How Do Chickens Stay Warm in the Winter?
Most breeds of chickens generally do just fine in cold temperatures, but the better you understand just how a chicken stays warm, the easier it will be for you to do a few easy things to make winters more comfortable for your flock.
During the day, I always give my chickens the option to go outside, and as long as they can find a nice sunny, sheltered area outside, they'll spend most of the day outside which is important to give them fresh air, sunshine and some exercise on all but the most blustery days.
It's the cold nights that pose the greatest challenge to chickens staying warm, of course.
Overnight temperatures here in Maine can plummet to well below zero in the dead of winter and often don't go above freezing for weeks on end.
Despite that, and despite not heating my coop, my chickens do just fine in their straw-filled, draft-free, dry coop.
For the most part, as long as they can stay dry and out of the wind, your chickens should be just fine.
How Do Chickens Stay Warm in the Winter?
While the optimal temperature for chickens is between 65-75 degrees Fahrenheit, they are perfectly comfortable in temperatures down to 40-45 degrees, and will do just fine if temperatures drop below freezing - and even below zero!
Interestingly enough, many of the ways our domesticated chickens stay warm are the same ways wild birds stay warm.
So how DO chickens stay warm?
Fluffing their Feathers
Chickens will fluff their feathers when it gets cold. Wild birds do this as well. Their downy feathers trap tiny pockets of air next to the body, allowing the chicken to warm those pockets of air with its body heat and hold that warm air close to the body, preventing cold air from touching the skin. It works like insulation for them.
The more air that stays trapped, the warmer the chicken. They'll fluff up their outer feathers when it's cold outside to trap as much air in the down as possible. One reason why chickens molt each fall is so they have nice, new feathers come winter.
Fun Fact: the technical term for fluffing up their feathers is “ptiloerection".
A Leg Up
Chickens' legs and feet are thin and featherless (at least most breeds are), so therefore they lose heat rapidly. You might notice your chickens standing on one foot during the day in the winter.
They do this to reduce heat loss through their feet and to warm up one foot at a time, tucking it into the feathers on their abdomen, and then switching feet.
In the coop, wide wooden roosts are best to keep the toes and feet warm through the night, completely covered by the hens' body.
A 2x4 board with the 4" side facing up is perfect. That way the roosting chickens' toes don't hang over the edge where they would be exposed to the cold.
Creating Energy Through Digestion
Living things generate heat when they digest their food. You can give your chickens a leg up on the cold by offering a pre-bedtime treat of whole or cracked grains and dried corn which are harder to digest and therefore require the chickens' body to produce more energy/heat overnight.
In general, it's good practice to put out feed and leave it out all day for your flock in the winter. They will eat more in the winter because they burn more calories trying to stay warm and there's no grass or bugs to eat to supplement their diet.
It's also not a bad idea to feed more high-calorie/high-fat treats like corn or suet because a layer of subcutaneous fat will also help your chickens stay warm through the winter.
The Head Tuck
You might notice your chickens tuck their heads under a wing when they go to sleep. They do this to protect their comb and wattles from frostbite.
A chickens' comb acts as a "radiator", allowing heat to escape from the body, which is why many of the cold-hardy chicken breeds have small or non-existent combs, while the heat-hardy breeds tend to have large combs that will allow them to release body heat in hot weather.
Critical in the summer to help the hen cool off, it's just as important to retain the body heat in winter and reduce heat lost through comb.
The Buddy System
At night, your flock will snuggle together for warmth. By roosting side by side, they each reduce the surface area of their body that is exposed to the cold air - but of course no one wants to be on the end!
A hen gives off about 10 watts (35 BTUs) of energy, so ten chickens give off about as much heat as a 100 watt light bulb.
DO's and DONT's to Keep your Chickens Warm
DO
• Be sure the coop stays clean and dry with lots of warm bedding (I highly recommend straw or consider using the deep litter’ method)
• Be sure your coop has adequate ventilation up high to reduce drafts but still allow moisture to escape. If you're seeing condensation on the inside of your coop windows, you need more ventilation - too much moisture can cause frostbite
• Scatter straw in the run and at the coop entrance to reduce the amount of mud and snow that gets tracked in from outside. Straw paths also encourage your chickens to spend more time outside and help them keep their feet warmer
• Put logs, stumps, outdoor doors or pallets in the run to allow your chickens to get up off the cold ground
• Create a wind block out of plywood or tarps in a nice sunny spot for your chickens to hang out in during the day
• Offer feed all day long along with clean, unfrozen water and give scratch grains before bedtime
DON’T
• Don’t leave water inside the coop – it just causes moisture and dampness. Moving the feed and water outside helps keep rodents out of the coop and also encourages your chickens to come outside for some fresh air while they eat
• Don't make your chickens live in a drafty coop - all vents should be up high, i.e. above your chickens' heads when they roost. I hung drapes across the small pop door in my coop to block drafts
• Don’t use a heat lamp or other type of heat – in addition to the risk of fire, a loss of power could be devastating or even deadly to chickens not allowed to gradually get used to the cold
• Don't dress your chickens in sweaters - should be a given, but bears repeating: DO NOT PUT SWEATERS ON YOUR CHICKENS! That prevents them from being able to fluff their feathers, which is one of the main reasons they stay warm.
(Of course battery hens, a heavy molter or otherwise sickly chicken should be brought into the house, put under heat or put in a sweater when the temperatures drop - but they're exceptions to the rule.)
http://beheco.oxfordjournals.org/content/early/2011/12/13/beheco.arr208.full.pdf