Pikas (Ochotona princeps) are small territorial mammals about the size of guinea pigs. They inhabit rocky alpine and sub-alpine zones feeding on the vegetation that fringes their preferred talus slopes. Colored gray to brown with round ears and no tail, they blend in with their rocky home and agilely maneuver between and underneath obstacles. Because pikas do not hibernate, this relative of the rabbit must gather enough plant materials during the short growing season to survive the winter. Piles of drying vegetation, called haystacks, and a distinctive high-pitched call are the most recognizable indicators of active pika habitat. Prolific breeders, pikas usually have two litters of young each summer. The mortality rate is high for the youngsters and the first litter has a greater rate of survival. These small mammals are sensitive to temperatures above 77.9°F; therefore, they are most active during cooler parts of the day.
Quick Facts about Pikas
Did You Know?
Prior to the establishment of the National Park Service, the U.S. Army protected Yellowstone between 1886 and 1918. Fort Yellowstone was established at Mammoth Hot Springs for that purpose.