Counting Ibex: Fall Prey Surveys Completed

There is nothing that’s more important for the snow leopard than its wild prey. Studies have repeatedly shown that the abundance of prey species like ibex or argali is the key to a healthy snow leopard population.

Hunting, loss of habitat, increased livestock grazing and diseases can put ibex and other wild ungulates under pressure – with potentially fatal consequences for the snow leopard. Everywhere we work, we make it a priority to monitor these prey species through so-called prey surveys.

This fall, our team in Mongolia teamed up with local rangers to conduct such surveys in two mountain ranges, Tost and Noyon.

The team, led by Regional Ecologist Justine Shanti Alexander and Research and Monitoring Manager Purevjav (Puji) Lkhagvajav, trained 17 rangers from the nearby communities and the protected area administration in how to count ibex and argali, how to classify them by age and sex, and how to register their location with a handheld GPS device.

After the course, the rangers set out for the mountains in groups of two, conducting so-called ‘double observer surveys’ of the ibex and argali populations. They spent a total of 11 days in the mountains, walking along pre-determined sectors of the mountain ranges and looking for animals.

Having analyzed the data the rangers have collected, Justine and Puji estimate that there are around 1150 ibex and 150 argali sheep in Tost, and about 1500 ibex and 240 argali in Noyon.

“It’s hard to draw conclusions from one year of data, because population size can vary from year to year and between seasons. But if we look at the numbers from the past five years for Tost, it looks like the populations of both ibex and argali are relatively stable right now”, Justine says. “These populations should be large enough to feed around 15 snow leopards, which is roughly as many as we think live in these mountains.”

For Noyon, it’s too early to detect any trends, as the team only started counting prey there last year.

For some, hiking through the mountains and looking for ibex for 11 days may be a perk in and of itself – but a few lucky surveyors were in for an extra treat: “Boldmaa, one of the two female rangers in the team, saw two snow leopards while she was scanning the ridgeline for signs of ibex. A few days later, Gana, our new local staff member who also helped with the surveys, saw another female snow leopard with a cub in a different location”, Puji says.