Is There Enough Wild Prey for Tost’s Snow Leopards?

June 1, 2015

Snow Leopard Trust scientists count ibex and argali in Mongolia’s Tost Mountains. Their numbers appear stable – and just sufficient for now to sustain the area’s snow leopard population. But it’s a fragile balance.

In Mongolia’s Tost Mountains, ibex and argali are the snow leopard’s preferred prey species. We’ve calculated that an adult snow leopard kills and eats an ungulate roughly every 8 days – or between 40 and 50 animals a year.

From our long-term camera trapping in the Tost mountains, we have estimated that the area is home to 10 to 14 adult snow leopards at any given time.

What we didn’t know for a long time was whether there was enough prey in Tost to sustain these cats. 

snow leopards have a taste for game

The problem: counting ibex and argali in the rough, inaccessible landscape of Tost is almost as difficult as counting the famously elusive snow leopard.

However, over the last three years, our field team, led by Sumbee Tumursukh, have refined a method to reliably estimate the population of these wild ungulates in Tost for the first time: the so-called “double observer technique”, which had previously been used by our India team to count ungulates in the Himalayas.

Now, Sumbee and his colleagues have published the results of their hard work in the peer-reviewed journal Oryx¹.

The good news: Tost appears to have just enough wild prey to sustain the local cat population.

the ibex, a snow leopard favorite

Our scientists believe that it takes around 75 ibex or 50 argali per snow leopard in an ecosystem for the cats to survive. In the case of Tost, that would add up to around 1100 ibex (or 750 argali) as a minimum for 14 snow leopards.

“We have counted an annual average of roughly 900 ibex and 160 argali, and these populations appear to be stable, or, in the case of the argali, slightly increasing”, says Sumbee Tumursukh. “Those numbers are just sufficient to support the cats we know to live here.”

An argali on a cliff. Photo by Paulo Fassina

Still, it’s a fragile balance – one that could be upended all too easily: “If an epidemic, or a sustained drought, were to decimate the ungulate population for a year or so, it could have very serious consequences for the snow leopards of Tost. Ideally, we’d like to see larger, more robust ungulate populations that would be able to absorb such events and would eventually allow for the number of cats to grow”, Sumbee says.

Tost currently enjoys some protection. After a series of mining exploration licenses had been issued for the region, local communities teamed up with our Mongolia partner, the Snow Leopard Conservation Foundation, to save this fragile ecosystem.

In 2010, Tost was declared a Locally Protected Area by the administration of Gurvantes soum, the local authority – which meant that no new mining licenses could be issued. More than 20 existing licenses, however, remained valid.

Now, our Mongolia team is once again assisting the communities of Tost in their fight to better protect their ancestral lands. Our research in the area has proven that it’s an important habitat for the endangered snow leopard and its prey species. This latest study, the first reliable count of wild ungulates in the region, underlines the importance – and fragility – of this unique ecosystem even further.

“The National Government of Mongolia is currently considering to make the Tost Locally Protected Area into a Nature Reserve; a much more wide-reaching status”, Sumbee says. “Most importantly, any future mining activities would be ruled out. We’re hoping that our research will help convince the decision makers to make this important step.”
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¹ Lkhagvasumberel Tumursukh, Kulbhushansingh R. Suryawanshi, Charudutt Mishra, Thomas M. McCarthy and Bazartseren Boldgiv. Status of the mountain ungulate prey of the Endangered snow leopard Panthera uncia in the Tost Local Protected Area, South Gobi, Mongolia. Oryx, available on CJO2015. doi:10.1017/S0030605314001203. Abstract: http://dx.doi.org/10.1017/S0030605314001203

We would like to thank People’s Trust for Endangered species for funding this work and the Whitley Fund for Nature for support to our programs in Mongolia and across the snow leopard range. We thank Panthera, who was a partner in the Long Term Ecological Study.

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