gray jay

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

• noun A bird (Perisoreus canadensis) of North American coniferous forests, having gray plumage and a black-capped head.

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

• noun A mostly gray bird, Perisoreus canadensis, that inhabits coniferous forests of North America.
• noun Any bird of the genus genus.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a jay of northern North America with black-capped head and no crest; noted for boldness in thievery