Green-winged macaws have large beaks for applying up to 1,000 pounds per square inch of force. Both the upper and lower beak can open separately, and they both have muscles attached for additional biting force. The beak is made of bone with a thin layer of keratin on top, providing the rigidity needed to prevent breakage under so much force. The upper layers of keratin do crack sometimes, but they are replaced with fresh keratin from lower layers. They eat nuts, fruit, berries, and leaves. They can supplement mineral and sodium intake by eating clay.
Their four toes on each foot are arranged two forward, two back. This is called a “zygodactylous” foot and is better for climbing on branches than the three forward, one back that many birds have. They can also use their feet to hold fruit and nuts while they eat. Macaws are messy eaters, which makes them important for seed dispersal. Fruit and nut trees grow wherever a flock of macaws drops its leftover food.
Sexual maturity occurs around 3 to 4 years of age. Green winged macaws are monogamous and mate for life. They build nests in tree hollows as high as possible to avoid predators. The female lays 2 to 4 eggs per clutch. Incubation lasts around 25 days and is completely accomplished by the female. Juveniles remain with both parents for around 3 months while they learn how to feed and fly.
They travel in large flocks between foraging spots, following the seasonal abundance of different fruits and nuts. They can fly up to 55 km/h! All macaws, including the green-winged macaw, have a bare patch of skin somewhere on their face. This is to exchange heat with the environment.
Green-winged macaws have a maximum lifespan of 80 to 100 years.