Weddell seals are the southernmost ranging mammal on Earth, and spend much of their time below the Antarctic ice. They stay close to the fast ice—ice that is fastened to the coastline—and use breathing holes to surface for air and to enter and exit the water. The breathing holes are vital, and the Weddell seals maintain them by using their specially-adapted incisors to bite away the ice.
With their cat-like faces, spotted undersides and whiskers that curl up at the ends, Weddell seals are fairly easy to identify. They rank among the largest of all seal species, reaching lengths of 3.5 meters and weighing as much as 600 kg. Their bulk is matched by their bark, as Weddell seals are noisy creatures. Individual Weddell seals produce their own unique songs, and are particularly vocal during mating season. Their vocalizations are so loud they can be heard through the ice.
Weddell seals dive to forage for food. They can stay submerged for up to an hour and reach depths of 600 meters. They are clever hunters, and often dive beneath their prey so that the fish are backlit by the ice above and are easier to spot in silhouette. Another tactic involves blowing air into cracks in the ice, flushing out fish for a well-deserved meal. As they spend much of their time under the ice, Weddell seals are relatively safe from air-breathing predators such as killer whales and leopard seals. There is always a degree of threat, however, and juveniles and pups are particularly vulnerable when swimming.
When up on the fast ice, Weddell seals have no natural predators. The seals mate underwater but return to fast ice colonies during the spring for birthing, often returning to the same breeding sites as in previous seasons. The females give birth in less than five minutes. The newborn pups are about 1.25 meters long and weigh around 25 kg. When they are only one or two weeks old, the pups are ready to swim, and at just six weeks they are capable of hunting for themselves.
Other Antarctica Wildlife
Adélie Penguin / Chinstrap Penguin / Emperor Penguin / Gentoo Penguin / Macaroni Penguin / Crabeater Seal / Elephant Seal / Fur Seal / Leopard Seal / Ross Seal / Blue Whale / Fin Whale / Humpback Whale