| ||||||
| ||||||
Phoca vitulina Linnaeus, 1758Harbor Seal; Phoca |
|---|
| Links |
We parsed the following live from the Web into this page. Such content is managed by its original site and not cached on Discover Life. Please send feedback and corrections directly to the source. See original regarding copyrights and terms of use. |
| Names | |
| |
| Following modified from North American Mammals, Smithsonian Instiution |
| |||||||||||||||||||||||||||||||||||||||||||||||||||||
| Following modified from Animal Diversity |
Home
Phoca vitulina
|
|
|
|
|
|
By Matthew Steinway
Phoca vitulina is the most widely distributed pinniped. This species is found in temperate, subarctic, and arctic coastal areas on both sides of the North Atlantic and North Pacific oceans. Five separate subspecies have been identified, each common to a specific coastal region.
Biogeographic Regions:
nearctic
(
native
);
palearctic
(
native
);
atlantic ocean
(
native
);
pacific ocean
(
native
).
Other Geographic Terms:
holarctic
.
Harbor seals bask and sleep on coastal islands, ledges, and beaches and sandbars that are uncovered at low tide. They stay close enough to water to facilitate feeding and mating.
These animals are found in the following types of habitat:
temperate
;
saltwater or marine
.
Aquatic Biomes:
coastal
.
Harbor seals can be up to 6 feet long and weigh up to 375 pounds, males characteristically being slightly larger than females. The rounded, fusiform body is covered by a coat made of thick, short hairs that range from nearly white with dark spots to black or dark brown with white rings. The dorsal surface is usually more densely covered with spots or rings than the ventral surface.
The limbs of the harbor seal have been modified into flippers. The foreflippers (pectoral flippers) are composed of 5 digits of similar length and webbed together. Claws on the foreflippers are used for scratching, grooming, and defense. The hind flippers also have 5 digits; however, the first and fifth digits are long and stout, while the middle digits are shorter and thinner. The hind flippers propel the seal forward by moving side to side. On land, the harbor seal moves by undulating in a caterpillar-like motion.
Some key physical features:
endothermic
;
bilateral symmetry
.
Sexual dimorphism:
male larger.
Pre-mating behavior is exhibited by both males and females, such as rolling, bubble-blowing, and mouthing each other's necks. This behavior ends once mating begins. Males initiate behavior by chasing, playfully biting, and embracing females. Females respond, and the act of copulation usually takes place in the water. One male may mate with multiple females. Harbor seals return to the same breeding grounds every year.
Mating systems:
polygynous
.
It is believed that males become sexually mature once a weight of around 75 kg is achieved; females mature at about 50 kg. This occurs between 3 and 7 years of age for males and at 2 to 6 years for females. While the mating season varies between the different subspecies, it generally occurs from late spring through fall. About 6 weeks after they give birth to their previous year's pups, the females come into estrus. The gestation period lasts between 9 and 11 months, and usually only 1 pup is born each year.
Key reproductive features:
iteroparous
;
seasonal breeding
; gonochoric/gonochoristic/dioecious (sexes separate);
sexual
;
viviparous
;
delayed implantation
.
Harbor seals are usually solitary animals, with reproduction and "haul outs" being the only exceptions. Seals "haul out" onto land for various reasons including resting, thermoregulating, giving birth, nursing, molting, and facilitating digestion. Another possible reason for haul outs is protection from predators by being in a group. During haul outs, adult individuals do not make physical contact with each other and respond to touching angrily. Younger seals interact with each other along the edges of the group and stay away from the adults.
Aggression is shown by growling, snorting, threateningly waving a foreflipper, and head-thrusting, which is a sharp, rapid retraction of the neck. Vocalization occurs only when they feel threatened.
Key behaviors:
natatorial
;
motile
;
nomadic
;
solitary
.
The diet varies with the season and region. Their food consists of crustaceans, mollusks, squid, and a variety of fish. Harbor seals do not chew their food; they either tear it into chunks or swallow it whole. Their molars allow them to crush hard objects like shells and crustaceans. Adults consume around 4.5 to 8.2 kg of food per day, which is 5-6% of their body weight.
Primary Diet:
carnivore
(
piscivore
, eats non-insect arthropods,
molluscivore
).
Animal Foods:
fish; mollusks; aquatic crustaceans.
Harbor seals are eaten by great white sharks and killer whales.
Harbor seals often interfere with commercial fisheries, eating the fish that have been caught in nets and becoming trapped in the nets themselves.
Harbor seals are hunted primarily for their skins, oil, and meat. They can also be used in the production of jewelry and trinkets and as meat for mink feeding. Phoca vitulina can also serve as tourist attractions at aquariums and can be used in experimental research.
Ways that people benefit from these animals:
food
; body parts are source of valuable material;
ecotourism
.
IUCN Red List:
[link]
:
Lower Risk - Least Concern.
US Federal List:
[link]
:
No special status.
CITES:
[link]
:
No special status.
The U.S. Marine Mammal Protection Act of 1972 made it illegal to hunt or harass any marine mammal in U.S. waters. In Canada, Norway, and the United Kingdom, it is legal to shoot harbor seals to protect fisheries or fish farms. Many fish species eaten by harbor seals are also commercially fished, and the seals often become entangled and drown in fishing nets and gear.
The 5 subspecies and there habitats are: eastern Atlantic harbor seal ( P. v. vitulina ); western Atlantic harbor seal ( P. v. concolor ); eastern Pacific harbor seal ( P. v. richardsi ); western Pacific harbor seal ( P. v. stejnegeri ); and Ungava seal ( P. v. mellonae ).
Find Phoca vitulina information at
Matthew Steinway (author), University of Michigan.
Phil Myers (editor), Museum of Zoology, University of Michigan.
To cite this page: Steinway, M. 2003. "Phoca vitulina" (On-line), Animal Diversity Web. Accessed February 09, 2010 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Phoca_vitulina.html.
Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students . ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.
Other formats: OWL
| Home ¦ About Us ¦ Special Topics ¦ Teaching ¦ About Animal Names ¦ Help |
Structured Inquiry Search — preview |
Sponsored in part by the Interagency Education Research Initiative,
the Homeland Foundation and the
University of Michigan
Â
Museum of Zoology
.
This material is based upon work supported by the
National Science Foundation
under Grants DUE-0633095 and DRL-0628151.
The ADW Team gratefully acknowledges their support.
Report Error
—
Comment
©1995-2008, The Regents of the University of Michigan and its licensors.
All rights reserved.
| Following served from Wildlife |
| Following served from Terrambiente |
| Following modified from Cresli |
| |||||||||||||||||||||||||||||
| Following modified from CalPhotos |
| |||||||||||||||||||||||||||||||||||
| Following modified from CalPhotos |
| |||||||||||
| Discover Life | Top |
| © Designed by The Polistes Corporation |
he waters nearby. Usually wary of humans, they are known to follow fishing boats, feeding on the scraps thrown overboard and occasionally harbor seals will haul out on someone's dock or even in their boat.
Male harbor seals generally grow to 5 - 5 ½ feet in length, weighing 200 - 250 pounds, while the smaller females reach approximately 4 ½ to 5 feet, weighing 150 - 200 pounds. Harbor seals are thought to live to at least 25 years. Males mature at 4 - 6 years, females earlier. Pups, weighing 12 -20 pounds and measuring about 2 ½ feet, are born in the spring. Unlike many other seal pups, harbor seals are able to swim from birth, although they are dependent on care and milk from the mother for 3 - 6 weeks before they venture out on their own. While tending their young, harbor seal mothers are very protective and will sometimes push the pup beneath the surface or carry it on her shoulders to avoid danger. 
