The polar bear is the largest bear species.
Adult males are 2.4-3 m tall and weigh 350-680 kg. Females are slightly smaller, about 1.8-2.4m and weigh between 150-250kg. However, the title of the article at first glance seems to raise an idiot question,
But,
What color are polar bears? [The answer is not as simple as you think]
If you have seen pictures of polar bears, you will definitely think that they are white.
But in fact nature deceives us! So, what color are polar bears?
Let me reveal the answer directly here,
The polar bear skin is not white at all!
They actually have black skin and two layers of semi-transparent hollow fur.
However, they appear white only because their fur reflects white sunlight.
This is why polar bears are mostly grey on cloudy days,And the reason for the red color at sunset.
Next, let's talk about the fur and fur of polar bears.
What color is polar bear fur?
Polar bears have two coats; undercoat and guard. These two coats provide polar bears with additional thermal protection. The two layers of hair are translucent, and the black skin is hidden underneath.
but still they look white.
According to WWF , this is because the translucent hairs reflect sunlight, causing them to appear white. If you've seen many photos of polar bears, you'll notice that they appear a little grey in cloudy weather, and even a little reddish at sunset, so their fur is responsible for the polar bear's body color depends entirely on The light they reflect .
If you look at polar bear fur under a microscope, you will also find that their fur is hollow inside. so trapped air inside keeps the cold arctic weather out, thermal insulation is also waterproof, it also helps them get better buoyancy, which is what polar bears can do in the sea One of the reasons it swims so well.
New research proves that the polar bear's protective fur can also absorb any infrared heat emitted by the polar bear's body, without losing this escaping heat to the cold outside.
This is another special ability polar bears have to adapt to cold climates, which explains why they appear black under UV optics.
What color is the polar bear's skin?
Under the translucent fur, a polar bear has generally black skin. In fact, other bear species, including grizzly bears, have near-black pink skin. Polar bear cubs have pink skin for up to five months after birth, but turn black as they mature.
Scientists still aren't sure why polar bears have black skin . The earliest research suggests that dark skin is part of the thermal radiation effect that helps polar bears absorb heat from the sun's ultraviolet rays.
However, this theory was later disproved , when it was found that UV light had difficulty getting through their fur.
Also, it doesn't make sense that polar bears are particularly dependent on the sun for warmth, since Arctic The coldest part of the year doesn't have much sun.
Also, there are actually some other interesting questions about polar bear fur color.
Why are some polar bears green?
Many people may spot polar bears with green fur, which is common in zoos or when polar bears are taken out of their natural habitat.
According to experts,Polar bears appear green due to the algae growing inside small holes in their fur.
Why are some polar bears yellow?
Some polar bears in the Arctic may also appear yellow. This is due to the fact that their diet consists mainly of a local species of seal.
Like other marine mammals, the blubber of these seals contains a lot of fatty oils that polar bears consume in large quantities, eventually causing their fur to turn yellow. This usually happens before they shed their hair in May or June each year.
Are polar bears black at night?
At night, the polar bear's skin is black and the fur is translucent, just like during the day. If you illuminate a polar bear with visible light at night, it will still appear white due to the way the fur reflects the light.
However, if you look at polar bears through an infrared camera without visible light, they appear black.
What color is the polar bear tongue?
In addition to black skin, polar bears have black noses, lips and tongues.
But they are not the only animals with black tongues, others include , chow chow , giraffes too.
There is little research on why polar bears have black tongues, which are said to reflect UV light.
What color are the polar bear's eyes?
Polar bears have dark brown eyes. Although humans need special goggles to protect their eyes from the sun reflecting off the snow, also known as snow blindness ,But polar bears' eyes have built-in membranes that filter out harmful UV rays.
In short, polar bears can adapt to the vast white Arctic environment and the extremely cold ocean area.
has evolved a set of equipment libraries to survive.
But with global warming, scrawny polar bears with scruffy fur are starting to appear in many places.
are facing a near extinction future as the Arctic Ocean melts and loses their territorial and food to survive. . .
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