The plumage is mostly scarlet, but the lower back and tail feathers are light blue, the upperwing coverts are yellow, the upper sides of the flight feathers of the wings are dark blue as are the ends of the tail feathers, and the undersides of the wing and tail flight feathers are dark red with a yellow-gold colour. Occasionally some individuals may have green in the wings. It is often confused with the Red-and-green Macaw, which is slightly larger and has more distinct red lines in the face and no yellow in the wing

With their wide strong wings, macaws can reach speeds of 35 miles per hour. They often fly in pairs or small groups and often call to each other in raucous hoarse voices.

Macaws appear to prefer higher elevations and riverine forests. They are known to have very large territories. They prefer to nest in holes high up in trees and lay one or two eggs. They feed on specific fruits such as polewood, roaming large areas searching for clumps of their favorite foods.

The Scarlet Macaw is a CITES I listed species, meaning that they are illegal to take from the wild without specific special permits. Although not currently listed as endangered they are very vulnerable to the pet trade. Like many rarer parrot species today, they are occasionally smuggled to the United States or Canada where they wind up seized by authorities, unfortunately not all perpetrators are caught and some birds are sold illegally. Many smuggled parrots die from stress or suffocation during the journey.

Scarlet macaws can live up to 80 years in captivity, they require a large size cage and plenty of time out free to exercise their muscles and socialise, they require a great deal of stimulation, attention, and affection.