Snake River Plains ground squirrel
The Snake River Plains ground squirrel is a species of rodent in the family Sciuridae endemic to Idaho in the western United States. It was formerly considered to be a subspecies of the Piute ground squirrel, before being identified as a distinct species on the basis of genetic differences in 2025.
Taxonomy and systematics
The species is part of the "small-eared" species group of Urocitellus ground squirrels, which are endemic to the Great Basin and surrounding cold desert ecosystems of the western United States. Historically, populations north of the Snake River in Idaho were classified as subspecies of the Piute ground squirrel under the names U. m. idahoensis and U. m. artemesiae.Integrative taxonomic analysis using two multilocus nuclear DNA datasets provided decisive support for recognizing these northern populations as a distinct species. Genetic divergence between populations north and south of the Snake River is deep, with the lineages even being non-sister taxa.
Description
The Snake River Plains ground squirrel is a small-to-medium-bodied, fossorial ground squirrel within the small-eared group. Members of this group are characterized by pale coloration and adaptations to arid, desert-dwelling environments.Cranial morphology shows differentiation between the two subspecies : U. i. idahoensis is generally larger-bodied with a more robust cranium and dentition, while U. i. artemesiae is relatively smaller with a more slender cranium.
Like other small-eared Urocitellus, it is an obligate heterotherm, hibernating through winter and estivating in summer.