Cyanocorax is a genus of New World jays, passerine birds in the family Corvidae. It contains several closely related species that primarily are found in wooded habitats, chiefly in lowland tropical rainforest but in some cases also in seasonally dry forest, grassland and montane forest. They occur from Mexico through Central into southern South America, with the green jay and brown jay just entering the United States in southernmost Texas, and the azure and plush-crested jays occurring southwards to the lower Paraná River basin. This genus is considered especially close to Cyanolyca, an upland radiation occurring throughout the American Cordillera from Mexico to Peru and Bolivia, who look very similar to the blue-and-black species of Cyanocorax except for being a bit smaller. The North American blue jay genera Aphelocoma, Cyanocitta and Gymnorhinus seem to be slightly less closely related.
Cyanocorax jays are generally black-and-blue, often with considerable amounts of white plumage, but brown or yellow to green in a few species. Some species have elongated neck plumes, some others have crests or bristle tufts on the forehead; a few have patches of bare skin on the face. The eyes are bright yellow in just over half the species, the bills black in adults (yellow to pinkish in juveniles), and the feet usually black, but brown or yellow in a few species.
The genus Cyanocorax was described by the German zoologist Friedrich Boie in 1826, with the plush-crested jay as the type species. The generic name is derived from the Ancient Greek words κυανος (kuanos), meaning "dark blue", and κοραξ (korax), meaning "raven".
Systematics and evolution
With the merge of the formerly separate genera Calocitta (the two magpie-jays) and Psilorhinus (brown jay) into Cyanocorax, the genus now contains around 20 species:
The expanded genus Cyanocorax can be neatly divided into two clades, the first containing the former Calocitta and Psilorhinus, as well as the South American lineage which was...
