New Scientist

Image: Dick Culbert

At the summit of Llullaillaco, a volcano in the Andes that rises 6739 metres above sea level, lives a mouse. It is the highest dwelling mammal in the world – and how it survives in an environment so hostile that it has been compared to Mars has left scientists baffled.

Life isn’t easy at the top of Llullaillaco. Average temperatures are -15°C and the air pressure is so low that there is less than half as much oxygen in each lungful of air as at sea level.

Humans can’t survive for long at the peak. In 1999, archaeologists uncovered the frozen and perfectly preserved mummies of three Inca children who had been drugged and left to die on the summit 500 years ago, as part of a ritual sacrifice. But the yellow-rumped leaf-eared mouse (Phyllotis xanthopygus) apparently thrives here. Read more on newscientist.com…