Grizzlies move into Canadian polar bear territory

Will there be more “pizzlies”/” grolar bears”?

Someone put up a version of this on our “have you run across any interesting news page.” Now for a full post.

Grizzlies encroach on polar bear territory
By Doreen Walton
Science reporter, BBC News

Seems like I read polar bears are a more recently evolved species than the big brown grizzly bear (called by other names in Asia and Europe)

4 Responses to “Grizzlies move into Canadian polar bear territory”

  1. SEAK Mossback Says:

    Brown (grizzly) bears definitely seem to be a rising star on the north slope of Alaska as well and seem to be increasingly present along the coast and even occasionally out on the ice. In several recent summers, my family and I have gone on personal adventure and hunting trips into the north slope of the Brooks Range out of Kaktovik (Barter Island). There were polar bears and as well as a brown bear roaming around town the last time we were there in August. The brown bear had worn out its welcome (you could track its location through the village at night by the barking dogs) and some locals were asking me to shoot it (I was the only one in town with a brown bear tag which I carried only to be able to keep a bear rather than turn it over in the event we had to shoot one in self defense).

    The postmaster told me the brown bears really started showing up on the island about 5 years ago after about 300 caribou moved there one the winter when they would normally have migrated with the rest of the Porcupine herd to the south side of the mountains around Old Crow and Arctic Village. Locals shot all they needed and the rest all starved because of ice cover on the vegetation. All the carrion the next spring attracted brown bears and they have never really left.

    Polar bears swim in from the Beaufort Sea and congregate in August in anticipation of the September whale hunt but the grizzlies, although far smaller, are much more aggressive and less social and often drive the polar bears off the carcass and into the ocean. Oddly, grizzlies are thought to be one of the primary factors in the virtual disappearance of muskoxen from the Arctic Refuge. The population had been stable at about 350 animals since the mid-80s until some bears apparently figured out how to effectively kill them around 1999 – recent annual USF&W Service counts have been as low as 1 animal (although our pilot told us there were a few more than that). Several groups of dead animals were found and wanton poaching was initially suspected. A pilot actually witnessed a grizzly run at a pair of big bulls standing butt-to-butt west of Kaktovik and jump high over the horns and kill both.

    I thought brown bears were amazingly abundant during our trips although granted you can see a long distance up there (we passed 3 adults in less than 2 miles of river floating one morning). The most likely reason I can think of for the apparent increase and expansion of brown bears along the coast is the increasingly lushness of the vegetation on the north slope, as documented by satellite imagery (and also remarked on by Barter Island locals I spoke with). The bears are always on the look-out for anything they can run down and kill, particularly when groups of caribou are coming through, but most we saw were feeding on vegetation. Some have argued that if the sea ice situation gets too precarious, polar bears will survive on land. I don’t see it. They are such specialists compared with grizzlies. You might see grizzlies out catching seals but I doubt you will ever see polar bears finding much to eat on land – and that niche is completely filled.

  2. Ralph Maughan Says:

    SEAK Mossback,

    Thanks for your detailed observations of the spread of grizzly/brown bears.

    Under a changing environment, generalist animals, including generalist omnivores or carnivores like grizzly bears, will displace more specialized competitors like polar bears. Grizzlies are omnivores and polar bears are carnivores. This gives grizzlies a great advantage. As you wrote, grizzlies are more aggressive too.

    Wolves are generalized carnivores too. That is why they have such a wide distribution on the planet. It is also why I think their kills appear sloppy compared to cougars, for example.

    If we look at middle sized carnivores, coyotes really do well under so many conditions, and their smaller size lets them escape human notice where wolves and big bears don’t.

    Raccoons are an incredibly adaptive omnivore.

    Stability breeds specialization. Conditions are getting to be unstable, a suitable situation for generalists.

  3. bryantolsen Says:

    It is my understanding that Polar Bears evolved from Grizzly(Brown) Bears about 100,000 years ago. Both have only spread into the new world rather recently, south and east of Alaska, in the last 15,000 years. Grizzly Bears were once found in northeastern Canada, being called the Ungava Grizzlies, but were all killed off pretty early there(1900?). There have always been accounts of individual Grizzlies that go out on the ice and hunt seals like polar bears. Before Grizzlies and Polar Bears, North Americas dominant Bear was the extinct Giant Short-faced Bear, as heavy as the biggest Polar Bears, but leaner and built for stalk/rush hunting of the now extinct megafauna. Evolution will create new bears adapted for a new climate,but only if we let some of them survive.

  4. monty Says:

    thanks for the excellent comments!

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