leave the nest
Verb
Meaning
To leave home; To stop living with one's parents.
To become independent; To begin to act without supervision or in ways that are not prescribed.
Used other than figuratively or idiomatically: see leave, nest.
Source: en.wiktionary.orgSynonyms
Examples
Both parents incubate a brood for 23 to 24 days, and the precocial young leave the nest shortly after hatching.
She will "sit" or "set" on the nest, protesting or pecking in defense if disturbed or removed, and she will rarely leave the nest to eat, drink, or dust-bathe.
Barn Owl chicks are ready to leave the nest when they are seven to eight weeks old.
Squabs grow rapidly, but are slow to fledge and are ready to leave the nest at 26 to 30 days weighing about convert.
Fledglings leave the nest at between 40 and 55 days.
In most species, chicks leave the nest just before, or soon after, they are able to fly.