
Scientific Name: Cystophora cristata
General Description: The hooded seal is also known as the crested seal. Genetic studies have concluded that all the world's hooded seals are the same species, and not individual subspecies specific to different regions. Young hooded seals are known as "bluebacks", and do not shed their first coat until they are about 15 months old. Adults have a face that is darker than the rest of the body, and a bluish-grey coat, lighter on the sides and front, with black, irregular marks scatted over the body.
Size: Bulls typically measure 2.5 m long, with a maximum of 3 m, and weigh about 300 kg, with a maximum of 400 kg. Adult females average 2.2 m in length, with a maximum of 2.4 m, and weigh about 160 kg (maximum 230 kg). Pups are born 100-120 cm long and weighing 10-15 kg.
Longevity: 30-35 years
Range and Habitat: The hooded seal is migratory, found only in the central and western North Atlantic. They are typically wide-ranging loners, regularly crossing vast expanses of the North Atlantic to feed and breed. They move between the Davis Strait in summer and their whelping grounds in late winter. The four main breeding areas are off the coast of Newfoundland and Labrador, of the east coast of Greenland, in the Gulf of St. Lawrence (usually in the vicinity of the Magdalen Islands), and in the Davis Strait.
Individuals have been known to wander large distances, occurring as far west as Alaska and as far south as the Canary Islands and Guadeloupe in the Caribbean.
Diet: Diet varies from one area to the next. Pups feed mainly on capelin, polar cod and amphipods, while fish species commonly consumed by adults include Greenland halibut, redfish, cod, wolffish, capelin and herring. They also eat mussels, starfish, squid, shrimp and octopus.
Predators: Humans, killer whales, polar bears and Greenland sharks.
Population: The total population is estimated at 650,000, with the Jan Mayen population numbering 250,000 and the northwest Atlantic Ocean population 400,000. The population appears to be growing, attributed to the decline of cod stocks off Canada's east coast, and subsequent explosion of other fish species not valued by humans.
Reproduction: Females mature between ages 3 and 6, while males mature from 5 to 7. Pregnancies are timed precisely to coincide with the behaviour of ice flows. Pups are born about 1 m long in mid-March to early April with a well-developed blubber layer and having shed their light grey pre-natal (lanugo) coat. They are weaned on average for just 8 days, and sometimes as short as 4 days, the shortest period of any mammal, during which they double in size from about 24 kg to about 47 kg. They are then abandoned by their mothers. Their coat at birth is a slate blue-grey coat (hence the name "blueback"), with a pale cream color on the belly, which they moult after about 14 months.
After the cows give birth, they are often observed with their pups on ice floes with bulls in attendance, circling the floes and providing protection. However, the bulls are not the fathers of the pups. Bulls circle the new mothers waiting to mate after the pups leave. Once mating is complete, the animals separate forever. In a process called delayed implantation, the cow's body prevents the embryo from developing for 3-4 months to time the birth of its next pup with the cycle of the ice.
IUCN Status: LOWER RISK (LR) - A taxon is Lower Risk when it has been evaluated, does not satisfy the criteria for any of the categories Critically Endangered, Endangered or Vulnerable. Least Concern (lc). Taxa which do not qualify for Conservation Dependent or Near Threatened.