If you hear a sharp little call coming from a mountain of broken rock, look carefully.
There may be a pika watching you from between the stones.
American pikas are small relatives of rabbits and hares that live in talus — fields of fractured rock with deep spaces underneath. At Mount Rainier, those rock piles are not just places to hide. They are part of the animal’s climate-control system.
Pikas are built remarkably well for winter. They have dense insulating fur and a high metabolism, and they do not hibernate.
The tradeoff is heat.
The National Park Service notes that pikas are prone to overheating; research cited by the park found that prolonged exposure to temperatures above about 82 degrees Fahrenheit can be fatal. On a hot summer day, the spaces beneath talus can remain much cooler and more stable than the air above.
So the pika disappears into the rocks.
Then it comes back out to work.
All summer, pikas gather grasses, wildflowers, ferns, bits of shrubs and other vegetation. Instead of eating everything immediately, they carry mouthful after mouthful back toward the talus and build haypiles for winter.
They are making groceries while the mountain is still green.
When snow and cold arrive, the pika stays awake. The stored plants become the winter pantry, while the spaces beneath the rocks help buffer the worst temperature extremes outside.
It is an elegant way to live in a difficult place: meadow for food, talus for shelter, summer for gathering, winter for eating what you saved.
But the same specialization that makes pikas so good at cold mountains can make warmer conditions difficult. Some populations have disappeared from warmer parts of their range, while others persist where rock structure, snow, moisture and local microclimates still provide refuge.
And there is a simple geographic problem with moving higher.
Mountains get smaller near the top.
Every step upslope leaves less land above it.
The pika is tiny, but its world depends on something enormous: a mountain cold enough, rocky enough and high enough to keep making room for it.
Find it in Nature™.