These large seals inhabit remote islands and shoals on both sides of the
northern Atlantic. In North America most live along the Canadian Maritime
provinces, although smaller numbers are found along the shores of New
England. Their distinctive long nose has earned them the name of "horsehead."
Their scientific name means "hook-nosed pig of the sea." Grey seals
have color patterns that are similar to, but bolder than those of harbor
seals.
Grey seals are sexually dimorphic in size. Males grow to 8 feet
and weigh about 800 pounds, while females are smaller, growing to 7 feet and
weighing about 400 pounds. Female grey seals are estimated to live to at
least their mid 30's. Males are estimated to reach only their mid 20's,
which may be a result of the fierce competition between males for mating
rights with the females. The mating system for grey seals is
polygynous (poly = many; gyny = female), in which males mate
with many different females. Mating occurs on land and at
sea. The nearest grey seal pupping area is in
Nantucket Sound, on Muskeget Island, west of
Nantucket Island.
Breeding takes place on rocky or sandy islands or land fast
ice after pups are weaned. Newborn pups averaging 3 feet and weighing
about 35 pounds are born in January and February. Pups are born with a
creamy white coat called lanugo ( a reminder of their ancestral
association with ice), which is shed shortly before the mother leaves them
at about 3 weeks of age. Unlike the harbor seal, grey seal pups are rather
helpless, staying on land in the birth area while the mother attends to
them. The mother will leave the pup to feed, and upon return will
recognize her offspring by its unique smell. Mothers are fiercely
protective of their young.
