Tree squirrel Tree squirrel Tree squirrels are the members of the squirrel family (Sciuridae) commonly just referred to as "squirrels". They include over a hundred arboreal species native to all continents except Antarctica and Oceania. They do not form a single natural, or monophyletic group; they are related to others in the squirrel family, including ground squirrels, flying squirrels, marmots, and chipmunks. The defining characteristic used to determine which species of Sciuridae are tree squirrels is dependent on their habitat rather than their physiology. Tree squirrels live mostly among trees, as opposed to those that live in burrows in the ground or
Vicente Pérez Rosales National Park reeds. A diversity of animals of the rodent group live in the park. The larger ones are coipo, coypu, "Myocastor coypus", a webbed-feet animal that inhabits reedy lake and river banks; and Wolffsohn's viscacha, "Lagidium wolffsohni", of the family Chinchillidae, whose preferred habitat is above the timber line. Among the smaller rodents, scientists have shown particular interest for Chilean climbing mouse, "Irenomys tarsalis", and for the long-clawed mole mouse, "Geoxus valdivianus". The park is home to two species of marsupial mammals. Monito del monte, "Dromiciops gliroides", has a semi-arboreal habit. It has been discussed why this South American marsupial appears