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
Habitat fragmentation interior habitat. Another mitigation measure is the enlargement of small remnants in order to increase the amount of interior habitat. This may be impractical since developed land is often more expensive and could require significant time and effort to restore. The best solution is generally dependent on the particular species or ecosystem that is being considered. More mobile species, like most birds, do not need connected habitat while some smaller animals, like rodents, may be more exposed to predation in open land. These questions generally fall under the headings of metapopulations island biogeography. As the remaining habitat patches are smaller,