Meaning of juvenal plumage

ju've•nal plum'age

Pronunciation: ( j'vu-nl), [key]
— Ornith. Ornith.
  1. the first plumage of birds, composed of contour feathers, which in certain species follows the naked nestling stage and in other species follows the molt of natal down.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.