POLAR BEAR - ursus maritimus (ALASKA ZOO)

A Visit to Alaska ZOO - Just the polar bear!

                    FAST FACTS

Height: 8 to 10 feet (2.4 - 3m)

Weight: Adult males 550-1700 lbs (250-771 kg); females 200-700 lbs (91-318 kg)

Lifespan: 20 - 25 years

Numerous adaptations uniquely suit polar bears to life in icy habitats. Their fur is thicker than any other bears’ and covers even their feet, for warmth and traction on ice. A thick layer of blubber beneath their fur provides buoyancy and insulation. 

The long neck and narrow skull of the polar bear probably aid in streamlining the animal in the water, and the front feet are large, flat and oarlike. The polar bear is an excellent swimmer and individuals have been seen in open Arctic waters as far as 200 mi (320 km) from land. 

Diet

Staples: Polar bears feed almost exclusively on ringed seals and, to a lesser extent, bearded seals.
Polar bears travel great distances in search of prey.  They are also known to eat walrus, beluga whale and bowhead whale carcasses, birds, vegetation and kelp. 

Population

The World Conservation Union (IUCN) estimates that there are between 20,000-25,000 polar bears in the world.

Range

Did You Know?

The polar bear is the most carnivorous member of the bear family: most of its diet consists of ringed and bearded seals.

Polar bears are only found in the Arctic region and are highly dependant on the pack ice there since they spend much of their time hundreds of miles from land. The most important habitats for polar bears are the edges of pack ice, where currents and wind interact with the ice, forming a continually melting and refreezing matrix of ice patches. These are the areas of greatest seal abundance and accessibility.

Individual polar bears can travel thousands of miles per year following the seasonal advance and retreat of sea ice. Polar bears are distributed throughout the Arctic region in 19 subpopulations. Alaska, Canada, Russia, Greenland and Norway have polar bear populations. 

Behavior

Polar bears are highly dependent on older stable pack ice in the arctic region, where they spend much of their time on the ice hunting, mating, and denning. They are generally solitary as adults, except during breeding and cub rearing.

Unlike brown bears, non breeding polar bear females and males do not hibernate or den in the winter. Pregnant polar bears need to eat a lot in the summer and fall in order to build up sufficient fat reserves for surviving the denning period, during which time they give birth to one-pound cubs and then nurse them to about 20-30 pounds before emerging from the den in March or April.

Did You Know?

At birth, polar bear cubs are 12 to 14 inches long and weigh around one pound.

Reproduction
Mating Season: Late March through May
Gestation: About 8 months with delayed implantation
Litter size: 1-4 cubs; 2 cubs most common
Female polar bears locate denning sites in October on thick stable pack ice or on land. The young are born from November through January while the mothers are hibernating. Cubs will remain with their mothers for at least 2 ½ years. Female polar bears can produce five litters in their lifetime, which is one of the lowest reproductive rates of any mammal.

Climate Change and Other Threats

Polar bears could be extinct by 2050 as their habitat melts away due to climate change. The loss of snow pack, thinning and disappearing sea ice all reduce essential habitat. Loss of sea ice leads to higher energy requirements to locate prey and a shortage of food.

Did You Know?

Polar bears are so adapted to living on ice that don't need to drink water: they get the liquid they need from the prey they eat.

Polar bear survival is entirely dependant on sea ice as a platform for hunting the marine mammals that provide their nutritional needs. Polar bears stalk the seals using their breathing holes in the ice, as the total ice diminishes it will vastly decrease successful hunts and their overall food source. Though polar bears are excellent swimmers they are not adept at catching seals in open water.

Female polar bears require soft deep snow for dens to keep their cubs insulated from the harsh weather, and sufficient fat reserves to survive denning after giving birth to their cubs. Seals, a primary source of prey for polar bears, also require icy habitat to breed and raise their young. Changing ice conditions have forced the seals to move and give birth in different areas, making them more difficult to find.

Polar bears are the largest carnivores and a unique symbol of the Arctic. Nineteen populations of polar bears are distributed in Alaska, Canada, Greenland, Norway, and Russia. The world wide population is estimated to be 22,000-25,000 bears. Two populations occur in Alaska: the southern Beaufort Sea stock, shared with Canada; and the Bering Chukchi/Seas stock, shared with the Russian Federation.

In Alaska, the Marine Mammal Protection Act (MMPA) protects polar bears by prohibiting "take" of polar bears. The MMPA provides for specific exceptions to the prohibition on taking, including a provision that allows Alaska Natives to hunt polar bears for subsistence and the creation of handicrafts.

World wide, polar bear populations remain relatively stable; however, climate change, contamination of the Arctic environment, potential over-harvest, and increasing human development in polar bear habitat pose conservation challenges for polar bears.

Polar Bear enjoying Sun Bathing!

Look at how big they are!

ALASKA IS FAMOUS WITH THE SNOWVY POLAR BEAR! If you're interest in the Alaskan Animals, look also into Cute Little Puffin Bird !!