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Common Seal

Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Suborder: Pinnipedia
Family: Phocidae
Genus: Phoca
Species: P. The conservation status of a Species is an indicator of the likelihood of that species remaining extant either in the present day or the near future Near Threatened ( NT) is a Conservation status assigned to species or lower taxa which may be considered threatened with extinction in the near future although The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List) created in 1963 is the world's most comprehensive inventory of the global Chordates ( Phylum Chordata) are a group of Animals that includes the Vertebrates together with several closely related Invertebrates Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands The diverse order Carnivora (kɑrˈnɪvərə or sometimes /ˌkɑrnɪˈvɔərə/ from Latin carō (stem carn-) "flesh" + vorāre Pinnipeds ("fin-feet" lit "winged feet" or fin-footed mammals are a widely distributed and diverse group of semi-aquatic marine Mammals comprising The true seals or earless seals are one of the three main groups of Mammals within the seal Suborder, Pinnipedia. Phoca is a genus of the earless seals within the Family Phocidae. vitulina
Binomial name
Phoca vitulina
Linnaeus, 1758
Range of Phoca vitulina
Range of Phoca vitulina
This article is about the marine mammal. Carl Linnaeus (Latinized as Carolus Linnaeus, also known after his ennoblement as, May 23 new style (13 May old style 1707 who laid the foundations for Year 1758 ( MDCCLVIII) was a Common year starting on Sunday (link will display the full calendar of the Gregorian calendar (or a Common For the common seal of a company, see company seal. Generally a company is a form of Business organization. The precise definition varies A company seal (sometimes referred to as the corporate seal or common seal) is an official seal used by a company.

The Common Seal (UK, Ireland), Harbor Seal (U.S.) or Harbour Seal (Canada), Phoca vitulina is a true seal found along temperate and Arctic marine coastlines of the Northern hemisphere. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Ireland ( Irish: Éire, ˈeːrʲə is a country in north-western Europe. The United States of America —commonly referred to as the Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page The true seals or earless seals are one of the three main groups of Mammals within the seal Suborder, Pinnipedia. Northern Hemisphere is the half of a Planet that is North of the Equator —the word hemisphere literally means 'half ball' They are found in coastal waters of the northern Atlantic and Pacific Oceans as well as those of the Baltic and North Seas, making them the most wide-ranging of the pinnipeds (walruses, eared seals, and true seals). The Pacific Ocean is the largest of the Earth 's Oceanic divisions The Baltic Sea is a Brackish inland sea located in Northern Europe, from 53°N to 66°N Latitude and from 20°E to 26°E Longitude. The North Sea is a marginal, Epeiric sea of the Atlantic Ocean on the European Continental shelf. Pinnipeds ("fin-feet" lit "winged feet" or fin-footed mammals are a widely distributed and diverse group of semi-aquatic marine Mammals comprising

Common seals are brown, tan, or gray, with distinctive V-shaped nostrils. An adult can attain a length of 1. 85 meters and a mass of 130 kilos. Females outlive males (30-35 years versus 20-25 years). Common seals stick to familiar resting spots, generally rocky areas where land predators can't reach them, near a steady supply of fish to eat. Males fight over mates underwater. Females mate with the strongest males, then bear single pups, which they care for alone. Pups are able to swim and dive within hours of birth, and they grow quickly on their mothers' milk. A fatty tissue called "blubber" keeps them warm

Their global population is 400,000 to 500,000, and subspecies in certain habitats are threatened. Seal hunting, once a common practice, is now mostly illegal.

Contents

Description

Closeup of a Harbour seal
Closeup of a Harbour seal

With each individual possessing a unique pattern of fine, dark spots (or light spots on a dark background in some variants), they vary in colour from brownish black to tan or grey; underparts are generally lighter. The body and flippers are short, with a proportionately large, rounded head. The nostrils appear distinctively V-shaped; as with other true seals, there is no ear flap, or pinna. The pinna ( Latin for Feather) is the visible part of the Ear that resides outside of the head (this may also be referred to as the auricle or A relatively large (for a seal) ear canal may be visible posterior to the eye. Including the head and flippers, they may reach an adult length of 1. 85 metres and a weight of 55 to 168 kg (120 to 370 lbs). [1] Females are generally smaller than males.

Population

With an estimated 400,000 to 500,000 individuals, the population is not threatened as a whole; most subspecies are secure in numbers with the Greenland, Hokkaidō and Baltic Sea populations being exceptions. Greenland (Kalaallit Nunaat meaning "Land of the Greenlanders" Grønland is a self-governing Danish Province located between the WikipediaWikiProject Japanese prefectures for guidelines --> formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan 's The Baltic Sea is a Brackish inland sea located in Northern Europe, from 53°N to 66°N Latitude and from 20°E to 26°E Longitude. Local populations have been reduced or eliminated through outbreaks of disease and conflict with humans, both unintentionally and intentionally. Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus While it is legal to kill seals which are perceived to threaten fisheries in the United Kingdom, Norway and Canada, commercial hunting is illegal; the seals are also taken in subsistence hunting and accidentally as bycatch in fishing nets. For the fishing industry and the practice of fishing see Fishing. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Norway ( Norwegian: Norge ( Bokmål) or Noreg ( Nynorsk) officially the Kingdom of Norway, is a Constitutional Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page In the United States stricter protection applies, and it is illegal to kill any seals oEATS PEOPLEr any marine mammals, as they fall under the Marine Mammal Protection Act. The United States of America —commonly referred to as the Marine mammals are a diverse group of roughly 120 species of Mammal that are primarily Ocean -dwelling or depend on the ocean for food The Marine Mammal Protection Act of 1972 prohibits with certain exceptions the taking of Marine mammals in United States waters and by U On the East Coast of the United States their numbers seem to be increasing quite steadily as they are reclaiming parts of their range, and have been seen as far south as South Carolina. South Carolina ( is a state in the southern region ( Deep South) of the United States of America.

Female common seals have a life span of 30-35 years while male lifespans are usually 20-25. Scientists have suggested that this is due to stresses male seals are subjected to during breeding seasons.

Subspecies

There are four or five subspecies:

Habitat and diet

Common seals at Prins Karls Forland, Svalbard, Norway
Common seals at Prins Karls Forland, Svalbard, Norway

Characterized as showing a strong degree of site fidelity in their choice of resting sites, they may spend several days at sea and travel up to 50 kilometres in search of feeding grounds, and will also swim some distance upstream into freshwater in large rivers. "Riverine" redirects here For the use of that term in Maritime geography, see there Resting sites may be both rugged, rocky coasts such as that of the Hebrides or the shorelines of New England, or sandy beaches. See also Hebrides (disambiguation The Hebrides (ˈhɛbrɨˌdiːz "HEB-ri-deez" Gaelic: Innse Gall) comprise a widespread and diverse History See also History of New England New England's earliest inhabitants were Algonquian -speaking Native Americans including the They also inhabit sandy intertidal zones; some seals may also enter estuaries in pursuit of their fish prey. An estuary is a semi-enclosed Coastal body of Water with one or more Rivers or Streams flowing into it and with a free connection to the open Some have even taken to feeding and playing in New York Harbor and Boston Harbor in recent years. New York Harbor, a geographic term refers collectively to the rivers bays and tidal estuaries near the mouth of the Hudson River in the vicinity of New York City The Port of Boston is a major Seaport located in Boston Harbor and adjacent to the City of Boston. The seals frequently choose to congregate in harbours, lending the animals their other common name. The feeding habits have been studied closely in many parts of their range; they are known to prey primarily upon fish such as menhaden, anchovy, sea bass, herring, cod, whiting and flatfish, and occasionally upon shrimp,mollusks and squid. Fish are aquatic Vertebrate animals that are typically ectothermic (previously Cold-blooded) covered with scales, and equipped with two The anchovies are a family ( Engraulidae) of small common salt-water fish Sea bass refers to many fish species of various families including Black sea bass ( Centropristis striata, in the family Serranidae) Herring are small Oily fish of the genus Clupea found in the shallow temperate waters of the North Atlantic, the Baltic Sea, the North Cod is the common name for the Genus Gadus of Fish, belonging to the family Gadidae, and is also used in the common name of a variety The flatfish are an order ( Pleuronectiformes) of Ray-finned fish, also called the Heterosomata sometimes classified as a suborder of Perciformes True shrimp are swimming decapod Crustaceans classified in the Infraorder Caridea, found widely around the world in both fresh Molluscs are animals belonging to the phylum Mollusca. There are around 250000 extant Species within the phylum with an estimated 70000 Squid are marine Cephalopods of the order Teuthida, which comprises around 300 species They are able to dive for up to ten minutes, reaching depths of 457 metres (approx 1500 feet) or more, but average dives may be three minutes long at depths of about 20 metres (approx 66 feet) {Carl, 1964}. A foot (plural feet or foot; symbol or abbreviation ft or sometimes &prime – the prime symbol) is a non-SI unit

Behavior and reproduction

Common Seal resting on ice
Common Seal resting on ice
A Common Seal colony in Helgoland, Germany
A Common Seal colony in Helgoland, Germany

While not forming groups as large as some other seals, they are gregarious animals. Heligoland (Helgoland Heligolandic: deät Lun) is a small German Archipelago in the North Sea. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. When not actively feeding, the seals will haul themselves out of the water and onto a preferred resting site. The seals tend to hug the coast, not venturing more than 20 kilometres offshore. Both courtship and mating occurs underwater. Courtship is the traditional dating period before engagement and marriage In Biology, mating is the pairing of opposite- Sex or hermaphroditic Organisms for copulation and in Social animals also to raise their The mating system is not known, but thought to be polygamous. The term polygamy (a Greek word meaning "the practice of multiple marriage" is used in related ways in Social anthropology, Sociobiology, and Females are thought to give birth once per year, with a gestation period of eleven months. Gestation is the carrying of an Embryo or Fetus inside a Female Viviparous Animal.

Birthing of pups occurs annually on shore, beginning in February for populations in lower latitudes, and as late as July in the subarctic zone. The mothers are the sole providers of care with lactation lasting four to six weeks; males occupy themselves with fights between other males. Researchers have found that males gather underwater, turn on their backs, put their heads together and vocalise to attract females ready for breeding. The pups are born singly and well developed, capable of swimming and diving within hours. Suckling for three to four weeks, pups feed on the mother's rich, fatty milk and grow rapidly; born weighing up to 16 kilograms, the pups may double their weight by the time of weaning. Weaning is the process of gradually introducing a Mammal Infant, either human or animal to what will be its adult diet and withdrawing the supply of its mother's

Common Seals must spend a great deal of time on shore when moulting (shedding off their fur), which the seals undergo shortly after breeding. In Biology, moulting (or molting, also known as shedding or for some species Ecdysis) signifies the manner in which an animal routinely Fur is a body hair of any non-human Mammal, also known as the Pelage. This onshore time is important to the life cycle and can be disturbed when there is substantial human presence (Sullivan, 1989). A female will mate again immediately following the weaning of her pup. This pinniped is sometimes reluctant to haul out in the presence of humans, so that shoreline development and access must be carefully studied in known locations of seal haul out. Pinnipeds ("fin-feet" lit "winged feet" or fin-footed mammals are a widely distributed and diverse group of semi-aquatic marine Mammals comprising

Physical Characteristics

The physical characteristics of Harbor Seals include their size, body shape, and coloration. Human body shape has sophisticated details and purposes Shape or figure is defined mainly by skeletal structure Muscles and fat The size of male harbor seals can reach about 1. 4 to 2 meters in length with a mass of 70 to 170 kilograms. The size of female harbor seals can reach about 1. 2 to 1. 7 meters in length with a mass of 50 to 150 kilograms. As for the body shape of Harbor Seals, they have a rounded, spindle-shaped body. Human body shape has sophisticated details and purposes Shape or figure is defined mainly by skeletal structure Muscles and fat Also for their physical appearance, coloration varies. Harbor Seals range in color from light gray to silver with dark spots. Others are black or dark gray to even brown with white rings. Spots or rings are visible on the dorsal, or back, surface and much more sparse on the ventral, or underside, surface {Bush Gardens; SeaWorld: Harbor Seals}.

Aspects particular to California

Harbor Seals along 17-Mile Drive
Harbor Seals along 17-Mile Drive

The California population of subspecies richardsi amounted to approximately 25,000 individuals as of the year 1984. Pacific harbor seals or Californian harbor seals are found along the entire Pacific coast shoreline of the state. They prefer to remain relatively close to shore in sub-tidal and intertidal zones, and have not been seen beyond the Channel Islands as a pelagic form; moreover, they will often venture into bays and estuaries and even swim up coastal rivers. The Channel Islands of California are a chain of eight islands located in the Pacific Ocean off the coast of Southern California along the Santa Barbara Channel

Frequently they will haul out in small to medium sized groups onto rock outcrops, mudflats, sandy beaches or even fishing piers. Some of the best locations for viewing Harbor Seals up close are at Children's Pool Beach in La Jolla, Cannery Row in Monterey, Moss Landing on Monterey Bay or at Bolinas Lagoon in Marin County. Children's Pool Beach, or the Casa or Casa beach is a small sandy beach located at 850 Coast Boulevard at the intersection of Jenner Ave in La Jolla, California La Jolla (ləˈhɔɪə "luh-HOY-uh") is a wealthy Seaside resort community of up to 42808 residents within the city of San Diego, California Cannery Row is the waterfront Street in the New Monterey section of Monterey California, the site of a number of now-defunct Sardine canning factories Moss Landing is a Census-designated place (CDP in Monterey County, California, United States. Bolinas Lagoon is a tidal Estuary, approximately in area located at in the West Marin region of Marin County California, United States They feed in shallow littoral waters on herring, flounder, hake, anchovy, codfish and sculpin (Newby, 1978). Littoral refers to the coast of an ocean or sea or to the banks of a river lake or estuary Herring are small Oily fish of the genus Clupea found in the shallow temperate waters of the North Atlantic, the Baltic Sea, the North Flounder (rarely fluke) are Flatfish that live in ocean waters ie The term hake refers to Fish in either of family Gadidae (subfamily Phycinae family Merlucciidae (both The anchovies are a family ( Engraulidae) of small common salt-water fish Cod is the common name for the Genus Gadus of Fish, belonging to the family Gadidae, and is also used in the common name of a variety ( For the American submarines named "Sculpin" go to USS Sculpin) A Sculpin is a Fish that belongs to the Order Scorpaeniformes

In California breeding occurs from March to May, and pupping between April and May depending on local populations. Reproduction is the Biological process by which new individual Organisms are produced There is no indication this species has territorial characteristics in water, and it definitely displays none on land. As top level feeders in the kelp forest, Harbor Seals enhance species diversity and productivity. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales They are preyed upon by the apex predator, the Great white shark. The great white shark, Carcharodon carcharias, also known as white pointer, white shark, or white death, is an exceptionally large lamniform

Considerable scientific inquiry has been carried out by The Marine Mammal Center and other research organizations beginning in the 1980s regarding the incidence and transmission of diseases in Harbor seals in the wild, including analysis of phocine herpesvirus (Goldstein, 2004). The Marine Mammal Center is a private non-profit US organization centered on rescue rehabilitation environmental research and education regarding Marine mammals The Herpesviridae are a large family of DNA viruses that cause diseases in animals including humans In the San Francisco Bay, some harbor seals are fully or partially reddish in color. This may be caused by an accumulation of trace elements such as iron or selenium in the ocean or a change in the hair follicle.

References and external links

References

  1. ^ Kindersley, Dorling (2001,2005). The Herpesviridae are a large family of DNA viruses that cause diseases in animals including humans California ( is a US state on the West Coast of the United States, along the Pacific Ocean. Animal. New York City: DK Publishing. ISBN 0-7894-7764-5.  
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