How feathers grow

When I was a child I always wondered how a naked bird got their feathers. I knew they grow out of the skin, but how? It can't be the same way like naked puppies get their fur because a feather is a lot more complicated than a single hair. Nowadays I know how a chick looks like when it get its bigger feathers. Let's see it under the cut!

Some chicks hatch naked, some others have a down feather plumage when they enter to our realm. But both kinds don't have full grown wing- and tail feathers yet. These feathers are strong and big, so how do they grow without getting damaged?

There are three stadia of a feather:

1. When a feather starts to grow and force trough the skin it is fully covered with chitin. That's the same material like our hair, fingernails or horn are made of. The little chitin stub is very dark, because the quill is supplied with blood. 
2.  After a while the top of the chitin coat crumbles away and the tip of the feather comes through it. It looks like a brush and hence it's called "brush stadium" in the German language. There's still a blood flow in the quill, because the feather isn't fully grown yet.
3.  The fully grown feather isn't supplied by blood anymore and the chitin coating has crumbled away. The feathers is now a lifeless thing without nerves, very much like our hair. 

The chitinous coating protects the growing feather, so it can't get damaged easily. A bird with a damaged plumage won't survive for long. During this process a young bird can look like a punk! xD

A young hoopoe.

I found these chitin-covered crow feathers near the lake on the ground. Maybe the young bird fell out of its nest and a fox or a cat found it. Who knows?

Fact is, that the "killer" must be a land predator, not a bird of prey. Why I know that? Look at the quills of the feathers, they look bitten off. A bird of prey would pull out the whole feather so remains intact.

Birds who eats other birds in my area are normally goshawks and sparrowhawks. Sometimes kites get nosey and like to visit a crow's nest (nom nom!). That's why crows tend to chase birds of prey away every time they feel bothered by them.

Feathers are so fascinating, aren't they? And I'm very happy that I have some "unfinished" feathers in my collection as well.