The Polar bear (Ursus maritimus) is a hypercarnivorous bear found within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the largest extant bear species, as well as the largest extant land carnivore. Although it is the sister species of the Brown bear, it has evolved to occupy a narrower ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting seals, which make up most of its diet. Although most Polar bears are born on land, they spend most of their time on the sea ice. Their scientific name means "maritime bear" and derives from this fact. Because of their dependence on sea ice, Polar bears are classified as marine mammals. For thousands of years, the Polar bear has been a key figure in the material, spiritual, and cultural life of circumpolar peoples, and these bears remain important in their cultures. Historically, the Polar bear has also been known as the "white bear". It is sometimes referred to as the "nanook", based on the Inuit term nanuq.
Diurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While sc...
Terrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Altricial animals are those species whose newly hatched or born young are relatively immobile. They lack hair or down, are not able to obtain food ...
Natatorial animals are those adapted for swimming. Some fish use their pectoral fins as the primary means of locomotion, sometimes termed labriform...
Nomadic animals regularly move to and from the same areas within a well-defined range. Most animals travel in groups in search of better territorie...
An apex predator, also known as a top predator, is a predator at the top of a food chain and has no natural predators. These animals usually occup...
A burrow is a hole or tunnel excavated into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct ...
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract ...
Polygyny is a mating system in which one male lives and mates with multiple females but each female only mates with a single male.
Dangerous animals demonstrate aggression and a propensity to attack or harass people or other animals without provocation.
Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy charac...
NoNot a migrant
Animals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
CaCanada Province Animals
Polar bears are one of few large mammals that have been able to adapt well to life on the ice. Their fur consists of a layer of dense underfur and an outer layer of guard hairs, which appear white to tan but are actually transparent. The white coat usually yellows with age. The feet of these massive animals are very large to distribute load when walking on snow or thin ice and to provide propulsion when swimming; they may measure 30 cm (12 in) across in an adult. The pads of the paws are covered with small, soft papillae (dermal bumps), which provide traction on the ice. The claws are deeply scooped on the underside to assist in digging into the ice of the natural habitat.
Polar bears are found in the Arctic Circle and adjacent land masses as far south as Newfoundland. While they are rare north of 88°, there is evidence that they range all the way across the Arctic, and as far south as James Bay in Canada. Their range includes the territory of five nations: Denmark (Greenland), Norway (Svalbard), Russia, the United States (Alaska), and Canada. Polar bears prefer to live on the annual sea ice covering the waters over the continental shelf and the Arctic inter-island archipelagos. These areas, known as the "Arctic ring of life", have high biological productivity in comparison to the deep waters of the high Arctic. Polar bears frequent the areas where sea ice meets water, such as polynyas and leads (temporary stretches of open water in Arctic ice), to hunt the seals that make up most of their diet.
Polar bears live solitary life. They may come into competition with each other when there is the chance to scavenge when a seal is killed. In such cases, the smaller bear usually runs away. Polar bears can dive underwater to catch their prey, keeping their eyes open while holding their breath for as much as 2 minutes. They are inactive for a good part of the time, lying, sleeping, or waiting (still hunting). The rest of the time is usually spent traveling, either walking or swimming, feeding or stalking prey. They may travel far in search of food. Polar bears are usually quiet but do communicate with various sounds and vocalizations. Females communicate with their young with moans and chuffs, and the distress calls of both cubs and subadults consist of bleats. Cubs may hum while nursing. When nervous, bears produce huffs, chuffs, and snorts while hisses, growls, and roars are signs of aggression. Chemical communication can also be important: bears leave behind their scent in their tracks which allows individuals to keep track of one another in the vast Arctic wilderness.
Most of what Polar bears eat is the blubber and skids of Ringed seals. They often leave the rest of the carcass, which becomes an important food source for other animals. They also eat birds, fish, berries, reindeer and sometimes walrus. Carcasses of walruses, seals and even whales can provide a regular source of food for Polar bears. They sometimes break into underground seal dens to hunt the pups inside them.
Polar bears are polygynous and do not form pairs. Courtship and mating take place on the sea ice in April and May, when they congregate in the best seal hunting areas. A male may follow the tracks of a breeding female for 100 km (60 mi) or more, and after finding her engage in intense fighting with other males over mating rights; fights often result in scars and broken teeth. After mating, the fertilized egg remains in a suspended state until August or September. When the ice floes are at their minimum in the fall, ending the possibility of hunting, each pregnant female digs a maternity den consisting of a narrow entrance tunnel leading to one to three chambers. In the den, she enters a dormant state similar to hibernation. Between November and February, cubs are born blind, covered with light down fur, and weighing less than 0.9 kg (2.0 lb). On average, each litter has 2 cubs. The family remains in the den until mid-February to mid-April, nursing her cubs on fat-rich milk. By the time the mother breaks open the entrance to the den, her cubs weigh about 10 to 15 kg (22 to 33 lb). For about 12 to 15 days, the family spends time outside the den while remaining in its vicinity; the grazes on vegetation while the cubs become used to walking and playing. Then they begin the long walk from the denning area to the sea ice, where the mother can once again catch seals. The younf usually remain with their mother for 2 to 3 years. Females begin to breed at the age of 4years in most areas, and 5 years in the area of the Beaufort Sea. Males usually reach reproductive maturity at 6 years; however, as competition for females is fierce, many do not breed until the age of 8 or 10.
Polar bears are still hunted for fur and meat by the Arctic's native peoples. They are also threatened by drilling for gas and oil, increased shipping activity, and pollution from industrial chemicals. But the major threat is climate change and global warming causing the sea ice to melt earlier in the year and forcing the bears to shore before they have built sufficient fat reserves to survive the period of scarce food. It is suggested that Polar bears could be extinct in the wild within the next 30 years.
According to IUCN, as of 2010, between 22,000 and 31,000 Polar bears are estimated to be roaming near the North Pole, most being in northern Canada. Currently, this species is classified as Vulnerable (VU) on the IUCN Red List.
Polar bears are the top Arctic carnivores. The remains of seals left by the bears are likely to be an important food source for younger, less experienced bears and Arctic foxes.