Arctic ground squirrel

The Arctic ground squirrel (Urocitellus parryii) (Inuktitut: ᓯᒃᓯᒃ, siksik) is a species of ground squirrel in the squirrel family Sciuridae that is native to the Arctic and Subarctic regions of the Northern Hemisphere, mainly in North America and Asia. It is the largest species in the genus Urocitellus, its range extends farther north than that of any other squirrel, and it is the only member of the squirrel family with a Holarctic distribution. For some people in Alaska, particularly around the Aleutian Islands, the rodents are known as "parka" squirrels, likely due to their pelts being used for the ruff on parkas and other cold-weather clothing. Subspecies listed alphabetically. The species was long placed in the genus Spermophilus. A 2009 generic revision of the Holarctic ground squirrels, prompted by molecular evidence that Spermophilus as then defined was paraphyletic, moved it to Urocitellus. Phylogeographic studies of mitochondrial DNA have identified geographically distinct clades within the species. An Arctic clade occupies Arctic and subarctic populations north of the Yukon River in northern Alaska and Canada, while a Southeast clade, which includes U. p. plesius, occurs south of the Yukon River in south-central Alaska and western Canada; further clades occur in western and southwestern Alaska and on the Bering Sea islands. A 2026 ancient DNA study of Pleistocene squirrel droppings from the Klondike found that U. parryii mitochondrial lineages do not form a single group, and its authors concluded that the current taxonomy of the species is not monophyletic and called for nuclear genomic work to resolve it. The Arctic ground squirrel typically has a beige-tan pelage with a lightly spotted backside.