Bears as Predators ~

[Polar]

(05-18-2016, 04:20 AM)peter Wrote:

(01-31-2016, 05:56 AM)brotherbear Wrote: Grizzly Years by Doug peacock.

The Bitter Creek Grizzly was the only bear I knew of in Yellowstone that regularly killed moose and bison. He attacked younger animals - ambushed them from nearby timber, then dragged them back into the trees, sometimes covering the carcasses with dirt and sticks. I had seen this too many times to believe that these animals had all conveniently died during the winter. His was not the usual pattern of predation for grizzlies. In 1977, when I first crossed paths with the Bitter Creek Griz, a biologist had found another grizzly who had passed up many carcasses for live elk: The bear liked to kill what he ate. A few bears learn to kill healthy adult elk during all seasons, and cow-struck bulls during the rut were especially stupid and approachable. Yellowstone grizzlies also prey on elk calves, as they do caribou calves in Alaska, and moose calves in both places. Adult moose were generally a match for a grizzly except when snows were deep and lightly crusted: grizzlies can walk lightly over a thin crust, distributing their weight evenly on their plantigrade feet, and they glide over the top of deep drifts in which moose wallow.

I thought that grizzly predation was not as common here as it had been a decade or more ago. The predatory segment of the population had probably been killed off selectively, and continues to be culled as they were born into it, because predatory bears are bolder and more visible. The Bitter Creek Griz was a holdover from the days when bears could afford to be bold and aggressive. Which served, as it always had, an important ecological function vital to survival of the species.

" ... The predatory segment of the population had probably been killed off selectively, and continues to be culled ... , because predatory bears are bolder and more visible. The Bitter Creek Griz was a holdover from the days when bears could afford to be bold and aggressive ... " (from your post).

One has to add that predatory bears also could be more dangerous to people. Bears know proteine beats salads in more than one way. Bears doing proteine are larger than others. As size results in more access to food and females, males in particular prefer proteine. When proteine is not available, you make it available. In order to do this, you need to be inquisitive and bold. You also need to learn how to find proteine and how to stalk and kill. Once you've mastered the art, why discriminate between animals and humans? An opportunity is an opportunity and food is food.

The difference between bears and big cats is bears are omnivorous by nature, whereas big cats are born predators. Bears shifting from pasta to proteine have to discover proteine first and then learn how to exploit the new opportunities. Predation, therefore, is acquired, not inborn. For this reason, selective culling of predatory bears could affect the habits of all bears in the region where they are hunted.

Not so in big cats. This is why today's tigers, percentagewise, kill as many humans as they did a century and a half ago.

Although most large predators are not dangerous for humans, some are. Big cats are born hunters and opportunists. Some would hunt humans as readily as animals. Tigers always hunted humans. The only exception seems to be eastern Russia. Not Manchuria and Korea (also Panthera tigris altaica), but eastern Russia. There has to be a reason and as it most certainly isn't hunger (quite many Amur tigers face starvation on a regular basis), my guess for now would be culture.  

Why would tigers, percentagewise, still kill as many humans as they did a century and a half ago? One is it is inborn in some individuals, two is tigers were hunted everywhere a century ago (and not today) and three is opportunities in most parts of Asia. I think we need to add prey depletion (destruction is everywhere) and hunting as causes as well. 

All in all, one could say eating proteine is an acquired habit in some bears, whereas it is the essence of every big cat. If you take predatory bears out in a region, chances are it will affect the habits of all bears. Not so in big cats.

Interesting post, Brotherbear. Bears who shifted to proteine deserve a special thread because it is an atypical habit in many regions. The next step is man-eating. In what way are man-eating bears different from man-eating big cats?

The polar bear (and quite possibly Agriotherium) both seem to be naturally adapted to being obligate carnivores, unlike any other bear species. As always, Peter, your posts are always fun to read!


Big cats do seem to hunt man with their instinctive hunting skills; however, man-eating bears seem to think more about how they will hunt the man down: it doesn't come naturally to them to hunt a bipedal foe unlike some big cats, so bears tend to use more reasoning (particularly reasoning directed to their prey's morphology, behavior, and situation). Big cats automatically know to bite the throat, regardless of the prey's morphology and they don't have to use as much reasoning to attempt the attack.

In short, your viewpoint is still very agreeable and conclusive: man-eating cats have more primal hunting instincts than man-eating bears. Reply