,000 metres.
A study by Global Tiger Forum (GTF) in 2019 said that high altitude regions in India, Nepal and Bhutan have the potential to become suitable habitats for the tiger. The GTF study identified a potential tiger habitat of 52,671 square kilometres in the high altitude area across India (38,915 sq km) , Nepal (2,213 sq km) and Bhutan (11,543 sq km).
“The factors that foster tiger presence in western Himalaya region, which includes Uttrakhand and Nepal are gentle elevation, high forest cover, high drainage density, high temperature variation and moderate dry condition,” said Karki. “Tiger sighting at 2,500m provides solid ground for tiger conservation in the Mahabharata range. There is no doubt that tigers can not be in Mahabharata range, provided there is a connecting corridor, no disturbance and prey.”
According to Karki, the finding also expands Nepal’s known tiger distribution beyond the TAL, the only landscape known to be inhibited by tigers in the country, and widens potential tiger habitats in the country at a time when the whole world is battling to protect its existing range.
Still, tiger conservation faces challenges such as habitat conervation and negative interaction with humans. Loss and fragmentation of tigers’ habitat and death of tigers in vehicular accidents along the national highways that traverse the country's protected areas remain a threat for the country of 235 tigers.
“Maintaining and restoring key wildlife corridors is essential to expanding tiger populations,” said Karki. “But increasing threats from infrastructure development is fragmenting these key habitats.”
Earlier this month, a tiger from Parsa National Park was killed by an overspeeding car along the East-West Highway, raising concerns for the safety of valuable wildlife dwelling in protected areas and their adjoining forests.
A rapid assessment of linear projects in the Tarai region has found adverse consequences on forests, wildlife habitats and animal movement. They have also increased negative interactions between humans and wildlife. Highways are turning into a death trap for wild animals, including tigers as three tigers have died in vehicular accidents along the highway.
According to statistics of the Department of National Park and Wildlife Conservation, 108 wild animals were killed in road accidents in the last fiscal year. Such incidents were high in Parsa, Banke and Bardiya national parks.
“Such highways cause a barrier to their movement and fragmentation of wildlife habitat,” said Karki. “There should be signage for motorists to alert them about wildlife. Also, there should be wildlife-friendly structures for their passage.”
According to Shyam Shah, a chief conservation officer of Banke National Park, where 102-km of East-West highway passes through the park area, the park authorities have been enforcing several measures to minimise wildlife-vehicle collisions.
“We have placed signage along the highway. We also use speed guns to monitor vehicle speed,” said Shah. “Besides, arboreal canopy bridges installed for animals to cross the highway have also proved effective for animals, mostly monkeys.”