Just like human beings, birds are endothermic or warm-blooded. This means that their bodies are able to produce heat as well as maintain a temperature even during cold weather.
Unlike some animals, birds can’t afford to store extra fat because it will deter their flying and ultimately put them at the mercy of predators. That’s why most birds have feathers and highly effective organs like their kidneys to regulate their body temperature.
Small birds can even lose more than 10% of their body weight overnight.
The warmth of a bird’s body is generated by the internal chemical reactions that continuously take place in its cells. This internal furnace, called metabolism, requires matched production of energy and heat by both the catabolic (breakdown) and anabolic (assembly) phases of cell activity.
The average metabolic rate for small birds is around 50 kilocalories per day. This level of energy production is sufficient to maintain their relatively large brains, but it’s not enough to support growth or reproduction.
With that, let’s look at the ways that small birds can keep warm in the winter.
For a lot of cold-weather animals, insulation is a thing of immense importance. Cold climate birds increase their weight during the tail end of fall and summer in anticipation of winter. Even with this, feathers will still play a large role.
Birds keep warm by using the trapped air they store close to their bodies. The major reason why this is possible is because of their clean and dry feathers. This cleaning process (also known as preening) normally depends on the bird’s species.
All birds generate oil thanks to a gland close to their tail. A handful of birds actually make use of the oil to make their feathers weatherproof.
Birds like mourning doves, herons, and egrets grow peculiar feathers that will turn black when wet. These are called “raindrops” and the reason why it happens is still debated among biologists.
Irrespective of the weatherproofing method used, preening provides birds with a way to keep their top layer water-resistant.
Birds, just like humans, shiver to remain warm. They possess high metabolic rates that make them burn a lot more energy than us to keep warm. The black-capped chickadee weighs less than an ounce, but it can maintain the body temperature of 100°F even if the air is 0°.
This is achieved because of its pristine insulation, perpetual activity, and being able to remember where its food is stored.
It is important that they have enough food because these birds eat 35% of their weight each day. When compared to other birds, their hippocampus is quite large. This is the portion of the brain in charge of spatial memory.
Keeping little feet warm
A lot of small birds have to stay active during cold weather to be able to keep their body temperature up. Because they can use energy so quickly, they need a way to keep their feet warm since it’s very easy to lose heat through them.
According to research, this is how they do it: The arteries that carry warm blood from the bird’s body circulate very close to its legs. When these vessels contract, such as when a bird shivers, the reduced flow of blood causes the feet to feel cold and limit their loss of body heat.
Vasodilation is the exact opposite of vasoconstriction. In this case, arteries would inflate and allow blood to flow freely from the bird’s body to its legs. This makes it easier for cold-blooded animals like birds to ensure that their legs aren’t a limiting factor when it comes to keeping warm.
Cuddling and roosting
Just like people that decide to cuddle for warmth, birds love to gather in vines, shrubs, and trees so they can share their body heat.
Their metabolic rates can also be slowed down to conserve energy. Woodpeckers, titmice, and nuthatches make use of nest boxes and tree cavities to keep warm. These will help to provide protection from predators as well as the harsh weather. Even larger birds flock together to generate warmth.
Cavity-dwelling birds like owls and bluebirds will roost together in winter.
Birds that live alone, like any other pet bird, might need an owner to help them out with this problem. If a bird is kept inside during the cold months, it’s crucial that they have proper food and shelter to retain body heat and keep the owners from worrying about them. It’s best to have an avian veterinarian design a proper routine so they can help their pet cope with winter too.
Tucking feet and bills
Tucking their feet and beaks into feathers is a common behavior among birds that live in cold climates.
They do this to stay warm and keep the chill out so they can get on with what they need to do: find food, water, and shelter.
The waterfowl circulates blood via a heat exchange which isolates the blood that flows in the legs – instead of circulating it around the whole body. This will help to ensure that the body’s temperature is kept at a high degree.
In addition to this, birds have special scales on their legs and feet that help in minimizing heat loss. Swans, gulls, pelicans, geese, and ducks also conserve their body heat by sitting down or standing on a leg.
Tricolored herons, ducks, and loons are other examples of birds that manage to keep their legs warm during cold weather.
When it comes to other types of small birds, they spend the winter in pairs or singly. They will also find shelter in cavities to protect themselves from predators like the red-tailed hawk.
If you have a pet bird that can’t find its way to a shelter during cold weather, just be sure to provide the essentials they need to keep themselves warm. It’s best if these items are placed near an area that will stay warm like a heat lamp or radiator.
It’s important that small birds like parakeets and budgies are covered on top of their cage with something like a blanket to keep them warm.
Just like other pets that stay outside, it’s crucial that they have access to water during the cold weather. Birds will be more prone to frostbite if their feet become wet and sticky so make sure you change their water bowl during wintertime.
When it’s cold, birds will find a way to keep their body heat up. It’s just a matter of finding the right equipment and supplies to ensure their safety and well-being during the winter.