The passerine birds of the genus Aphelocoma[A]) include the scrub-jays and relatives. They are New World jays found in Mexico, western Central America and the western United States, with an outlying population in Florida. This genus belongs to the group of New World (or "blue") jays - possibly a distinct subfamily - which are not closely related to other jays, magpies or treepies (Ericson et al, 2005 ). They live in open pine-oak forests and chaparral scrub habitats.

Aphelocoma jays are slightly larger than the Blue Jay and differ in having a longer tail, slightly shorter, more rounded wings, and no crest on the head. The top of the head, nape, and sides of the head are a rich deep blue. Some species have a white stripe above the eye and dark ear coverts. The breast is also white or grey-white and the back is a grey-brown contrasting with the bright blue tail and wings in most species. One species, Unicolored Jay, is blue all over, superficially similar to the Pinyon Jay from much further north. The bill, legs, and feet are black.

Food is taken both on the ground and in trees. Acorns and pine nuts are the most important foods, making up the great bulk of the diet, with grain, berries and other fruits making up the rest of the vegetable diet. Many insects and other invertebrates are also taken, and eggs and nestlings, small frogs, mice and reptiles.

Wild Aphelocoma jays are frequent visitors at campsites and picnics and have frequently learned to eat from the hands of people where they have become accustomed to being fed.

The nest is in a tree or a bush, sometimes quite low down. The nests are compact and lined with hair and fine roots with an outer diameter of about 30cm to 60cm. Usually 2 to 4 eggs are laid and incubated over 14 to 16 days. There are two main variations of egg shell color: green with olive markings or a paler background of grayish-white to green with red-brown markings. The Florida Scrub-jay and the Mexican Jay both have cooperative breeding systems involving several 'helpers' at each nest, usually siblings of the main pair.

Aphelocoma jays are quite vocal and have a huge range of sounds and calls; common calls include a cheek, cheek, cheek and a guttural churring krr'r'r'r'r. Aphelocoma jays are also, like all other jays, often quite aggressive at feeding areas, and sometimes regarded as a nuisance.