Having acquired adult feathers (5,7)
I believe the answer is:
fully fledged
(Other definitions for fully fledged that I've seen before include "Completely developed" , "In finished state; ready to fly" , "leave home for a lark?" , "Mature" .)
I believe the answer is:
fully fledged
(Other definitions for fully fledged that I've seen before include "Completely developed" , "In finished state; ready to fly" , "leave home for a lark?" , "Mature" .)