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Ringed Seal

Phoca hispida

Photo: Ringed seal just below the surface

Photo: Ringed seal just below the surface (View larger version)

Photograph by Paul Nicklen

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The most common and widely distributed seals in the Arctic, ringed seals make their home throughout the Northern Hemisphere’s circumpolar oceans, where they feed on polar and arctic cod and a variety of planktonic crustaceans. Different populations have different names and some variation in behavior and appearance. But ringed seals—the smallest seal species—get their name from the light-colored circular patterns that appear on their darker gray backs. Some of these markings are so dense, in fact, that they take on the look of splattered paint.

Most of the ringed seals' time is spent near shore ice, but their ability to maintain cone-shaped breathing holes—which the animals excavate in the ice using the claws of their front flippers—allows them to occupy areas much farther from the ice edge than other seals can reach. Physiological adaptations help them make deep, sustained dives, reaching depths of 300 feet (90 meters) and remaining submerged for up to 45 minutes. But before surfacing, they sometimes blow bubbles up their breathing hole to check for polar bears, their main predator.

The only time these largely solitary creatures come together is when they gather on sea ice to breed, molt, and rest, sticking close to breathing holes and cracks in the ice in case they need to make a quick escape. They build lairs—a kind of snow cave—as soon as enough snow accumulates, becoming very territorial about them and the breathing holes and underwater areas beneath them.

Females reach sexual maturity at about six years old. After mating, implantation is delayed for several weeks. Then, following a gestation period of 9 to 11 months, the female gives birth to one pup, raising it within the seclusion of a lair. The shelter protects the newborn from harsh weather and predators.

After about two months, pups are weaned and left to fend for themselves. Although they learn to dive shortly after birth, they’re still preyed upon heavily by arctic foxes, birds, walruses, polar bears, and other animals.

Native hunters kill ringed seals for subsistence throughout their range, and pollutants affect populations in the Baltic seas. But a more widespread threat to their numbers is climate change, which is reducing the expanse of their icy world.

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