Environmental limits of animal life are invariably revised when the animals themselves are investigated in their natural habitats. Here we report results of a scientific mountaineering expedition to survey the high-altitude rodent fauna of Volcán Llullaillaco in the Puna de Atacama of northern Chile, an effort motivated by video documentation of mice (genus Phyllotis) at a record altitude of 6,205 m. Among numerous trapping records at altitudes of >5,000 m, we captured a specimen of the yellow-rumped leaf-eared mouse (Phyllotis xanthopygus rupestris) on the very summit of Llullaillaco at 6,739 m. This summit specimen represents an altitudinal world record for mammals, far surpassing all specimen-based records from the Himalayas and other mountain ranges. This discovery suggests that we may have generally underestimated the altitudinal range limits and physiological tolerances of small mammals simply because the world’s high summits remain relatively unexplored by biologists.

当动物本身在其自然栖息地进行调查时，动物生命的环境限制总是会被修改。在此，我们报告了一次科学登山探险的结果，该探险旨在调查智利北部阿塔卡马角 (Puna de Atacama) 尤拉亚科火山 (Volcán Llullaillaco) 的高海拔啮齿类动物群，这项工作的动机是对小鼠（ Phyllotis属）在创纪录的海拔 6,205 m 高度的视频记录。在海拔超过 5,000 m 的众多诱捕记录中，我们在海拔 6,739 m 的 Llullaillaco 山顶捕获了黄腰叶耳鼠 ( Phyllotis xanthopygus rupestris ) 标本。这个顶峰标本代表了哺乳动物海拔高度的世界记录，远远超过了喜马拉雅山和其他山脉的所有基于标本的记录。这一发现表明，我们可能普遍低估了小型哺乳动物的海拔范围限制和生理耐受力，仅仅是因为生物学家相对尚未探索过世界最高峰。