any of about 35 to 40 bird species belonging to the family Corvidae (order Passeriformes) that inhabits woodlands and is known for its bold, raucous manner. Most are found in the New World, but several are Eurasian. Jays are nearly omnivorous; some are egg-stealers, and many store seeds and nuts for winter use. They make a twiggy, cuplike nest in a tree. After breeding, most species are gregarious.

The 30-centimetre (12-inch) blue jay (Cyanocitta cristata), blue and white with a narrow black neckline, is found in North America east of the Rockies; westward it is replaced by the dark-blue, black-crested Steller's jay (C. stelleri). Another conspicuous and abundant jay, found throughout western North America and in Florida, is the scrub jay (Aphelocoma coerulescens), locally called “blue jay” but lacking a crest. The Eurasian jay (Garrulus glandarius) occurs over most of the continental Old World except sub-Saharan Africa; about 33 cm (13 inches) long, it is pinkish brown, with blue-and-black-barred shoulders, white rump, and white wing-patches. Among brightly coloured forms in tropical America is the green jay (Cyanocorax, sometimes Xanthoura, yncas).