What is going on with this new mutant feather?

[Macawdamia Nut]

My macaw has a new tail feather growing in. I would say it is about 80% fully grown. Today I noticed a “bald” stripe running the length of it that is visible when the feather is held up to the light. I have never seen this sort of thing before. Any ideas of what caused this stripe? Damaged follicle? Foreign object in follicle? Other ideas?

 

[DonnaBudgie]

It almost looks like overzealous grooming may have damaged it. The stripe doesn't run down to the quill- only a part of one side. Perhaps he ran the feather through his beak and folded it hard in the process, making a damaged stripe.

 

[Macawdamia Nut]

It almost looks like overzealous grooming may have damaged it. The stripe doesn't run down to the quill- only a part of one side. Perhaps he ran the feather through his beak and folded it hard in the process, making a damaged stripe.

He is such a delicate preener! This feather stands out because all other feathers are perfect. Maybe it got trapped in the waxy sheath and folded in on itself? I would love to hear other theories.

 

[rheashard2]

I tend to agree that feather got a 'kink' or bend to side while developing.

 

[wrench13]

Fluoride in the drinking water? Prayer in the classroom? Coca-Cola changed the formula in Classic Coke?

 

[DonnaBudgie]

He is such a delicate preener! This feather stands out because all other feathers are perfect. Maybe it got trapped in the waxy sheath and folded in on itself? I would love to hear other theories.

It does look like a crease. This feather may not be perfect, but its perfect enough, and now you can pick him out in a macaw lineup, like having a birthmark or a tattoo, at least until it's replaced.

Watch for the next time he gets a new feather out of that follicle and see if it's normal. I realize that may be two years for a large macaw's tail feather.