The bears were at 73 degrees North latitude, well north of the usual grizzly habitat. What first appeared to be a polar bear turned out to be a hybrid, something still rare but becoming increasingly common as warming temperatures send grizzly bears farther north.
According to Yale’s environment360:
Up until about 20 years ago, sightings of grizzlies in the High Arctic were relatively rare. But that began to change as a succession of brown bears started showing up on the Arctic islands, following caribou perhaps that routinely cross over from the mainland. No one had seriously thought that these grizzlies would eventually mate with polar bears until Roger Kuptana, an Inuit guide from Sachs Harbour on Banks Island, led an American hunter to one in the spring of 2006. The killing of that animal made headlines around the world.
This is not the first time climate change has led to hybrid bears. Researchers at Pennsylvania State University and the University of Buffalo traced genome sequences of a polar bear, three brown bears and a black bear. In addition, they were able to study samples from 23 other polar bears, including one that had lived some 120,000 years ago. They found that although polar bears and brown bears became two separate species 4 to 5 million years ago, they had interbred during a time of warming climate half a million years ago.
Next: New Hybrid Spotted by Hunter
The new hybrids were first identified in 2006, when an Idaho hunter, Jim Martell, was on a hunting expedition with an Inuit guide, Roger Kuptana. The white-furred bear he shot had characteristics not seen in polar bears: long claws, a humped shoulder, brown eye patches and an unusual snout. DNA testing proved it to be a hybrid.
Others have spotted hybrids since then. In appearance they fall somewhere between grizzlies and polar bears. Their behavior tends to be more akin to polar bears, relying on a more carnivorous diet than grizzlies.
At the moment the hybrids are rare and not a threat to the continuation of either species. What threatens both is loss of habitat. Dr. Steven C. Amstrup, chief scientist at Polar Bears International, says:
Polar bears are likely to starve out of their present ranges long before their genes are swamped by those of grizzly bears. If some polar bear genes persist in grizzly bears, after polar bears have disappeared from their current sea ice home, that fact will be irrelevant with regard to efforts to retain the magnificent and highly specialized life form we now know as the polar bear.
Whether we call the hybrids pozzles, grizzpos or Arctic bears, they are a reminder that human tampering with the planet carries threats whose consequences scientists have been predicting for decades. Dr. Armstrup makes this observation:
Discussions of hybridization aside, it is important to remember that by the time we allow the world to warm enough that the polar bears’sea ice habitat disappears, challenges to humans will be so great that no one will be thinking about polar bear conservation.
Related Care2 Stories
Photo credits: Thinkstock