In one corner, step right up, its Ursus Maritimus, otherwise known as the Polar Bear! Not content to pose for cute Coke commercials, Polar takes on seals from ice floes with nothing more than "a single bite." Polar roams the coasts of Hudson's bay weighing in at 1500 lbs!!
And in the other corner, the brown terror, Ursus Arctos Horribilis, featured in many beer commercials and bad John Candy movies. He can smell a blueberry at 100 paces, and he's got claws that would make Wolverine question his manhood!
And thanks to the rapidly warming Canadian arctic, this particular prizefight is about to happen.
A new report offers the first documented evidence the temperamental grizzlies are migrating into polar bear territory. Researchers found that seven grizzlies have been spotted in Wapusk National Park south of Churchill, Man., between 2003 and 2008.
Since then, sightings have multiplied.
"In 2008, I saw the first one I'd ever seen," said study author Robert Rockwell, an ornithologist with the American Museum of Natural History who has been researching snow goose populations around Churchill for 41 years. "But last year, I saw three different ones. Clearly they are settling in."
This development is so recent that the Wikipedia article on polar bears says it can't even happen.
More recent genetic studies have shown that some clades of brown bear are more closely related to polar bears than to other brown bears, meaning that the polar bear is not a true species according to some species concepts. In addition, polar bears can breed with brown bears to produce fertile grizzly–polar bear hybrids, indicating that they have only recently diverged and are genetically similar. However, because neither species can survive long in the other's ecological niche, and because they have different morphology, metabolism, social and feeding behaviors, and other phenotypic characteristics, the two bears are generally classified as separate species.
And since grizzlies and polar bears are interfertile, that raises some interesting conundrums. What if they make love, not war? Grizzly/Polar bear hybrids would not be fully adapted to either's habitat, and the mixing of their traits could result in the dilution of each lineage's beneficial traits. Males from one species could begin to compete with the other's for mates, with consequences that might prove disastrous for polar bears. Since grizzly/polar bear hybrids are fertile, the offspring of such a union would be capable of getting in on natural selection, and changing the game completely.
(Yep, that's a real polar/brown hybrid.)
Polar bears have highly specialized teeth, a hard won adaptation achieved during the last glacial period. Grizzlies are omnivores who eat more plants than meat, and grizzly style teeth would be a disadvantage to a hybrid trying to eke out a polar bear existence (which it would - the hybrids display behaviors more characteristic of polar bears than grizzlies.)
When given large toys to play with, such as tractor wheels or barrels, both bears used their front legs to stamp on the object, just as polar bears stamp onto ice to break through to seal dens.
(Hybrid bear feet are partially covered with fur; polar bear feet are fully covered and brown bear feet uncovered)
The hyrbids also used their teeth to hurl jute-bags from left to right, as polar bears may hurl prey. Brown bears given similar bags do not show this behaviour.
And then of course there's the loss of the pure white coat, useful in camouflaging polar bears in winter.
We live in interesting times. Whether polar bears make war or make peace, ursine life in Manitoba is about to get very, very different.