A New Snow Leopard Population Estimate Has Scientists on Edge
A new estimate of the global population of snow leopards—a rare big cat thought to prowl about 1.2 million square miles of remote, rugged mountain terrain across 12 Central Asian nations—would appear to be an uncommon bit of good news for wildlife conservation.
Published last month in Snow Leopards, a 644-page compendium on snow leopard science and conservation, the estimate puts the global snow leopard population at 4,700 to 8,700 animals across 44 percent of the species’ range, compared with earlier projections of around 3,900 to 7,500 animals in total.
There was not enough information available to estimate how numerous the ghostly spotted leopards might be throughout their mountainous habitat, said Peter Zahler, the coordinator of the snow leopard program at the Wildlife Conservation Society, who coauthored the Snow Leopards chapter containing the population estimate. “As scientists, we know what we know, and we have not looked at the quality of those other areas—the other 56 percent,” he said.
Other experts say the available data don’t support the revised figure even across a subsection of the animal’s range, and they worry that it could create complacency among government officials and the public about curbing threats to the snow leopard’s survival.
“This will have a tremendous (negative) impact on snow leopard conservation throughout its range,” Som Ale, a biologist at the University of Illinois at Chicago and a member of the International Union for Conservation of Nature’s cat specialist group, wrote in an email. “I envisage that [the] snow leopard would be listed as low priority and [a] low-funding species while the opposite is what is necessary.”
Ale, whose research and conservation work have focused on snow leopards in the Himalayas, is among the nearly 200 authors who contributed to Snow Leopards.
This disagreement among big-cat experts follows an unusually public controversy over the global tiger count. An upbeat report released during an April meeting of government officials from tiger range nations claimed a 20 percent increase in the species’ global population since 2010. But the announcement was criticized by tiger conservation organizations as a science-light publicity exercise.
Both disputes highlight the challenges of studying elusive big cats in their native habitats and how conscious all sides are of managing the public’s enthusiasm for saving them.
“To me the exciting part is—and it’s not a terribly complex story—is that there are more of these animals than we thought, and that is rare in these times,” said Zahler. “Tigers have lost over 90 percent of their population over 100 years, and lions have lost 40 percent in the last 20 years. The signs are pointing down fast. So it’s a piece of good news in the big-cat world where there hasn’t been much.”
The count was based on field data and observations shared in 2008 at a conference in Beijing attended by government officials, scientists, and conservationists. Improved technologies for assessing snow leopard populations, including more durable camera traps and satellite tracking collars, “have given us a better idea of what snow leopards’ home range is,” Zahler said. “The fact is, suddenly you could really track snow leopards—where they’re going and how far. At first there was no way to do it.”
Zahler and Tom McCarthy, the executive director of the snow leopard program for the conservation group Panthera and coeditor of Snow Leopards, both anticipated criticism of the revised population count.
“I know some people that will argue that ‘Well, we still do our camera trapping in only the best possible places, because we want to get good pictures of snow leopards,’ ” McCarthy said. “That might have been the case 10 years ago. But what we’re seeing now, particularly with Panthera—we’ve got five or six hundred cameras out in snow leopard range, and we don’t just target high-level population areas. We target a number of places where we’re not even sure snow leopards occur. So that argument doesn’t hold a lot of water.”
Gustaf Samelius, assistant scientific director of Snow Leopard Trust, lauded Snow Leopards as “a fantastic source of information put together” but said that the authors of the book’s population estimate chapter “have been a little uncritical at how they arrived at the numbers.”
While some of the data were gathered via tracking, camera trapping, or genetic sampling of snow leopard fecal samples, the studies are being conducted across too small an extent of the cat’s range to justify the higher population estimate, he said. The rest is still guesswork, even if it comes from people working on the ground in snow leopard range states.
“I teach a wildlife biology conservation class,” Samelius said. “We talk about estimating abundance a lot. I tell them, ‘We can land on the moon, but we have a very hard time estimating abundance of animals.’ ”
McCarthy agreed that with an animal as difficult to observe as the snow leopard, informed guesses continue to play a big part in estimating the size of the population. “I would not say that what we have still goes much beyond a guesstimate,” he said. “But the key takeaway here is [that] for once much more of the population figure was based on camera trapping, or genetic assessments, using fecal counts, sign surveys, rather than just more wild guessing.”
All the researchers agreed on at least one thing: With snow leopards facing multiple threats—including poaching of both the cats and their prey, retribution killings by herders for livestock losses, increased mining and road building in their habitats, and climate change—it would be a mistake to cut back on conservation efforts.
“It’s important to make sure it’s not lost that regardless of the total count of snow leopards, we know that there are some real threats out there, and they need to be dealt with,” said Zahler. “They are not going to go away without concerted effort.”