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Post by brobear on Jun 5, 2020 3:56:19 GMT -5
"Dietary biology of the brown bear" ( Ursus arctos ) is where we will discuss and seek the scattered references to this topic. Here is what I have learned over the years: 1- The Pleistocene brown bear of Europe was ( estimated ) about 80% carnivore. 2- The N. American grizzly became ( estimated ) 80% carnivore after the demise of the Ice Age mega-fauna. His carnivore diet was changed by human activity. The ability of the brown bear, as an omnivore, to shift his diet from mostly vegetarian to mostly carnivore is just one of this mammal's extraordinary survival traits. An good example is the highly vegetarian Himalayan brown bear ( red bear ) as compared to the much more carnivorous Tibetan brown bear ( blue bear ).
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Post by brobear on Jun 5, 2020 4:02:40 GMT -5
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. So; over the decades beginning with the grizzly slaughter of the mid-1800s, which included the notorious so-called "outlaw grizzlies", the most predatory bears have been selectively killed off. This culling of predator bears continues...
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Post by brobear on Jun 5, 2020 4:12:25 GMT -5
Reply #1 - WORLD'S RECORDS GRIZZLY BEAR: Greatest length of skull without lower jaw: 17 4/16 Greatest width of skull: 10 9/16 SCORE: 27 13/16 WORLD'S RECORDS ALASKA BROWN BEAR: Greatest length of skull without lower jaw: 17 15/16 Greatest width of skull: 12 13/16 SCORE: 30 12/16 This record grizzly skull ( inland grizzly ) was not killed by a hunter but was found by a hunter. It was a very rare discovery of a grizzly skull from the days when grizzlies followed the massive bison herds. Less than one inch difference in length from the *record Kodiak bear skull. Roughly two inches narrower in width. Consider that this is a discovery of a random bear - not likely the "biggest bear in the woods" - which would be a huge coincidence - and it is a Kodiak bear sized grizzly. The skull has a narrower shape. The grizzly populations which tend to be the most carnivorous tend to have narrow skulls. ( more polar bear-like ). The bears of the Old West who followed the bison herds were big and highly carnivorous.
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Post by brobear on Jun 5, 2020 4:32:58 GMT -5
From wildfact.com/forum/ by Peter: " ... 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? ( in the topic: "Bears as Predators" ).
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Post by brobear on Jun 5, 2020 4:41:32 GMT -5
By Polar: 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.
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Post by brobear on Jun 5, 2020 4:42:44 GMT -5
By Dr. Panthera ( Pharmacist and biologist ): For once I disagree with Peter, bears predation on humans is as instinctive as big cats predation on humans, seeking human as prey is a habitual behavior of male polar bears and male American black bears, the folklore of the aboriginal people here in Canada ( Natives and Inuit ) speak how for thousands of years bears sought humans as prey ( not the case with cougars, nor wolves) , granted the females usually kill humans in defense of their cubs but the males do it systematically as if they are born with the knowledge that humans are edible. A male black bear can grow to 500 pounds and knows that an adult human will provide as much meat as a large buck yet it is much slower, weaker, and less attentive...the rest is a gruesome picture.
Big cats on the other hand avoid man and have an innate fear of man and they are far more likely to avoid him and threaten him versus actually attack him and kill him and possibly eat him. In many areas man-eating tigers, lions, and leopards are individual isolated cases that developed for specific reasons yet we have the curious cases of cultural man-eating where generations of animals , mothers to cubs, sub-adults to healthy prime aged adults to old individuals on their last legs...all relish human flesh and seek human prey. The best two examples are the tigers of the Sundarban and the lions of the Lindi district in southern Tanzania, despite intensive research and intervention human victims succumb to the attacks by these big cats.
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Post by brobear on Jun 5, 2020 4:44:07 GMT -5
Peter says: Polar is right and so is Dr. Panthera: there's no question that polar bears are true carnivores. Furthermore, they are confirmed man-eaters. Why then did I leave them out? The answer is they are very different from other bears. To me, they are catbears. A new species. As a result of the climat changes, the attempt to start a new branch most probably will fail. Loss of habitat and less opportunities to hunt have significant consequences: intra-specific predation has become prominent and it's likely the population will sharply decline in the next decades.
As to polar bears and humans. Many years ago, a friend took me to a zoo somewhere in Holland. As she was very interested in polar bears, we took our time to see the big male they had. As she sensed I had a very different view of the male bear than she had, she became a bit agitated. I didn't want to tell her what I felt, but I didn't need to as the bear did it for me in that he suddenly became very personal.
Why did the bear change his behaviour? The answer is he knew the zoo had closed. All gates had been closed as well. Same for the entrance to his corner, meaning we couldn't get out. Although he had plenty of bars to negociate, he was willing to give it a try. As it would take some time for them to check the large zoo and find us, he knew he had a bit of time to find a solution for the problem at hand: how to get to us. As his attempt was very convincing, she suddenly realized what he was after. When people panick, instinct takes over. They lose control, which can result in dangerous situations. It also encourages the attacker. I will spare you the details, but can tell you she decided to climb the gate. She had nearly reached the top when a zoo vehicle came round the corner. She didn't wait for them, but immediately jumped. No bones were broken, but it took quite some time to calm her down.
Some time later, the keeper started talking about that bear and his interest in humans. They had been warned by the director of the zoo where he was born and the bear hadn't disappointed them in any way. Hence the decision to build an extra gate. The male bear was at least a 1000 pounds, but he was as athletic as a big cat one third his size and he most certainly knew how to communicate. Although the zoo was spacy and comfortable, the atmosphere was bad. There have been quite a number of incidents. People didn't hear about them, but they sensed something wasn't quite right. The animals 'told' them.
I saw and heard a lot of things you never read about. This is the reason I stopped reading articles written by biologists who can 'prove' animals can't do this or that or the opposite. Animals, and predators in particular, are much more capable than many think. They also have very pronounced personalities. Most people don't know, because they never interact with animals. Not really, I mean. But trainers do and they know all about animals. For this reason, they treat them as they treat their humans friends (if not better). All trainers told me bears are very intelligent and capable. Polar bears either like you or they don't. When they like you, there never will be a problem. When they don't and you have to work with them, you need a friend. The best friend you could have is another polar bear. If you don't have one, better leave it. As to American male black bears and humans. Although some males actively hunt humans at times, they do not quite compare to lions and tigers. Percentagewise, the big cats are as dangerous as before. This is not true for bears. The reason is it is an acquired habit. If you consistently remove dangerous individuals for a long time in a region, habits will be affected. Attempts to take a dangerous bear out seldom fail.
Big cats, on the other hand, are about eating meat and hunting. Although there is a difference between hunting animals and hunting humans, the bridge isn't a large one. Many who crossed it were taken out, but things didn't really change: percentagewise, big cats as as dangerous as a century and a half ago. The reason is genes. One could make a case for an inborn 'interest' in humans in some bears in some regions as well, but if we add the numbers we have no option but to distinguish between bears and cats. Polar bears are the exception to this rule.
It's true that most big cats have an innate fear of humans, but there are many exceptions and it doesn't take a lot to change the situation. A century and a half ago, complete districts were deserted in Java, Sumatra, parts of central and northern India, Nepal, Indochina, China, Manchuria, Korea and the Caspian region. After 1945, outbreaks of man-eating were seen in Indochina (Vietnam war), India, Sumatra, China and the Caspian region. This is apart from individuals who operated in the other regions where tigers and people are neighbours. Today, tigers still hunt humans. The Sunderbands top the list, but I wouldn't underestimate northern India. Lions hunting humans seldom make headlines, but they definitely compare. I've read plenty of books on man-eating lions.
There are some good case-studies on man-eating big cats, but there never was an attempt to get to a few conclusions at the level of species. Boomgaard's book ('Frontiers of fear', Yale University Press, 2001), based on official documents, has a lot of numbers. They are quite staggering. Although well-written and interesting, it is no attempt to get to an explanation. Maybe the attempt to find one should start in southeastern Russia, where man-eaters always were the exception to the rule. The question is why that is.
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Post by brobear on Jun 5, 2020 4:48:15 GMT -5
Dr. Panthera says: Peter has a great point regarding "the individuality" of animals, science is concerned with the patterns, the norms, the regular and repetitive behavior..so not much is devoted to how an individual animal has a personality different than its conspecifics, yet any person who studied a group of animals for a while from a sheep herder to the most renowned field biologist can attest on how different animals have different personalities. Another gruesome man-eating episode happened in Kruger in the late 90's, illegal immigrants from Mozambique infiltrated into South Africa at night through the national parks that form the border areas between the two countries, the Greater Limpopo Ecosystem, some lions started preying on these unfortunate refugees, and then proceeded to take more and more victims which they clearly distinguished from other humans eventually when the refugees stopped coming through the area the lions staring attacking other humans in daylight and needed to be put down. American black bears continue to be the main predator of humans in North America outside the arctic area they account to more "eaten" humans than grizzly bears, cougars, and wolves despite more frequent attacks on humans and human fatalities by the first two.
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Post by King Kodiak on Jun 5, 2020 4:50:11 GMT -5
Brobear, are you going to post all the debates from Wildfact to here? Those are just posters debating, knowledgeable ones yes, but all that has been debated on that forum already, lol.
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Post by brobear on Jun 5, 2020 5:15:34 GMT -5
Brobear, are you going to post all the debates from Wildfact to here? Those are just posters debating, knowledgeable ones yes, but all that has been debated on that forum already, lol. I am actually seeking ( at your request ) for the evidence of the historical grizzlies carnivorous diet. I am posting that which is relevant to the topic. Do you mind?
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Post by King Kodiak on Jun 5, 2020 5:20:56 GMT -5
Brobear, are you going to post all the debates from Wildfact to here? Those are just posters debating, knowledgeable ones yes, but all that has been debated on that forum already, lol. I am actually seeking ( at your request ) for the evidence of the historical grizzlies carnivorous diet. I am posting that which is relevant to the topic. Do you mind? Not at all, keep going. I am reading everything. But i was specifically talking about the California grizzly.
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Post by brobear on Jun 5, 2020 5:30:12 GMT -5
The only grizzly ( type ) that was ever described as being more vegetarian was the Mexican grizzly ( also referred to as the smallest and least aggressive grizzly ). Also note that brown bears which consume greater amounts of protein are the largest brown bears and more aggressive. The California grizzly was described as large and aggressive. *Its going to take some searching to locate the conversation I'm seeking on W.F.
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Post by brobear on Jun 5, 2020 6:02:26 GMT -5
wildfact.com/forum/topic-bears-of-the-pleistocene Bears of the Pleistocene GrizzlyClaws: The two respective studies were based on two different species of the Cave bears. The regular Cave bears (Ursus spalaeus) were as herbivorous as the Giant Panda, but those Cave bears (Ursus ingressus) from the Southeast Europe were extremely carnivorous. Me: I wonder if there might have been some direct competition between the grizzly, Ursus arctos and either or both cave bears, Ursus spelaeus or Ursus ingressus? We will probably never know. GrizzlyClaws: Ursus spelaeus were gentle teddy bears and would probably co-exist peacefully with other bear species. While Ursus ingressus and the giant European Pleistocene Brown bears would probably attack each others. The giant European Brown bears from the mid-late Pleistocene were also larger and more carnivorous than the modern Brown bears.
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Post by King Kodiak on Jun 5, 2020 8:57:45 GMT -5
The short faced bears, both from North and South America were highly carnivorous also according to some researchers, we just dont know the actual percentage.
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Post by brobear on Jun 5, 2020 9:05:29 GMT -5
shaggygod.proboards.com/thread/280/male-grizzlies-yellowstone-meat-eaters October 14th, 2010 - To assuage our fear of bears, we're often told grizzlies are omnivores with "90% of their diet consisting of vegetation." But an article in Yellowstone Science written by park bear specialist Kerry Gunther and colleagues says "Yellowstone adult male grizzlies" have a diet that's 80% meat, and 20% plants. Gunther also noted that "Yellowstone grizzlies preying on livestock outside the park" had a diet consisting of 15% plants, and 85% meat." Interagency Grizzly Bear Study Team annual reports show that from 2007 to 2009, grizzly bear predation on cattle accounted for 188/539 conflicts in the Yellowstone region. That's 35% of all conflicts. Conservationists, of course, ask why the U.S. Forest Service still has active grazing allotments in grizzly country. The 6 million acre "primary conservation area" for Yellowstone-area grizzlies includes 2.2 million acre Yellowstone Park, and about 4 million acres of U.S. Forest Service land. In addition, grizzlies now occupy another 3 million acres of Forest Service land outside the "primary conservation area." If seven million acres seems like a lot for grizzlies, bear in mind that the U.S. Forest Service leases tens of millions of acres of land to ranchers at a bargain-basement price. Are humans on the menu for Yellowstone's meat-eating male grizzly bears? Rarely. It's almost unheard of. Nevertheless, it can happen. And the fear of being killed and eaten by a wild animal is in our genes. This author used to live in Yellowstone Park, and I did a bit of tent camping in grizzly country. I can assure you than when you're in a tent and you hear something moving around outside in the middle of the night, your partner won't turn to you and whisper, "Do you think it's an elk?"
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Post by brobear on Jun 5, 2020 9:12:30 GMT -5
Reply #15 is relevant but not what I'm searching for. Yes, GrizzlyClaws, Wolverine, and Tigerluver and other can back-up their claims. Over the decades since the invention of the breech-load rifle; the old bison-hunters of the prairie were completely exterminated, leaving ( below the Canadian border ) only Rocky Mountain grizzlies ( Yellowstone type ) and these ( as Doug Peacock has mentioned more than once in his books ) has been systematically culled of their most predatory bears. The killing continues... Edit and add: According to the books I've read on the historical grizzly; the Rocky Mountain grizzlies never were as big as those of the Great Plains; thus probably they always were a little less carnivorous.
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Post by King Kodiak on Jun 5, 2020 9:14:32 GMT -5
From the link you posted at Shaggygod. Ok brobear, this was what i was looking for, an actual study and graph. The contemporary Yellowstone adult male grizzly is 80% carnivorous. The adult male grizzlies outside the park are 85% carnivorous.
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Post by tom on Jun 5, 2020 10:30:01 GMT -5
Would it be safe to say that carnivorous in Brown Bears even in todays bears is highly dependent on location would it not?
For instance. A coastal Brown Bear or Kodiak would have higher percentage of his diet come in the form of meat (fish to be more accurate). An Inland Grizzly would be less Carnivorous and have to scavenge more for his meals. Or am I way off on this?
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Post by brobear on Jun 5, 2020 10:46:13 GMT -5
Would it be safe to say that carnivorous in Brown Bears even in todays bears is highly dependent on location would it not? For instance. A coastal Brown Bear or Kodiak would have higher percentage of his diet come in the form of meat (fish to be more accurate). An Inland Grizzly would be less Carnivorous and have to scavenge more for his meals. Or am I way off on this? Not wrong on any points Tom. What I'm looking for over in W.F., is a group conversation about the grizzly beginning at the demise of the American lion, the saber-toothed cats, and the giant short-faced bear. From that point onward, the grizzly was without any predator competition other than man; and not so much from man before the breech-load rifle. The grizzly was then, for better than 10,000 years the monarch of N. America wherever he lived ( with the exception of polar bear country ). We know from some scant remains and from the tales told that these were some huge meat-eating bears. Since then, the grizzly has been reduced to a much more complacent bear who is much more vegetarian than his forebears.
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Post by King Kodiak on Jun 5, 2020 14:12:47 GMT -5
So we have the Adult male grizzly bear at Yellowstone national park that is 80% carnivorous. According to animal planet, the Ussuri brown bear is 20% carnivorous at max, makes sense having the Amur tiger as a competitor.
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