How Do Wild Birds Keep Warm in Winter & Survive?

Winter is a fun season with lots of fun activities to do – we can build snowmen, ice skate, snowball fight, and even build snow forts. But at night, when the cold becomes too much to bear, even wrapping yourself in a thick blanket or sipping hot choco seems not to be enough to warm yourself up. In this article, we explore how do birds stay warm in winter months.

Then, you look outside your window and see these beautiful birds eating bird seeds without anything wrapped around them. Did it ever make you wonder how they could survive the cold weather? 

Well, we all did. And that’s why researchers around the world have found ways to figure out the “hows.” And that’s exactly what we’ll learn in this article. We’ll discuss: 

• How cold is too cold for birds
• How birds keep warm
• The different ways birds stay warm in different regions
• Winter Birds Myths and Facts
• FAQs

If you want to learn more about these, read on… 

How Cold is Too Cold For Birds? 

The birds’ body temperature is slightly higher than ours, and during the winter, they can generate heat much quicker. That and other more adaptive features help them survive in winter. But there’s still a limit as to how much they can handle. 

So, how cold is too cold? This depends on the kind of bird. 

Aquatic birds, for example, can survive temperatures of up to negative 90 degrees Fahrenheit. This is because most of the time, they would need to swim underwater to catch prey, even if it’s so cold. 

Birds of prey, including snowy owls, can resist a weather of nearly 40 degrees Fahrenheit below freezing point. In contrast, pet birds, or mainly tropical birds like Parrots, may not be able to handle those temperatures.

How Birds Keep Warm? 

The average body temperature of birds is 105 degrees Fahrenheit. It fluctuates depending on their diet, activities, and the season which helps keep them warm even during the coldest temperatures. 

However, aside from their body temperature, other physical adaptations help birds survive in the winter. 

First is their feathers. The birds’ feathers always served as an insulation tool for birds. It hugs them like a blanket which helps keep them away from the cold’s harm. 

Most of the birds even grow extra feathers for even thicker protection. On top of that, the oil found on the birds’ feathers provides additional insulation plus waterproofing. 

Next, we have the birds’ legs and feet. Although these parts don’t have feathers to protect them from too much cold, they have specialized scales that help keep the heat in. The birds also know how to control the temperature on their legs and feet by constricting the blood flow to these areas. 

Lastly, birds can build up fat reserves for extra insulation and energy to generate heat. They do this by eating a lot of food during the fall to be fat enough by the time winter arrives. 

While these three features help the birds keep warm, they’re not enough to help them survive. The birds also need to have behavioral adaptations to survive even the harshest winter periods. 

Different Ways Birds Keep Warm

Fluffing

While the birds’ feathers serve as great insulators, it’s not enough to just have them. To create further insulation, birds have also learned to fluff out their feathers. 

By fluffing their feathers, the birds can trap air pockets around their bodies for additional insulation, making the birds look fat and puffy. But in exchange, they’re also very toasty. When you’ve looked out the window and saw fat birds in winter, you’re already probably witnessing fluffing. 

Roosting and Cuddling

Cuddling is probably one of the ways we humans survive winter. We love cuddling in our own blankets or probably cuddling with our favorite people. The action helps distribute heat between two bodies, making us feel warmer. And this same reason is what leads to birds cuddling for warmth as well. 

Roosting or cuddling is an action most seen in smaller birds. You’ll often see them crowded together in shrubs, vines, or evergreens to share heat between their bodies. At the same time, it makes it safer for them to slow down their metabolic rate to conserve energy as they’re getting help from other birds to generate heat. 

Some birds roost or cuddle together in bird boxes for more effective heat distribution. While larger birds learned to flock together for warmth, even if they’re from different species, 

Tucking

We already talked about how birds have specialized scales on their legs and feet that help keep the heat in. But certain bird species also learned to further conserve heat on their legs by tucking one or two legs in their bodies. 

These birds include: 

• Ducks
• Geese
• Pelicans
• Gulls
• Swans

You’ll often see these bird species standing on one leg or sitting down in winter to hide one or both of their legs.

Sunning

Another way birds keep warm is by taking advantage of the sun. 

Although winter is cold, there are days when the sun comes out and still shines its rays on us. On these days, birds will turn their backs to the sun and raise their feathers slightly to take in some heat. Their backs are the largest part of their body, which makes heat distribution in their skin and feathers a lot faster. 

Some birds also droop or spread their wings to catch the sun, and there are others who even spread their tails to absorb the heat as well. This additional action helps the birds warm up faster than just simply exposing their backs. 

Shivering

The next behavioral adaptation we know is shivering. 

You’ve already probably noticed that when you’re cold, you shiver, and your teeth clatter. And while this can be frustrating to feel, it’s actually a body’s natural response to the cold, helping us warm up. 

The same thing applies to birds. Birds shiver to help increase their metabolic rate, which helps them generate more heat in a shorter amount of time. 

The only problem is this action requires birds to use more calories, which can also endanger them, especially if the food supply in the area is low. That’s why birds often reserve this adaptation for the most extreme temperatures and if the food availability is high. 

Torpor

Last but not least, we have torpor.

Torpor is when the birds decide to switch off to preserve their remaining energy. They go into a hibernation-like state at night for a few hours or even throughout the night. 

It’s very effective, especially during the coldest nights. However, at this state, birds can also be vulnerable to predators as they won’t have time to react or fly away because their energies are low. 

Some birds even have to perform shiver to bring up their temperature immediately. Sadly, however, this action also costs them to lose calories. 

In other words, when birds go into torpor, they must have food to eat by the time they wake up to replenish energy immediately. 

How Birds Stay Warm In Different Regions

While birds have several behavioral adaptations to survive during winter, many bird species would choose to migrate to other places where the winter conditions are not as harsh. And depending on the region they go to, winter adaptations may be quite different. 

We summarized this in the table below: 

Region	Winter Bird Species Found In The Area	Winter Adaptations
Southern US	Tree Swallows Eastern Phoebes Yellow-rumped warbler House Wrens Gray Catbirds Brown Thrashers	Fluffing, shivering, roosting, eating
Mexico and Central America	Western Tanagers Philadelphia Vireos Western Kingbirds Baltimore oriole Wood Thrushes Ruby-throated hummingbird	Fluffing, shivering, roosting, eating
Caribbean	Indigo bunting American Redstarts Black-throated Blue Warblers Cape May Warblers	Eating
South America	Rose-breasted grosbeak Scarlet Tanagers Eastern Kingbirds Bobolinks Chimney Swifts American Golden-plover Swainson’s hawks Blackpoll Warbler	Fluffing, shivering,
Canada	Black-capped chickadee White-breasted Nuthatches Finches Northern cardinal Blue jay American goldfinch Common Redpolls White-breasted Nuthatches Brown Creepers Cedar Waxwings Harlequin Duck Snowy Owl Bald Eagle Arctic Redpoll	Torpor, grow more fur and feathers, shivering, roosting, tucking, fluffing
Alaska	Ravens Snowy Owls Gyrfalcons Murres Gulls	Growing extra feathers, shivering, roosting, communication, eating

As we can see, the behavioral adaptations of birds highly depend on where they are. The cold the temperatures, the harsher the adaptations to survive even the most frigid weather. 

Let’s dive deeper into this topic… 

How Birds in the Southern US Cope With The Cold

Birds in the southern US are either residential birds or short-distance migratory that can handle only a bit of cold. Their winter adaptations are pretty simple, which usually include: 

1. Preserving more fat reserves during the fall to provide them enough energy to survive migrations and the winter
2. Fluffing to surround their bodies with extra warmth
3. Shivering to send a short-term supply of heat to their bodies

Because winter in these areas is not as harsh as the ones in the north, the birds can still have the energy to fly around and look for food from time to time. 

How Birds in Mexico and Central America Cope With The Cold

Birds in Mexico and Central America have almost the same winter adaptations like the ones from Southern US. Birds here are usually resident birds or short-distance migratory birds that don’t love the winter temperatures in the Southern US. 

Winter adaptations include: 

1. Eating to gain more fat reserves that will provide extra energy for migration and winter survival
2. Roosting together to distribute heat among same species
3. Fluffing their feathers for extra warmth
4. Shivering to heat their bodies when they’re too cold

How Caribbean and South American Birds Cope With The Cold

The Caribbean and South America is probably one of the places most birds migrate to because it’s not as cold as the northern parts. Most birds that fly here for winter are either resident birds or long-distance migratory birds. 

Winter adaptations would usually only include eating a lot to gain more fat reserves so they can survive the long travels. In areas where it really snows, birds can fluff or roost together to feel warmer. 

How Birds in Canada Cope With The Cold

Many birds in Canada choose to travel further down south to survive the harsh winter. However, some choose to stay and fight through the cold. 

Because winters can be very cold up there, birds need to undergo extreme measures to survive. Most of the time, they just follow through the same behavioral adaptations mentioned above: 

1. Fluffing their feathers to warm themselves
2. Shivering to increase their body heat
3. Roosting to distribute heat amongst themselves
4. Torpor to preserve energy
5. Tucking their feet to preserve heat

But some bird species go through more lengths to survive the cold. 

For example, the chickadees were able to develop a sharper memory, allowing them to remember where they stashed their food. This way, when food sources start to get scarce, they know where to get food. 

Waterfowls do what we call the counter-current blood-warming system which helps them control the blood flow in their feet. This helps preserve the heat in it, especially in the coldest temperatures when simply tucking their feet in is not enough. 

But the most impressive of all is the Arctic Redpoll. Researchers found that these birds can survive up to 20 hours even without food and in very cold temperatures. They also have esophageal pouches that allow them to hold seeds and slowly digest them so they can maintain their energy. 

How Alaskan Birds Cope With The Cold

For birds in Alaska, winter is all about surviving. The weather is so cold, but some of the bird species here just refuse to migrate down south. 

Instead, they stay through the winter and work through different behavioral strategies to survive the cold. This includes: 

1. Fluffing up
2. Shivering
3. Gorging more on food
4. Surrounding their bodies with down
5. Tucking their legs to their bodies

A lot of birds, even if they’re from different species, gather together to help distribute heat. And because food sources can be scarce or temperatures are just so cold, most of these birds undergo hibernation to save their energy. 

There are even bird species, like the Ptarmigan and grouse, that take advantage of the snow. Making it a water source or even burying themselves underground as a form of insulation to stay warm through the night. 

Can You Help The Birds During Winter?

Yes, you can help birds during winter. 

As a matter of fact, it’s during these coldest seasons that they need your help because they are very vulnerable. The food source is scarce, temperatures are cold, and they can hardly move around because they need to preserve their energy. 

It’s during these times that birds highly depend on bird feeders. And most of the time, they stay in backyards where there’s food to eat the whole winter. 

The first thing you can do is to install a heated birdbath in your backyard to provide birds with water. As many lakes and rivers are frozen, the next option for birds is snow. But even drinking snow will cost them energy, so at best, you need to provide them with something that is already warm. 

Next, you should provide birds shelter. As temperatures are too cold, it would really help birds if they stay in an area that won’t leave them vulnerable to the outside elements. So having bird boxes around your backyard will be deeply appreciated. 

It’s also nice if you plant some trees or shrubs where the birds can hide and rest when they need to. 

Most importantly, don’t forget to serve the right food. 

Because it’s so cold, birds need high-energy foods the most. Some great options for you are peanuts, sunflower chips, and suet. The best part about this food is that they’re very easy to eat, allowing birds to conserve their energy. 

Don’t forget to keep it full because birds are going to need a lot of food during this season. 

FAQs About How Wild Birds Keep Warm

Where do birds go in the winter? 

Birds usually have only two options when the winter season comes. It’s either they stay in the area or migrate somewhere that is not too cold. 

But wherever they are, birds will always look for a place that will help them keep warm, a shelter. This could either be in a nest box, a hole in a tree, a small gap in a building, or even under the snow itself. 

Some birds flock and huddle together in the branches of a tree to distribute heat around them. 

Where do birds sleep at night in the winter? 

Birds need to conserve their energy to survive the cold weather. Their energy is mainly what keeps them warm and allows them to search for food, which means they need a lot of time to rest. 

The birds will often look for tree cavities or small between tree trunks where they can hide for the night. As most of these birds go into torpor or hibernation, they can’t hide in plain sight because they’ll be leaving themselves vulnerable to predators. 

Can birds freeze to death? 

Despite having these natural and behavioral defenses to survive, some birds can still succumb to cold and freeze to death. 

There’s no number as to how high or low the mortality rates are. But it highly depends on how cold it is or how scarce the food is. 

When birds aren’t able to get enough food to supply them with energy, there’s a high chance that they’ll die somewhere in the cold and freeze. Another circumstance is when the birds get injured and they don’t get immediate help, the weather will surely freeze them. 

What dangers do birds face in winter? 

Aside from the cold temperatures, birds face other dangers in winter. This includes: 

• Outdoor cats
• Glass collisions
• Lack of food resources
• Habitat loss
• Birds of prey

The fact that birds don’t have enough energy in winter makes them a lot more vulnerable, especially to predators. 

Final Thoughts On How Wild Birds Keep Warm

Winter is a harsh season for many creatures, and that includes birds. Fortunately, their bodies are developed to survive the cold and they have adapted some behaviors that help them survive. 

There are six adaptations that we know: 

• Fluffing
• Shivering
• Torpor
• Roosting
• Tucking
• Sunning

But what the birds do to survive highly depends on where they are or how cold the temperature is. If they are in Canada or Alaska, they’d have to undergo extreme measures to survive, including hibernating. On the other hand, birds who moved further down south might just need to stick to eating more or roosting. 

Now, while birds have developed all these to survive, they would still need our help. So, don’t hesitate to hang bird feeders, set up bird boxes, or install heated bird baths for the birds. These things are what these birds need the most during these times, and they would deeply appreciate your help. 

References: 

• https://www.fws.gov/story/how-do-birds-keep-warm-winter
• https://www.birdsadvice.com/how-cold-can-birds-survive/