Coming together: Hybrid bears emerge as climate alters territories

In nature, extremely rare species of bears are appearing. We are talking about so-called grolar and pizzly bears, which are hybrids of polar bears and grizzly bears. Although there are currently few of them, scientists note that their numbers will increase.

Scientists continuously report the identification of entirely new animal species previously unknown to science. One of the most recent discoveries was the discovery of a snake, Rhynchocalamus hejazicus, in Saudi Arabia. Now, researchers from Polar Bears International write about new species of bears in the journal Conservation Genetics Resources.

These are hybrids of polar bears and grizzly bears. Such grolar and pizzly bears are extremely rare specimens because they usually crossbreed in zoos. They can also meet in the wild, but this is generally not a common scenario. Nevertheless, both species are increasingly shifting their territories, which increases the chance of crossbreeding in their natural habitats.

Scientists examined several hundred wild polar and grizzly bears to determine how both species' hybrids are developing in nature. They found that due to climate change, grolar and pizzly bears will increase. The environment, in turn, influences this previously mentioned shifting of their territories. As a result, polar bears are increasingly meeting and crossbreeding with grizzly bears in nature.

The difference between the two hybrids stems from the offspring's origin. Scientists explain that a grolar is the offspring of a male grizzly bear and a female polar bear. Meanwhile, a pizzly is the offspring of a male polar bear and a female grizzly bear.

– The territories of polar bears and grizzly bears overlap. This usually happens in the summer when polar bears appear on the land's coasts, waiting for the ice to form – explains Dr Ruth Rivkin from Polar Bears International.

Scientists are aware that crossbreeding of the two species in natural conditions is extremely rare. However, they predict that grolar and pizzly hybrids will become more common in the future. Therefore, they decided to develop a genetic sequencing chip to study samples from polar and grizzly bears more accurately.

Thanks to the mentioned chip, among the 371 samples collected from polar bears and 440 from grizzly bears, scientists identified only 8 grolar hybrids. If global average temperatures continue to rise, scientists expect an increase in the number of bear hybrids in the environment.