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Polar Bears - Data, Pictures and Videos
Polar Bears - Data, Pictures and Videos
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Polar Bears - Data, Pictures and Videos
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  *This image is copyright of its original author  *This image is copyright of its original author Here is “Stan” the 810 KG (1785 LBS) polar bear biologist Stenhouse and Nick Lunn caught in Southhampton Island in 1985. My take: he is the largest and strongest scientifically verified extant carnivore and land predator.  *This image is copyright of its original author POSER BEAR Polar bear lies on ice block with its bum in the air in hilarious snaps A POLAR bear lies on an ice block with its bum in the air — one of a string of comedy poses it pulled for watching photographers. They encountered the performing bear on an expedition to the archipelago of Svalbard, Norway. Frede Lamo, 52, said: “It looked like he was trying to impress us for about 35 minutes.” Earlier this year adorable polar bear cubs were see waving at photographers in Manitoba, Canada. And last year in Churchill, Canada, polar bear cubs were seen venturing out of their den and into the snow for the very first time. https://www.thesun.co.uk/news/18279464/p...ow-norway/  (04-02-2022, 08:19 PM)GreenGrolar Wrote: Didn't Stan weigh 803 kg?  *This image is copyright of its original author Huge specimen from coasts of Alaska (04-23-2022, 01:30 PM)Jerricson Wrote:(04-02-2022, 08:19 PM)GreenGrolar Wrote:  *This image is copyright of its original author https://web.archive.org/web/201109301948...mwtht.html More like 800kg but regardless 803 and 810 are not so far off  .
DOWN TO THE BEAR BONES: HOW POLAR BEARS EVOLVED FROM GRIZZLIES TO HUNT IN THE ARCTIC.
Katmai National Park in Alaska holds an annual “Fat Bear Week”, in which Twitter followers are asked to vote for the fattest bear in the park. This year’s winner was Holly, somewhere in the range of 500 to 700 lbs. That’s a big bear. However, in 1960, a male polar bear in Kotzebue Sound, Alaska, weighed in at 2,209 lbs. In fact, on average, polar bears weight up to 60% more than Grizzly bears, their closest animal relative.  *This image is copyright of its original author Holly, aka Bear 435, the 2019 winner of the Fat Bear Contest. From Katmai National Park via Twitter. So just how did Polar Bears get so big? Well, as anyone in the Midwest knows, a harsh winter requires a good winter coat. The advantage of thick skin and fur, as well as a higher capacity to put on weight made heavier polar bears more adept to survive. However, bigger bears that could survive the cold were more likely to fall through the ice, so these adaptations required better foot mechanics. Consequently, polar bears developed a distinctive gait. A rotary gait is a “double suspension” gait, meaning the animal bounces both off the hind limbs and then the fore limbs . This is contrasted from the grizzly bear’s transverse gallop, which involves only one “bounce,” — this loads each limb for a longer time and more vertically. The rotary gait improves stability, giving the polar bear the ability to travel quickly and smoothly on icy surfaces.  *This image is copyright of its original author A series of drawings depicting the gait of a polar bear. Modified from S. Renous, J.P. Gasc, and A. Abourachid, Netherlands Journal of Zoology (1998). Another significant difference between the species are their skulls, which, while similar in size, vary greatly in bite force and bone strength. The polar bear has a stronger bite, but a weaker skull. Polar bears are one of the most rapid instances of evolution in surviving species of animals, having evolved from the grizzly bear within the last five hundred thousand years. So why are their skulls weaker if their bite is stronger? Simply put: seals are easy to chew. Grizzlies are omnivores, as most bear species. Their diet subsists of salmon, elk, and small game, but includes a hefty amount of vegetation. Polar Bears, in the ice and cold, were forced to eat seals (as well as penguins, fish, even belugas). Seals are largely blubber, providing the caloric intake necessary to sustain these large beasts, but offering little resistance in the chewing process.  *This image is copyright of its original author https://sites.nd.edu/biomechanics-in-the-wild/2019/12/27/down-to-the-bear-bones-how-polar-bears-evolved-from-grizzlies-to-hunt-in-the-arctic/
Longest recorded underwater dive by a polar bear
The maximum dive duration for a wild polar bear (Ursus maritimus) of any age is unknown, and opportunities to document long dives by undisturbed bears are rare. We describe the longest dive reported to date, by a wild undisturbed adult male polar bear. This dive was made during an aquatic stalk of three bearded seals (Erignathus barbatus) lying several meters from each other at the edge of an annual ice floe. The bear dove for a total duration of 3 min 10 s and swam 45–50 m without surfacing to breathe or to reorient itself to the locations of the seals. The duration of this dive may be approaching its maximum capability. Polar bears diverged from brown bears (Ursus arctos) about 4–500,000 years ago, which is recent in evolutionary terms. Thus, it is possible that the ability to hold its breath for so long may indicate the initial development of a significant adaptation for living and hunting in its marine environment. However, increased diving ability cannot evolve rapidly enough to compensate for the increasing difficulty of hunting seals because of the rapidly declining availability of sea ice during the open-water period resulting from climate warming. https://www.researchgate.net/publication/277573604_Longest_recorded_underwater_dive_by_a_polar_bear  *This image is copyright of its original author This seems to explain why a male polar bear can take heavy damage especially during mating season, the time when they get most aggressive:  *This image is copyright of its original author Not sure if this account is allowed, However it is from the New York Times back in 1922. It is the only one of of two accounts of polar bears actually killing a brown bear. Perhaps a polar bear might one day lose its temper and turn on a grizzly? We will never know but being much larger, it is capable of doing so. Togni Circus, Polar Bear kills a Brown Bear out of envy.  *This image is copyright of its original author (Originally in Italian) “ad un tratto un orso bianco, Narvik, aggrediva, si crede per gelosia, un orso bruno.” “Nonostante il pronto intervento del domatore, Narvik azzannava alla gola del rivale uccidendolo.” Here's the translation. “suddenly a white bear, Narvik, threatened, maybe out of envy, a brown bear.” “Although the interference of the trainer, Narvik bit his rival's throat killing him.” Another account from the old AVA forum: 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! https://www.tapatalk.com/groups/animalsversesanimals/fox-basin-polar-bear-vs-katmai-grizzly-t4055.html It seems the larger and older males are less likely to be frighten off. Generally younger bears are more skittish than their older counterparts.  (04-02-2022, 08:19 PM)GreenGrolar Wrote: I have this information about this big bear:  *This image is copyright of its original author Here is another bear, based in the date of capture, I guess:  *This image is copyright of its original author Someone told me that this is the same bear "Stan", but I am not sure, but certainly is huge!  *This image is copyright of its original author
(04-25-2022, 08:03 PM)GuateGojira Wrote:(04-02-2022, 08:19 PM)GreenGrolar Wrote: Guate , here's the original document mentioning Stan's weight https://www.enr.gov.nt.ca/sites/enr/file...script.pdf . Check out page 19 in this document . The 803 kg bear is indeed 'Stan' because same scientists , same location and same year of capture . The figure of 810kg was misquoted in a newspaper actually . (04-27-2022, 07:06 PM)Jerricson Wrote: Guate , here's the original document mentioning Stan's weight https://www.enr.gov.nt.ca/sites/enr/file...script.pdf . Check out page 19 in this document . The 803 kg bear is indeed 'Stan' because same scientists , same location and same year of capture . The figure of 810kg was misquoted in a newspaper actually . Thank you very much for sharing that information. I saved the document and now I know the correct weight.
Polar bears, Ursus maritimus, feeding on Beluga Whales, Delphinapterus leucas.
Code: The high density of Belugas migrating in the spring along restricted openings in sea ice provides opportunities for predation by Polar Bears. Although there are not many documented sightings of Polar Bear predation on Belugas from Alaskan coastal areas (seven were reported by Lowry et al. (1987) since 1967, four of which occurred in April 1984 during a period of dense ice cover), the rate is high considering the low likelihood that anyone would come across a bear kill on the sea ice and report such a sighting to a scientist. Furthermore, moving ice and snow accumulation tend to cover evidence of kills. There have been several reports of Polar Bears eating Belugas in the Canadian High Arctic, including Freeman (1973), Heyland and Hay (1976), Mitchell and Reeves (1981), and Smith (1985), but the only documented observations of Polar Bears killing Belugas were made by Degerbol and Freuchen (1935), Kleinenberg et al. (1964), and Smith and Sjare (1990), along with an observation made by Harry Brower Sr.', a principal whaler in Barrow. However, the sighting reported by Lowry et al. (1987) and the original sightings of dead Belugas reported here included blood tracks on the ice, indicating relatively fresh kills. Because of their negative buoyancy. Belugas tend to sink when killed (Kemper 1980; Finley et al. 1982; Lowry 1985). This reduces opportunities to scavenge a dead Beluga until internal gasses expand, the carcass floats to the surface, and it becomes available for scavenging by Polar Bears. Since most sightings of dead Belugas on ice occur when sea ice is dense and whales are forced to use small openings in the ice, it appears that the whales are being killed by the bears and not scavenged after having succumbed due to other causes. Entrapped whales are probably vulnerable to predation, but pulling a whale onto the ice is an impressive feat because a Beluga may weigh five times as much as a Polar Bear (Freeman 1973).https://carnivora.net/polar-bear-feats-t9622-s15.html#p215757 |
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