Aphelocoma

The passerine birds of the genus Aphelocomainclude the scrub jays and their 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 is not closely related to other jays, magpies or treepies. They live in open pine-oak forests, chaparral, and mixed evergreen forests. Seven species of Aphelocoma are generally recognized currently. They are believed to have evolved in the Pleistocene, and the Florida species is known to have been recognizably distinct and present in its current range for at least 2 million years. The inland, coastal, and Santa Cruz island populations of the (former) western scrub jay are now considered three distinct species, namely Woodhouse's, the California and the island scrub jays. Two different populations of the Mexican jay might similarly represent two distinct species. The western scrub jay is now made up of three species. These would be separated by the Great Basin, with the Pacific coastal lineage (California scrub jay) and the island scrub jay, as well as the inland lineage (Woodhouse's scrub jay), with the Florida scrub jay being a sister species. This treatment fails to address the problem of birds from inland southern Mexico. Nonetheless, it is actually because the molecular diversity pattern is so badly resolved that it supports the view that rapid Late Pliocene radiation of the North American scrub jays led to the present diversity. Studies on the evolutionary history of Aphelocoma jays suggests that all New World jays originated in North America or Mesoamerica. 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, the unicolored jay, is blue all over, superficially similar to the pinyon jay from much further north. The bill, legs, and feet are black. The diet consists mainly of acorns and pine nuts. However, grain, berries, and other fruits are often eaten as well. These birds can also be omnivorous; their diet can include insects, eggs and nestlings, small frogs, mice, and reptiles. As food-storing birds, the scrub jays demonstrate a unique episodic memory. They can find their food hiding places with great precision, even several days after the initial cache. 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 30 cm to 60 cm. 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 relatives of the breeding pair.