About Cyanocorax chrysops (Vieillot, 1818)
The plush-crested jay, Cyanocorax chrysops, is a medium-sized bird. Most of its plumage is dark blue, with cream-yellow underbelly, undertail coverts, underwings, and tail tip. The upper breast, neck, and most of the head are black. Its cheeks and nape are lighter blue, which fades into the darker blue of the body. It has a light-colored spot above its yellow eyes, and its bill ranges from dark blue to black. It has a rounded crest on its head, which gives the species its common name. The plush-crested jay's range starts in southern Brazil's Southern Region and extends into Uruguay, approaching but not reaching the South Atlantic coast. It avoids a 150 to 400 km wide coastal strip. Its coastal-inland range runs 3500 km from São Paulo south to Rio Grande do Sul on Uruguay's border. Its inland range continues into northwestern Uruguay, then extends northwest through northern Argentina, Paraguay, and Bolivia, through the Pantanal in the southern Cerrado. The range splits into two arms: one goes northwest to northern Bolivia, and the other goes northeast to the headwaters of the Tapajós River in the Amazon Basin. In the Amazon Basin, the northwest edge of the range is in central Bolivia, along headwater tributaries of the north-northeast flowing Madeira River. The range skips the Guaporé River, a northwest-flowing tributary of the Madeira on the Brazil-Bolivia border, and reappears at the Tapajós River headwaters, connecting east to the extreme headwaters of the Xingu River. A separate disjunct range block measuring 850 by 750 kilometres lies downstream on the Tapajós and east toward the Xingu River. Two more small localized populations exist in the Amazon Basin: one on the Amazon River, and one on the downstream Madeira River.
