Polar bears are a very popular animal among society and have become even more so as a result of an increasing awareness of climate change and how it is affecting them. Polar bears have some pretty surprising adaptations to allow them to survive in the freezing climate of the Arctic. Here is the ultimate list of polar bear facts.
What do polar bears eat?
Polar bears are at the top of the food chain in the Arctic. They are mainly carnivores and prefer to eat meat as their main source of food. They mainly feed on seals. Seals are particularly good because they hold a lot of fat which has lots of calories. They mainly eat ringed and bearded seals but depending upon their location, they may also eat harp, hooded and ribbon seal. When there are seals in abundance, they will only eat the fat reserves and leave the rest as it is the fat which is most beneficial to them. The carcass is then left for scavengers such as foxes, ravens and younger bears.
Food can be hard to come by for polar bears. That is the case now more than ever as the ice caps are melting due to global warming. Polar bears usually hunt by waiting patiently for seals on ice caps and attacking when they are most vulnerable.
Their sense of smell is one is one of the best in the animal kingdom. They can smell food up to 20 miles away. Sometimes, they will hunt down carcasses for food using only their sense of smell.
When food is scarce, polar bears may look for sustenance along the shore. Polar bears are known to eat muskox, reindeer, small rodents, eggs, berries and even human garbage in some cases. If they are really struggling for a meal, they will try to hunt beluga whales and adult walrus.
Recently, due to global warming, the summers are getting longer and the winters shorter, thus forcing the polar bears to hunt alternate prey such as fish. Polar Bears in eastern Greenland and southern Svalbard are catching fish.
The sea ice serves as the polar bears main hunting ground and they heavily depend on it. Catching seals on the ice is a lot easier than catching them in the open water as seals are naturally better swimmers. Now with the extra length added to the summers, the sea ice melts forcing the polar bears to stay by the shore.
This change in the seasons has affected their hunting patterns and they are forced to hunt in an unfamiliar setting. Fish is not enough to keep polar bears lean, but it helps when other food is scarce.
Where do polar bears live?
Polar bears live in countries that ring the Arctic circle. This includes countries such as Canada, Russia, the United States (Alaska), Greenland and Norway. According to the world conservation unit, they estimate that there are between 20,000 and 25,000 polar bears on earth, which are scattered throughout the Arctic circle. However, many areas of these countries have a declining population of polar bears.
Areas such as the southern Beaufort Sea and the Kane Basin in Canada and the Baffin Bay on the south-west coast of Greenland are all declining. This is largely due to the ice melting in these areas, which is the polar bears main hunting grounds.
Polar bears population is expected to decline by around 30% by 2050. This is largely due to the ice melting in these areas, which is the polar bears main hunting grounds.
The polar bear is the largest carnivorous mammal on the planet. Elsewhere, the only other bear similar in size to the polar bear is the Kodiak bear, which is a subspecies of brown bear. Adult male bears can weigh from 770 up to 1500 pounds and measure from 2.3 to 3 meters in height in length. Adult females are roughly half the size of adult male polar bears.
The largest polar bear ever recorded was found in northern Alaska in 1960. It reportedly weighed 1002kg (2,209lb) and stood 3.39M (11 ft 1 in) tall.
How are polar bears adapted to the cold climate?
Temperatures in the Arctic can range from 0°C to -34°C in the winter and 3°C to 12°C in the summer. Naturally, polar bears would have had to adapt to these extremely cold temperatures in order to survive.
One way they are adapted to these freezing temperatures is that polar bears actually have black skin. Although their fur is notoriously white, underneath that thick fur is a black hide. This black hide helps the polar bear keep warm as it absorbs the sunlight and it certainly helps during the winter.
Polar bears have superb insulation and are insulated by up to 10cm of adipose tissue. Their hide and fur are so thick that they are nearly invisible under an infrared camera. Polar bear fur consists of a layer of dense underfur and an outer layer of guard hairs. The guard hair is around 5-15cm long and it covers the majority of their body. These hairs play a key role in keeping the bear insulated.
As the ice melts and polar bears have to travel further and further to look for more ice and food, they have to adapt. Thankfully, they are excellent swimmers. Swimming for days is not an unusual task for them. One polar bear swam continuously for 9 days for 400mi (700km) to reach ice from land. With its high body fat, it provides excellent buoyancy for swimming with ease.
This is why mothers are reluctant to swim with their cubs as they have very little body fat.
Their ears are small and round, while their tail is short and compact. This helps keep the heat in a small area and helps to conserve it.
On days when it is colder than usual, they sometimes will dig burrows in the snow and curl up in a ball in there. Although they can get very cold, typically they deal with overheating more than freezing. This is why they prefer to walk at such a slow pace.
Reproduction and lifecycle
Mating usually takes place every year in April and May when the polar bears gather in the best seal hunting areas. A male may follow the tracks of a female polar bear to potentially meet a breeding partner. Other males may follow and intense fights may ensue over mating rights.
During the pregnancy, the mother will fatten up as much as possible. She will then find shelter and go into a dormant state similar to hibernation were her heartbeat drops from 46 to 27 beats per minute on average. Temperatures will not drop like they do in other mammals.
Between November and February cubs are born. When a cub is born, it weighs less than 2lbs and is born blind. The mother continues her fast while the cubs feed on her nutrient-rich milk, up until they reach around 10-15kg. Mothers can often fast up to 8 months.
The cubs will remain in the same area for approximately 2 weeks while they gather their bearings and learn how to walk.
Polar bears struggle to live beyond 25 years old. The oldest wild bear every recorded lived to 32, whereas the oldest captive bear was a female who lived until 43 in 1991.
In the wild, polar bears mainly die when they become too weak and old to catch food and eventually starve to death.
Human interaction with polar bears
Polar bears have long provided indigenous people with raw materials in the Arctic regions like the Inuit, Yupik, Chukchi, Nenets, Russian Pomors and others. Their hunting tactics involved using the dogs as a distraction while they spear the bear or shoot it using a bow and arrow.
However, the hunters had the utmost respect for these animals, putting almost all the parts of the polar bear to some use. The fur of the bear provided warmth for these hunters as it was fashioned into trousers. It was also used to make footwear called tobok. Sinew from the muscles was used as a thread to sew the clothes and the fat was used in food and as a fuel for lighting homes.
Hunters also put the organs to good use. Medicine was made by drying out the gallbladder and heart. Only the liver was not used, as its high concentration of Vitamin A is poisonous if ingested.
Controlled captive environments like zoos play a vital role in the global effort to conserve polar bears. Most modern zoos hold the bears in large chilled pools of water stocked with fish, land for the bears to hide and sleep and to emulate as natural an environment as possible.
These zoos can help educate and inspire the public in helping these beautiful creatures. They also help orphan sick cubs. This will be a vital part of our future if we are to help prevent animals like polar bears from becoming extinct.