A majestic emblem of the Arctic regions, the polar bear is generally represented with an attractive white coat. Besides, one may wonder why the coat of the polar bear always seems white to us? You will see that the reality is quite different and has some surprises in store for us. What mystery does this hide? Let’s delve into the secrets of this astonishing phenomenon and also discover the unique adaptations that the polar bear has to survive in its environment.
Presentation of the Polar Bear
Polar bears have adapted very well to the Arctic environment. They are mainly found in Russia and Canada. The white bear is also known as the polar bear. In Latin, its name is translated as Ursus maritimus, which means: sea bear. Indeed, this mastodon which lives on the ice floe is capable of swimming across the sea for hundreds of kilometers.
Despite its harshness, the sea ice is vital for the survival of these large predators. This territory allows them to hunt, rest and reproduce. This intrepid hunter is considered the largest carnivore on the planet. In addition, polar bears have fur that varies in length from 5 to 15 centimeters. This is renewed between May and August. However, it is another particularity of this fur that captivates the attention of scientists: unlike brown bears, the fur of the white bear has no color.
Did you know ? in fact, the polar bear is not white
White has always been closely associated with the polar bear. However, depending on the seasons and individuals, there is a range of nuances when talking about the fur of this animal. Aside from these nuances, the coat of polar bears never changes to a darker color in summer, as is the case with arctic foxes. Interestingly, this giant’s coat may appear slightly yellowish or even greenish. So why is it called a “polar bear”?
The polar bear’s coat
Let’s first focus on the hairs that make up the fur of these Arctic giants. The polar bear has two layers of hair. The layer that is visible from a distance is called the jar. It is characterized by long hair. Above all, it is she who reminds us of the big, cuddly white teddy bears of our childhood. The second layer, much less visible from a distance, is called the wadding. In fact, it is a kind of black down that helps absorb the light emitted by the sun’s rays, which helps warm the animal’s body against the cold. Interesting, when we remember that we have to withstand temperatures ranging from -30 to -40 degrees.
A beautiful optical illusion
The white color that our eyes see is simply the reflection of light in the transparent hairs. In fact, a polar bear’s hair has no color. They are unpigmented, colorless, transparent and hollow. They are reminiscent of optical fiber. Like many other animals, polar bear hair is made up of cells that contain keratin. However, in polar bears, these cells are hollow and filled with air instead of being filled with pigments. Thus, the light which diffuses through the hair without being absorbed is ultimately reflected in an apparently white or discreetly yellowish appearance.
This is due to the fact that this hair is capable of absorbing violet or ultraviolet rays. Thus, combined with the action of keratin proteins, the coat of this large carnivore can take on this shade or even another. For example, when sunsets in the Arctic are pink-orange, the fur of polar bears takes on the same color.
The polar bear’s coat: a great adaptation for survival
The multiple colorations of polar bears are a physical adaptation crucial to its survival. These different refractions and reflections of light through the hollow hairs which give it the white appearance, in the same way as snow, is a mimicry. In other words, it is a camouflage that allows it to approach its prey without being spotted. Furthermore, the different colorings can be caused by microscopic algae that grow on bears’ fur. This occurs particularly when they are found in humid environments or coastal areas.
Another important fact is that polar bears’ coats are slightly oily. This natural oil, secreted by their skin, contributes to their thermal insulation. A feature that allows them to stay dry, even when swimming in a freezing ocean, because water cannot penetrate their fur.
So yes, it’s true that the polar bear’s hair is really not white, but transparent, a characteristic which gives it effective camouflage in a snowy environment. Despite this truth, the term “polar bear” remains valid, since it is simpler to refer to them by this expression. Plus, let’s be honest, the term ‘slightly yellowish bear’ doesn’t sound as good. Is not it ? To think that this big teddy bear made us see all the colors.