by Tanya Mulford

Mother seals who give birth to their pups in the waters of the Gulf of St. Lawrence and in an area called "the Front" off Newfoundland and Labrador have traveled in large groups from Greenland to their Canadian nursery. Their trip could be more than 1,555 miles or 2,500 kilometers. Once they reach their chosen nursery area, the mother seals leave the males and gather in large groups to give birth to a single pup each.

Pups usually weigh around 24 pounds (11 kilograms) at birth and have no blubber to insulate themselves. But, they gain weight quickly when nursing—growing to about 51 lbs. (23 kilograms) within four or five days. The pups gain weight steadily until they weigh as much as 88 lbs. (40 kilograms) when weaned.

Mother seals don't eat while nursing, and they lose more than a quarter of their body weight during that time in order to nourish their pups.

The HSUS/Glover

Mothers leave their baby seals to fend for themselves when the pups are two weeks old.

The First Few Days

They will stay with their pups almost constantly for their first few days. They might start venturing out after those days, but the mothers stick close to their pups. The adults might slip into the water, but will pop their heads up through the ice periodically to check on their pups. They make sure that no other seals are approaching them and listen to see if they are crying out for a meal.

Pups spend most of their early days sleeping and eating—they will stay still so long in one place that their body heat will melt a seal-shape cradle in the ice.

Pups keep their white coats (which are actually transparent hairs that reflect sunlight and help keep them warm) for about two weeks. Then, the white hairs fall out to reveal a silvery grey coat with black spots. At this stage they are called "ragged jackets." When their grey and black coat has completely grown in, they are called "beaters," it's said because of the way their flippers beat helplessly in the water as they are learning how to swim. It will take four or five years for the harp shaped pattern to appear on their backs.

Weaning Time

While the females are giving birth and tending to their pups, the males gather in large groups, keeping their distance. As weaning nears, the males will wander through the group of females, seeking a mate.

After about two weeks, a mother seal will decide it's time for her pup to be on his own. She will abruptly stop feeding him and leave him to fend for himself. At that time, she'll mate and start the long swim back to the waters around Greenland for the summer months.

On Their Own

The HSUS

A ragged jacket seal pup loses it's white fur at around two weeks old.

Once their mothers have left, seal pups lie in large groups on the ice pack, where they will stay until it breaks up.

At first, they cry out for their mothers, but they eventually adapt, learning to swim and eat (small fish and crustaceans) on their own.

Then they too will start their own migration up towards Greenland. By the time they have made the trip, the one-time "beaters" will be swift, strong swimmers, able to reach speeds of 16 feet (5 meters) a second.

Throughout their relatively long lives (as long as 30 years), the seals face the occasional predators of Greenland sharks, orcas and polar bears. But the only predator to threaten their survival as a population are humans.

Further Reading

Lavigne, D.M. and Kovacs, K.M. 1988, Harps & Hoods: Ice Breeding Seals of the Northwest Atlantic. University of Waterloo Press: Waterloo, Ontario, Canada.

Feldhamer, G.A., B. C. Thompson and J.A. Chapman (eds.) 2003. Wild Mammals of North America, 2nd edition. The Johns Hopkins University Press: Baltimore, MD, USA.

Smithsonian National Museum of Natural History: Phoca groenlandicas

Posted April 6, 2007