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+--- Thread: Will the Polar Bear Survive? (/topic-will-the-polar-bear-survive)
Will the Polar Bear Survive? - brotherbear - 06-11-2016
Will the polar bear survive the oncoming weather changes? Can he possibly survive on his native turf, the North Pole? Or, will he be forced to move southward in a desperate attempt to adjust to new environments and a new diet?
*This image is copyright of its original author
RE: Will the Polar Bear Survive? - Polar - 06-11-2016
He will be justified to move southward, and live in the Canadian/Alaskan tundra with their smaller brown bear companions (or enemies, depending upon one's viewpoint): the Inland Tundra Grizzly. This is assuming that prey drops significantly and ice is reduced to 5% in the polar bear's native habitat.
Both will compete in terms of mates, food-abundant regions, and instinctive male rivalry. Competition for food type should not be a problem; polar bears are more carnivorous, and the grizzly is more suited to fruity shrubbery and carrion.
The problem is where to acquire their food. Both share similar territory (assuming the Arctic King moves south into the Brute King's headquarters), for example, if a polar bear hunts a small elk in a dominant brown bear's berry field, there will be problems. This situation would be similar to someone stealing a unfavorable food item from another's cart; even though the food item in question is unfavorable, the victim will most likely become angered.
Another problem with food: polar bears are best suited for aquatic animals, they rarely give chase to their musk oxen or caribou when predating. They implement ambush similar to their feline cousins (although, also like other bears and some felines, they can fight face-to-face with their prey.) So when a moose or large bison comes along in their path, they won't have that intuition or adaptability to know how to hunt those two animals.
Smaller prey are not an option; remember, we are talking about a 800-1200 pound bear with a greater nutritional load, slightly slower sprinting, and much quicker overheating than a 200-pound bison or moose calf.
Polar bears would face plenty of issues if the situation is described as above, but, like other bears, they will adapt quickly (albeit a tiny bit slower since they are specialists in cryo-environments and their specific physical needs.)
RE: Will the Polar Bear Survive? - brotherbear - 06-12-2016
It is my belief that before the great whale slaughter, during the 18th and 19th centuries, there were more beached whales as well as more seals and walrus; thus bigger polar bears. I would wager that in those days, 2,000 pound polar bears were not so uncommon. But, if polar bears ever begin living further south where they must change their diet, even though it might be a mostly meat diet, I believe that polar bears will reduce in size. In time, interbreeding will become so common between grizzly and polar that pure-polar bear will continue to be fewer and fewer. -Just my opinion.
RE: Will the Polar Bear Survive? - brotherbear - 06-13-2016
http://shaggygod.proboards.com/
First posted by Grraahh ( 2012 ) - Food habits of polar bears on land during the ice-free period in western Hudson Bay were examined between 1986 and 1992. In contrast to previous studies, feeding on vegetation during the ice-free period was common. Between August and October, evidence of feeding was found in 34% of the females and 26% of the males captured over 10 km inland from the coast. The primary forage was Vaccinium uliginosum and Empetrum nigrum berries. Feeding was most common in subadults and females. The incidence of feeding on berries varied annually from 2 to 41%. We were not able to determine the energetic importance of terrestrial foraging, but the intake may reduce the rate of weight loss of bears on land, particularly in years when berries are abundant.
*This image is copyright of its original author
RE: Will the Polar Bear Survive? - parvez - 06-13-2016
I expect scientists find a way to protect the polar bear in its natural habitat. Many power generation alternatives have come including tidal energy, solar energy, wind energy etc which does not generate any pollution. So, percentage of CO2 can be considerably reduced. If electric vehicles come into place, it will be much more effective. Only thing we have to worry is about refrigerators and aeroplanes, that emit CFHC and CO2 much more than anything else. If they could find alternative for this, we can easily protect the polar bear habitat and thus the polar bear.
RE: Will the Polar Bear Survive? - brotherbear - 06-13-2016
http://www.virtualmuseum.ca/edu/ViewLoitDa.do?method=preview&lang=EN&id=1224
View of a polar bear paw. See how big it appears. It can measure over 30 cm. Notice the big toes beneath the abundant fur, but no trace of claws. The grizzly bear and the polar bear have about the same size of paw. The difference lies in the amount of fur beneath the paw and the length of their claws.
*This image is copyright of its original author
RE: Will the Polar Bear Survive? - brotherbear - 06-13-2016
http://www2.gi.alaska.edu/ScienceForum/ASF20/2018.html
An ancient jawbone has led scientists to believe that polar bears survived a period thousands of years ago that was warmer than today.
Sandra Talbot of the USGS Alaska Science Center in Anchorage was one of 14 scientists who teamed to write a paper based on a polar bear jawbone found amid rocks on a frigid island of the Svalbard Archipelago. The scientists determined the bear was an adult male that lived and died somewhere between 130,000 to 110,000 years ago, and that bear was similar to polar bears today. Charlotte Lindqvist of the University at Buffalo in New York was the lead author on the paper, published in the March 2010 issue of the Proceedings of the National Academy of Sciences.
An Icelandic researcher in 2004 found a fossilized lower jawbone, in excellent condition and complete with a canine tooth, on a narrow spit of land on the far west edge of Norway’s Svalbard Archipelago. It was a stunning find because there aren’t many fossils of polar bears around. The largest bears in the world spend most of their lives on sea ice, so they often die there, and their remains either sink or get scavenged by something else.
With bone and tooth in hand, scientists got to work with the latest techniques for finding the age of formerly living creatures and determining their genetic backgrounds. The latter is the specialty of Sandra Talbot. She is a research wildlife geneticist who earned her doctorate degree at the University of Alaska Fairbanks by helping determine that the mitochondrial DNA of brown bears on Admiralty, Baranof and Chichagof islands of Southeast Alaska is more closely related to that of polar bears than to the DNA of other brown bears.
Talbot says the evidence of a polar bear from 130,000 years ago shows that the creatures somehow survived conditions warmer than they face today.
“This is verifying that the polar bear lived through at least one warming period,” Talbot says. “The Eemian was a very hot period, and polar bears survived it,” she says.
During the Eemian, about 125,000 years ago, the planet was warm enough that hippos lived where London is now. Polar bears, now adapted to eating seals that live only near sea ice, somehow made it through a few thousand years when there may not have been much sea ice, if any existed at all.
“It gives us hope that they survived that stage,” Talbot says. “It does make you think about refugia more.”
“Refugia” are places that polar bears may survive without ice. The Svalbard Archipelago may have been one of those places. Biologists today think polar bears would have a difficult time living on land, because other species like the grizzly bear could outcompete them.
The warm period of the Eemian might have come at a time when the polar bear wasn’t such an ice specialist, Talbot says.
“We can’t predict whether the polar bear is too far out (in its evolution towards a life on ice),” she says. “It’s interesting that there are a few examples of hybridization (between polar bears and brown bears). That’s something worth watching.”
And maybe polar bears have been trying to adapt to life on land, but one species has blocked that avenue of evolution. Polar bears that wander onto land, especially near a human settlement, tend to get shot. And humans — who didn’t wander out of Africa until about 45,000 years ago — weren’t present on the edge of the sea ice when polar bears first made it their home.
“We weren’t impacting them then the way we are now,” Talbot says.
Though the polar bear perhaps prospered through hot times in the past, what they have in store ahead may be their greatest challenge ever.
“We’re going into a very similar period of time, but it’s generally thought that this is going to be warmer than (the last great warm period),” Talbot says.
RE: Will the Polar Bear Survive? - brotherbear - 06-13-2016
One thing remains clear, during the Pleistocene, wildlife was much more abundant than in today's world. Even though the barren ground grizzly is a "meat-lover" he feeds primarily on vegetation. The arctic tundra is not thick with caribou and musk ox. For the polar bear to survive any drastic climate change, he must comply with some drastic changes in his diet. -IMO.