As the world warms and Arctic sea ice melts, starving polar bears are forced further south, where they meet grizzlies, whose ranges are expanding northward. With increased contact between the two species comes more mating, and thus more sightings of their hybrid offspring. But did you know polar bear and grizzly bear hybrids all came from the same mother polar bear?
All eight known polar bear-grizzly bear hybrids are descended from the same mother polar bear.
The Grizzly Bear Hybrid
According to DNA analysis, the bear’s father was a grizzly bear, and his mother was a polar bear. The bear’s white fur was interspersed with brown patches. He also had long claws, a concave facial profile, and a humped back, all of which were grizzly features.
It’s of interest because it’s rare, but that’s kind of it, I don’t think there’s more to it than that.
Rosa Meehan, Chief of Marine Mammal Management with the US Fish and Wildlife Service in Anchorage, Alaska.
Meehan is in charge of an investigation into how changing environmental conditions in the Arctic are affecting polar bears. The study aims to determine whether animals deserve federal protection as endangered species in the United States. She claims that the hybrid sheds no light on the species’ possible endangered status or the role of global warming in the species’ decline.
David Paetkau is the president of Wildlife Genetics International, a company based in Nelson, Canada, that confirmed the bear is a hybrid. He claims it is too early to draw any conclusions about the discovery. (Source: National Geographic)
Naming the Grizzly Bear Hybrid
Ian Stirling, a research scientist and polar bear expert with the Canadian Wildlife Service in Edmonton, says unofficial names include grolar bear and pizzly. Stirling claims that grizzly bears have appeared in Canada’s western Arctic as far north as Banks Island and Victoria Island in the province of Nunavut regularly for the past 50 years.
This is one instance. As a scientist, you can’t say anything about one instance, other than, What should we name it?
David Paetkau, President of Wildlife Genetics International
The Polar Bear Genetic Pool
The genetics expert Paetkau believes that grizzly and polar bears are the most closely related of the living bear species. The two species are close enough that the hybrid could theoretically have mated with either a polar bear or a grizzly bear.
Prehistoric polar bear fossils are difficult to find because polar bear ancestors lived in environments that were unsuitable for bone preservation, according to Paetkau. However, the two species most likely diverged less than a million years ago.
North American black bears and grizzly bears, on the other hand, diverged about five million years ago, according to him.
The habitat of polar bears and grizzlies overlaps in the western Canadian Arctic around the Beaufort Sea. Grizzlies are known to venture out onto the ice in the spring to feed on seals killed by polar bears, according to Stirling of the Canadian Wildlife Service.
Meehan of the United States Polar bear and grizzly bear encounters have been reported in Kaktovik, the Arctic National Wildlife Refuge’s only permanent settlement on the North Slope. However, there is no romance there.
The interactions are aggressive
Rosa Meehan, Chief of Marine Mammal Management with the US Fish and Wildlife Service in Anchorage, Alaska.
(Source: National Geographic)
Image from LiveScience