The danger of having all your eggs in one basket--winter crash of the re-introduced Przewalski's horses in the Mongolian Gobi.
Authors: Kaczensky Petra, Ganbataar Oyunsaikhan, Altansukh Nanjid, Enkhsaikhan Namtar, Stauffer Christian, Walzer Chris
Journal: PloS one
Summary
# Editorial Summary: Winter Crash of Reintroduced Przewalski's Horses in the Mongolian Gobi When the Mongolian Gobi experienced an exceptionally severe winter in 2009/2010, researchers seized the opportunity to examine how reintroduced Przewalski's horses (Equus ferus przewalskii) and sympatric Asiatic wild asses coped with catastrophic environmental conditions compared to local livestock populations. Using GPS telemetry, ranger surveys, and spatially explicit livestock loss data, the team tracked survival outcomes across the region and correlated them with space-use strategies and local snow depth variations. The results revealed starkly different outcomes: whilst herders lost an average of 67% of livestock and Przewalski's horses suffered approximately 60% mortality, Asiatic wild asses experienced minimal losses by shifting westward into areas with better grazing conditions—a migratory flexibility the Przewalski's horses, constrained by extremely conservative home-range behaviour, could not employ. These findings underscore the critical vulnerability of small, spatially confined populations in unpredictable environments and emphasise that effective management of reintroduced equids requires dispersed populations across multiple sites, coordinated disaster planning with local communities, and landscape-level conservation strategies that permit nomadic movement patterns rather than relying on fixed protected-area boundaries.
Read the full abstract on PubMed
Practical Takeaways
- •Equine populations confined to small geographic areas face catastrophic risk during extreme weather—multi-site re-introduction strategies with spatially dispersed populations are essential for species survival
- •Przewalski's horses show conservative, non-adaptive movement behavior during crises (remaining in home ranges despite starvation risk), suggesting poor flexibility in responding to sudden resource depletion
- •Landscape-level management and migration corridors beyond protected area boundaries are critical for equid survival in unpredictable rangeland environments prone to severe climatic fluctuations
Key Findings
- •Przewalski's horse population in Mongolian Gobi experienced 60% average mortality during winter 2009/2010, with significant east-west variation in losses
- •Conservative space use behavior—Przewalski's horses did not venture beyond known home ranges despite severe resource scarcity, unlike Asiatic wild asses that shifted ranges westward
- •Livestock herders lost an average of 67% of their animals with losses following an east-west gradient correlating with local snow depth variation
- •Small, spatially confined populations are highly vulnerable to stochastic climate events in unpredictable environments, demonstrating the need for multiple geographically dispersed re-introduction sites