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Post by grrraaahhh on Sept 11, 2010 14:48:41 GMT -9
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Post by grrraaahhh on Sept 11, 2010 15:00:33 GMT -9
Hunters often have knowledge of the sorts of places and types of dens that the bears tend to use. Denning and active black bears are also subject to predation by other Asiatic black bears, brown bears, and tigers (Seryodkin et al. 2005).Ursus thibetanus Asiatic Black Bear liveassets.iucn.getunik.net/downloads/asiatic_black_bear.pdf
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Post by warsaw on Mar 22, 2011 8:33:49 GMT -9
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Post by Deleted on Jul 2, 2011 22:06:37 GMT -9
Great pictures there, accrding to Scott Schalieber, some large male polar bears acctually ignore grizzlies rather than retreating. The grizzlies don't seem too keen to press on their bluff after that.
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Post by grrraaahhh on Jul 3, 2011 19:46:30 GMT -9
Great pictures there, accrding to Scott Schalieber, some large male polar bears acctually ignore grizzlies rather than retreating. The grizzlies don't seem too keen to press on their bluff after that. Good reference. I am a fan of Scott Schliebe: www.arctic.noaa.gov/essay_schliebe.html
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Post by grrraaahhh on Oct 8, 2011 3:56:12 GMT -9
Great pictures there, accrding to Scott Schalieber, some large male polar bears acctually ignore grizzlies rather than retreating. The grizzlies don't seem too keen to press on their bluff after that. Good reference. I am a fan of Scott Schliebe: www.arctic.noaa.gov/essay_schliebe.html Follow up: By chance, I was able to watch another video meeting on Planet Green's Expedition Alaska Episode 2 (2008) of a grizzly bear - polar bear encounter. This meeting is a different video footage from the earlier Discovery Channel film. The location in and around the Prudhoe Bay area is the same as the earlier DC documentary, however, the dynamics and end result a little different. In this case, local native hunters having completed their whale hunt (by law, they are allowed to hunt whale) left behind discarded whale meat which attracted about 40 polar bears which is amazing in of itself because of the solitary lifestyle of the polar bear. During the night a barren ground grizzly bear emerges to join and eat the left over whale meat remains. As seen in the DC documentary, the presence of the grizzly bear caused about one-third of the polar bears to exit but there were a majority two-thirds who remained (they were the larger older males). The whole Planet Green Expedition Alaska Episode 2 grizzly bear/polar bear encounter film was short in duration not even thirty seconds: GRUMBLE, GRUMBLE . The grizzly bear & polar bears ate side by side. Because the sea ice had not formed, the left over whale meat help to feed the polar bears and bridge the gap of time until the sea freezes over allowing the polar bears to move away from land and hunt seal on the frozen ice. In any event, pretty cool footage!
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Post by warsaw on Oct 30, 2011 11:25:12 GMT -9
"...A large male polar bear and a large male grizzly bear. Nose to nose, they gave each other a serious stare, each trying to loudly out roar one another. Their breath steamed the air, their gruff voices echoed off the crashing waves. A quiet moment passed, and a silent truce was met. And just like that it was over, each walking in opposite directions. The grizzly bear to the south, the polar bear to the north, naturally..." grizanderson.com/tag/grizzly/Two Polar Bears surround a Grizzly Bear atop a bowhead whale carcass. grizanderson.files.wordpress.com/2011/09/2011-09-26_06-47-30_156.jpg
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Post by grrraaahhh on Nov 1, 2011 9:33:53 GMT -9
"...A large male polar bear and a large male grizzly bear. Nose to nose, they gave each other a serious stare, each trying to loudly out roar one another. Their breath steamed the air, their gruff voices echoed off the crashing waves. A quiet moment passed, and a silent truce was met. And just like that it was over, each walking in opposite directions. The grizzly bear to the south, the polar bear to the north, naturally..." grizanderson.com/tag/grizzly/Two Polar Bears surround a Grizzly Bear atop a bowhead whale carcass. grizanderson.files.wordpress.com/2011/09/2011-09-26_06-47-30_156.jpgGreat find. I look forward to the up coming video documentary. Very similar encounter to the video segment I watched (see previous post). On one hand I am interested in the natural interactions between these two species of bears but on the hand I lament the worsening environmental conditions which produce these meetings.
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Post by Deleted on Nov 4, 2011 17:49:18 GMT -9
Good article and pciture there. It looks like it is not so one sided as some claim . It seems only the younger polar bears get scattered while the older males seem totally unfazed. I find the two young polar bears interactionw with the female grizzly especially asmussing: I returned to the bone pile last night around 1 am. As usual, the whale carcass was covered in polar bears. I watched them interact, and move about the bone pile when all of a sudden the vibe changed. All the polar bears lifted their head and looked into the darkness to the south. From the shadows, a grizzly emerged, hesitant at first, but then in typical grizzly style, it lowered its head and marched into the pile like a bulldog. I was so thrilled I could not believe it. I was witnessing something very few people ever have, let alone, it was all being capture in HD for our polar bear episode! The polar bears definitely acted a little different toward their brown cousin at first, but then they all settled in and devoured the whale in peace. This was awesome! We gathered as much footage we could. This was truly a special event but things even got better. A few minutes passed and then another grizzly entered the scene! We had 6 polar bears and 2 grizzly bears in one place at one time, a ridiculously amazing situation! I could not get enough! All went well for awhile, but then those pesky two year olds got curious. They approached the smaller grizzly from behind, and one of them poked the grizzly in the butt with it¡¯s nose. The grizzly whirled around and huffed at them, backing them up a step. This was not enough for the grizzly, so she gave them a little bluff charge. The 2 year olds were unfazed. Their wonder outweighed their wisdom. They pressed in closer now, ganging up on the grizzly. Well, the grizzly would not have it, she lurched forward even harder this time and back the twins off a few meters. The grizzly continue to sway its head low walking forward with purpose, and pressed the polar bears toward the ocean. The young bears back off slowly. But as soon as the grizzly thought the point was made and would turn to return to the whale, the young bears would close the gap. This would cause the grizzly to spin around again and charge the polar bears. This back and forth went on for awhile, but the action was drifting my way. The energy of the interaction increased in it¡¯s tempo and before I knew it the 3 bears were coming my way fast. Again the crew and I hustled to take cover in our vehicle, but the bears were so close, I grabbed my bear spray and readied it. I might be the only man that has popped the safety trigger off their bear spray because a grizzly bear and a polar bear were approaching them at the same time. Just saying. We safely retreated and the bears continued the face off until they disappeared into the night. I was like a kid in the candy store. I had ringside seats to the greatest show on earth! grizanderson.com/tag/grizzly/
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Post by sarus on Apr 26, 2012 21:26:06 GMT -9
FEATURE ARCTIC GRIZZLIES Grizzlies on ice What is Aklak doing in the kingdom of Nanook? Excerpt of story by Ed StruzikBiologist Mitch Taylor was searching for polar bears from a helicopter over the sea ice on Viscount Melville Sound in the High Arctic when he spotted something dark moving in the distance. Thinking the light was playing tricks on him, he signalled the pilot to fly in for a closer look. Instead of running away, as most polar bears do when they hear an engine, this animal abruptly turned and ran defiantly toward the aircraft. "That’s when I was positive it was a grizzly bear," recalls Taylor, now a polar bear biologist for Nunavut. "It was weird. It’s rare, but not unheard of, for anyone to see a grizzly bear on the sea ice. As far as I know, though, no one has ever encountered one 600 kilometres north of the mainland." That wasn’t the only surprise Taylor got that day in the spring of 1991. It all started when he spotted the bloody remains of several seal pups on the ice. Nearby was what was left of the carcass of a young polar bear. Taylor and the pilot decided to follow the killer’s tracks to see what it was up to. After tranquilizing the grizzly, he determined that it was a perfectly healthy bear. "It was pretty clear to me that this bear had been hunting seals, then spotted a young polar bear doing the same thing," says Taylor. " It likely killed the bear to eat it. The grizzly was in really good shape. It may have even denned up there that winter. It’s possible, if unlikely, that it started off from the mainland that spring and headed north. These animals can cover a lot of distance in a relatively short time." Some scientists initially likened the episode to one of those peculiar wonders of nature that happen from time to time, says Taylor. But there have been more and more sightings of barren-ground grizzlies over the past 15 years on the ice on the Beaufort Sea, near Banks and Victoria islands, north of the Kent Peninsula, and in the northeast on Wager and Hudson bays. ---------------------------------------------------------------------------------------------- ► www.canadiangeographic.ca/magazine/nd03/arcticgrizzly.asp► books.google.com.br/books?id=162ycz325jsC&pg=PA132&lpg=PA132&dq=%22carcass%22+%22young+polar+bear%22+%22killed%22+%22grizzly%22+%22ice%22&source=bl&ots=xhvEjPBne3&sig=bi870q7hXlWmOYzqH9JB3rOlGXA&hl=en&sa=X&ei=FjCaT47QOoXq9ATcv5iTDw&redir_esc=y#v=onepage&q=%22carcass%22%20%22young%20polar%20bear%22%20%22killed%22%20%22grizzly%22%20%22ice%22&f=false----------------------------------------------------------------------------------------------
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Post by Deleted on May 10, 2012 22:23:49 GMT -9
According to a book which I recently read called 'Spirit of the Bear':Younger male bears are acctually preferred by the younger female bears. That explains why barren ground grizzlies are able to mate with female polar bears. Remember polar bears just like brown bears fight to death during the mating season and since full grown mature male polar bears are too big and strong for even the biggest male grizzly, the grizzly most likely might have mated with young female polar bears as they are able to fight of the younger and less experience male polar bears. I believe the program graaaah watched on Planet Green's Expedition Alaska Episode 2 (2008) of a grizzly bear - polar bear encounter which says the grizzly on manages to scatter one third of the polar bears - the younger ones. The mature male polar bears are too strong for a grizzly and remain unfazed. Correct me if I am wrong in any way. Has anyone read this book?
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Post by Ursus arctos on May 12, 2012 1:08:49 GMT -9
According to a book which I recently read called 'Spirit of the Bear':Younger male bears are acctually preferred by the younger female bears. I have read this as well, according to observations of scientists studying coastal brown bears at McNeil. They claimed that all other groups of bears appeared to have a lot of fear for the large adult males (8.5+ y.o.); total bear activity at the falls dropped when they began to show up (~11:00 pm) as other age/sex classes left. For this reason females also appeared to be less receptive to the large males. However, data from a microsatelite DNA analysis by Craighead on a non-hunted population of grizzlies found no evidence for reproductive success by any grizzly bears under 9 years old (interestingly, 8.5 was the cutoff for classifying males as adolescent vs adult males in the Alaskan population based on behavior as well; note that sexual maturity comes at a much younger age than this). Also of note: only 50% of bears older than this were found to have had reproductive success, indicating very high levels of competition (for comparison, male black bears had an even lower number, at 33%, but younger males did manage to reproduce). The coastal population could be different, but in this one at least it appears that females strongly preferred the older males. Info on the Swedish brown bears (heavily hunted) found much more equality in reproductive success, however young bears still didn't come off well-age was positively correlated with reproductive success in the North and South. While in the South body mass (which is correlated with age) was more strongly related to reproductive success than age (suggesting the correlation between yrs and age was a result of the relationship between yrs and body mass) it was the other way around in the North. The article attributed this to a biased sample however, as reproductive success in the North was dominated by a very old male. Whatever observations may show, data on actual relationships consistently shows much higher reproductive success for older male bears. Perhaps apparent preferences are merely a ruce to reduce the probability of infanticide. To draw more confident conclusions (apparent preference was observed in a coastal population of brown bears; the two studies on paternity of brown bears involved non-coastal populations, and American black bears are a different species entirely) more studies would be needed. References: Microsatelite Analysis of Paternity and Reproduction in Arctic Grizzly Bears, by Lance Craighead, et al. The Social Behavior of Brown Bears on an Alaskan Salmon Stream, by Allan Egbert and Allen Stokes. Determinants of male reproductive success in American black bears, by Costello, et al. Genetic estimates of annual reproductive success in male brown bears: the effects of body size, age, internal relatedness and population density, by Zedrosser, et al.
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Post by grrraaahhh on May 15, 2012 10:31:15 GMT -9
According to a book which I recently read called 'Spirit of the Bear':Younger male bears are acctually preferred by the younger female bears. That explains why barren ground grizzlies are able to mate with female polar bears. Remember polar bears just like brown bears fight to death during the mating season and since full grown mature male polar bears are too big and strong for even the biggest male grizzly, the grizzly most likely might have mated with young female polar bears as they are able to fight of the younger and less experience male polar bears. I believe the program graaaah watched on Planet Green's Expedition Alaska Episode 2 (2008) of a grizzly bear - polar bear encounter which says the grizzly on manages to scatter one third of the polar bears - the younger ones. The mature male polar bears are too strong for a grizzly and remain unfazed. Correct me if I am wrong in any way. Has anyone read this book? IMO, it is very likely the Barren ground grizzly bears mating with the polar bear are older males. A grizzly bear leaves the bone pile. "The sky was clear and the air was brisk. The northern lights danced subtly, a hazy green shimmer next to a vibrant Pleiades constellation. Just below, on the shore of the arctic ocean, two massive bears faced one another. A large male polar bear and a large male grizzly bear. Nose to nose, they gave each other a serious stare, each trying to loudly out roar one another. Their breath steamed the air, their gruff voices echoed off the crashing waves. A quiet moment passed, and a silent truce was met. And just like that it was over, each walking in opposite directions. The grizzly bear to the south, the polar bear to the north, naturally." A large male polar bear follows in the grizzly bear's footsteps...... grizanderson.com/tag/grizzly/FWIW, I agree with the earlier DC broadcast, the older male polar bear which are on average about twice the size of a male barren grizzly bear and twice (plus) the weight of a sow grizzly bear should dominate any meeting, however, I think there is something else very primal occurring when brown & polar bear meet (remember, these bears are ancestral cousins).
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Post by Deleted on May 16, 2012 15:54:49 GMT -9
IMO, it is very likely the Barren ground grizzly bears mating with the polar bear are older males. Yeah that was poor explanation on my part. I forgot to mention that . The older grizzlies mating with the younger female polar bears are because they can fazed off the younger less experieced polar bears and avoid the older male polar bears. FWIW, I agree with the earlier DC broadcast, the older male polar bear which are on average about twice the size of a male barren grizzly bear and twice (plus) the weight of a sow grizzly bear should dominate any meeting, however, I think there is something else very primal occurring when brown & polar bear meet (remember, these bears are ancestral cousins). Regarding the truce made between the two bears, without being baised, the polar bear is porbably younger than the grizzly yet a good size larger? The other thing very primal could be mutual respect between the bears?
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Post by grrraaahhh on May 18, 2012 16:33:38 GMT -9
They are isolated events. I don't think male polar bears are in the picture. It's an aggressive barren ground grizzly boar pursuing then mating with a female polar bear; sometimes, infanticide occurs.
Yes, even a young adult boar polar bear will be larger than the common barren ground grizzly bear boar and of course sow.
It is interesting to observe how the polar bears reacted to just the scent of the barren ground grizzly. It's been awhile since I saw the DC episode (DVR copy has been erased) but my guess, it is probably the younger polar bears who are getting rattled not the experienced battle-scared older boars.
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