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Hunting takes its toll on Himalaya’s blue sheep, favored prey of snow leopards

  • Blue sheep in Nepal’s Dhorpatan Hunting Reserve appear to be more wary of humans than those in a nearby conservation area where hunting isn’t permitted, a new study shows.
  • Researchers say the behavioral changes, apparently instigated by hunting activity — both legal and illegal — threaten the fitness and well-being of the species.
  • They warn this could have a cascading effect on the ecosystem, as blue sheep, also known as bharal, are the favored prey of the region’s snow leopards.
  • They also say reserve managers should engage local communities in conservation efforts and in revenue sharing, in a bid to ease the illegal hunting pressure.

KATHMANDU — The Dhorpatan Hunting Reserve in western Nepal is known for its pristine high-altitude grasslands, and buzzes with helicopter traffic every October and November, at the onset of winter.

The choppers carry more than half a dozen foreigners, mostly from the U.S., Russia, Canada, Norway and Germany, typically clad in camouflage and wielding hunting rifles. They pay thousands of dollars each to private operators and in government fees to hunt two native species of wild goat: the Himalayan tahr (Hemitragus jemlahicus) and the blue sheep, or bharal (Pseudois nayaur).

The reserve was established in 1987 to both generate revenue and preserve this 1,325-square-kilometer (512-square-mile) alpine ecosystem. But hunting, both legal and illegal, may be having a negative impact on the ecosystem’s keystone species, a recent study suggests.

The hunting quota for blue sheep, the main prey of snow leopards (Panthera uncia), is determined every five years when officials count the number of individuals found in the reserve and assess their age and sex.

“However, when doing so, officials don’t take [account of] the behavioral changes in the animals that may have been triggered by hunting,” says Sanjay Kandel, lead author of the study published in the journal Global Ecology and Conservation. “Hunting must have changed their behavior in some ways, for example they may be afraid of people in general, we thought. So we decided to see it for ourselves.”

 

Lead author Sanjay Kandel and his assistant look for blue sheep at the Dhorpatan Hunting Reserve in western Nepal. Image courtesy of Sanjay Kandel.

For their study, the team decided to compare the behavior of blue sheep at the hunting reserve to those in the Nar-Phu region (often referred to as “Little Tibet” because of its pristine and untouched pastures) in the nearby Annapurna Conservation Area, where hunting is prohibited. The other difference between the two areas is that Dhorpatan is managed by the Department of National Parks and Wildlife Reserves, while the Annapurna Conservation Area has a higher share of community involvement.

The team surveyed the two areas from October to November 2021, and observed the blue sheep as they foraged, walked, exhibited vigilance, and engaged in other kinds of behavior. In total, they kept tabs on 235 sheep: 136 in Dhorpatan and 99 in Annapurna.

“We found that vigilance behavior of blue sheep was around 25% higher in Dhorpatan compared to the animals in Annapurna,” Prashant Ghimire, co-author of the study says. “The difference between the behavior of the sheep in the two areas is so stark that even a non-researcher can feel it,” said Kandel.

Snow leopard from a camera trap at Marjhong in Upper Mustang in 2014. Image courtesy of Madhu Chetri.

The study also found that the blue sheep in Dhorpatan walked around a lot less compared to those in Annapurna, likely to compensate for the energy they lost while remaining vigilant. Observational data also showed that the Dhorpatan sheep jumped three times the distance as the Annapurna ones when they encountered humans.

“As the observations were done a year after the COVID-19 outbreak, when tourism and trophy hunting was halted, we believe that the sheep may have had some time to recover and the effects of hunting would have been more pronounced during the pre-COVID-19 days,” Ghimire tells Mongabay.

Ghimire, who has done similar work looking at woolly necked storks (Ciconia episcopus) and their interactions with humans in their farmland habitats, says the blue sheep findings have important ramifications for the conservation of the species, which plays an important role in the mountain ecosystem.

“If blue sheep run away from people from afar, it would not only be difficult for hunters to kill them, but also for tourists to spot them,” he says, adding that would impact the visitor revenue that keeps the reserve running.

“But that’s the least of our concerns,” Kandel says. “As blue sheep spend a lot of energy on vigilance, it impacts their fitness and well-being. When they are not fit and well, they can’t provide enough and adequate nutrition to snow leopards.”

Ghimire says controlled hunting of the species for a few months every year may not be solely responsible for this change in behavior. Illegal hunting may also be contributing; revenue generated from the reserve isn’t shared with the local communities, which means they don’t have any incentive to help conserve the species.

A Himalayan blue sheep spotted at the Gangotri National Park in India. Image by Sirsendy Gayen via Wikimedia Commons (CC BY 4.0)

Kamal Thapa, a conservationist who has studied both snow leopards and blue sheep, says he agrees with the findings of the study.

“We need to reassess how we manage the blue sheep population in Dhorpatan,” he tells Mongabay. “I believe that the whole system of assessing the population and coming up with the number of sheep to be killed every year is not scientific. It is based on a decades-old methodology that didn’t account for the dietary needs of snow leopards.”

Even park officials agree on the need to conserve the blue sheep. Birendra Kandel, which warder of the Dhorpatan Hunting Reserve, says illegal hunting of the sheep is rampant in the area.

“During the Maoist insurgency in Nepal in the ’90s and early 2000s, it was very difficult to secure the area. It is believed that many sheep were hunted during the period,” he says. “Also, local people, especially during the festivities, think that it is their right to kill and eat blue sheep meat.”

Warden Kandel says he’s been trying to talk to the local communities to help them establish a buffer zone council, like the ones in Chitwan and Bardiya national parks, which are home to another big cat: the Bengal tiger (Panthera tigris). Through such a council, local people can get a share of the revenue the reserve collects through trophy hunting.

“But that hasn’t materialized yet as people are afraid the park is trying to expand its area by developing a buffer zone program,” Kandel, the warden says.

Ghimire says another important takeaway from the study is that while hunting may continue in a more managed way, ecotourism also needs to be promoted so that communities get involved in conservation.

Citation:

Kandel, S., Ghimire, P., Silwal, T., & Low, M. (2022). Potential impact of trophy hunting on vigilance and flight behaviour in Blue Sheep (Bharal: Pseudois nayaur). Global Ecology and Conservation, 40. doi:10.1016/j.gecco.2022.e02317

Banner Image: Blue sheep graze on grass at a rangeland in the the Annapurna region in Nepal. Image courtesy of Sanjay Kandel.

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