It is found in eastern Brazil, central and eastern Bolivia, Paraguay, and northern Argentina. It is found in a wide range of wooded habitats, from humid subtropical forest to arid Caatinga. It is fairly common throughout a large part of its range. It is typically seen in pairs or small flocks. The scaling to the head for which it is named is typically far less distinct than the bright red undertail coverts (a feature found in all members of the genus Pionus).
In Brazil, they are called cocotas or maritacas (from mbaÃ©’taka, tupi for “noisy bird”)
Pic from www.jboyd.net
Info from www. wikipedia.org