飛羽長成

Also known as fledge, fledgeling, leaving the nest

thumb|upright=.8|Fledging stage of the northern mockingbird (Mimus polyglottos) Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable condition in the nest, the nestling and fledging stage can be the same. For precocial birds, those that develop and leave the nest quickly, a short nestling stage precedes a longer fledging stage.