The yellow-rumped leaf-eared mouse has just shattered the world record for the highest-dwelling mammal ever documented. The tiny but mighty mouse has an elevation range of more than 20,000 feet, the world’s largest for any species of mammal.
The mountaineering mouse surprised experts on a recent scientific expedition when one was discovered on Llullaillaco, the world’s second-highest active volcano and one of the most uninhabitable places on Earth. This cements the fact the species can live from sea level all the way up to the towering summits of the Andes—the broadest altitude distribution on the planet. Also, another world record.
Volcán Llullaillaco is a dormant stratovolcano that sits on the edge of the Atacama Desert. Quite possibly of the driest places in the world. Straddling the border of Chile and Argentina the summit of Llullaillaco is also home to the highest archaeological site in the world: the mummified remains of three Inca children, known as the Children of Llullaillaco.
The yellow-rumped leaf-eared mouse was found at 22,110 feet taking the crown from the large-eared pika (Ochotona Macrotis), another mountain-dwelling mammal, who was discovered at a reported altitude of 20,111 feet. The National Library of Medicine states the discovery suggests that scientists 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.
Jay Storz, an evolutionary biologist at the University of Nebraska–Lincoln, and mountaineer Mario Pérez Mamani had made the discovery. Storz said in a press release,
“No one expected mammals to be able to survive and function at such an extreme altitude.”
The team managed to capture a few of the yellow-rumped leaf-eared mice, including the summit-topping rodent. In addition to capturing three other species of mice descending from a range of high altitudes. Following the discovery, the research team plans to examine and study genetic changes that might have equipped these animals to endure such high elevations.