Harp Seal (Pagophilus groenlandicus)
Body and Skeletal Structure:
Harp seals typically measure to be about 5.25 to 6.5 ft (1.6-1.98 m) long while their weight averages about 265 to 298 lbs (120-135 kg). The males are usually heavier and larger than the females.
The adult harp seal is typically distinguished by the black markings on the upperside of its body, which create a harp or horseshoe shape. Their fur is silvery-grey, and may be speckled with black spots in the female. The male typically has a black band running down its sides. It has a black, wide face with said color extending to just behind its closely set eyes. The female, on the other hand, has a somewhat paler, spotted face. Both also have well-developed, sensitive whiskers and fore and hind flippers bearing black claws. Harp seal pups are known as ‘whitecoats’ due to their thick, white, insulating fur, which becomes whiter in the first two weeks of life. After two weeks, this fur begins to moult, revealing the silvery-grey and black fur beneath.
Fun Fact: The scientific name for the harp seal, Pagophilus groenlandicus, means ‘ice-lover from Greenland.’
Harp seals are primarily piscivores mammals that eat up to 67 species of fish and 70 species of marine invertebrates. Fish and invertebrates consumed by harp seals vary depending on their age, location and the season. Some of the main fish that make up their diet are capelin, polar cod, and Arctic cod. Pups mainly tend to feed on small invertebrates such as crustaceans.
Fun Fact: Harp seals forage for food at depths of 492 to 656 ft (150-200 m), typically lasting up to 15 minutes underwater.
These seals live to be about 20 to 35 years of age.
Mating Season: February to April (About 10-12 days after females give birth)
Gestation Period: About 11.5 months (including about 3 months of delayed implantation)
Birthing Months: Late February to April
Litter Size: 1 pup
Communication and Behavior:
Harp seals may travel up 5000 km in a year. Their migratory patterns depend on where the seal population breeds and molts. Harp seals breed on the southern edge of their range in the winter and molt nearby in the spring. After molting, harp seals migrate to the northern end of their range for the summer. Harp seals begin their journey back to their breeding grounds in September. Though harp seals come together during their breeding season and when molting, they tend to spend the rest of their time as solitary creatures. No social system or hierarchy has been identified within populations of harp seals. Harp seals spend most of their time in the open waters, but come out of the water on a regular basis (called “haul out”) to spend some time on land. Seals tend to haul out at night. The two longest haul outs take place during the breeding season and when it is time to molt. If extended amounts of time are spent on the ice, harp seals make holes (called “breathing holes”) in the ice for easy access to water and to breathe when swimming under the ice. Also, when the mating ends, females gather in groups to give birth. Young harp seals are born on the ice, and mothers identify their own offspring from the multitudes by their smell. Female harp seals are the sole providers of care to their pup. Harp seals birth one pup at a time, they are nursed and cared for by their mother for 10 to 12 days. The mother’s milk is 48% fat and the pups gain an average of 73 lbs (33 kg) while they nurse. While the pup is still nursing, the mother is very active and leaves the pup alone for extended periods of time. Pups remain near the area where the mother enters the water. Once the pup is weaned, it is abandoned by its mother and remains alone on the ice as it waits for its silver-gray pelage to grow in so it can go into the water. While the pup waits, it loses up to 50% of its body fat. Pup mortality is 20 to 30%. After about four weeks the pup will become fully independent and forage for its own food.
Their main form of long and short distance communication is underwater calling. Harp seals may use underwater calling to attract mates and to coordinate herds. Besides this, harp seals may use growls, clicks, trills, and other bird-like sounds on land, especially to attract mates or to respond to a predator getting too close to a pup. Harp seal pups make bawling noises when they are hungry, as well as mumbling sounds while playing with each other.
Habitat and Range:
Harp seals are highly migratory and spend a majority of their time in coastal ocean waters near pack ice. When harp seals are on land, they prefer rough ice that is at least 9.8 in (25 cm) thick.
As of late, harp seals have been classified as a species of least concern. Nonetheless, they are still threatened by environmental contaminants (such as oil from spills), overfishing (of their essential prey), overhunting (for their fur when young), and global warming.