American Pika

A high-pitched whistle from a rocky pile signals you are looking at a house belonging to the American pika. Nicknamed the “rock rabbit,” the tiny pika is the size of a tennis ball with babies the size of walnuts. Covered year-round in heavy fur, pikas are highly susceptible to overheating, and when temperatures climb above 75 degrees Fahrenheit, they can die in less than an hour. Pikas live at high elevations, though lately rising temperatures have been chasing them upslope to cooler climates. However, mountains have tops, and these resourceful rock rabbits may soon run out of habitat.

Scientific name: Ochotona princeps
Region: West, Southwest, Rockies