There is bare white skin around the eye and from there to the bill. Tiny white feathers are contained on the face patch. The upper mandible is mostly pale horn in color and the lower is black. Juveniles have dark eyes; adults have light yellow eyes.
It is frequently confused with the slightly larger Green-winged Macaw, which has more distinct red lines in the face and no yellow in the wing.
Scarlet Macaws make very loud, high and sometimes low-pitched, throaty squawks, squeaks and screams designed to carry many miles to call for their groups.
The Scarlet Macaw can live up to 75 years in captivity, although a more typical lifespan is 40 to 50 years.
Data reffer : http://en.wikipedia.org/wiki/Scarlet_Macaw