Many people adopt a bird without knowing his exact age. Knowing the age of your bird can help your veterinarian develop a more accurate list of potential illnesses or disorders that might affect your bird. The following might give you some hints:
Feathers. The feathers of young psittacines are typically dull-colored. The brilliant colored plumage typically associated with the species develops at maturity. For those species whose young have coloration similar to adults, the tail feathers are typically shorter than adult birds.
Beak color. In some species, beak color varies with age. If the adult bird has a dark bill, juveniles usually have light-colored bills. Those birds that have light colored adult bills will have dark colored or dark bands at the base of the beak when young.
Iris color. This can also be used to determine age. In most psittacines, the iris color of very young birds is brown or dark colored. In macaws, this color fades to grey within 1 year of age, changes to white at age 1 to 3 and yellow as the bird ages beyond 3 years. In some Amazons, the iris changes to red-orange as the bird matures. The iris of African Grey’s change from brown to grey to white as they mature.