Marmots are large ground squirrels in the genus Marmota, with 15 species living in Asia, Europe, and North America. These herbivores are active during the summer, when they can often be found in groups, but are not seen during the winter, when they hibernate underground. They are the heaviest members of the squirrel family. Marmots are large rodents with characteristically short but robust legs, enlarged claws which are well adapted to digging, stout bodies, and large heads and incisors to quickly process a variety of vegetation. While most species are various forms of earthen-hued brown, marmots vary in fur coloration based roughly on their surroundings. Species in more open habitat are more likely to have a paler color, while those sometimes found in well-forested regions tend to be darker. Marmots are the heaviest members of the squirrel family. Total length varies typically from about 42 to 72 cm (17 to 28 in) and body mass averages about 2 kg (4+1⁄2 lb) in spring in the smaller species and 8 kg (18 lb) in autumn, at times exceeding 11 kg (24 lb), in the larger species. The largest and smallest species are not clearly known. In North America, on the basis of mean linear dimensions and body masses through the year, the smallest species appears to be the Alaska marmot and the largest is the Olympic marmot. Some species, such as the Himalayan marmot and Tarbagan marmot in Asia, appear to attain roughly similar body masses to the Olympic marmot, but are not known to reach as high a total length as the Olympic species. In the traditional definition of hibernation, the largest marmots are considered the largest 'true hibernators' (since larger 'hibernators' such as bears do not have the same physiological characteristics as obligate hibernating animals such as assorted rodents, bats and insectivores). (Source: Wikipedia.org, CC BY-SA)