Hooded Seal

Hooded Seal

Scientific Classification

Common Name
hooded seal
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Pinnipedia
Family
Phocidae
Genus Species
Cystophora cristata

Fast Facts

Description
Hooded seals have a light gray to blue-gray coloration with irregularly shaped light or dark blotches.
Male: Males exhibit a characteristic enlarged nasal cavity (hood) which is inflated for display during courtship and as an aggressive posture for defense.
Size
Male: 2.74 to 3.04 m (9 to 10 ft.)
Female: 1.83 to 2.14 m (6 to 7 ft.)
Weight
Male:  408 kg (900 lbs.)
Female: 317 kg (700 lbs.)
Diet
Hooded seals feed on squid, starfish and mussels. They also eat several types of fish including Greenland halibut, redfish, Atlantic cod, Arctic Cod, capelin and herring.
Gestation
11.5 months with a delayed implantation of up to 3.7 months: pups are born at approximately 1 m (3 ft. 3 in.) in length and 24 kg (52 lbs.).
Estral Period
Typically at the end of lactation
Nursing Duration
Hooded seals have the shortest lactation period of any mammal, with most pups nursing for only 4 days. Pups weigh an average of 48 kg (105 lbs.) at weaning, and on average double their birth mass in the short nursing period.
Sexual Maturity
Male:  4 to 6 years
Female: 2 to 9 years
Life Span
25 to 35 years
Range
Hooded Seals are found at high latitudes in the North Atlantic, and seasonally they extend their range north into the Arctic Ocean. They breed on pack ice and are associated with it much of the year, though they can spend significant periods of time pelagic, without hauling out. Found primarily in Canada; Greenland; Iceland; Norway. Small numbers of individuals are increasingly seen along the Atlantic coast from Maine to Florida. Individuals (usually juveniles) have been found as far south as the Virgin Islands and Puerto Rico.
Habitat
Gather in large numbers on ice floes to breed. Feed in deep, pelagic waters.
Population
Global: Although there is no reliable, current estimate for hooded seal abundance, the population is thought to be relatively large, numbering some few hundreds of thousands. All populations appear to be declining.

Based on population size, geographic range, habitat specificity, diet diversity, migration, site fidelity, sensitivity to changes in sea ice, sensitivity to changes in the trophic web, and maximum population growth potential, Hooded Seals are rated to be among the top three arctic marine mammal species in terms of sensitivity to climate change.
Status 
IUCN: Vulnerable
CITES: Not listed
USFWS: Not listed

Fun Facts

  1. Hooded seals belong to the scientific order Pinnipedia, which includes seals, sea lions, and walruses.
  2. Seals differ from sea lions in a number of ways, including having shorter, stouter flippers, and no visible earflaps.
  3. Hooded seals are named for the bi-lobed hood, an enlargement of the nasal cavity on the heads of males. The male can inflate the hood and move air back and forth between the two lobes. In addition, the male can also inflate a bright, red, membranous "balloon" that usually originates from the left nostril. The inflated hood and balloon are often used in visual displays for courtship, for dominance, and as a threat.

Ecology and Conservation

As for other marine mammals, the U.S. Marine Mammal Protection Act of 1972 protects hooded seals in U.S. waters.

Polar bears and killer whales are known hooded seal predators. These predators are thought to be having increased impacts on hooded seals in the West Ice following the deterioration of breeding ice used by this species; Greenland sharks also take at least young hooded seals. Greenland sharks also take at least young hooded seals.

Hooded seals have been hunted throughout their range for their oil, meat and skins, especially the thick pelts of newborn seals (called bluebacks). Because of bans in the U.S. and Europe, the market for pelts is currently poor, which reduces hunting pressure on pups.

In Canada, hooded seals are federally managed by Fisheries and Oceans Canada. This protection provides annual hunting quotas for hooded seal populations, prohibits the hunting of pups (bluebacks), and prohibits the hunting of adults when they are on the breeding grounds.


Bibliography

Bonner, N. Seals and Sea Lions of the World. New York. Facts on File, Inc. 2004.

Byrum, J. Pinnipeds From Pole to Pole: Seals, Sea Lions and Walruses. SeaWorld Education Department Publication. San Diego. SeaWorld, Inc. 2000.

Jefferson, T.J. Leatherwood, S. and M.A. Webber. FAO Species Identification Guide. Marine Mammals of the World. Rome. FAO, 1993.

Nowak, Ronald M. (ed.). Walker's Marine Mammals of the World. Baltimore: Johns Hopkins University Press, 2003.

Parker, S. (ed.). Grizmek's Encyclopedia of Mammals. Vol. IV. New York: McGraw-Hill Publishing Co., 1990.

Reeves, R. R., Stewart, B.S., Clapman, P.J., and J.A. Powell (Peter Folkens illustrator). National Audubon Society: Guide to Marine Mammals of the World. New York: Random House, 2002.

Reeves, R.R., Stewart, B.S. and S. Stephen. The Sierra Club Handbook of Seals and Sirenians. San Francisco: Sierra Club Books, 1992.

Ridgway, S.H. and R.J. Harrison (Eds). Handbook of Marine Mammals: Volume 2: Seals. London. Academic Press, 1981.

Riedman, M. The Pinnipeds: Seals, Sea Lions and Walruses. Berkeley and Los Angeles. University of California Press. 1990.

Fisheries and Oceans Canada
http://www.dfo-mpo.gc.ca/seal-phoque/facts-faits/facts-faits2004_e.htm

Kovacs, K.M. 2016. Cystophora cristata. The IUCN Red List of Threatened Species 2016: e.T6204A45225150. http://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T6204A45225150.en/. Downloaded on 25 September 2018.

NOAA Fisheries – Hooded Seal Species Profile. https://www.fisheries.noaa.gov/species/hooded-seal/. Downloaded on 25 September 2018.