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Post by Deleted on Apr 8, 2019 2:59:11 GMT -5
Thanks. Still the grizzlies breed with polar bears but have never really preyed on them. Female polar bears actually breed earlier than female brown bears.
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Post by OldGreenGrolar on Jun 10, 2019 23:42:17 GMT -5
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Post by OldGreenGrolar on Jun 10, 2019 23:44:42 GMT -5
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Post by OldGreenGrolar on Jun 10, 2019 23:51:05 GMT -5
Male grizzly and female polar bear.
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Post by OldGreenGrolar on Jun 10, 2019 23:54:36 GMT -5
Looks like the grolar bear is more adaptable than the polar bear.
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Post by tom on Jun 17, 2019 6:15:41 GMT -5
Male grizzly and female polar bear. Gentlemen prefer blondes. 😁
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Post by King Kodiak on Jun 17, 2019 6:28:36 GMT -5
Male grizzly and female polar bear. Gentlemen prefer blondes. 😁 Ha ha ha, looks like love is in the Artic.
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Post by King Kodiak on Jun 21, 2019 6:50:09 GMT -5
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Post by OldGreenGrolar on Jun 21, 2019 8:07:12 GMT -5
There was an account(on the old carnivora proboards years ago) of an adult grizzly bear which killed a 2 year old polar bear before taking over its hunting spot. Polar bears also enter mating season earlier than grizzly bears do and male grizzly bears kill polar bear cubs as they emergeor before they emerge from their dens. Yet there is still no record of one killing a full grown 1000 pound male.
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Post by King Kodiak on Jun 21, 2019 16:11:14 GMT -5
There is no record of a grizzly killing no adult polar bear. Only cubs and juveniles (subadults), up to now. There is no way a 300 lb grizzly is killing an adult male polar bear.
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Post by OldGreenGrolar on Jul 21, 2019 7:02:55 GMT -5
Arctic Grizzlies Bully Polar Bears
It isn't the size of the bear in the fight; it's the size of the fight in the bear, according to a recent study. BY KIERAN MULVANEY PUBLISHED ON 12/17/2015 4:38 PM EST Polar bears are the largest of all bear species, while the grizzlies that live on Alaska's North Slope are the smallest brown bears in that state - some no bigger than the black bears that try to break into garbage cans on the hillsides around Anchorage. So should the two ever encounter each other, the seal-eating denizens of Arctic ice might be expected to have the advantage, right? Actually, not so much. In fact, according to a recent study, not at all. In an article for Alaska Dispatch News, Yereth Rosen spoke with Susanne Miller of the U.S. Fish and Wildlife Service, who explained that diminishing amounts of summer and fall sea ice in the southern Beaufort Sea off the North Slope have forced polar bears to spend more time ashore, grabbing whatever food they can on land. Among their targets are bowhead whale scraps left by Inupiat whalers on the shore by villages such as Kaktovik. Miller and colleagues resolved to study the polar bears that visited these "bone piles" to see if they could ascertain any behavioral changes as a result of not being on the sea ice; but, she told Rosen, they soon found they had a problem: Grizzly bears got in the way. "Brown bears just showed up and polar bears left," she said. The North Slope is not an area of high brown bear concentration, and the grizzlies that do live there tend to be smaller than those farther south; conditions are much harsher and food rarer than in many other parts of the species' range, and the bears generally depend on plants and a smattering of mostly lean prey animals. So a concentration of fatty whale remnants is a welcome indulgence that naturally attracts grizzlies in the area as it does polar bears. But because the arrival of the former frequently meant the departure of the latter, Miller and her colleagues switched the focus of their study to the interspecies interactions around the bone pile. The scientists observed a total of 137 encounters between the two bear species, polar bears reacted submissively, even though the grizzlies did not obviously act aggressively toward them; in roughly 50 percent of the encounters, grizzlies displaced the polar bears completely, writes Rosen, even though, in Miller's words, "they look like they're about half the size of the polar bears." The reason why can perhaps be determined from differences in the two species' behavior and ecology. Brown bears are naturally territorial, fiercely defending areas that have food and females from interlopers whose areas have less of either. Polar bears are not, given that they inhabit a constantly shifting mosaic of ice floes. Indeed, although polar bear males will occasionally cannibalize cubs, and older males will display dominance over younger ones should they converge at a kill, instances of intraspecific aggression in polar bears are rare - outside of mating season, when males will fight ferociously over females. One of the study's co-authors, Richard Shideler of the Alaska Department of Fish and Game, told Rosen that, " I think it's attitude ... (Grizzlies are) more aggressive in terms of bear-bear interaction." Scent, however, may also play a role, with Miller noting that even a brown bear carcass on the bone pile was enough to spook some polar bears. As well as being an intriguing insight into bear behavior, the study is particularly relevant given that decreasing sea ice means that polar bears are likely to spend greater time ashore along the North Slope and to come into greater contact with grizzlies, and perhaps into competition with them, in the future. It isn't the size of the bear in the fight; it's the size of the fight in the bear, according to a recent study. www.seeker.com/arctic-grizzlies-bully-polar-bears-1770629298.htmlcarnivora.net/showthread.php?tid=6657Credited to Taipan from Carnivora.
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Post by OldGreenGrolar on Jul 21, 2019 7:06:21 GMT -5
Journal Reference: Susanne Miller, James Wilder, Ryan R. Wilson, Polar bear–grizzly bear interactions during the autumn open-water period in Alaska, Journal of Mammalogy, Volume 96, Issue 6, 24 November 2015, Pages 1317–1325, doi.org/10.1093/jmammal/gyv140Abstract Reduction of summer sea ice extent has led some polar bear (Ursus maritimus) populations to increase their use of land during the summer/autumn open-water period. While terrestrial food resources are generally not sufficient to compensate for lost hunting opportunities on the sea ice, marine mammal carcasses, where available, could help reduce the energetic cost of longer periods of land use. Subsistence-harvested bowhead whale (Balaena mysticetus) remains are available annually near local communities along the Alaskan portion of the Beaufort Sea coast to bears that come to shore. Relatively large numbers of polar bears and some grizzly bears (U. arctos) use these resources, creating a competitive environment among species and social classes. We documented competitive interactions among polar bears and between polar and grizzly bears for bowhead whale remains adjacent to a small community in northeastern Alaska in September 2005–2007. We observed temporal partitioning of the resource by bears, with lone adult polar bears and grizzly bears primarily feeding at night, and higher use by polar bear family groups and subadults during dawn and dusk. Interspecific interactions were less frequently aggressive than intraspecific interactions, but polar bears were more likely to be displaced from the feeding site by grizzly bears than by conspecifics. Female polar bears with cubs were more likely to display aggressive behavior than other social classes during intra- and interspecific aggressive interactions. Our results indicate that grizzly bears are socially dominant during interspecific competition with polar bears for marine mammal carcasses during autumn. academic.oup.com/jmammal/article/96/6/1317/1174934carnivora.net/showthread.php?tid=6657Credited to Taipan from Carnivora.
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Post by King Kodiak on Jul 21, 2019 10:57:01 GMT -5
Thats a nice report there. I can see that there are alot more interactions than what we thought. And there are no conflicting reports about this, the grizzlies dominate the polar bears at kill sites. of course, we already know that an actual fight would be much different.
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smedz
Ursus abstrusus
Recent Graduate
Posts: 410
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Post by smedz on Jul 21, 2019 11:05:15 GMT -5
Yes, normally the larger predator dominates the smaller one when it comes to solitary predators. But this appears to be an exception, the barren grizzlies aggression doesn't cease to amaze me.
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Post by tom on Jul 21, 2019 18:29:24 GMT -5
yes, were hearing of more and more of these Grizzly/Polar confrontations and it seems in every case the Polar Bear submits so there is something about the Grizzly that Polar Bears want nothing to do with. When I read that even if the Grizzly is not being aggressive and they still submit it makes me to believe it's something other than aggressive tendencies. They mentioned the Grizzly as being much more territorial when it comes to it's feeding areas or even scent as they mentioned. More study needed I guess.
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Post by brobear on Nov 14, 2019 10:58:49 GMT -5
Teeth ( 42 )
Brown bear: flat and broad crowns on molars; premolars and molars for grinding; first lower molar and second upper molar wider and longer than in the American black bear ( species comparison ).
Polar bear: canines larger, longer, and sharper than in other bears; molars smaller than those of land bears; molars more for shearing, premolars more for biting than grinding.
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Post by brobear on Nov 14, 2019 10:59:18 GMT -5
Claws: curved, nonretractable ( unlike a cat's ), fixed in an outstretched position, and longer on the forepaws than the hind paws, claws are a bears more specialized tools, used for battle, digging ( forepaws ), climbing, and handling foods. Claw lengths of species and individuals within the species will vary with the time of year, amount of digging, and type of terrain where the bear travels and digs. Foreclaws are normally longer than hind claws. Grizzlies have often been observed removing eggs from fish using a single claw. Robert Busch writes in The Grizzly Almanac, "At McNeil River, Alaskan writer Tom Walker once saw 'a bear try to shake the water out of its ears, then insert a single claw into its ear and gently scratch at the irritation,"
Brown bear: Large and slightly curved. Used for digging. Foreclaws 4 to 5 inches long. Color dark, almost black. Longer and narrower than those of other bears. Foreclaws longer than hind claws.
Polar bear: Shorter than those of the brown bear. Color black. Used to climb ice and hunt. Immense. 2 to 3 inches in length. Thick. Less worn than those of the brown bear ( no digging, except in den preparation ).
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Post by brobear on Nov 14, 2019 10:59:41 GMT -5
Tracks of any animal species are the exciting and intriguing sign left behind as they move through their habitat. A single bear track will increase the hunter's flow of adrenaline, peak the hiker's perception of wilderness, and heighten the alertness of both. Adolph Murie notes in A Naturalist in Alaska, "A bear track at any time may create a stronger emotion than the old bear himself, for the imagination is brought into play." "I went up from camp along a sandy stretch and was surprised to discover what I took to be the fresh print of the bare foot of a man," wrote Frederick Dellenbaugh in A Canyon Voyage. "Mentioning this when I returned, my companions laughed and warned me to be cautious and give this strange man a wide berth unless I had my rifle and plenty of ammunition. It was the track of a grizzly bear." ( Frederick Dellenbaugh was the artist and topographer for Major John Wesley Powell's second expedition on the Green ans Colorado Rivers in 1871 and 1872. ) Tracks are as individual as human fingerprints, and particular tracks may be identified by this spoor ( width/length ratio, specific cracks in the sole, broken claws ). Tracks of individuals within a species of bear will vary due to age, weight, sex, or the type of surface over which the bear is traveling. ( Track measurements are of average adult males and do not include claw length. )
Brown bear: Track often indistinct. Toe pads joined. Toes close together; form a relatively straight line. Foreclaws twice as long as toe pads. Claws sometimes not evident in track. Single round heel pad sometimes not visible. Forpaws track 6 to 8 inches long and 7 to 9 inches wide. Hind paw track 12 to 16 inches long and 8 to 10.5 inches wide.
Polar bear: Tracks often indistinct due to hair; normally visible only in soft snow or mud. Tracks have fringed edges due to hair. Toes form arc much like tracks of American black bear. Claws commonly not visible in track. Forepaw 5.75 inches long and 9 inches wide. Hind paw 13 inches long and 9 inches wide.
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Post by brobear on Nov 14, 2019 11:00:13 GMT -5
www.shadowofthebear.com/Brown,%20Grizzly%20or%20Kodiak%20Bear.html Brown bear, grizzly bear or Kodiak bear, they are all members of the brown bear family, ursus arctos. Scientific names differ amongst groups of brown bears found in specific regions such as coastal and grizzly bears, which have been given the name, ursus arctos horribilis. Though there is a wide variety of brown bears found throughout the world, all having unique scientific names, they are still all members of the brown bear family, ursus arctos. Middendorffi is the one exception and only scientifically recognized sub species of brown bear, due to the fact that they have the smallest gene pool of all brown bears and have a definite larger bone structure than other brown bears. Brown bears found inland and in mountainous habitats are called "grizzlies" while brown bears living in coastal areas are called coastal brown bears. The Kodiak brown bear is isolated to Kodiak Island in Alaska. Kodiak bears are not grizzly bears, the name “grizzly” comes from the silver tipped hairs these bears get, as they grow older. In comparison, the grizzly is considerably smaller than both the coastal brown bear and the Kodiak brown bear. This size difference is due to the abundance of food available in coastal areas and on Kodiak Island. The Kodiak bear has been isolated to Kodiak Island for some 12,000 years. The bone structure of the Kodiak is much larger than other brown bears, they have a more diverse social structure than other bears due to the close proximity in which they live and they have a gene pool that is much smaller than that of other bears. FYI: The Kodiak brown bear is the world’s largest bear while the polar bear being a direct descendent of the brown bear (200,000 years) is the world’s heaviest bear. Polar bears have been reclassified as marine mammals due to the amount of time these bears spend in the water. The bear pictured is a Kodiak brown bear photographed on Kodiak Island in Alaska. This is a she bear or sow, terms often used in reference to a female bear. Art cards available of this image. Send e-mail for details. www.shadowofthebear.com/index.htmlNote: The brown bear is more robust in his forequarters while the polar bear is bigger in his rear quarters, where the most fat is stored on a bear's body. If we could take a mature male of each species and weigh each half separately, I believe that we might discover that the brown bear is heaviest up front and the polar bear in the rear half.
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Post by brobear on Nov 14, 2019 11:00:38 GMT -5
[BEARS by Ben East:
There is little question that on the average the brown bear is the biggest land carnivore left on earth. An occasional very large polar bear may equal for weight his counterpart among the browns. There are even those who believe that the ice bear is the heavier of the two. But, if a hundred full-grown browns picked at random were weighed and their weight measured against an equal number of polar bears, it seems very likely that the browns would be found to average heavier. One thing is certain. The brown is a giant among bears, so much so that the initial reaction of a hunter or any other human seeing a big one for the first time is likely to be stunned disbelief. Standing erect on his hind legs, which is something they frequently do, such a bear would have to scrooch to walk through an eight-foot doorway. Stretched to full height, he can leave claw marks on a tree twelve feet above the ground. It is hard to accept the fact that such an animal exists. The strength of the brown giant is in keeping with his size. He is very powerfully built, a heavy skeleton overlaid with thick layers of muscle as strong as rawhide rope. He can hook his long, grizzly-like front claws under a slab of rock that three grown men could not lift, and flip it over almost effortlessly if he has reason to believe there is a ground squirrel underneath.
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