All About the Semi-Aquatic Polar Bear and Its Constant Search for Food in the Wild
A Loving Mother and Her Babies
A Polar Bear's Most Prominent Feature
A polar bear (Ursus maritimus) is large enough to cause you to do a double-take, even when being viewed through the thick glass provided by a zoo, but its size is not its most prominent feature - that distinction goes to its gorgeous coat, which will range from a pure white to a creamy yellow color. The fur is long and thick and provides the semi-aquatic bear significant protection from the cold, and provides an effective camouflage for them in the snow and ice. They are classified as marine mammals since they spend most of their lives on the sea ice of the Arctic Ocean.
Polar bears living in the wild are only found where the sea freezes during the winter months. For the summer months, they will move northward as they follow the limit of the drift ice, but in the winter they move southward following open water zones that lie between the fissures between the ice floes. All of these movements are done in their constant pursuit of food.
Polar bears are huge animals, usually about 7-8 feet tall, weighing up to about 1,600 pounds. In regard to a polar bear's body build, they are quite different from other species of bears. They are not stocky, but rather have a sleek, almost graceful appearance. Their necks are long, but their heads are quite small in comparison to other bears.
The pads of a polar bear's large feet are rough and leather-like and they have fur between their toes, all of which enables them to maneuver the slippery surfaces of their environment as they go on their ceaseless journey to find food.
Strong But Slow Swimmers
Polar bears are strong but slow swimmers. The longest they are able to remain submerged is about two minutes, which makes being a predator an endeavor that requires careful planning since their favorite prey, the seals can stay underwater for up to a half an hour. This means they are not able to catch the seals while they are swimming, but instead must ambush them when they come up through the holes in the ice for air.
Often, they move toward their prey on land with the stealth-like moves of a cat sneaking up on a mouse. Then, as the bear closes in it will use blocks of ice as cover and pounce on the seal as it tries to retreat.
In the case of polar bears needing to attack their prey from underwater, they will swim almost completely submerged with only the snout above the water. During the last few yards of the approach, they will submerge completely then leap straight up onto the ice to attack a seal who has been none-the-wiser as it most likely has been enjoying a bit of sunshine on the ice.
A polar bear can devour up to about 30 pounds of seal blubber in one sitting.
The Only Completely Carnivorous Bear
Thanks to its year-round camouflaging fur blending in with its usual background of snow and ice, the polar bear - the only completely carnivorous species of bear - is able to continue its hunt for prey.
Plus, they are extremely nomadic and have been known to rest on ice floes over 200 miles out to sea. If their resting spot should melt, they will swim to the nearest shore. If they are forced to swim in rough water, they will swim with their eyes and nose submerged, although they prefer to be able to "dog paddle" whenever possible, swimming with their head above water.
These bears, swimming at sea, are as defenseless as the seals they hunt are on land. They can, however, sustain a pace of about 5-6 miles per hour by paddling with their front paws and holding their hind legs flat like a rudder.
The Way Most People View Polar Bears
The Ugly Side of a Polar Bear
Mating for these bears occurs in about mid-April or May and the males will track the female bears over great distances. During that time, however, the males become extremely irritable toward other males (and humans).
During the winter, a female polar bear will excavate a shallow den under the snow for the upcoming birth of her cubs, which are about the size of a full-grown guinea pig when they are born. The mother, who never ventures away from her makeshift shelter, will live off her of fat reserves until the cubs are able to follow her around, which is usually around early summer when they are weaned on berries and Arctic hares. It is usually several months before the cubs are taught to hunt the seals, which will become their dinner of choice throughout adulthood.
Reasons for Low Populations
The cubs stay with the mother for so long that breeding only takes place every other year, which contributes to the low population of polar bears. Another reason would be that Eskimos hunt polar bears and hunters in amphibious planes shoot them while they are swimming (very unsportsmanlike).
While hunters are considered to be enemies to the polar bear, the only natural enemies to it are the killer whale (and the walrus at times). In 2015, the International Union for Conservation of Nature (IUCN) reported that the global population of polar bears was 22,000 to 31,000, although the current population trend is unknown.
Declining habitat now and the assurance that it will decline in the future are the reasons the polar bear was listed as a threatened species in the United States under the Endangered Species Act in May 2008. An ongoing and potential loss of their sea-ice as a result of climate change is a continued threat because a shorter duration of ice cover over their productive hunting area means they have less opportunity to hunt.
It appears as if the fate of the polar bear may lie in the hands of Mother Nature.
- The Illustrated Encyclopedia of the Animal Kingdom (1972), the Danbury Press, Pp 69-75
- Great Book of the Animal Kingdom (1988), Arch Cape Press, Pp. 261, 288-289
- Encyclopedia of the Animal World (1972), Mandarin Publishers Ltd.
© 2018 Mike and Dorothy McKenney