Brains
Polar bears aren’t just ordinary big white bears (they’re actually not white at all…), they’re highly specialized for life in the harshest environments. Here are nine amazing facts about polar bears.
1. They’re thought to have evolved from brown bears that became isolated due to glaciation in the eastern part of Siberia. The latest research has the two species diverging genetically around 400,000 years ago. Most brown bears have between 2% and 10% polar bear DNA, suggesting recent interspecies mating.
2. Pizzly Bears and Grolar Bears, or polar-grizzly hybrids, have been recently confirmed in the wild. In 2006, the first hybrid bear was confirmed by DNA testing after being shot on Banks Island in Canada’s Northwest Territories. Although possible hybrid bears have been reported in the Arctic since the 1800s, in the last 20 years, grizzly bears have been migrating further north into polar bear country, meaning these bears could become even more common in the future.
3. Their taxonomic name, Ursus maritimus, means “Sea Bear.”
4. They are the largest land carnivore in the world. Adult male polar bears can weigh over 1,500 pounds.
5. Unlike brown and black bears, polar bears don’t hibernate. Only pregnant females will den up for the winter months. Research has shown that genes driving nitric oxide production in polar bears differ compared to those genes in brown and black bears. Nitric oxide controls whether cells use nutrients to produce energy or convert it to heat. Polar bears produce much higher levels of nitric oxide, which is thought to help them produce more heat to stay active through extreme cold.
6. They can swim up to 10km per hour. That’s crazy fast. For comparison, the men’s 10km open water swim in the 2016 Olympics was won in 1 hour 53 minutes. They’ve been spotted in the ocean as far as 60 miles offshore, and scientists have recorded them swimming up to 220 miles at a time. Even if you’re Michael Phelps, don’t try to out-swim a polar bear.
7. Polar bears are so well insulated they’re almost completely invisible to infrared cameras! Scientists trying to track polar bear populations have difficulty picking out the camouflaged bears against the white snow. Using infrared cameras at night has proved no better. Only heat from the bear’s face and breath distinguish them from the heat patterns of the snow. Up to 4 inches of blubber and 6 inches of dense fur keep the bear’s heat loss to an absolute minimum
8. During prime hunting season, they only eat the high-calorie blubber of their prey (seals) and leave the rest for scavengers. A bear can eat up to 10% of its body weight in just 30 minutes. When food is scarce, the bears will eat just about anything – reindeer, rodents, birds, shellfish, eggs, fish berries, and, unfortunately, human garbage. They can go months at a time without eating if they are unable to find food.
9. Polar bears are listed as vulnerable due to climate change. Declining sea ice makes it harder and harder for polar bears to hunt seals. Their population is expected to decline by 30% by 2050.
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