University of Miami Rosenstiel School of Marine and Atmospheric Science
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Seal Information

Seals are semi-aquatic mammals belonging to the Pinnipedia family.  With more than 33 different species, these carnivorous pinnipeds include walruses, eared seals such as sea lions and furred seals, and earless seals such as elephant seals.  While seals may differ in size and color, all seals have a streamlined body with four fins that are modified as flippers.  These flippers serve both for swift swimming and crawling along on land, though some species of seal have more mobility on land than others.  Seals can swim up to 27 miles per hour in the water.  The diet of a seal usually consists of fish, squid, and crustaceans, with only the larger species of seals capable of feasting on larger prey such as sea birds, and even penguins in the case of leopard seals.  Seals spend half of their time in usually coastal waters, and the other half on land along rocky shorelines.  This dual habitation is beneficial when avoiding certain major predators such as killer whales and sharks.  Polar bears and humans are also known to consume or hunt seals though, and may pursue from either the land or the sea.

The land time for seals is reserved especially for times of rest, sunbathing, breeding, birthing, and molting old skin and fur off.  Seals will generally live in herds on the shore, with males that compete with one another during the mating season for the right to mate with most or all of the females in a territory.  The females will reach sexual maturity Picture1between 3-5 years.  Gestation for seals takes between 11-12 months with most births occurring in the warmer spring and summer months, and only one seal pup is born at a time to a mother.  These seal pups may not survive if they become separated from their mother early on, or become trampled by the more aggressive male seals.  Those that do survive will be capable of learning to swim within just six hours of being born and may only require to breast-feed off their mother for a month.  The lifespan of a seal can be anywhere between 15-25 years, with a few that have even been known to make it to 40 years of age.

While a larger prey animal, the seal is a favored food source by many predators.  This coupled with the fact that seals only give birth to one pup per year, pups don’t always survive, and a female will need at least three years to reach sexual maturity, makes the seal species prone to being threatened.  Several laws prohibit the killing of certain seal species when their blubber and oil have become an unfortunate commodity.