The beak is strong and is used to crush the seeds and nuts, while the thick fleshy tongue is used to move the food around. Very hard nuts are cracked open after the macaw files down the thickness of the shell in one place. This is done with the lower part of the beak. Although their diet consists mainly of fruits, seeds, nuts, leaves and bark, they also feed on small animal life. Macaws are monogamous.
Breeding takes place during the first half of the year.
The nest is usually in a hole at the top of a tall dead tree. The hole may previously have been made and used by a woodpecker. The female lays one or two eggs and incubates them for 24-26 days, while the male feeds her. On hatching, the young are blind and almost naked. The eyes open after 7-14 days.