Press release, March 9, 2018
After 45 years of being considered ‘Endangered’, the snow leopard was down listed to ‘Vulnerable’ in 2017 by the IUCN’s Red List. This status change implies that the population of snow leopards is higher than what was assumed earlier, and that the rate of population decline is less than feared.
Given recent reports of habitat loss and widespread poaching (with over 480 cats killed annually since 2008), the status change would appear to be a rare dose of good news. Instead, it split scientists, while all range-country governments rejected IUCN’s decision.
In their letter to Science published yesterday (3/9/2018), Ale and Mishra point out the scientific fallacies underpinning the down listing of snow leopards.
Along with other factors, IUCN assessments use estimates of so-called mature individuals as one key metric: a species that has fewer than 2,500 mature individuals remaining in the wild is considered to be ‘Endangered’, while a species with more than 2,500 mature individuals would be ’Vulnerable’. This figure depends on a species’ overall population size, and on demographic parameters such as the age at which animals first reproduce. The larger the overall population and the lower the reproductive age, the higher the number of mature individuals.
“When it comes to age of reproduction, the value that was used in the assessment is simply not supported by the facts”, Charu Mishra says. “In the assessment of the snow leopard, the IUCN assumed an age of reproduction of two to three years. However, studies of wild snow leopards have shown no reproduction whatsoever at two years old, and in zoos, there have only been three recorded cases, out of 344 documented births. And yet, the IUCN assessment presumed that 25% of the two-year old snow leopards could breed in the wild. That’s analogous to assuming that since there are examples of 12-year old girls becoming pregnant, 25% of all girls will get pregnant at that age.”
This unsubstantiated assumption, according to Mishra and Ale, has a powerful impact on the projected population size and produces an inflated number of so-called mature individuals – high enough to fall above the 2,500 threshold and result in the species’ down listing to ‘Vulnerable’.
“We still don’t know with any certainty how many snow leopards there really are. But recent surveys paint a rather less optimistic picture than the revised IUCN status implies”, says Som Ale. “Camera trap studies in Bhutan revealed fewer leopards nationwide than earlier estimates. Surveys from Pakistan were even direr: only 23 cats were found in the country’s best habitats, compared to 300-420 that were estimated. If at all, snow leopards might be rarer than believed earlier.”
“The data simply doesn’t support this status change”, Charu Mishra says. “And it’s not just an academic question. Erroneous down listing of a species gives the false impression of a reduced risk of extinction, and may lead to a reduction in conservation effort at a time when such effort is needed most.”
Indeed, threats to the snow leopard are perhaps more acute today than ever before. Poaching and retaliation killing continue at high rates, as reported by TRAFFIC in 2016. More and more formerly remote snow leopard habitats are being opened up to development, with new roads and railways being built and mining operations expanding. Climate change is putting additional pressure on the cat and its ecosystem. “The snow leopard is at a critical point”, says Charu Mishra.
The Snow Leopard Trust commends the efforts of all scientists, conservationists, and officials working to protect the snow leopard and its high mountain ecosystems. There is widespread agreement within the conservation community about the need for a scientifically sound assessment of the global snow leopard population, using rigorous methods that are universally accepted as valid for estimating a species’ population. Once we have such a scientifically robust estimate, we will be able to accurately assess the status of the snow leopard and develop and monitor our collective efforts to save this magnificent cat.
Under the Global Snow Leopard & Ecosystem Protection Program (GSLEP), such an assessment will be conducted within the next five years, with the cooperation and support of all twelve range countries, academic institutions and a variety of international and national conservation organizations.