Why is the bird's feet not frozen in winter?

According to Scienabc, if you've ever walked to the street on a cold winter day with bare feet, you will feel how terrible the pain is. You can hardly stand anymore.

However, there are many birds that do exactly these things without any problems. Some species like penguins, ducks, gulls . spend a lot of time on ice or cold water.

So, why can birds protect their legs from being so good at frostbite?

Short answer: Many birds simply pull their feet closer to their bodies, some ruffled to get warm air, some keep warm with the upstream exchange system.

Some simple methods to shield your body from the cold

There are nearly 10,000 bird species in the world; some of them live in the tropics where they enjoy sunlight and warm weather most of the time of the year. Meanwhile, some species live in Antarctica and Arctic, where they face extreme cold temperatures. Therefore, birds have different ways to protect their bodies from the cold.

Picture 1 of Why is the bird's feet not frozen in winter?
Birds have many different ways to protect their bodies from the cold.(Photo: Greg B Miles).

There are some basic techniques that many birds use to keep their bodies warm. Birds often do not have large feet (proportional to the body) and therefore, loss of heat through the legs is usually not much. Moreover, birds are hot-blooded species meaning they can maintain their body temperature and adapt well to ambient temperatures.

Some birds like quail, let me . simply pull their feet close to their bodies , like the way people fold their arms or legs to keep warm.

Because birds are hot-blooded, they can maintain their body temperature by increasing the metabolic rate regardless of the coldness of the environment. In contrast, when the ambient temperature is high, birds mobilize water and lose heat through evaporative cooling (like sweating in humans). Some birds such as black vultures excrete their legs to cool their bodies.

Some acts keep warm

Picture 2 of Why is the bird's feet not frozen in winter?
Many birds ruffled feathers to warm the body.

Many birds ruffled feathers to warm the body. When the ruffled bird will create more air space between the feathers, the air is a very good insulating layer, so it helps keep the bird warm.

Besides, birds tend to let the beak in the middle of the wing feathers to breathe the warmer air. Birds also tend to gather in groups , snuggle together to share their body temperature and keep the group warm. Some species (like snow grouse) are hidden in the snow cave in search of warmth.

Many birds also use an interesting technique, but are highly effective to keep warm in the long winter: they will eat, and eat a lot. Besides, this way is not only a source of stored energy but also creates a layer of natural fat to protect the body from the cold.

Upstream exchange system - a biological advantage

Picture 3 of Why is the bird's feet not frozen in winter?
Some species such as ducks and gulls spend considerable time standing on icy seas.

Most birds use the above methods to keep the body warm, but some species like ducks don't have small feet. In contrast, their feet are particularly large and flat (and this is the worst thing to minimize heat loss). In addition, some species such as ducks and gulls spend considerable time standing on frozen seas.

To protect their feet against cold, the bird has a blood circulation system called a backward exchange system . In this circulatory system, diseased intestinal blood has a warm temperature, while arterial blood returns from a lower temperature foot. When cold blood comes from the foot towards the center of the body, it absorbs most of the heat from the artery due to transmission. The blood vessels in this bird's legs will help this process take place.

Picture 4 of Why is the bird's feet not frozen in winter?
Blood circulation system in bird's feet .

In this way, the blood to the bird's feet is quite cold, meaning that heat will not enter the surroundings. This is why ducks and gulls can stand in icy waters just above freezing temperatures and still maintain their body temperature of about 104 degrees Fahrenheit (equivalent to 40 degrees Celsius).

If humankind has this kind of circulation, we will not need to keep warm and can go across the Arctic.