Alaska Marine Mammals: Polar Bears

Marine Mammals: Polar Bears

Alaska's State Flower is the "Forget-Me-Not. Forget me not flowers are very fragrant in the evening and night time, though there is little or no scent in the daytime. They can be annual or perennial plants. Their seeds are found in small, tulip shaped pods along the stem to the flower.

Polar bears are specially adapted to the polar marine environment in which they live. Adaptations include: white coloration for camouflage; water repellent guard hairs, dense underfur, and black skin for absorbing warmth; small “suction cups” on the soles of their feet for traction on slippery ice; teeth specialized for a carnivorous rather than omnivorous diet; and the ability to store large amounts of fat when food is available and then use it later when food is unavailable. Polar bears’ primary food source are ringed seals but they also hunt bearded seals, walrus, and beluga whales, and will scavenge on beached carrion such as whale, walrus and seal carcasses found along the coast.

The polar bear is the largest terrestrial carnivore, being more than twice as big as the Siberian tiger. It shares this title with the Kodiak Bear. Adult males weigh 750–1500 pounds and measure 7.9–9.8 feet in length.] Adult females are roughly half the size of males and normally weigh 330–550 pounds, measuring 5.9–7.9 feet in length. When pregnant, however, they can weigh as much as 1,100 pounds. The largest polar bear on record, reportedly weighing 2,210 pounds was a male shot at Kotzebue Sound in northwestern Alaska in 1960

Compared with its closest relative, the brown bear, the polar bear has a more elongated body build and a longer skull and nose. As predicted by Allen's rule for a northerly animal, the legs are stocky and the ears and tail are small. However, the feet are very large to distribute load when walking on snow or thin ice and to provide propulsion when swimming; they may measure 12 inches across in an adult. The pads of the paws are covered with small, soft papillae (dermal bumps) which provide traction on the ice.

The polar bear's claws are short and stocky compared to those of the brown bear, perhaps to serve the former's need to grip heavy prey and ice. The claws are deeply scooped on the underside to assist in digging in the ice of the natural habitat. Despite a recurring Internet meme that all polar bears are left-handed, there is no scientific evidence to support this claim. Unlike the brown bear, polar bears in captivity are rarely overweight or particularly large, possibly as a reaction to the warm conditions of most zoos. The 42 teeth of a polar bear reflect its highly carnivorous diet. The cheek teeth are smaller and more jagged than in the brown bear, and the canines are larger and sharper.

Alaska’s polar bear populations are concentrated along its Arctic coastlines. In the winter, they are most common in the Kuskokwim Delta, St. Matthew Island, and at the southernmost portion of St. Lawrence Island. During the summer months, they migrate to the coastlines of the Arctic Ocean and the Chukchi Sea. Conservation efforts, including the 1972 Marine Mammal Protection Act, have limited polar bear hunts, though polar bear populations may be threatened by oil development and global warming

Polar bears generally live alone except when concentrating along the coast during the open water period, or when mating or rearing cubs. Pregnant females will enter maternity dens in October/November; most dens in the circumpolar Arctic are located on land in areas where snow accumulates, such as along coastal bluffs or river banks. In Alaska, dens are excavated on either sea ice or on land. One to three cubs are born in December/January; cubs remain with their mother for about 2 1/4 years.

From the first encounters with indigenous hunters of the Arctic and the earliest explorers, polar bears have captured the attention of Arctic residents and visitors. Polar bears have been and continue to be an important renewable resource for coastal communities throughout northern Alaska. Polar bears provide a source of meat and raw materials for handicrafts, including functional clothing such as mittens, boots (mukluks), parka ruffs and pants. Polar bears and polar bear hunting were an important part of earlier religions, myths and legends, and continue to play an important role in the Inupiat and Yupik cultures; polar bear hunting is a source of pride, prestige, and accomplishment.

Prior to passage of the Marine Mammal Protection Act (MMPA), polar bears in Alaska were reduced by excessive hunting. The MMPA now prohibits polar bear hunting except by Alaska Natives for subsistence and handicraft purposes. Harvest monitoring has been conducted since 1980. Blubber serves as an efficient insulation layer in the cold marine environment and plays an important role in energy storage. Blubber is a dynamic tissue and its thickness can vary greatly depending upon the nutritional state and life history stage of the animal. Like most diving marine mammals, walrus store oxygen in their blood and muscles. Due to this adaptation, they have an enormous blood volume; up to 2 to 3 times larger than a terrestrial animal of comparable size.

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