Why Is My Chicken Molting Out of Season?

By John Walker · Backyard chicken keeper in Dallas, Texas since 2017

Why is my chicken molting out of season? A chicken that loses feathers in spring or summer, rather than in the usual autumn moult, is usually responding to stress, a change in light, illness, or a feed problem, and the cause matters because an off-season moult is a sign that something has upset the bird. A normal moult happens once a year in autumn, when the days shorten and the bird sheds old feathers and grows new ones, stopping laying for 6 to 12 weeks. An off-season moult can happen at any time, and it is often patchy, with feathers lost from the neck, back, or vent, rather than the whole body at once. This guide explains the causes, how to tell a moult from feather pecking or parasites, and what to do.

Why is my chicken molting out of season?

A chicken molts out of season because something has stressed her body enough to trigger feather loss outside the normal autumn cycle, and the most common triggers are stress, a sudden change in light, illness, and poor feed. The moult is the bird's response to a disruption, and it is a sign to look for the cause.

Stress is the most common cause, and it can come from a predator attack, a move to a new coop, a new bird joining the flock, overcrowding, or a change in routine. A stressed bird may lose feathers from the neck and back, and she may stop laying at the same time, which is a clue that the moult is stress related.

A sudden change in light can also trigger a moult, because the bird's moult is driven by day length, and a coop light that is turned on or off suddenly can confuse the bird's hormones. This is why a light that is added in winter should be added gradually, and why a light that fails suddenly can trigger a moult.

Illness, parasites, and poor feed are the other main causes, and they are covered in the sections below. The key point is that an off-season moult is not normal, and it is worth investigating, even if the bird seems otherwise well.

What is a normal moult and when does it happen?

A normal moult happens once a year, usually in autumn, when the days shorten and the bird sheds old feathers and grows new ones. The moult lasts 6 to 12 weeks, and the bird stops laying during it, because her body is using protein to grow feathers rather than to make eggs.

The moult starts at the head and neck, moves down the body to the back and wings, and finishes at the tail, and the new feathers, called pin feathers, grow in as the old ones fall out. A bird in a normal moult looks scruffy, with bare patches and pin feathers, but she is otherwise healthy and active.

Young birds have their first moult at about 18 months old, and after that they moult every autumn. A bird that is forced to lay through winter with artificial light may moult later or more slowly, because the light delays the hormonal trigger, and this is normal for a flock that is lit.

The difference between a normal moult and an off-season moult is the timing and the pattern. A normal moult is whole body, in autumn, and lasts weeks, while an off-season moult is often patchy, in spring or summer, and may be limited to one area, such as the neck or the back.

Stress moult: the most common cause

Stress moult is a partial moult triggered by a sudden stress, and it is the most common cause of feather loss out of season. The bird loses feathers from the neck, back, or vent, often in patches, and she may stop laying at the same time, which is a sign that the stress has affected her hormones.

Common stresses include a predator attack, a dog chasing the flock, a move to a new coop, a new bird joining the flock, overcrowding, and a sudden change in feed or routine. Any of these can trigger a moult, and the feathers usually start to fall within a few days of the stress, with new feathers growing back over the next few weeks.

To help a stressed bird, remove the cause of the stress if you can, and give the bird a calm, stable routine with good feed, clean water, and a secure coop. Extra protein, such as cooked egg or mealworms, helps the bird grow new feathers, and the moult should finish within a few weeks if the stress is gone.

If the stress continues, the moult may continue, and the bird may lose more feathers and stop laying for longer. A flock that is overcrowded, or where one bird is being bullied, will show repeated stress moults, and the keeper should address the crowding or the bullying rather than just treating the feathers.

Light, feed, and illness as moult triggers

A sudden change in light can trigger a moult, because the bird's hormones respond to day length, and a light that is turned on or off suddenly can confuse them. If you use a coop light, add it gradually in autumn and remove it gradually in spring, and use a timer so the light is consistent each day.

Poor feed can also trigger a moult, because feathers are mostly protein, and a bird that is short of protein will lose feathers and grow them back slowly. Check that the flock is eating a good layer feed, with enough protein, and offer extra protein during a moult, such as cooked egg, mealworms, or a higher protein feed.

Illness and parasites can cause feather loss that looks like a moult, but is actually a different problem. Mites and lice cause itching and feather loss, especially around the vent and under the wings, and a bird with parasites will peck at itself and lose feathers in patches, which can be mistaken for a moult.

A bird that is losing feathers and also shows other signs of illness, such as dullness, loss of appetite, or loose droppings, should be checked by a vet, because the feather loss may be a symptom of a deeper problem. Our chicken first aid kit guide covers the basics of checking a sick bird.

Moult vs feather pecking and parasites

Moult, feather pecking, and parasites all cause feather loss, but they look different, and telling them apart matters because the fix is different. A moult is a natural shedding of feathers, with pin feathers growing back, while feather pecking is caused by other birds pulling feathers out, leaving bare, red skin, often on the back or vent.

Parasites cause itching, and the bird will peck at itself, scratch, and lose feathers in patches, especially around the vent, under the wings, and on the neck. Check the skin for tiny moving mites or lice, and for clusters of eggs at the base of the feather shafts, because these are signs of parasites rather than a moult.

Feather pecking is often caused by boredom, overcrowding, or a lack of protein, and it can be reduced by giving the birds more space, more enrichment, and a higher protein feed. A bird that is being pecked should be separated if the skin is broken, because the other birds will peck at blood and make the injury worse.

Our molting calculator can help you work out when a normal moult should happen and how long it should last, and it is a useful check when you are trying to decide whether a moult is normal or out of season.

What to do for a chicken molting out of season

First, look for the cause, because a moult out of season is a symptom, not a disease, and the bird will not recover fully until the cause is fixed. Check for stress, a change in light, poor feed, parasites, and illness, and fix what you find, whether that is more space, a steadier light, better feed, or a vet visit.

Give the bird extra protein, because growing feathers uses a lot of protein, and a moulting bird needs more than a laying bird. Offer cooked egg, mealworms, or a higher protein feed, and make sure the bird has oyster shell for calcium, because she will need it when she starts laying again.

Keep the bird warm and dry, because a moulting bird with bare patches loses heat quickly, and she is more vulnerable to cold and draughts. Make sure the coop is dry and draught-free, and avoid handling the bird more than necessary, because the new pin feathers are sore and can bleed if they are broken.

Be patient, because a moult takes weeks, and the bird will not lay again until it is finished. A hen that moults out of season will usually return to laying within a few weeks of finishing, as long as the cause is fixed, and the new feathers will be healthy and full.

A note on health: this guide is general information, not veterinary advice. If a bird shows signs of illness or injury, separate it, keep it warm and dry, and consult a veterinarian — ideally one experienced with poultry — before treating it.

Sources: Oregon State University Extension, backyard chicken moult and poultry.extension.org.

Related tools and guides

For more on the same topic, see Chicken First Aid Kit & Common Injuries.

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