The nominate subspecies above left with lighter head and white brow is known as just the Hawk-headed or as the Buff or Guyana Hawk-headed Parrot, Deroptyus accipitrinus accipitrinus. It comes from north of the Amazon (Guyana/North Brazil).
The other of the two subspecies above right with dark head and dark brow is known as the Brazilian Hawk-headed Parrot, Deroptyus accipitrinus fuscifrons.
It comes from Brazil (obviously), south of the Amazon.
The Hawk-headed is one of the most striking looking parrots with its nape and chest feathers of claret bordered with light blue and its bright green cloak.
When threatened or excited, it raises its claret and blue crest above its head like a frilly bonnet (above left). "Cubs' honour" (above right).
Brazilian Hawk-headed Parrot (above and immediately below)
Buff Hawk-headed Parrot (above and below)