gray squirrel

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A common squirrel (Sciurus carolinensis) of eastern North America, having grayish or blackish fur.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Sciurus griseus, a species of squirrel, found along the western coast of the United States and Canada, the eastern gray squirrel.
• noun Sciurus carolinensis, a species of squirrel, found in the eastern and midwestern United States and Canada, and western Europe, western gray squirrel.