Not all birds fit neatly into categories, but it is common and practical to describe altricial birds as hatchlings, nestlings, or fledglings.
|Hatchlings are naked or have minimal feather/down development. They are usually less than a week old and have closed eyes. Hatchlings require warmth and frequent feedings.|
|Nestlings can have just a covering of down, or be nearly feathered. They may have patches of exposed skin or tufts of down poking out of their feathers. Their eyes are open. They can move around somewhat, but they tend to stay in one spot. Nestlings require warmth and food.|
|Fledglings are fully feathered birds, often with very short tails. They are active and mobile; they walk and jump and are learning to fly. Fledglings range in flying ability from very poor to some ability to fully flighted. These birds are too old to be returned to a nest–they will not stay put.|
|These are birds such as eagles, hawks, falcons and owls.|