Growing streamers of Drongo

Going through old images, I was glad to come across a couple of images, although not so sharp, of an immature Greater Racket-tailed Drongo and its just emerging streamers. 

I was lucky to capture too this set of images, as a comparison, that suggest that a Drongo does not grow its streamers evenly in length.
Another learning experience, another fascinating observation of an avian trait.