In the past few years, a new animal has made an appearance in northern Canada and Alaska, with polar bear-like fur and grizzly bear-like paws and bone structure. Recent studies published by University of Alaska evolutionary biologist Brendan Kelly, along with Andrew Whiteley and David Tallmon, suggest that, "the rapid disappearance of the Arctic ice cap is removing the barrier that's kept a number of species isolated from each other for at least ten thousand years," (December 15, 2010, accessed January 2011). The hybrids are known as "grolar bears," and while few have been spotted in the wild, DNA testing has confirmed that these animals are indeed the result of sudden mating between grizzly and polar bears.
Recent Discovery
According to an OnEarth Magazine article entitled "Grolar Bears and Narlugas: Rise of the Arctic Hybrids," the most recent hybrid was killed in April, 2010, and was discovered to be a second-generation hybrid, meaning that these grolar bears are fertile and are mating with one another (December 15, 2010, accessed January 2011). Moreover, this fact implies that the trend has been going on for some time. Authors Kelly, Whiteley, and Tallmon suggest that this recent hybridization could potentially happen in marine mammals, such as pinnipeds, who share the same number of chromosomes with one another, allowing for the creation of fertile offspring.
The Potential Causes and Effects
While it is natural for hybridization to occur, never before has it been the result of rapid, dramatic climate change, introducing two isolated species to one another. And what will happen to polar bear and grizzly bear populations if they continue mating and producing hybrid offspring? Kelly, Whiteley, and Tallmon fear that it's all a "number's game," in that melting ice caps could push polar bears ashore, where they will mate with grizzly bears who are attracted by the cooler climate up north, and that the polar bears will eventually die out as a species, as fewer and fewer pure polars are left in the wild (Kelly et. al, 2010). This is dangerous considering that polar bears are an endangered species today.
Questions for the Future
There are many things that are up in the air right now, as researchers and conservation groups attempt to find a way to protect and monitor these animals, while ensuring that they do not lead to the extinction of endangered animals like the polar bear. In addition, it is unclear whether these new hybrids will have the survival capabilities required to live in their new environment, and whether their offspring will number high enough to ensure survival.
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