Did you know that polar bears aren't actually white?
Fact. Their color is determined by lighting and the climate of their surroundings. Polar bears can come in all types of colors: yellow, gray, orange, and even green. That's because polar bear fur is transparent and hollow, so when light strikes the outer fur some of it is absorbed while the rest is deflected. Consequently, the fur can appear as different colors under different lighting. Normally, polar bears look white. That's because their fur is scattering sunlight, which is also white. But on a cloudy day, the bears can look slightly gray. At sunset, they can even appear reddish-orange.
Polar bears in zoos have even been known to turn green. This happens when concrete floors in their pens scrape against the fur and the abrasions create small holes in their hairs, opening a means for algae to live and breed inside. In the Arctic, temperatures are too cold for algae. But wild polar bear fur can even change color to yellow due to oils from their prey that stain their fur.
The most surprising thing about polar bears is that underneath all that hair, their skin is actually black. Black skin readily absorbs sunlight to keep the bear warm.
Polar bears aren't just the ambassadors of the North Pole. *They're masters at manipulating color to survive.
(source http://www.businessinsider.com/what-color-is-polar-bear-fur-2017-12)
Photo taken at the St. Louis Zoo, one of the only free zoos in the USA.
!steemitworldmap 38.64 lat -90.29 long St. Louis Zoo St.Louis, MO d3scr
Images taken with Samsung Galaxy S7 Edge
© 2018 Nina Haskin. All rights reserved
