At over 20,000 feet above sea level, where the air is thin and temperatures freeze, a tiny mouse makes its home on the summits of volcanoes in Chile. This surprising discovery has puzzled scientists for years, but a new study finally explains how these mammals manage to thrive in such a harsh environment.
The High-Altitude Hideout
The Andean leaf-eared mouse, known scientifically as Phyllotis vaccarum, has been found living on the peaks of several volcanoes in the Atacama region of Chile. These summits are among the most extreme habitats on Earth, with oxygen levels roughly half of those at sea level and intense solar radiation. The study, published by researchers including Jay Storz, documents how these mice not only survive but appear to be active and healthy at these elevations.
How They Do It
The research team, led by scientists from the University of Nebraska and collaborators in Chile, captured live mice at these high-altitude sites. They found that the mice have evolved remarkable physiological adaptations. Their blood carries oxygen more efficiently, and their cells use energy in ways that reduce the need for extra oxygen. The study also notes that the mice likely seek shelter in rocky crevices and snow tunnels to escape the cold, and they may feed on insects and seeds blown up from lower slopes.
Why Locals Care
For local communities in Chile, these mice are more than just a curiosity. The volcanoes are sacred in Andean culture, and the presence of life at such extremes challenges assumptions about where animals can live. The study also has implications for understanding how mammals might adapt to changing climates and high-altitude environments elsewhere. The researchers emphasize that the mice are not a separate species but the same leaf-eared mouse found at lower elevations, which makes their adaptability even more remarkable.
A New Benchmark for Survival
The findings set a new record for the highest elevation where a mammal has been documented living year-round. While other animals like birds and insects have been seen at similar heights, this is the first confirmed case of a rodent making its permanent home at such extreme altitudes. The study opens the door to further research on how other small mammals might cope with extreme conditions, and it reminds us that life finds a way even in the most unlikely places.
