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

Research published this month in the journal Oryx reports that khulan are now regularly observed in multiple groups east of the Trans-Mongolian Railway. For decades, fencing along the railway limited movement of khulan and other migratory species, restricting access to key habitats.

Recent conservation efforts have focused on restoring movement across this barrier. These include temporary unfenced sections of railway and the creation in May 2025 of a monitored “safe passage” zone near the China–Mongolia border where fencing is removed.

Monitoring data indicates that khulan have crossed the railway in recent years, including during winter periods. Follow-up surveys have recorded hundreds of individuals on the eastern side, suggesting not only movement through the area but the beginning of population re-establishment.

Experts involved in the study described the return as a major conservation development, linking it to restored connectivity in fragmented landscapes that allows wide-ranging species to recover.

The Mongolian Gobi is home to the world’s largest khulan population, estimated at around 91,000 animals, representing more than 84 percent of the global total. Despite this, the species continues to face pressures from habitat fragmentation, livestock competition, illegal hunting, and climate change. Khulan depend on large connected areas due to their wide-ranging movement patterns.

Officials involved in the project stated that cooperation with local authorities, border agencies, and railway managers helped enable safe crossings, supported by testing of temporary fence gaps that did not lead to increased train collisions.

Plans are now underway to establish a new protected area east of the railway aimed at supporting long-term habitat stability and further recolonization.

Experts noted that reducing fragmentation from infrastructure such as railways could benefit not only khulan recovery but also other migratory wildlife affected by development and climate pressures.

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