Although the Eastern Fox Squirrel is not a native species to Oregon, this squirrel is not listed as “invasive” by the Oregon Department of Fish and Wildlife definition:
Invasive species are animals and plants that are not native to an ecosystem and that cause economic or environmental harm. While not all non-native species are invasive, many become a serious problem. They damage Oregon’s habitats and can aggressively compete with native species for food, water and habitat.
The City of Portland does list five urban squirrels, including the Eastern Fox Squirrel, on its List of Invasive Animals.
Fox Squirrels were brought to Oregon from the eastern United States and have established themselves in urban and suburban habitat through the state. They are the most common tree squirrels found in Portland and have contributed to the decline of native squirrel species.
Fox Squirrels are reddish brown in color with large bushy tails and tan undersides. Oregon’s Fox Squirrels are notorious for breeding “out of season,” and infant and very young squirrels found later than Oct. 1 and earlier that April 1 are typically members of this species. Cut from: Urban Squirrels- Audubon Society of Portland