Eight species of palm are central to its diet. Its exceptionally powerful bill, the largest of its kind in the world, allows it to eat otherwise inaccessible nuts and seeds. Macaws can eat some poisonous seeds and unripe fruits that no other animal can digest. Scientists believe this is possible because the birds eat chunks of clay from river banks. The clay is thought to help absorb the poisons or make them harmless.
Macaws play an important role in seed dispersal.
They are messy eaters, carrying and dropping many nuts and seeds. All 18 species of macaws are threatened. The primary causes are habitat loss and heavy exploitation for the pet trade. The hyacinth macaw is especially vulnerable to capture and habitat destruction because it is noisy, intrinsically fearless, predictable, and dependent on palm trees. This high price fosters a dangerous level of poaching and smuggling.