The Asiatic wild ass, known locally as the khulan (Equus hemionus), has returned to eastern Mongolia and is showing clear signs of re-establishing a population after more than 65 years of absence from the region.

For decades, fencing along the Trans-Mongolian Railway (TMR) has restricted movement of khulan and other migratory species. Recent efforts to create safe crossing points are now allowing animals to move more freely across this barrier and recolonize their ancestral lands.

Collaborative efforts between Wildlife Conservation Society, the Mongolian government, and in-country private partners have seen the fencing taken down along several stretches of the railway, while also designating a monitored, “safe passage” zone last May near the China–Mongolia border—also free of fencing.

Findings published this Month in the journal Oryx show that the interventions are working, the animals are responding to them, and that the khulan are now regularly present in multiple groups east of the TMR.

Monitoring shows that crossings occurred in recent years, and follow-up surveys have since recorded hundreds of khulan on the eastern side. This suggests that khulan are not only passing through, but beginning to re-establish in the region.

“Documenting khulan crossing this long-standing barrier and beginning to re-establish in their former range represents an extraordinary conservation breakthrough,” said Buuveibaatar Bayarbaatar, a senior scientist at the Wildlife Conservation Society who lead the study.

“It demonstrates that restoring connectivity in fragmented landscapes can support population recovery for wide-ranging species.”

The Mongolian Gobi supports the world’s largest khulan population—approximately 91,000 animals, more than 84% of the global total. The species nevertheless faces ongoing threats from habitat fragmentation, competition with livestock, illegal hunting, and climate change.

As one of the most wide-ranging terrestrial mammals, maintaining connectivity across this landscape is critical for khulan, allowing them to move between seasonal grazing areas and water sources in a highly variable and arid environment, and supporting the broader functioning and resilience of Mongolia’s steppe ecosystem.

“The return of khulan to eastern Mongolia reflects years of collaborative work with provincial authorities, border protection agencies, and railway managers, as well as careful testing of temporary fence gaps that showed wildlife could cross safely without increasing train collisions,” said Justine Shanti Alexander, WCS Mongolia Country Director.

MORE STEPPELAND STORIES: 100 Miles of Derelict Fencing Removed by Rewilders Across the Great Plains in Montana

WCS has advanced wildlife connectivity and khulan recolonization in eastern Mongolia through the vital support of several key partners, not least of which was the Mongolian government.

Plans are advancing for a new local protected area east of the railway to support long-term habitat security and khulan recolonization.

An unsubstantiated claim on Mongolia’s Wikipedia page suggests that after gaining independence, there was “enthusiasm to declare 100 percent of the country as a national park,” but that the country eventually settled on 30%—a marker that recently became an international standard.

The country currently protects 13% of its land and water, but a recent agreement with the Nature Conservancy will see that taken to 30% if all goes to plan.

Published Date:2026-05-12