Striding across the arctic ice, the polar bear is the largest land carnivore in the world. But while they are the apex predators in this biologically diverse habitat, they are in trouble, thanks to global climate change, according to Defenders of Wildlife.
But before we find out why climate change is harming these magnificent bears, let’s learn a little more about them.
Amazing Polar Bear Facts
Uniquely adapted to live in their cold climate, these bears have fur that is so thick it even covers the skin between their toes, giving them extra warmth and excellent traction on slippery ice. Underneath that luxurious fur is a thick layer of fat that provides insulation and buoyancy — and that’s important because these bears love the water.
Polar bears are powerful swimmers
In fact, they are such strong swimmers that they have been found as far away as 200 miles from land. But swimming so far from land can be dangerous for young polar bears because it requires an astounding amount of energy to do this.
What do polar bears eat?
These huge mammals primarily hunt ringed seals and bearded seals, but they have also been known to eat walrus and beluga whales. In addition, they also have a fondness for bowhead whale carcasses and bird’s eggs. On rare occasions, they snack on vegetation.
Polar bears are the largest carnivores on land
As the largest species of bear, an adult male can stand up to 10 feet (three meters) tall, and weigh as much as 1,200 pounds (544 kilograms), Live Science reports. Females, on the other paw, are smaller and, at around 330 to 650 pounds (150 to 295 kilos), weigh less than their male counterparts. Astoundingly, Canadian researchers discovered one bear that weighed 1,700 pounds (800 kilos).
For these bears, looks can be deceiving
And even though that beautiful fur appears white, it’s actually transparent. The reason the fur looks white is that light is refracted through the clear strands, The Animal Diversity Web reports. Amazingly, polar bears actually have black skin, and it works to absorb the light shining through, helping to keep these big bears warm.
Polar bear population
These magnificent predators live in the countries that make up the Arctic Circle — Canada, Russia, the United States (Alaska), Greenland, and Norway, and there are 19 subpopulations of the massive bears. Wintertime temperatures plummet to minus -29 degrees Fahrenheit (-34 degrees Celsius) and sometimes even as low as -92 F (-69 C). The IUCN Red List of Threatened Species estimates there are about 20,000 to 25,000 polar bears in the world.
These handsome bears prefer hunting on the edges of pack ice, where winds and currents blend together to form ice patches that melt and refreeze continually. Seals like to haul out in these areas, making the pickings a little bit easier for these large predators, who often wait patiently by the breathing holes seals make. This style of hunting is known as “still hunting.” Amazingly, the bears can even sniff out seal lairs, crashing through the ice to hunt the seals inside. Their sense of smell is so keen that they can actually detect a seal’s breathing hole from half a mile away. They can smell a seal on the ice from 20 miles (32 kilometers) away.
But even with all this evolutionary sophistication, polar bears successfully make a kill only 2 percent of the time, LiveScience reports.
The video below shows just how polar bears hunt
When the pickings are good, polar bears only eat a seal’s blubber. This makes for a calorie-loaded meal that helps them build up the fat reserves they need to survive the Arctic’s brutal winters. On average, a polar bear needs about 4.4 pounds (two kilos) of fat daily to maintain its body temperature. This adds up to about 121 pounds of seal (55 kilos) each week and gives the bear enough energy for about eight days.
Polar bear babies
After an eight-month gestation period, the mom usually gives birth in November or December. When she’s preparing to give birth, she digs a huge cave into a snowbank, and that becomes her maternity den. This is where her cubs will enter the world.
The female bear usually gives birth to twins, although single babies or triplets are born every now and then. At birth, these little guys usually weigh only 1.3 pounds (half a kilo), but they put on a burst of speed when it comes to growing. A polar bear mom’s milk is 36 percent fat, and that, along with cuddling with mom, gives these babies a good start at life. Springtime finds these adorable youngsters prowling around outside the den, exploring their new world. By the time they are two years old, they are full adults. Throughout her life, the female-only produces five litters, and the bears have one of the lowest birth rates of any mammal.
The polar bear in indigenous culture
While the Inuit people still hunt polar bears for food and fur, hunting is regulated strictly by a quota system. In Inuit culture, hunters pay respect to the bear’s soul (called “tattoo”) by hanging the skin in a revered place in their igloo. The Inuit name for the polar bear is “Nanuk,” and the bear is considered to be wise, powerful, and “almost a man.”
Among the Sami (or Lapp) people, the polar bear’s name is never uttered, for fear of offending the great bear. Instead, they call it “God’s dog,” or the “old man in the fur coat.”
And they do look kind of like a big dog, don’t they?
How anthropogenic global warming is threatening their existence
It is, in fact, the single biggest threat to their survival, The Guardian reports. Sea ice is shrinking so rapidly that the polar bear population is being decimated, and the IUCN has found that their numbers will shrink by a staggering 30 percent by 2050. All thanks to the loss of their habitat due to anthropogenically (human) caused climate change.
“There is a high risk of extinction and the threat is serious. You could consider polar bears to be a canary in the coal mine. They are an iconic and beautiful species that is extremely important to indigenous communities. But changes to their sea ice habitat are already being seen as a result of climate change.”
Rapidly shrinking habitat
But because the sea ice these bears depend on is shrinking so rapidly, this means it takes that much longer for it to regrow. The USGS notes that over the past 25 years, the summer sea ice melt period has lengthened, meaning that the summer sea ice cover has declined by nearly a half-million square miles.
And annual ice-free periods now last five months or longer, meaning that many bears are going hungry, and the species is heading for a “tipping point,” the IUCN notes. Reproductive failures and starvation are becoming widespread in some areas.
Warming temperatures may also spur diseases in seal populations, and pollution, oil drilling, and human encroachment are exacerbating problems for polar bears.
Humans vs. bears
As a result, human and bear conflicts are becoming increasingly common, especially in Canadian towns like Churchill, where the ice season has been shrinking by about one day per year during the past three decades. Cator adds:
“Human-bear conflict strategies are really coming into play in Churchill. Polar bears are opportunists, like other bears. They look for what they can eat. When there is no sea ice, they will scavenge anything from whale carcasses to small animals to human rubbish.”
In September, the polar bear range states — Norway, the United States, Russia, Greenland, and Canada, agreed to a “Polar Action Plan.” The plan, according to the IUCN, is “the first global conservation strategy to strive for the long-term persistence of polar bears in the wild.”
This is a good start for what’s likely to be a long journey to save these majestic bears.