Papers in the Biological Sciences


Date of this Version



PNAS | August 4, 2020 | vol. 117 | no. 31 | 18169–18171



This open access article is distributed under Creative Commons Attribution License 4.0 (CC BY).


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 6,205m. 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.

Storz PNAS 2020 movie 1.avi (63006 kB)
Footage of a leaf-eared mouse (Phyllotis spp.) at 6205 m on Volcán Llullaillaco, Región de Antofagasta, Chile (24°43.052'S, 68°33.323'W). Filmed by Matthew Farson.

Storz PNAS 2020 movie 2.avi (100610 kB)
Capture of a yellow-rumped leaf-eared mouse, Phyllotis xanthopygus, on the summit of Volcán Llullaillaco (6739 m), Región de Antofagasta, Chile (24°43.235’S, 68°32.208’W). Filmed by Mario Pérez Mamani.