Polar Bear
Ursus maritimus
Mammal
Range: Northern Arctic Circle Habitat: Pack ice Size: 8 feet (2.4m) or longer; Up to 1,700 pounds (800 kilograms) Diet: Seals Threats: Habitat loss Life span: Twenty to thirty years
Transcript:
Today on Animal Fact Files we’re talking about polar bears. Polar bears may just well be the most well known of the eight living bear species. They’re a circumpolar species, living in the far northern Arctic circle - and they only live in the Arctic, not the Antarctic - that’s why no one’s going to see a polar bear hanging out with a penguin in the wild (though the same can’t be said about advertisements…). Polar bears are also known as ice bears, sea bears, and white bears - and while those first two names make a lot of sense, the third is a bit tricky.
Polar bears aren’t actually white. Under all that fur polar bears have black skin which likely contributes to keeping them quite toasty in their icy landscapes. Springing from that cozy skin is not white but clear fur. Polar bear fur appears white in their arctic environments due to light, but sometimes they can even appear yellow or brown. Actually, we’ll be talking about brown tinged polar bears later in the video, so stay tuned!
Going back to other polar common names, sea bear is an appropriate name because polar bears are considered marine mammals - this is even evidenced in the polar bear’s scientific name! Because they’re marine mammals, polar bears are protected from sport hunting. This is good news for the bears since they face quite a few other challenges, including habitat loss, as a species listed as vulnerable to extinction.
As top predators of their domains, polars really only have other polar bears to fear. Male polar bears specifically may take unprotected cubs, but this is still a risky business as mama polar bears are fierce! Although they may be smaller than males, female polar bears will fight off a male looking to attack her cubs or steal a meal. A mother polar bear is not only feeding herself but also her cubs, of which there are typically two in a litter, and it would be a waste to let a big old male take over that food, so she’ll defend it!
When they aren’t fighting, male and female polar bears only really get together to breed and then part ways. Gestation in polar bears seems like it takes a long time, but this is because have a delayed implantation period - meaning the eggs don’t begin developing as soon as they’re fertilized. From the time the eggs implant in the female’s uterus, it only takes two months for the babies to be born. They’re born tiny and don’t leave their mother’s den until they weigh about thirty pounds (13.6 kilograms). They’ll spend at least the next two years with their mother and they won’t be ready to breed themselves until they’re at least five.
In size, polar bears are considered, on average, to be the largest bear species - something we discussed a few years ago in our sun bear episode (jeez, this channel is seriously that old?). Polar bears can weigh up to 1,700 pounds (800 kilograms) and reach more than eight feet (2.4 meters) in length - that’s the boys specifically, remember the ladies are much smaller!
Polar bears are most closely related to grizzly bears and are actually able to breed with them, though this is highly rare in the wild as their habitats don’t generally cross. Polar bears prefer to live on pack ice which consists of large chunks of floating ice that have been pushed together by wind. Here they spend most of their time hunting seals. Ringed seals are the most common prey species of polar bears but they will take other seal species, as well.
Polar bears have two modes of hunting. They’ll sit and wait at a seal breathing hole until the seal comes up for air, or they’ll sneak up on seals that are out on the ice or seal pups that are buried in dens. Polar bears usually only eat the blubber of their prey and they’ll leave behind the rest to be eaten by smaller arctic predators such as arctic foxes.
When polar bears are forced off of pack ice during warmer parts of the year in certain areas, polar bears will live in coastal areas. During this time they may come in contact with grizzly bears and potentially breed. There has been once documented occurrence of this in the wild and the resulting offspring was a whitish brown bear affectionately called the grolar bear.
For more facts on polar bears, check out the links in the description. Thank you to stevie kurudimov and chava feldman official for today’s request. Give a thumbs up if you learned something new today, and thank you for watching Animal Fact Files!
