No one has successfully crossed the Northwest Passage by human power, but author Kevin Vallely made one of the closest attempts in 2013—a rowing trip made possible by the dramatic impacts of climate change in Canada's far north. In this passage of his forthcoming book Rowing the Northwest Passage: Adventure, Fear and Awe in a Rising Sea, Vallely observes the northward migration of grizzly bears and the hybrid species spawned by interbreeding with polar bears.
Until two decades ago, grizzly sightings in the High Arctic were so rare that biologists considered any evidence of one a biological anomaly—more likely a bear lost for some unfortunate reason than a harbinger of things to come. But no more.
In 2003 Canadian glaciologist John England observed a grizzly bear along a river valley on Melville Island over 700 miles farther north than biologists would expect to find it. England described it as fat, healthy, and perfectly comfortable in its surroundings. "The clear implication was that this grizzly had denned somewhere up around Melville, far from where grizzly bears are normally found," England says in an article in the magazine of the National Wildlife Federation. "Presumably, it was feeding on muskoxen because apart from the occasional caribou you see high up on the Arctic islands there isn't much else for them to eat."
Biologists surmise that these grizzlies are following caribou on their annual migration from the mainland to the islands of the archipelago and, with rapidly melting sea ice breaking up seals, hibernating, and even interbreeding with polar bears.
The very idea of a polar bear and a grizzly interbreeding seems fanciful, but it appears to be a new reality. Polar bears diverged from grizzly bears about five million years ago yet still maintain enough genetic alignment to produce fertile young. Biologists have observed such interbreeding in captive bears, but the existence of a naturally occurring mixed bear was considered hypothetical until April 16, 2006, when hunter Jim Martell shot what he thought was a polar bear near Sachs Harbour on Banks Island, NWT. The bear had a creamy white coat like a polar bear but long claws, a shallow face, and a humped back like a grizzly. It even had brown patches around its eyes and on its nose, back, and one foot. Martell was understandably distressed, as unlawfully shooting a grizzly bear in Canada can carry a $1,000 fine and up to a year in jail, but when the authorities were brought in, DNA tests proved the animal had a polar bear mother and a grizzly father, exonerating Martell and giving him the dubious distinction of killing the first grizzly–polar bear found in the wild.
On April 8, 2010, David Kuptana, an Inuvialuit hunter, shot what he thought was a polar bear until DNA tests proved otherwise. Not only was this bear a hybrid bear, it was a second-generation one, with a grizzly for a father and grizzly–polar bear hybrid for a mother.
With its presence transcending myth, the hybrid grizzly—polar bear has become subject to the name game. The amusing "pizzly" defines a bear with a polar father and a grizzly mother, while the equally jovial "grolar" refers to the opposite. But despite the lighthearted names, there's nothing playful about this bear. "It's the meanest of the lot," Joe Illisiak said when we were at Brown's Harbour. "You don't want to run into one of them."
A barren-ground grizzly bear is terrestrial and territorial, while a polar bear is nautical and nomadic. A grizzly bear's diet ranges from berries and roots to ground squirrels and caribou, while polar bears eat seals exclusively. Grizzlies are shaggy and brown, well camouflaged in the tundra, while polar bears are creamy white and well camouflaged on the ice. Mix a polar bear and a grizzly bear together and you get a hybrid species not well suited to either of its parents' worlds. With Arctic warming, barren-ground grizzlies are venturing farther north than ever before while shrinking sea-ice habitat is forcing polar bears onto land. As the overlap between the two species' habitats increases, more pizzlies and grolars are inevitable. This new hybrid bear speaks loudly to the changes happening in the Arctic and to the threat facing the polar bear as a species. Scientists predict that two-thirds of the world's polar bears may disappear by the end of this century. This will be not only due to interbreeding but because they will be unable to adapt to food losses associated with a warming Arctic.
According to a 2006 study in the journal Science, researchers attached satellite collars and surgically implanted small logging instruments on over two dozen polar bears in the Beaufort Sea in order to track the bears' movement and record physiological data. The results showed the bears didn't slow down when faced with a reduced food supply. Scientists had previously surmised that polar bears would enter a state of "walking hibernation" when Arctic warming diminished their food supply, but this new research suggests that they will simply starve.
Excerpted from Rowing the Northwest Passage: Adventure, Fear, and Awe in a Rising Sea by Kevin Vallely, published September 2017 by Greystone Books. Condensed and reproduced with permission from the publisher.