Polar Bear-Grizzly Bear Hybrids Likely to Become More Common Thanks to Climate Change

As temperatures rise and species are forced out of their native habitats, pizzly bears, also known as grolar bears, are likely to become more common, according to Live Science. Their proliferation is a testament to the devastating ecological impact of global warming.

The hybrid offspring of polar bears and grizzly bears, pizzlies were first sighted in the wild in 2006. That year, a hunter in the Canadian Arctic's Northern Territories shot what he thought was a polar bear. When he examined the dead animal, however, he noticed that it possessed some of the distinctive physical characteristics of both species. His suspicions were subsequently confirmed by DNA testing, reports Live Science.

Climate change has caused polar bears to roam farther south and grizzly bears to roam farther north in search of food, increasing the amount of shared territory and thus the likelihood of contact. Because they diverged only around half a million years ago, they are still capable of conceiving and producing cubs together. Even pizzlies themselves seem to be fertile.

Thanks to their blend of features, pizzlies may be better equipped than polar bears to survive in the modern Arctic, Larisa DeSantis, a paleontologist and associate professor of biological sciences at Vanderbilt University in Tennessee, told Live Science.

A grizzly bear rests on a rock.
A grizzly bear rests on a rock. They are capable of mating with polar bears to produce pizzlies, AFP Contributor/Getty Images

"Usually hybrids aren't better suited to their environments than their parents, but there is a possibility that these hybrids might be able to forage for a broader range of food sources," she said.

Perhaps the most visible casualty of climate change, polar bears could be all but extinct by 2100. In fact, their numbers are expected to plummet by more than 30% in the next three decades.

One of the reasons for the bears' extreme vulnerability is the fact that they are physiologically designed to prey on and consume blubbery animals such as seals. For example, their molars "are smaller than is typical for their body size because all they eat is blubber all day," DeSantis told Live Science.

"Grizzlies, on the other hand, can eat whatever they want," she said. "We don't know yet, but perhaps the intermediate skull of the pizzly could confer a biomechanical advantage."

While the extinction of purebred polar bears is a tragic prospect, the existence of pizzlies may enable them to persist in some form.

"Apex predators help stabilize ecosystems, and looking forward I really hope the Arctic still has a polar bear," DeSantis said. "But, with that all being said, could the pizzly allow for bears to continue to exist in intermediate regions of the Arctic? Possibly, yes. That's why we need to continue to study them."