What a river in Bhutan can tell us about snow leopards in the Himalayas

A man in a puffy gray jacket sits on a rock by a mountain stream while a pump collects water samples nearby.

Bhutan’s stretch of the Himalayan Mountains is at once breathtaking and extreme. High above the tree line, snow leopards, Pallas’s cats, blue sheep, and other wildlife make their home in this terrain—often out of sight of anyone making a trek through the area. But a team, including WWF scientists from the US and Bhutan, is working to catch a glimpse of these animals in a different way: through the traces of DNA they leave behind in the flowing river water.

Environmental DNA, also called eDNA, helps us tell a more complete story of the area’s biodiversity. It also allows us to “see” or detect rare species that are very challenging to spot in person. 

“By collecting eDNA samples, we can reveal the hidden tapestry of life in these remote mountains.”

Arnaud Lyet
Lead Specialist, Wildlife Conservation, WWF

Telling a more complete story of an area’s biodiversity is extremely important as we face escalating biodiversity loss and crippling climate change impacts. Thankfully, eDNA is joining the conservation toolbox of useful monitoring methods. In a rugged landscape, like Bhutan, where monitoring biodiversity holds physical and practical challenges, it’s even more important to use efficient and thorough methods.

"By collecting eDNA samples, we can reveal the hidden tapestry of life in these remote mountains,” said Arnaud Lyet, lead specialist for WWF’s Wildlife Conservation Team. “This groundbreaking method not only confirms the presence of elusive species but also provides rich information on the biodiversity and ecosystems that support them. It's a game-changer for how we protect and understand our planet's most vulnerable wildlife."

In late spring, after ascending more than 13,000 feet in Jigme Dorji National Park in Bhutan’s Himalayas, Lyet and a team of scientists used a filtration and pump system to collect water samples from the Paa Chhu River. The process for collecting a single sample of eDNA takes over an hour. But the time is well worth it given what the samples can reveal about wildlife in the area.

Building Capacity for eDNA in Bhutan

A recent pilot study in Bhutan’s Royal Manas National Park looked at species biodiversity and assessed what could be detected from the park’s rivers and streams. By comparing eDNA findings to other biodiversity monitoring methods—such as camera trapping—research has shown how these techniques can complement one another and contribute to an even more complete portfolio of species in the area.

The pilot study revealed a lot more than traditional survey methods and illuminated over 325 unique taxa, of which 134 were identified at the species level. In fact, 33 species were on the IUCN Red List of Threatened Species: the red panda, golden mahseer, dhole, musk deer, and tiger were all detected within the water sampled. Data like this is vital in helping Bhutan’s government with overall conservation efforts and plans.

Conservation takes teamwork and determination

A close up of hands wearing blue gloves and holding a tube to collect water from a stream

WWF Bhutan and the Department of Forests and Park Services have been at the forefront of eDNA adoption in the country since 2022. Recognizing the potential of this innovative technique, a recent workshop and a hands-on training session for Bhutan’s government officials focused heavily on how eDNA can be best used in the country. The workshop addressed what questions eDNA could answer and the training got participants out practicing sample collection and diving deeper into data analysis.

“By collating the ideas and potential scenarios and contributions, it helps us to design and understand the wider context of how we can scale up eDNA and its use in Bhutan,” said Kuenley Tenzin, Program Officer, WWF Bhutan

The capacity for processing samples locally has emerged as an important step for making this a feasible solution for biodiversity monitoring in Bhutan. In partnership with ETH Zurich and the country’s College of Natural Resources, a new lab is being developed with the capabilities to analyze eDNA samples and local analysis.

eDNA gives us a chance to “see” rare species more regularly while disturbing them less

"Have you seen the snow leopard? No! Isn't that wonderful?" - Peter Matthiessen, The Snow Leopard

After collecting the samples, the scientific team’s return from the snow leopard landscape was guided by the river. The mountainsides displayed blooming rhododendrons and carried sweet birdsong as people crisscrossed over bridges and returned to the company of the trees.

Though they did not see any of the elusive cats, they hoped the water samples they carried would prove the presence of snow leopards. Really, there are two chances to see them: once in person and another in the data. In the next few months, Lyet and the team will have an answer.