When people think of polar bears, their white fur often comes to mind as an iconic symbol of the Arctic.

However, what seems like an indisputable fact is actually a common misconception. Polar bear fur isn’t white at all—it’s transparent!

This surprising discovery was made by Malcolm Henry, an American scientist specializing in polar bears. Using a scanning electron microscope, he found that what appears to be "white fur" under normal light is actually made up of transparent, hollow tubes. These unique hollow strands serve a crucial purpose: they allow ultraviolet (UV) rays to pass through, helping polar bears collect and retain heat in the frigid Arctic environment.

Here's Why Polar Bears Aren't White [+ Other Questions]

Video by Polar Guidebook

Why Do Polar Bears Look White?

The reason polar bears appear white to the human eye lies in the structure of their fur. The inner surface of these hollow hairs is rough and uneven, scattering light in multiple directions. This chaotic refraction creates the illusion of white fur. Essentially, their "whiteness" is a trick of light, a natural optical illusion.

During the summer months, polar bears don’t shed their fur for a darker coat like some Arctic animals. However, exposure to the elements can cause slight oxidation, which gives their fur a faint yellowish tint.

The Secret Beneath the Fur: Black Skin

Beneath the transparent fur lies an equally fascinating adaptation: black skin. This feature is especially evident around a polar bear's nose, paw pads, lips, and the areas around its eyes. Black skin is highly effective at absorbing and retaining heat from sunlight.

The hollow fur works in tandem with the black skin. Sunlight enters through the transparent hairs and is directed onto the black skin, maximizing heat absorption and helping polar bears stay warm even in temperatures that plunge far below freezing.

A Masterpiece of Arctic Adaptation

The combination of transparent fur and black skin creates an ingenious natural system for insulation. Together, they ensure polar bears can efficiently harness sunlight and maintain their body temperature in one of the most extreme climates on Earth.

So, the next time someone mentions that polar bears have white fur, you can confidently correct them: their fur is transparent, their skin is black, and their entire design is a marvel of nature’s engineering to survive the Arctic cold.