The Reason Grizzly Bears and Polar Bears Are Now Having Sex

If current trends in bear dating persist, you may need to learn the terms "pizzlies" or "grolars." Sex between Arctic polar bears and grizzly bears is on the rise in Alaska and Canada, according to Alaska Dispatch News.

If this continues, polar bears could be a thing of the past, and a hybrid species of polar bears and grizzlies could take their place.

polar bear

"I hate to say it, but from a genetic perspective, it's quite likely grizzly bears will eat polar bears up, genetically," said Andrew Derocher, a professor of biological studies at the University of Alberta, to Alaska Dispatch News.

Grizzly Bear (Ursus arctos ssp.)

The cross-breeding is actually a sign of something really scary.

Polar bears primarily hunt on arctic ice caps and global warming is melting their home turf, according to the U.S. Geological Survey. As a result, the population of polar bears is expected to decline by at least 30 percent by 2050, according to the World Wildlife Federation. Because of dwindling numbers of the vulnerable polar bear population, they'll be looking for mates among a more bountiful nearby population: grizzly bears.

In the science world, looking outside one's sub-species for mates is called "flexible mate choice."

While rare, an example of the so-called "pizzly" or "grolar" bear was found in the Canadian wild back in 2006, NBC reported at the time.

According to a 2010 Slate article by Christine Clisset, grizzly and polar bears have a similar genetic background, and are therefore able to produce fertile offspring. This is unlike horses and donkeys, for example, who can make baby mules, which are sterile.

Polar bears and grizzly bears aren't the only species to mix breeds.


The coywolf is a mixture of western coyote and an eastern wolf. They've only appeared around the last 100 years in Canada and northern states in the U.S. like New York, according to PBS. They will sometimes even edge out wolves from their own territory.

There is also speculation in the scientific community that the ancestors of modern human beings, homo sapiens, may have mixed with some of the Neanderthal population as they died out, according to the Smithsonian Museum of Natural History.

RELATED: 5 Terrifying Examples of What Climate Change Actually Looks Like