Meteorology

Archaeology

Mammal

Summit

Mathematics

Altitude (triangle)

Biology

Zoology

Physical geography

Fauna

Genus

Habitat

Composite material

Geography

Ecology

Materials science

Range (aeronautics)

Geometry

Mountaineering

Effects of high altitude on humans

Proceedings of the National Academy of Sciences

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 &gt;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.

Discovery of the world’s highest-dwelling mammal