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
Brazilian arboreal mouse Brazilian arboreal mouse The Brazilian arboreal mouse ("Rhagomys rufescens") is a South American rodent species of the family Cricetidae. It is found in the Atlantic Forest of southeast Brazil, often close to bamboo thickets. It can be distinguished from "Rhagomys longilingua", the only other species in its genus, by the absence of spines among the hair. Formerly believed to be extinct after no sightings were recorded for over 100 years, the species has since been found in four localities. However, it is nowhere common, and all of these are forest fragments, and ongoing deforestation threatens the species' survival. For these