A baby parrot goes through five basic developmental stages: neonate or hatchling, nestling, fledgling, weanling, and juvenile or pre-adolescent.
The first stage is the "neonate" or "hatchling." This newly hatched baby still has its eyes closed and is completely dependent on its parents or humans to provide food and a warm environment.
The second stage is the "nestling." At this point, the bird's eyes are open, but it still relies on a parent bird or human for feedings. It is very important that it also receive visual, touch, sound, and interactive enrichment for proper development.
The third stage is the "fledgling" parrot that is learning to fly. Fledglings often slim down at this stage as they are obsessed with flying and lose some interest in food. They still need to be provided with food, as they are unable to acquire it themselves.
The fourth stage of parrot development is called the "weanling," in which the bird begins to eat food on its own and take care of itself. Gathering food while foraging requires numerous motor skills that must be developed before birds can be completely weaned.
In the fifth and final stage, the bird earns the title of a "juvenile" or "pre-adolescent" bird. It will be completely weaned and independent from its parents but has not yet reached sexual maturity.
All of these stages occur at different times in different species, with some stages taking more time than others.