Meet the Piute Ground Squirrel, Urocitellus mollis, a smaller cousin to Alaska’s Arctic Ground Squirrel.
It used to be called Townsend’s Ground Squirrel, but biologists decided the Great Basin populations were a separate species; hence, the Piute Ground Squirrel. The Piute Ground Squirrel is a desert specialist, with a unique life cycle adapted to the harsh desert environment. The species hibernates in the winter, but rouses in late winter to forage, breed and disperse. Then, in the hot part of the summer, it enters a state of torpor – the technical term is aestivation – to survive the baking hot months. Ultimately, the species spends some 7.5 months of each year either hibernating of aestivating.
The lethargic life style doesn’t suppress their numbers. In good habitat, and Piutes prosper best in high sagebrush steppe, they number in the tens of thousands. In one mile along Swan Falls Road Sunday morning, WC counted 107 between the fence and the asphalt. In good habitat, it sometimes looks like the desert floor is crawling.
The incredible seasonal density of the species the reason there is a Morley Nelson Snake River Birds of Prey National Conservation Area. Four species of hawks – Red-tailed, Ferruginous, Swainson’s and Rough-legged – snack on Piute Ground Squirrels. American Kestrels will take juvenile Piutes. But the Prairie Falcons, especially, regard Piutes as preferred prey. Which is why the NCA has the highest density of Prairie Falcons in North America.
Hey, baby raptors have to eat, too. Someone has to be at the bottom of the food chain. In the sagebrush steppe of the Snake River Plain, it’s the Piute Ground Squirrel.