The World’s Highest-Dwelling Mammal Found Atop of the World’s Second-Largest Active Volcano

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The peak of Volcán Llullaillaco lies at an elevation of 6,739 m (22,110 ft) above sea level and is located at the border between Argentina and Chile.

Cold temperatures, that can drop as low as -60° Celsius, oxygen levels only 40% of what is found at sea-level, and sparse vegetation make existence on the world’s second-highest volcano too extreme for most species.

The environmental limits for most mammals is believed to be 5,200 m to 5,800 m above sea level. Food availability, tolerance for hypoxia (low-oxygen conditions), and extreme cold all play a factor in limiting animals that can survive at high altitudes.

Maps featuring the locations of trapping sites near Llullaillaco (left) and on the volcano itself (right). Maps: Storz et al., 2020, CC BY 4.0 -
Maps featuring the locations of trapping sites near Llullaillaco (left) and on the volcano itself (right). Maps: Storz et al., 2020 CC BY 4.0.

Scientists were able to document that the yellow-rumped leaf-eared mouse (Phyllotis xanthopygus rupestris) is the world’s highest-dwelling mammal.

A mountaineering expedition in 2013 captured video of a mouse scampering across the snow at 6,205 m above sea level. This inspired a February 2020 expedition to the summit of Volcán Llullaillaco to look evidence of this mouse’s existence at this altitude.

This expedition, led by a team of researchers from the University of Nebraska-Lincoln and Universidad Austral de Chile, were able to capture a live mouse right at the summit of Volcán Llullaillaco. The documented capture of the yellow-rumped leaf-eared mouse at the peak of Volcán Llullaillaco, makes this rodent the highest-dwelling mammal in the world.

Yellow-rumped leaf-eared mouse (Phyllotis xanthopygus rupestris). Photo: Marcial Quiroga-Carmon, CC BY 4.0
Yellow-rumped leaf-eared mouse (Phyllotis xanthopygus rupestris). Photo: Marcial Quiroga-Carmona, PNAS, CC BY 4.0

The researchers still have more work to do to understand how this rodent is able to survive at this high of an altitude. The summit is more than a mile above the vegetation line of Llullaillaco so researchers hypothesize that lichens and insects may form the diet of this mouse.

The yellow-rumped leaf-eared mouse is found at a wide range of elevations. Researchers also hope to better understand the physiological aspects of the mouse that enables it to live at such a high-altitude compared to sea-level dwellers of the same species.

Watch: The World’s Highest-Dwelling Mammal


Storz, J. F., Quiroga-Carmona, M., Opazo, J. C., Bowen, T., Farson, M., Steppan, S. J., & D’Elía, G. (2020). Discovery of the world’s highest-dwelling mammal. Proceedings of the National Academy of Sciences, 202005265.

Schrage, S. (2020, March 30). Mighty Mouse: Storz discovers world’s highest-elevation mammal



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