About Diopsittaca nobilis (Linnaeus, 1758)
The red-shouldered macaw, with the scientific name Diopsittaca nobilis (Linnaeus, 1758), measures 30 cm (12 in) long and weighs 165 g (5.8 oz), making it the smallest of all macaws. Like all macaws, it has a long narrow tail and a large head. Its body is covered in bright green feathers, with dark or slate blue feathers on the head just above the beak. The upper surfaces of the wing and tail feathers are bright green, while their lower surfaces are olive-green. The leading edges of the wings, especially on the underside, are red; these red feathers develop when the bird reaches puberty. The red-shouldered macaw has orange eyes and bare, white featherless skin around the eyes, matching the trait seen in larger macaws. Compared to most larger macaws, this bare patch of facial skin is smaller in proportion to the head. Hahn's macaws and noble macaws (subgroups of this species) can be distinguished by the color of their upper mandible: it is black in Hahn's macaws and horn-colored in noble macaws. The natural vocalizations of this species are more similar to screeches than to whistles.
