
Behold the molting hen, Gallus domesticus uglius.
Her feathers are loose and fall off everywhere, especially in the coop at night. You can see the prickly new pinfeathers growing in on her head and neck. She is cold, irritable, does not like to be touched. The photo above was taken on December 1.

Here is a photo taken yesterday of the same hen, Marianne, a barred Plymouth rock. She has grown her tail back and her head and neck are covered now too. She will be the last of my four hens to complete the annual molt, which typically occurs in mid-to-late autumn.
The new feathers look really nice! A couple of my birds had been looking ratty and disheveled for months. Ella the Easter Egger especially had a lot of broken feathers.

Here is Ella in August, just a few scraggly tail feathers, messy broken feathers on her back and neck. Not very photogenic. Some it it may be a slow (months-long) molting process.

Now (yesterday) look at her lovely new plumage.
Take a bow, Ella Fitzgerald. She is fatly feathered and fit for winter.

All birds molt.
A feather is a “dead” structure, somewhat analogous to hair or nails in humans. The hardness of a feather is caused by the formation of the protein keratin. Since feathers cannot heal themselves when damaged, they have to be completely replaced. The replacement of all or part of the feathers is called a molt. Molts produce feathers that match the age and sex of the bird, and sometimes the season.
Molting occurs in response to a mixture of hormonal changes brought about by seasonal changes. The entire process is complex and many questions remain regarding how the process is controlled.
None of my four hens are laying eggs right now, which is normal during molt and often in winter. They need more daylight (or artificial light) to stimulate laying.

Lucy the Rhode Island red, with shiny new feathers.
I prolonged laying their first year with light in the coop, but last year I let them have a break when they stopped laying during molt in December. They started again in early February, when daylight was over 10 hours rather than the 9 we get now (at the winter solstice).

Fluffy butt is a characteristic of the Buff Orpington breed.
Grace Kelly has an abundance of perfect new feathers. She has always been a perfectly lovely looking bird (even during molting), and a good layer, but she is not especially friendly.

She still has a few new pin feathers coming in around her neck. New feathers push out the old.
More on The Molt, from Hencam Blog…
Molting is a messy, lengthy, disruptive event. Each chicken has about 8,500 feathers. Some birds will lose all of them, seemingly at once. It’s as if the hen is a cartoon character that sneezes and then finds herself embarrassingly naked. More often than not, it’s a patchy affair, with some bald spots and other areas looking raggedy. A few chickens never look scraggly and you can tell that they’re molting only by the evidence of their feathers on the ground. Like the leaves falling in autumn, the a flock doesn’t molt at the same time or pace. It can take a several months for everyone to lose their feathers and during that time the coop will look as if there’s been a pillow fight overnight. Every night.
I like feathers.

Sometimes I pick them up and save them. Here is a feather from the barred rock, on the porch railing, with tiny snowflakes.
I brought a Ziplock bag full of chicken feathers to Thanksgiving and gave them to my 5-year-old niece who also likes feathers.

Lucy and Grace.
Last spring I read a book that made me appreciate the beauty and function of bird feathers even more than I already did: Feathers: The Evolution of a Natural Miracle, by author and biologist Thor Hanson.
Feathers are an evolutionary marvel: aerodynamic, insulating, beguiling. They date back more than 100 million years. Yet their story has never been fully told.
In Feathers, biologist Thor Hanson details a sweeping natural history, as feathers have been used to fly, protect, attract, and adorn through time and place. Applying the research of paleontologists, ornithologists, biologists, engineers, and even art historians, Hanson asks: What are feathers? How did they evolve? What do they mean to us?
Engineers call feathers the most efficient insulating material ever discovered, and they are at the root of biology’s most enduring debate. They silence the flight of owls and keep penguins dry below the ice. They have decorated queens, jesters, and priests. And they have inked documents from the Constitution to the novels of Jane Austen.
Feathers is a captivating and beautiful exploration of this most enchanting object.

From the Scientific American review:
The complex structure, development and growth of feathers can, to paraphrase one expert on the subject, be seriously damaging to your mental health. Feathers are just crazy, almost certainly the most complex structures to ever grow out of any animal’s external surface.
Yet for all their marvellous complexity, for all the interest that people have displayed in their evolutionary origins and diversity, for all their role in bird behaviour and ecology, and for all their economic and cultural significance to humans, it doesn’t seem that any one book has ever been devoted to feathers and feathers alone. Thor Hanson’s 2011 Feathers is thus a rather significant book, and very nice it is too.

From The Guardian:
Feathers are the most complicated artefact fashioned by nature from a single substance: the protein keratin. That’s the stuff that nails, hair and horse’s hooves are made from. But a hair is simply a string of dead protein fibres squeezed from the follicle, like glue from a nozzle. Bird feather keratin is similarly extruded from a follicle, but it is structured so that the barbs radiating from the central quill are held together by tiny Velcro-like fasteners. All this has to be cast in a single process.
