KATHMANDU — Scientists and government officials have embarked on the uphill task of coming up with a number, or even just a range, for the population of snow leopards in the Himalayan country.
To do so, they’re having to rely on several fragmented studies carried out during different periods of time in different landscapes across the country.
The undertaking is Nepal‘s commitment to the Population Assessment of the World’s Snow Leopards program, or PAWS. The program was adopted in 2019 by 12 countries that host populations of snow leopards (Panthera uncia) and is part of the Global Snow Leopard and Ecosystem Protection Program (GSLEP).
“Previous snow leopard population studies in Nepal as well as many other countries often faced limitations due to sampling bias, with smaller, high-density areas leading to inflated population estimates,” said Rinzin Phunjok Lama, a snow leopard researcher who’s on the newly formed government committee to conduct the count.
Because the range countries hadn’t agreed on a standardized approach, it became challenging to compare and aggregate data across regions before PAWS was rolled out.
In the context of Nepal, pioneering telemetry work by researcher Rodney Jackson and his team in the late 1980s and early ’90s form the bedrock of population estimates within the country. They first estimated the snow leopard population in Nepal to be around 150-300 in 1979 and later revised the number up to 350-500 individuals based on a computerized habitat suitability model. In 2009, researchers from WWF and the Department of National Parks and Wildlife Conservation (DNPWC) came up with a new estimate of 301-400 based on a model describing the relationship between sign (scrape) encounter rates, the snow leopard numbers assessed through genetic analysis, and the habitat suitability assessment in the Nepal Himalayas.
The figure was also acknowledged by the government’s inaugural Snow Leopard Action Plan (2005-15), revised in 2012. A 2013 estimate by the GSLEP, however, suggested the number to be around 300-500
The new population assessment committee, now headed by DNPWC senior ecologist Hari Bhadra Acharya, was set up in the middle of this year and had planned to come up with the number by Snow Leopard Day, Oct. 23. However, a host of issues related to the methodology of the estimate has delayed the process, a committee member told Mongabay.
“We have been working on the assessment for a few months now,” aid Kamal Thapa, a snow leopard researcher on the committee. “However, things have been difficult as we need to adhere to the PAWS guidelines and look into different studies employing different methodologies in different time periods [and] different landscapes.”
The PAWS guidelines, prepared by a team of experts in snow leopard science and conservation, addresses gaps in population assessment studies by implementing statistically robust methods like spatial capture-recapture modeling and expanding survey areas, aiming to provide more accurate, landscape-level estimates of snow leopard populations across their range.
While Nepal routinely carries out simultaneous, national-scale counts of its more celebrated big cat, the tiger (Panthera tigris), it has never done so for snow leopards in the eastern, central and western landscapes of the country in which they occur. Individual researchers and organizations have carried out both camera-trap and genetic studies in different landscapes, but these efforts have largely been isolated and uncoordinated.
For example, researcher Madhu Chetri from the National Trust for Nature Conservation (NTNC) focused on the Annapurna region of the central landscape; WWF works largely in the Kanchenjunga region of the eastern landscape; the assessment committee’s Lama, an award-winning conservationist, has specialized in Humla in the western landscape; and Bikram Shrestha, a leading researcher on snow leopards, focused on Sagarmatha, the local name for Mount Everest, in the eastern landscape.
Each has published their findings sporadically.
“The challenge is to aggregate all these publications and come with an estimate,” Thapa said.
The ideal scenario, he said, would be to set up camera traps across all known snow leopard habitats in the country at one go, just as is done in the case of tigers. “Although that would involve a lot of financial and technical resources, the government is certainly capable of doing it if it wishes to do so,” Thapa said.
Every four years, the DNPWC conducts a national survey of tigers and their prey to evaluate the effectiveness of conservation interventions. The fourth national survey was carried out between December 2021 and April 2022.
But not everyone agrees that a similar method would work for snow leopards. Shyam Kumar Shah, who was until recently the coordinator of the government’s snow leopard assessment committee, said the cat’s habitats cover vast landscapes, making it unfeasible to adopt a count method similar to that for tigers. “That’s why we need to come up with estimates,” he said.
Lama agreed, saying, “It’s just not possible to count snow leopards the way tigers are counted. The terrain is rugged and the climate harsh; the animal is very elusive.”
The PAWS guidelines set out standards for data collection and processing to come up with national population estimates. Lama said the methodology used by the government to come up with previous estimates would most probably be invalid under these new guidelines. For example, the guidelines say that camera trap-based population studies need to cover at least 500 square kilometers (nearly 200 square miles), which is difficult to adhere to in Nepal’s Himalayas.
The key challenge the committee has encountered is to make camera-trap data comparable with the genetic data. While some population studies are based on camera traps, others are based on DNA analysis of scat. Studies that use both methods, and therefore yield more accurate findings, are rare, Thapa said. The committee members are trying to come up with a way to capture the relation between camera-trap data and DNA data, Thapa told Mongabay. Similarly, there are potential snow leopard habitats in areas such as Dhorpatan, Dhaulagiri and Api-Nampa, in the country’s western region, where researchers are yet to carry out detailed studies.
The new estimate that the committee comes up with in the next few months will be important for snow leopard conservation in Nepal, experts say. Nepal is believed to be home to around 10% of the world’s snow leopards, and funding for conservation programs for the species is influenced by its share of the global population.
“We also need to get a sense of the number of snow leopards we have to assess if our conservation programs are working or not,” said conservationist Karan Bahadur Shah. “It’s as essential as a government conducting a census of its citizens.”
Would the number reflect the real population of the elusive cats in the country? Committee members have mixed responses. Thapa said the number the committee comes up with will be backed by science. “But at the end of the day it will remain an ‘educated guess’ as the cat is so difficult to track,” he said.
After it comes up with a number, the committee is expected to present its findings to the government as well as the PAWS committee, which will look at the methodology and findings. This, researchers say, should boost the robustness of the data.
Lama said he’s optimistic that the number, or the range, the committee comes up with will be an accurate reflection of reality. “First of all, the whole process and the data will be reviewed. Second, we now have covered around 50% of potential snow leopard habitat in Nepal with at least one camera-trap or genetic study,” he said.
He added his experience has shown that the bulk of the snow leopard population in Nepal is concentrated around the Annapurna region and areas to its west. “As these areas are well-represented in terms of population assessments, the final number will be close to accurate,” he said.
Committee members say they believe they’ll need another three or four months at least to carry out the assessment and make the figures public. Until then, snow leopard researchers and conservationists will have to make do with the 2009 findings
This article by Abhaya Raj Joshi was first published by Mongabay.com on 30 October 2024. Lead Image: A snow leopard photographed in Nepal’s Himalayas. Image courtesy of Sanjog Rai/ WWF Nepal.
What you can do
Help to save wildlife by donating as little as $1 – It only takes a minute.
Leave a Reply