Cascade Golden-mantled Ground Squirrel

The Cascade golden-mantled ground squirrel (Callospermophilus saturatus) is a species of rodent in the family Sciuridae, in the order Rodentia. It is the largest species of the three within the genus Callospermophilus. It is found in the Cascade Mountains in the province of British Columbia, Canada, and the state of Washington, United States. == Morphology == Larger in size than its C. madrensis and C. lateralis counterparts, C. saturatus has a vague russet color outlining its head and shoulders and running down the length of its body (at least 286 mm). == Distribution == C. saturatus occurs in the northwestern United States, north of the Columbia River, south of the Tulameen River in British Columbia, and west of the Similkameen River. No fossils have yet been found. C. saturatus is isolated from its sister species S. lateralis by the Columbia River; their differentiation is likely due to allopatric speciation. == Physiology == At birth, C. saturatus are ectothermic. Development of endothermy occurs gradually as individuals grow, increasing both body mass and amount of body fur. Individuals removed from their mother at 6 days of age lost body temperature at a faster rate than at 36 days, when individuals were able…