How rare are albino polar bears?

Probably not. The polar bear’s skin is actually black, as evidenced in the patch on the nose where no hair covers it. With translucent fur, they would be at a distinct disadvantage in hunting, as pink instead of black would show through everywhere. Thus, evolution has likely made arrangements to exclude albinism in polar bears, or if they are born, they starve early on. Doing an image search on Google, all I could find were fakes and albino black or brown bears.

As far as I know, albinism can affect many animals, not only mammals but also birds and reptiles. Wikipedia writes: “Many animals with albinism lack their protective camouflage and are unable to conceal themselves from their predators or prey; the survival rate of animals with albinism in the wild is usually quite low.” Yet this issue doesn’t seem to apply to polar bears.

There have been no credible sightings. It would be hard to spot since you would be looking for pink nose and eyes.

The way I remember it albino is thought to happen in all animals. This is going off of my high school memory, imprefect at best. Maybe it is vertbrate animals?

@ETpro I think if the bear was albino its skin would not be black, if indeed there skin typically is. Wouldn’t there be an absense of color?

I would think if animals also are blind or severly visually impaired like humans with full blown albino traits, that it would make it hard to survive. However, we have an albino raccoon in our woods that I saw for a couple years, not lately, that had made it to adulthood. I guess logically if the animal does not have great sight to begin with, and relies on other senses, it might not matter as much.

Why would their coat be translucent? Isn’t albinism a skin pigment issue? Wouldn’t their hair still be white? Maybe a more pale, strawy color white, but still white? I doubt you’d see their skin, which would be pink. You might see their eyes, which would also be pink, but as @marinelife said, by the time you saw the pinks of their eyes, you’d be lunch.

Anyway, I’d think a lack of pigment in an arctic environment could be disastrous. You might not have much skin showing, but that that did show would have no protection from the UV rays and would burn constantly. I don’t think an albino polar bear would last.

On the other hand, all polar bears look albino. Given that you couldn’t tell the difference between a true albino and a regular polar bear, they seem ubiquitous. But not for long. Unless they learn how to survive without ice fishing. Then again, I hope they have good deeds to their property, because when the ice all melts, they’re going to be a lot of people looking for oceanfront property up there.

@wundayatta – All polar bears have black skin and translucent fur. It’s a trick of the light that their fur appears white.

So either the skin is pink in an albino, but you still can’t see it due to the fur, in which case the fur would still appear to be white, or the pink skin affects the color of the fur. In either case, it still seems to me that being an albino bear would not be good because of the affect of the ultraviolet rays.

@wundayatta So, you don’t think the thick coat, even translucent, would protect from the sun? It does make sense in a part of the world where the sun shines so many hours of the day, sometimes never setting, that the UV protection would be very important.

@JLeslie I don’t know. But if the hair is translucent, it seems like too much uv rays might get through.

I found this:

Their experiments showed that a one-fifth inch strand of polar bear hair conducted less than a thousandth of a percent of applied ultraviolet light. So, the black skin absorbs very little ultraviolet light. Instead, Koon believes keratin, a basic component of the hair, absorbs the ultraviolet light.

source

Interesting. Then why is the skin black?

@wundayatta Maybe it is an evolutionary left over, or maybe it does provide some extra UV protection. I think the brown bear and polar bear are closely related, able to breed together. I just don’t know what color the brown bear’s skin is to try to support this hypothesis. I also don’t know what their common ancestor might have been. I know very little about bears. I just leanred on this Q about the polar bears black skin.

@JLeslie‘s source also goes on to say that the polar bear’s thick layer of fat is primarily responsible for keeping it warm… so much so that adult males can overheat rather easily.

If I had to guess as to the purpose of the polar bear’s black skin, I might suggest it works as a backup plan to capture heat (not UV) in bears which have hardly any store of fat… like newborns or perhaps bears that simply haven’t eaten enough.

@robmandu Hmmm. But, I would assume UV protection is very important for all animals. Without protection from the suns damaging rays humans get burnt, as bad as third degree, and cancer. However, if the brown bear that lives in the forest I would assume is brown for camoflauge reasons, maybe the fur simply changed to “white” as the polar bear migrated to live out in the open snow and water? And, the need for skin color change was not necessary, but also not a biological need, maybe the black skin just is? I have no idea. Interesting.

I think camouflage is very important in nature. I once did a Q about maybe man has whiter skin the further he moved away from the equator as a camouflage in the snowy environment, and then he tans in summer blending in with the wilderness. No one agreed with my hypothesis, they just insisted it was all about vitamin D absorption. I still think it might be both. Even blue eyes fits in well up in the cold weather as ice can actually appear blue. And, I wonder why white people evolved to generally have narrower noses? But, that is another discussion.

@JLeslie, the polar bear’s fur handles the UV protection already… as the source you cited explained. Also, pigs have skin with many similar properties to our own… and yes, they do get sunburned which is part of the reason why they stay covered in mud so much.

Human skin can develop a defense against sunburns – that’s why we tan.

Not sure what any of this has to do with albino polar bears, though.

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To your white people hypothesis, I’d think narrower noses would aid in warming the chilly winter air before it reaches the lungs.