Re: How do feathers grow?

ANSWERS:

There were a few different answers that I was able to come up with through some of my contacts... I have listed them in the order of complexity and what I think is probably correct.

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Here's answer #1 and I think it is the closest thing to a proper answer: Check out http://www.mindspring.com/~mi ntz/groom.html

"molt A process in arthropods, such as crustaceans and insects, as well as in some vertebrates, such as snakes, whereby the organism sheds its outer exoskeleton or skin periodically as it grows. Also refers to changing the pelage or feathers in a mammal or bird."
"Most birds molt, or replace, their flight feathers once a year; some do it more often. The alternating bands of lightly pigmented and heavily pigmented feather material are laid down while each feather is growing--a process that usually takes two to four weeks. The new feathers sprout from follicles in the skin, somewhat like human hair. But whereas hair keeps growing almost indefinitely, feathers grow until they are fully formed, then stop. The blood supply to the follicle cuts off, and the feather maintains its form until the next molting cycle."
"There are two categories of feather quality: Hard and Soft. Hard feathered birds have tight plumage and bright colors. Soft feathered canaries have downier plumage and the colors are subdued. In general, a Soft feathered bird should always be mated to a Hard feathered bird. If Soft feathered birds are bred together for a number of generations, feather lumps will begin to appear. Feather lumps are unsightly masses of ingrown feathers. The Gloster canary, the best examples of which are all Soft feathered, is especially prone to this malady of genetic origin."
"I'm sure they happen in nature, but broken blood feathers are probably more of a malady of domestic parrots whose flight feathers have been clipped. A blood feather is a new feather that is still developing, and which still has a supply of blood flowing into it. We usually notice them if they are wing or tail feathers, since those are bigger feathers with more potential for bleeding a lot! Feathers grow out of a follicle (just like do our hairs). Each new feather starts out as a little bud inside the follicle. As it grows, it will bump the older feather out of the way, and this other feather will fall off. The new feather grows in a telescoping fashion: the tip develops first, and it emerges well before the rest of the feather is built. A constant blood supply is necessary to transport the "building materials" to the growing feather. Once the feather is fully developed and unfurled, it stays attached to the rest of the bird by a "root" within the follicle. [...] People often ask 'well, if broken blood feathers are so dangerous, why don't birds bleed to death in the wild, all the time?!' The answer is in part that, since not all wing (or tail) feathers get molted at once, each new feather is in effect protected while it grows by flanking feathers. In a clipped bird, the new feather is exposed; as such, it has a better chance of getting damaged."