Pagophilus groenlandicus

Geographic Range

Harp seals are found in the Arctic and northern Atlantic Oceans. Their range extends east from around Baffin Island and Hudson Bay to Cape Chelyuskin in northern Russia. Pagophilus groenlandicus is native to Canada, Greenland, Iceland, Norway, Russia, Svalbard ,Jan Mayen, and the United States. Stray harp seals have been found in Denmark, the Faroe Islands, Finland, France, Germany, Spain, and the United Kingdom. Of the pinnipeds ( walruses , seals , fur seals and sea lions ) in the northern hemisphere, harp seals are the most abundant.

There are three main populations of harp seals, each of which has its own migratory route. The northwest Atlantic population, which breeds and molts in the Gulf of St. Lawrence, Labrador, and Newfoundland, travels to Hudson Bay, off the coast of Baffin Island, northwestern Greenland and northern Labrador to feed in early summer. The group that breeds in Jan Mayen spends its summers between Svalbard and Greenland. The population which breeds in the White Sea travels north to the Cara and Barents Seas for the summer. In September, all three of the groups begin to travel south again toward their breeding grounds. They will arrive in their respective breeding grounds in January or February. Some of the juvenile and non-breeding harp seals may remain in the northern feeding areas year round.

• Biogeographic Regions
• nearctic nearctic
  • native native
• palearctic palearctic
  • native native
• arctic ocean arctic ocean
  • native native
• atlantic ocean atlantic ocean
  • native native

• Other Geographic Terms
• holarctic holarctic

Habitat

Harp seals spend the majority of their time in coastal ocean waters near pack ice. Harp seals forage for food at depths of 150 to 200 m. When harp seals are on land, they prefer rough ice that is at least 0.25 meters thick. Harp seals brave open ocean waters when they migrate.

• Habitat Regions
• polar polar
• saltwater or marine saltwater or marine

• Terrestrial Biomes
• icecap

• Aquatic Biomes
• coastal coastal

Physical Description

Harp seals boast a wide range of pelages through their development. Harp seal pups are born with a white coat of embryonic fur or lanugo, which gives them the name “whitecoats.” Some pups’ fur may be dyed yellow at birth by amniotic fluid, but it fades to white after a few days. About 21 to 22 days later, pups begin to lose their white fur in tufts, creating a “jagged coat.” The lanugo is replaced by a silver-white coat with irregular black spots, which the juvenile seal or “beater” retains for a year. After 12 to 14 months the blacks spots grow larger and the seal is called a “bedlamer.” The seal remains a bedlamer until it reaches sexual maturity. When the seal reaches sexual maturity (around 5.5 years old), the blacks spots converge into a “harp” shaped design, which is composed of two black lines that run up the dorsal side of the seal’s flanks, starting at their pelvis and curving and converging between the shoulders. Also, adult harp seals develop a black head and may have black markings where the hind flippers meet the body of the seal. Some harp seals retain their spotted pelage (“spotted harps”). Of the seals that retain their spots, some have dark gray streaks, creating a completely gray pelage (“sooty harps”). The harp-shaped design on the backs of adults, along with the black head and sliver-white fur, helps Pagophilus groenlandicus stand out from the other members of Phocidae that share its habitat.

Harp seals are sexually dimorphic in size and pelage. Male harp seals weigh an average of 135 kg and are 171 to 190 cm long. Females weigh an average of 120 kg and are 168 to 183 cm long. Besides being larger than females, male harp seals tend to have a more-defined “harp” pattern and black head than females.

Adult harp seals have fairly small hind flippers and the fore flippers are pointed with short digit tips that boast large claws. Their heads are flat and wide and they tend to have a fairly long, but tapered snout.

The dental formula of Pagophilus groenlandicus is 3/2 incisors, 1/1 canines, and 5/5 post-canines.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry
• polymorphic polymorphic

• Sexual Dimorphism
• male larger
• male more colorful

Reproduction

Harp seals gather together at their breeding grounds in the winter. At the breeding grounds, there may be up to 2,000 seals per square kilometer. The mating system of harp seals is much disputed and they been described as monogamous, polygynous, and polyandrous. To attract females, some male seals blow bubbles and make noises beneath the ice near where females have made entry holes into the water. Males also may chase females or making pawing gestures towards them. To compete for females, male harp seals may splash and bite other males. Research has suggested that female harp seals may also choose their mates based upon the size of their baculum.

• Mating System
• monogamous monogamous
• polygynous polygynous
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Both male and female harp seals reach sexual maturity at around 5.5 years old, though they both don’t tend to copulate regularly until a few years later. The average reproducing age for females is 10 years old. Males don't successfully compete for breeding opportunities until they are 8 years old. Harp seals remain sexually active for the rest of their lives.

Harp seals breed 10 to 12 days following the birth of their pups. Females enter estrus and breed near the end of lactation. The gestation period is divided into four months of delayed implantation and 7.5 months of active gestation. Birthing of harp seal pups occurs from late February to April. Females give birth on the ice near open water. Harp seals birth one pup at a time, they are nursed and cared for by their mother for 10 to 12 days. The mother’s milk is 48% fat and the pups gain an average of 33 kg while they nurse. Once the pup is weaned it is abandoned by its mother and remains alone on the ice as it waits for its silver-gray pelage to grow in so it can go into the water. While the pup waits, it loses up to 50% of its body fat. Pup mortality is 20 to 30%.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous
• delayed implantation delayed implantation
• post-partum estrous

Female harp seals are the sole providers of care to their pup. Mothers nurse their pups for 10 to 12 days. While the pup is still nursing, the mother is very active and leaves the pup alone for extended periods of time. Pups remain near the area where the mother enters the water. Once the pup is weaned, it is left alone on the ice while it sheds its white coat and develops a silver-gray pelage. After about four weeks the pup will become fully independent and forage for its own food.

• Parental Investment
• precocial precocial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

Harp seals live 20 to 35 years in the wild. There is very little information on the lifespans of harp seals in captivity.

Behavior

Harp seals may travel up 5000 km in a year. The migratory patterns of Pagophilus groenlandicus depend on where the seal population breeds and molts. Harp seals breed (February to April) on the southern edge of their range in the winter and molt (April to May) nearby in the spring. After molting, harp seals migrate to the northern end of their range for the summer. Harp seals begin their journey back to their breeding grounds in September.

Though harp seals come together during their breeding season and when molting, they tend to spend the rest of their time as solitary creatures. No social system or hierarchy has been identified within populations of harp seals.

Harp seals spend most of their time in the open waters, but come out of the water on a regular basis (called “haul out”) to spend some time on land. Seals tend to haul out at night. The two longest haul outs take place during the breeding season and when it is time to molt. If extended amounts of time are spent on the ice, harp seals make holes in the ice (60 to 90 cm in diameter) for easy access to water and to breathe when swimming under the ice.

• Key Behaviors
• natatorial natatorial
• motile motile
• migratory migratory
• solitary solitary

Home Range

Because harp seals travel extensively to forage and have vast home ranges, there is little information regarding the size of their home ranges.

Communication and Perception

The main form of long and short distance communication for Pagophilus groenlandicus is underwater calling. Research suggests that harp seals actually listen to individual calls and respond with a specific response, rather than making random sounds. By actually listening to calls, seals can avoid masking other seals' calls. Harp seals may use underwater calling to attract mates and to coordinate herds.

Besides underwater calling, harp seals may use clicks, trills, and other chirp-like sounds on land, especially to attract mates or to respond to a predator getting too close to a pup. Terrestrial communication is quite uncommon.

Harp seals have acute vision and hearing, which is incredibly strong underwater, but a very poor sense of smell.

• Communication Channels
• visual visual
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Harp seals are primarily piscivores that eat up to 67 species of fish and 70 species of marine invertebrates. Fish and invertebrates consumed by harp seals varies with their location and the season. Some of the main fish that make up their diet are capelin , Arctic cod , and polar cod . Pups tend to mainly feed on small invertebrates.

Harp seals may dive to extreme depths to capture food. The average diving depth for harp seals is 150 to 200 m and the dives typically last 4 to 13 minutes.

• Primary Diet
• carnivore carnivore
  • piscivore piscivore
  • eats non-insect arthropods

• Animal Foods
• fish
• aquatic crustaceans

Predation

The main predators of harp seals are polar bears , killer whales , Greenland sharks , and walruses . Humans also kill harp seals for food, fur, and oil.

Though harp seals tend not to be very vocal on land, females may make a shrill call if a predator comes near her pup.

Ecosystem Roles

Harp seals are piscivores and consume large amounts of fish and crustaceans in their environment. Harp seals are also food for many predators in the Arctic region.

Harp seals are carriers of the Phocine distemper virus (PDV). PDV does not have any affect on harp seals, but they may have passed the virus onto harbor seals , ignighting a huge epidemic in Europe in 1988.

Economic Importance for Humans: Positive

Harp seals provide meat for some native Arctic peoples. Historically, harp seal fur, oil, and meat were incredibly important to humans. Currently, demand for harp seal products has dropped off considerably due to import regulations.

Harp seals have also become an important part of the tourist industry in Canada, where tourists can visit harp seal whelping sites.

• Positive Impacts
• body parts are source of valuable material
• ecotourism ecotourism

Economic Importance for Humans: Negative

Harp seals have been blamed for the decline of certain fish populations, which has an affect on the fishing industry. To try to control the decline of certain fish populations, the fishing industry continues to fight to increase the amount of seals allowed to be slaughtered each year.

Conservation Status

Due to limitations on slaughter and the involvement of conservation groups, harp seals not a threatened species and their numbers have actually begun to increase over the last few years. They are listed as "least concern" on the IUCN Red List.

Other Comments

There are two sub-species of Pagophilus groenlandicus , Pagophilus groenlandicus oceanicus and Pagophilus groenlandicus groenlandicus . Pagophilus groenlandicus oceanicus breeds in the White Sea and Pagophilus groenlandicus groenlandicus breeds in the western Atlantic Ocean off of North America and the coast of Jan Mayen in the Greenland Sea. Though the two subspecies do not seem to interbreed, they have no differences in morphology or protein polymorphisms.

Pagophilus groenlandicus was formerly known as Phoca groenlandica .

Additional Links

Encyclopedia of Life

Contributors

Alison McKenna (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor, Tanya Dewey (editor), Animal Diversity Web.

References

Jefferson, T., S. Leatherwood, M. Webber. 1994. Marine Mammals of the World . Rome: United Nations Environment Program and Food and Agriculture Organization of the United Nations.

Kovacs, K. 2008. "Pagophilus groenlandicus" (On-line). The IUCN Red List of Threatened Species. Accessed April 05, 2009 at http://www.iucnredlist.org/ .

Kovacs, K. 1995. Harp and hooded seals - a case study in the determinants of mating systems in pinnipeds. International Symposium on the Biology of Marine Mammals in the North East Atlantic, Developments in Marine Biology 4: 329-335.

Miller, E., L. Burton. 2000. "It's all relative: allometry and variation in the baculum (os penis) of the harp seal, Pagophilus groenlandicus (Carnivora: Phocidae)" (On-line pdf). Wiley Interscience. Accessed April 09, 2009 at http://www3.interscience.wiley.com.proxy.lib.umich.edu/cgi-bin/fulltext/118995635/PDFSTART .

Moulton, V., E. Miller, H. Ochoa-Acuña. 1999. "Haulout behaviour of captive harp seals (Pagophilus groenlandicus): incidence, seasonality, and relationships to weather" (On-line pdf). Accessed April 09, 2009 at http://www.sciencedirect.com.proxy.lib.umich.edu/science?_ob=ArticleURL&_udi=B6T48-3Y6GVP3-5&_user=99318&_coverDate=01%2F31%2F2000&_rdoc=5&_fmt=high&_orig=browse&_srch=doc-info(%23toc%234968%232000%23999349995%23149388%23FLA%23display%23Volume)&_cdi=4968&_sort=d&_docanchor=&_ct=6&_acct=C000007678&_version=1&_urlVersion=0&_userid=99318&md5=6d15c5a11b550334f43d5d6f3caf7c8e .

Novak, R. 1999. Pagophilus groenlandicus. Pp. 887-888 in Walker’s Mammals of the World , Vol. Volume II, Sixth Edition. Baltimore: The Johns Hopkins University Press.

Schliemann, H. 1990. Pagophilus groenlandicus. Pp. 221-224 in Grzimek’s Encyclopedia of Mammals , Vol. Volume 4, First Edition. New York: McGraw-Hill, Inc.

Serrano, A., J. Terhune. 2002. "Antimasking aspects of harp seal (Pagophilus groenlandicus) underwater vocalizations" (On-line pdf). Accessed April 08, 2009 at http://scitation.aip.org.proxy.lib.umich.edu/getpdf/servlet/GetPDFServlet?filetype=pdf&id=JASMAN000112000006003083000001&idtype=cvips&prog=normal .

2004. Harp Seals. Pp. 429-430 in Grzimek’s Animal Life Encyclopedia , Vol. Volume 14: Mammals III, Second Edition. Farmington Hills, MI: Gale Group, Inc.

2008. "Pagophilus groenlandicus" (On-line). OBIS Seamap. Accessed April 09, 2009 at http://seamap.env.duke.edu/species/tsn/622022 .

MarineBio.org. 2009. "Pagophilus groenlandicus: Harp Seal" (On-line). MarineBio. Accessed April 05, 2009 at http://marinebio.org/species.asp?id=302 .