Mouse Found at 22,000 Feet Breaks Record

Last summer, scientists reported finding the world’s highest-dwelling mammal, a yellow-rumped leaf-eared mouse, which was seen scampering among the upper reaches of Llullaillaco, the world’s highest historically active volcano, straddling Argentina and Chile.It’s incredible that anything could live that high, at 20,340 feet—there is no vegetation, and seemingly nothing to eat. Here, at the edge of the Atacama Desert, there is little rain, and temperatures sometimes plunge below minus 75 degrees Fahrenheit.

“It’s hard to overstate how hostile an environment it is,” says Jay Storz, a biologist at the University of Nebraska, Lincoln, and a National Geographic Explorer.