Data from: Stable isotopes reveal diet shift from pre-extinction to reintroduced Przewalski’s horses

The Przewalski’s horse (Equus ferus przewalskii), the only remaining wild horse within the equid family, is one of only a handful of species worldwide that went extinct in the wild, was saved by captive breeding, and has been successfully returned to the wild. However, concerns remain that after multiple generations in captivity the ecology of the Przewalski’s horse and / or the ecological conditions in its former range have changed in a way compromising the species' long term survival. We analyzed stable isotope chronologies from tail hair of pre-extinction and reintroduced Przewalski’s horses from the Dzungarian Gobi and detected a clear difference in the isotopic dietary composition. The direction of the dietary shift from being a mixed feeder in winter and a grazer in summer in the past, to a year-round grazer nowadays, is best explained by a release from human hunting pressure. A changed, positive societal attitude towards the species allows reintroduced Przewalski’s horses to utilize the scarce, grass-dominated pastures of the Gobi alongside local people and their livestock whereas their historic conspecifics were forced into less productive habitats dominated by browse.

普氏野马（Equus ferus przewalskii）是马科现存唯一的野生马类，也是全球少数几种经野外灭绝、通过圈养繁育获救后成功重返野外的物种之一。但目前仍存在潜在担忧：经过多代圈养后，普氏野马的生态习性及其原生分布区的生态环境已发生改变，或会威胁该物种的长期生存。我们对采自准噶尔戈壁（Dzungarian Gobi）的灭绝前种群与再引入种群的尾毛稳定同位素年代序列展开分析，发现二者的同位素饮食组成存在显著差异。其饮食结构已从历史上冬季为混合采食者、夏季为草食者的模式，转变为如今的全年草食模式，这一饮食转变趋势最合理的解释为人类狩猎压力的解除。当前社会对该物种态度的积极转变，使得再引入的普氏野马能够与当地居民及其牲畜一同利用戈壁地区稀缺的、以草本植物为主的牧场；而其历史野生种群则被迫栖息于以灌木为主的生产力较低的生境中。