The Mealy Amazon has a total length of about 38â€“41 cm (15â€“16 in) and weighs 540-700 g (19.01-24.64 oz). Captives commonly are heavier. It is among the largest parrots in the Americas, mainly being surpassed by the large macaws. It has a relatively short and squarish tail, as do the other members of the Amazona genus.
The Mealy Amazon is mainly green. The back and nape often have a whitish tinge; almost as if it had been covered in a thin layer of flour (“meal”; hence its name). The distal half of the tail is paler and more yellow than the basal half, thus resulting in a distinctly bi-coloured look. In flight it shows a bluish-black trailing edge to the wing and a conspicuous red speculum. Occasionally a few yellow feathers are apparent on the top of the head and two subspecies, virenticeps and guatemalae, have a bluish-tinged crown. The maroon to orange eyes (typically appear dark from a distance) are surrounded by a relatively broad white eye-ring of bare skin.
In South America, it is commonly confused with the Yellow-crowned Amazon, but can be recognized by its larger size, less yellow to the crown (not entirely reliable, as some Yellow-crowned may show almost none), the whitish tinge to its plumage, broader white eye-ring, and red of the leading edge of the wing placed near the phalanx (not near the radiale), but this is often difficult to see (especially on perched birds). Their voices are also strikingly different.
Info from www. wikipedia.org
Pic from www.pbase.com