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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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If the Polar bear has been proven to be a partial descendant of the Cave bear, then this could reasonably explain the 4-5 million years of their genetic divergence with the Brown bear.
Here's a couple of relatively recent studies on the polar bear evolution matter. It seems in almost all works the result is a relatively recently diverged species (~500 kya).
 *This image is copyright of its original author From Ancient Hybridization and an Irish Origin for the Modern Polar Bear Matriline.  *This image is copyright of its original author From Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage. 
If a grizzly can breed successfully with a polar bear; meaning that they have fertile offspring, as we know happens on occasion, then it seems reasonable to assume that a grizzly could also breed successfully with a cave bear - should one ever be cloned. I have also given thought that the Kamchatka and Kodiak bears appear very cave bear-like. Any chance this lineage could have a touch of cave bear?
About post #91, how does the black bear fit in? Have they, in some past time added their dna into the mix that produced the modern polar bear?
(01-06-2017, 12:56 AM)brotherbear Wrote: If a grizzly can breed successfully with a polar bear; meaning that they have fertile offspring, as we know happens on occasion, then it seems reasonable to assume that a grizzly could also breed successfully with a cave bear - should one ever be cloned. I have also given thought that the Kamchatka and Kodiak bears appear very cave bear-like. Any chance this lineage could have a touch of cave bear? Both Cave bear and Brown bear descended from the Etruscan bear, a native bear species from Europe. A group of Etruscan bears that migrated to China had became a new subspecies, and this new subspecies eventually evolved into the Brown bears. So they are sister species within the same genus, so it is very likely that they can produce the healthy fertile offspring. Other Cave bear species such as Ursus ingressus and Ursus deningeri were most likely the subspecific populations of the classic Cave bear Ursus spelaeus. (01-06-2017, 01:04 AM)brotherbear Wrote: About post #91, how does the black bear fit in? Have they, in some past time added their dna into the mix that produced the modern polar bear? The Black bear is too distantly related to the Brown bear within the same genus. Like lion and tiger, they can produce the unhealthy and mostly sterile offspring like the liger. However, the two Black bear species can successfully breed with each other and produce the healthy fertile offspring.
If they can discover some unknown lineage from certain population of the Brown bear, then it could be assumed it derived from the Cave bear.
If the Kamchatka bears and Kodiak bears contain these unknown lineages, then they could be considered as some Cave bear/Brown bear hybrid population. 
Data on size and weight of various polar bear populations
 *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author Some of the heaviest known polar bears on record;  *This image is copyright of its original author
I have two questions for Polar or others in-the-know:
There is the arctic tundra where lives musk ox, caribou, wolves, foxes, lynx, and grizzly bears. Then, there is the arctic of ice and sea water, apparently rocks beneath the ice, where lives seals, walrus, and polar bears. My question is, are there any common scientific names for the various levels of arctic? My second question is about the arctic fox. I was watching a documentary about polar bears. There was this fox that was very often following the bears. Since I have never thought of a fox as being a scavenger, what would a fox, living in the arctic of sea and ice hunt? 
Photo and information credits: Daryl Balfour
"Polar bear kiss?" from Barter Island, Alaska.  *This image is copyright of its original author
Polar Bear from Svalbard. Credits to Nicky Souness Photography.
 *This image is copyright of its original author
Credits to Liz Talbot - Wildlife Mad Travellers.
Here is the extended version of two of the play fighting male polar bears we encountered during our stay at Dymond Lake Lodge, north of Churchill, Manitoba. Can you tell which of the two bears kept losing the bouts? He's the one with the most berry juice splats on his back!! Click on it to play. 
Question from Kika: "Do polar bears drink water and if so, where do they find it? Living in a frozen world does not supply a lot of liquid fresh water."
Answer from Dr. Thea Bechshoft: Hi Lars – good question! Polar bears do indeed live most of their life out on the sea ice, surrounded by saltwater, which is no good for drinking. However, the bears have found a couple of ways to get around this lack of drinking water. The primary way polar bears get their water is – however odd it may sound - by eating as much seal fat as they can lay their paws on. When catching a seal, a polar bear will eat the energy-rich fat (blubber) first, often leaving the meat behind. There are several reasons for this, but one of them is that the physiological process of metabolizing (breaking down) meat protein requires water from the body, whereas the breaking down of fat actually releases water. In other words: the more fat the polar bear eats, the less water it will need to drink (if any at all). This holds true regardless of whether the bear is burning recently eaten seal fat or burning its own fat deposits. Polar bears will also sometimes eat snow, but usually not in great quantities as it requires too much energy to melt it. In fact, eating snow tends to be something the bears mainly do when they want to cool down, for example after sparring/fighting or on a sunny day. And finally, I imagine that polar bears will occasionally have a drink or two at the freshwater melt ponds that can form on the sea ice during the warmer months of the year  *This image is copyright of its original author
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