What do you get when you cross paths with a polar bear and a grizzly? A fluffy reminder of how climate change is transforming our planet at an alarming rate.
These hybrids, sometimes referred to as pizzly bears or grolar bears, have been spotted in the wild since like 2006. But with rising global temperatures due to carbon pollution, the habitats of the two species more often overlap. As the heat pushes grizzly bears north, polar bears move south in search of food as arctic sea ice continues to shrink. historical levels. And there’s a good chance the two aren’t just bumping elbows – they seem to be increasingly engaging in “opportunistic mating,” as Vanderbilt University’s Larisa DeSantis put it. a recent video published by the institute. A study in 2017, at least eight pizzlies were documented that dated back to a single female polar bear and two separate grizzly bears.
“We’ve known about pizza for a while, but they may appear more frequently with the ongoing arctic warming,” said DeSantis, associate professor of biological sciences. “As grizzly bears move north, they are more likely to come into contact with polar bears in areas where their ranges overlap. In addition, polar bears must increasingly seek other sources of food, as the seal hunt on sea ice becomes untenable. “
Polar bears and grizzly bears are known to congregate at whale carcass sites, she said. And since the two species only diverged about 500,000 or 600,000 years ago, their offspring are capable of reproducing. One study found a hybrid resulting from pizzly mating with a grizzly bear, according to DeSantis.
How suitable are these hybrids for survival in the wild? Researchers are still trying to figure this out.
“Most of the time, hybrids are not more vigorous than either of the two species,” DeSantis said, explaining that the species generally develop adaptations better suited to their individual habitats. However, there are cases where hybrid species can be more vigorous than their predecessors, “particularly if this environment deviates from what it once was”.
If carbon emissions follow their current path, experts predict the global temperature will rise by about 5.4 degrees Fahrenheit (3 degrees Celsius) from the end of this century. With this increase comes a few rather catastrophic side effects, including massive ecological upheaval, ocean acidification and sea level rise, among others. And, while significantly less catastrophic, more pizzly bears.