Weddell Seal Facts | Antarctica Wildlife Guide

This seal has the most southern range of all mammals, mating as far as 78°S. It is usually found within sight of land. Weddell seals remained undiscovered until 1823 when Captain James Weddell caught six individuals during his expedition to the South Pole. Though an Antarctic seal, these creatures have been found as far north as New Zealand, southern Australia, South Georgia, and even the Falkland Islands.

Male Weddell seals are about the same size as the females. In fact, the females often grow slightly larger than the males. The males establish underwater territories, where they will mate with females that enter, but they do not form harems. Mating takes place in the water.

The Weddell is a rather tubby animal that weighs up to 900 pounds, with a length of about 10 feet. These seals have gray coats and lighter undersides. Their entire bodies are marked with light gray splotches. Their small heads have large eyes that help them hunt prey in dark, icy waters. Fish make up the bulk of their diet. They also eat a fair amount of squid and krill. Their favored food is the large Antarctic cod, which can weigh 154 pounds.

The breeding season starts when the cows haul out on the fast ice in early September and give birth within one or two days. Males frequently battle each other if they are in close proximity, and females vehemently defend their young.

In six weeks’ time, the pups are weaned and have quadrupled in size, reaching a weight of more than 260 pounds. The cows will have lost about 300 pounds during the same period. Soon after birth, the pups begin to explore the ocean, though breaking sheets of ice may crush many of them. The mortality rate of pups is approximately 50 percent during their first two months of life.

Weddell seals in the Antarctic usually remain near land year-round. In winter months, they stay beneath the ice, popping up for air in breathing holes that they maintain. Seals cut these holes by using their sharp canines and lower incisors to trace a circle from below. Typically, the teeth of older Weddell seals have been filed down from years of ice cutting. These older seals are no longer able to sufficiently catch prey, and they may die of starvation.

Weddell seals are excellent divers and have been known to dive to nearly 1,900 feet and remain submerged for more than one hour. Perhaps because they meet few predators on or under the fast ice, they are not much concerned when they occasionally meet humans on land.

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