East of the Trans-Mongolian Railway, hoofbeats now compete with the sound of trains rumbling down the tracks. Long excluded from this region of the Gobi Desert, the khulan (Equus hemionus) is making a comeback.
 
The Trans-Mongolian Railway was constructed between 1940 and 1956. To reduce the likelihood of livestock collisions, large stretches were fenced. This had the unintended effect of reducing wildlife movement as well. The khulan was last seen east of the railway in the 1950s. 

“This fragmentation effectively isolated habitats east and west of the railway, preventing the khulan from accessing seasonal grazing areas, water sources and dispersal routes,” said lead author Buuveibaatar Bayarbaatar, a senior scientist with Wildlife Conservation Society (WCS) Mongolia.

“Over time, this loss of connectivity likely contributed to the disappearance of khulan east of the railway by limiting recolonisation opportunities and reducing long-term population resilience.”

In 2019, a conservation initiative led by WCS Mongolia led to the removal of some 1,500m of fencing between May 2019 and December 2021. The fencing was later replaced due to livestock-related train delays and collisions. The khulan appear to have availed themselves of these temporary passages, though. Surveys found four groups of the wild asses east of the railway in 2024 – totalling 384 individuals. 

Additional observations noted that khulan also cross at informal gaps in the fences, indicating a need for continuous access to the eastern regions. The conservationists visited one such site in Dornogovi Province and installed camera traps. 

“Many khulan attempted to use it, particularly during harsh winters when animals were searching for forage and better conditions,” Bayarbaatar claimed.

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WCS worked with Mongolian government and railway authorities to institute a safe passage zone at the Zamyn-Üüd border crossing in May 2025. However, the animals may encounter new challenges in this territory.

“In some areas, local communities and authorities have had little prior experience with khulan, creating risks of disturbance, or illegal hunting, particularly where awareness of the species’ protected status is limited,” Bayarbaatar said. “Competition around water and pasture resources with livestock may also emerge, especially as eastern areas can be more vulnerable to drought and have fewer places where khulan can access water.”

Published Date:2026-05-13