Tracking Predator and Prey

Snow Leopards Trust researchers are planning to track both wild snow leopards and ibex, their primary prey species, with GPS technology this spring.

The Snow Leopard Trust’s pioneering long-term ecological study of the endangered snow leopard in Mongolia’s Tost Mountains is entering a new phase this year.

“In this study, we’ve so far tracked a total of 23 individual snow leopards with GPS collars. Currently, we’re following four cats. This work will continue in 2018, with a heavy focus on filling in knowledge gaps related to reproduction and interaction between cats”, says Gustaf Samelius, the Trust’s Assistant Director of Science.

The ongoing GPS tracking of snow leopards in Tost is part of the world’s most comprehensive study on these cats and has resulted in several groundbreaking scientific publications already. Photo: SLCF / Snow Leopard Trust

“We have also been monitoring the population of key snow leopard prey such ibex and argali continuously for the last several years”, Gustaf explains, “but we have never before tracked such prey animals to gain a detailed understanding of how they use the habitat. This spring, we’ll begin tracking ibex with GPS collars for the first time. In the future, we’re also planning to put collars on domestic livestock in the same landscape.”

Ibex are among the snow leopard’s main prey species. Photo: SLT
Understanding Ecosystem Dynamics

The goal of this comprehensive research is to understand the whole ecosystem in the study area of Tost; from the snow leopard at the top of the food chain down to its prey, both wild and domestic, and how these animals use vegetation and water sources.

The researchers want to see how the different species and trophic levels interact and how one species’ behavior impacts the other. For example, does grazing pressure from livestock prevent the ibex from utilizing parts of the mountain range? Are the ibex affected so strongly by livestock that they alter their behavior in vicinity of herds? Or are they able to use the same pastures and resources without impacting each other?

Livestock herds are grazing in Tost during the winter. In summer, the pastures mostly belong to wild ungulates like the ibex. Photo: Charles Dye

“Since the herders of Tost are semi-nomadic and utilize the mountains almost exclusively in winter, this landscape provides us with a natural experimental setup: for more than half the year, there are almost no domestic goats and sheep in the mountains, allowing us to examine where the ibex go and how they behave in the absence of livestock. Then­­, in winter, 30 000 or so goats move into these pastures, which will allow us to observe how the ibex respond to a high density of livestock”, Gustaf says.

The human dimension of pastoralism is equally interesting and important. How do people respond when snow leopards or wolves kill their livestock? What are the ways in which such conflicts can be addressed? For example, our team in Mongolia has just completed a very interesting experiment in partnership with local herders to test whether fences can be effective to protected corralled livestock from attacks by predators.

A simple fence deters snow leopards and other predators from entering a livestock holding pen and killing valuable goats and sheep. Photo: SLT

“The first results are very encouraging”, says Bayara Agvaantseren, the Snow Leopard Trust’s Mongolia program director. “There were no attacks on livestock in any of the pilot areas where he has set up corral fences, and herders were very pleased with the solution.”

Study Trip to Gran Paradiso

To learn how to safely capture ibex, Gustaf Samelius and fellow scientist Örjan Johansson made a study visit to the ibex project in Gran Paradiso National Park in Italy in October 2016, the world’s leading ibex research study. The researchers in Gran Paradiso have captured over 1,000 ibex and are widely considered to be the foremost experts on the capture and handling of this mountain ungulate.

Based on the recommendations of the team in Gran Paradiso, Gustaf, Örjan and their colleagues developed so-called box traps to capture ibex. They made their first trial in the fall of 2017. The weather however, had other plans. “Winter arrived a little earlier than expected here in Tost”, Örjan wrote from base camp last October. “We got the season’s first snow about a week ago and since then it’s been 10-25 degrees below zero with strong winds.”

A so-called box trap, waiting for its first ibex. A bait (e.g. a salt lick) attracts the ibex. Once the animal is inside the box, the researchers can trigger a mechanism that closes the trap. Photo: SLT

The early arrival of winter, and in particular the snow, made it impossible to capture and collar ibex back then, as Örjan wrote:

“We were ready a few days ago. The traps were set near water holes where the ibex come to drink. We had tested the dart gun to immobilize them, and were basically waiting for our opportunity – and then it started snowing. Now the ibex eat snow instead of using the water holes, so they’re much less likely to walk into our traps. Also, the drugs in the dart freezes within a few minutes of loading into the rifle. It’s also simply too cold now to lay in wait for more than a few minutes. In short, we’ll have no choice but to postpone the attempt until spring.”

When winter arrives in Tost, field work becomes exceedingly difficult. Photo: SLT

This coming April, Örjan and Gustaf, who are being supported by our Mongolian colleagues Puji, Ghana, and Miji, will make another attempt at catching ibex and fitting them with GPS collars.

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