Learning How to Count Cats

Around 60% of the world’s snow leopard habitat are in China. Yet, in China as in other countries, robust population estimates to guide snow leopard conservation efforts remain scarce. But there are efforts underway to change that – most recently through two workshops on survey and analysis methods held in Beijing.

Part of the challenge in estimating snow leopard populations is logistical. The snow leopard’s habitat lies at high altitudes and is exceptionally remote. Combine that with the animal’s elusive nature and low natural population density, and it becomes easy to understand why we still don’t have anything even close to a solid estimate of how many of these cats remain.

The snow leopard’s elusive nature, remote habitat and low population density makes it an exceptionally hard species to study. Photo by Shan Shui / Panthera / Snow Leopard Trust

The other challenge is a scientific one. Estimating populations of wide-ranging carnivores based on relatively scarce data such as camera trap images is no easy task, even for a small study area. Both the data collection and the statistical analysis need to be rather sophisticated to achieve robust results.

Making data from different studies comparable in order to draw conclusions about the population status in larger landscapes is even trickier. It requires that sample methods as well as statistical analysis not only be sophisticated, but also follow common principles.

Under the moniker PAWS (Population Assessment of the World’s Snow Leopards), snow leopard range countries have recently launched an ambitious initiative coordinated by the Global Snow Leopard & Ecosystem Protection Program (GSLEP) to collect data using such methods across the snow leopard range and jointly come up with a reliable population estimate for the cat.

A team of snow leopard researchers is setting up remote-sensor cameras in the Himalayas to monitor snow leopard populations. Camera trapping is one of the methods recognized as reliable by the scientific community. Photo by NCF India.

“We will never be able to survey the entire snow leopard range or do a full count of the global population, so we have to work with samples. The big challenge we face is to ensure that these samples are representative of the natural distribution” says Snow Leopard Trust ecologist Dr. Koustubh Sharma, who also serves as International Coordinator for the GSLEP program.

“The snow leopard range isn’t homogenous. There are areas that have lots of prey and lots of cats, and other parts with much lower population densities. So our sampling has to take this into account. Until now, most snow leopard research has focused on the best habitats with the highest densities, because these are the best places to study these cats. But for a truly representative sampling of the entire snow leopard range, we’ll also need information from less optimal habitats”, Sharma explains.

Not all snow leopard habitat is created equal: so-called occupancy maps, such as this one from Himachal Pradesh, India, show how likely it is for snow leopards to be using specific parts of their potential habitat. This is a good indicator of habitat quality. Source: Abhishek Ghoshal et al: Assessing changes in distribution of the Endangered snow leopard Panthera uncia and its wild prey over 2 decades in the Indian Himalaya through interview-based occupancy surveys. Oryx, 2017

A scientific panel comprised of some of the world’s leading snow leopard ecologists and bio-statisticians has developed the procedural details to be used in PAWS. The scientists are currently working on developing tools, training manuals and capacity building packages that can provide appropriate guidance to collect, compile and analyze data to implement PAWS.

The GSLEP secretariat was assigned the task to coordinate the initiative, and with the help of its partners, they have begun building capacity in snow leopard range countries to apply these methods.

“For PAWS to be a success, everyone in the snow leopard conservation community needs to work together towards this common goal”, says Dr. Justine Shanti Alexander, a Snow Leopard Trust ecologist working with local teams in various range countries. “But in order for that to be possible, we need to build capacity at the ground level and train local conservationists, scientists and government officials. This won’t just help with PAWS, but also with strengthening scientific leadership in these countries.”

Training local rangers and volunteers to conduct wildlife surveys is a key component of PAWS. Photo by Snow Leopard Trust

Earlier this year, partner organizations met for two training workshops on snow leopard population assessment techniques in Beijing, China. One workshop featured 15 participants from local NGO Eco-Bridge Continental and the Beijing Forestry University. The other workshop was jointly organized by Peking University Conservation and Social Development Research Center, Shan Shui Conservation Center, and the World Wide Fund for Nature (WWF) for their staff and partners including WCS and Cats Felid Conservation Alliance.

Koustubh Sharma introduces some core principles of PAWS at a workshop in China. Photo by Snow Leopard Trust

The workshops aimed to introduce key methodological approaches for assessing snow leopard population density and abundance; the Spatially Explicit Capture Recapture framework, as well as the Occupancy framework, which allows researchers to develop probabilistic distribution maps.

Using colorful candy, Koustubh Sharma demonstrates how the Spatially Explicit Capture Recapture framework can help estimate snow leopard populations. Photo by Snow Leopard Trust

Not all the workshop participants currently focus on snow leopards in their work. They cover a range of species such as the Amur tiger, Northeast leopard subspecies and other large carnivores as well small and medium-sized carnivores such as Tibetan foxes and Pallas’s cats.

Similar workshops have been held previously in other range countries, including Mongolia and Kyrgyzstan. In 2019, more countries will follow – and the GSLEP secretariat is developing a range of tools to help researchers use and practice these methods. “The response so far has been extremely encouraging. There is a lot of excitement in the snow leopard conservation community as well as the snow leopard range countries around PAWS”, Koustubh Sharma says.

The PAWS trainings and training materials have been funded through a GEF-funded project aimed at Transboundary Cooperation for Snow Leopard and Ecosystem Conservation. The project is implemented by the United Nations Development Program (UNDP) and executed by Snow Leopard Trust.


  1. Such a gargantuan job! we are extremely grateful for the hard work you are doing…such important work. i am very appreciative of your detailed explanatory emails. wish i could be with you…but your posts are excellent. thank you.

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