American red squirrel

Description

The American red squirrel (Tamiasciurus hudsonicus) is one of three species of tree squirrels currently classified in the genus Tamiasciurus, known as the pine squirrels (the others are the Douglas squirrel, T. douglasii, and the southwestern red squirrel, T. fremonti). The American red squirrel is variously known as the pine squirrel, North American red squirrel and chickaree. It is also referred to as Hudson's Bay squirrel, as in John James Audubon's work The Viviparous Quadrupeds of North America (hence the species name). The squirrel is a small, 200–250 g (7.1–8.8 oz), diurnal mammal that defends a year-round exclusive territory. It feeds primarily on the seeds of conifer cones, and is widely distributed across North America wherever conifers are common, except on the Pacific coast of the United States, where its cousin, the Douglas squirrel, is found instead. The squirrel has been expanding its range into hardwood forests. Red squirrels can be easily distinguished from other North American tree squirrels by their smaller size, 28–35 cm (11–14 in) total length (including tail), territorial behavior, and reddish fur with a white venter (underbelly). Red squirrels are somewhat larger than chipmunks. The Douglas squirrel is morphologically similar to the American red squirrels, but has a rust-colored venter and is restricted to the southwestern coast of British Columbia and in the Pacific Northwest of the United States. The ranges of the American red squirrel and the Douglas squirrel overlap in southern British Columbia, northwestern Washington and eastern Oregon. American red squirrels should not be confused with Eurasian red squirrels (Sciurus vulgaris); since the ranges of these species do not overlap, they are both commonly referred to as "red squirrels" in the areas where they are native. The specific epithet hudsonicus refers to Hudson Bay, Canada, where the species was first catalogued by Erxleben in 1771.A recent phylogeny suggests the squirrels as a family can be divided into five major lineages. Red squirrels (Tamiasciurus) fall within the clade that includes flying squirrels and other tree squirrels (e.g., Sciurus). There are 25 recognized subspecies of red squirrels. The southwestern red squirrel (T. fremonti) was long considered conspecific with T. hudsonicus, but a 2016 phylogenetic study found it to be a distinct species.