Gray Seal

Halichoerus grypus

Classification

  • Domain Eukarya- The animals in this group have cells that are multicellular. This means they have a nucleus. Some can also be single-celled
  • Kingdom Animalia- This is one of the four kingdoms in domain eukarya. They lack a cell wall, and they are also heterotrophs. This means they can't make their own food.
  • Phylum Chordata- Animals in this group have bilateral symmetry, and a complete digestive system. These animals also have a nervous system ( brain).
  • Subphylum Vertebrata- These animals are vertebrates, this means they have a backbone. Animals in vertebrata also have large digestive glands, liver and a pancreas.
  • Class Mammalia- Can product milk by using a sweat gland called a Mammary gland. They have three middle ear bones and you can characterize them by their teeth.
  • Order Carnivora- Animals in this group have a large fourth upper molar and lower molar, these teeth are made for cutting. Their skulls have a lot of different forms.
  • Family Phocidae-Animals in this group have different sizes and they lack an external ear.
  • Genus Halichoerus- This is the Gray seal
  • Speicies- Halichoerus grypus

General Description

  • Male Length- The length for a male Gray seal is 2.2- 7.5 meters.
  • Female Length- The length of a female can be 1.8- 6 meters.
  • Male Weight- The male weight can be between 220-880 kg.
  • Female Weight- The Female weight can vary between 150-560 kg.
  • Pup weight- The weight for the pup can be 16 kilograms and the weight for an eleven year old Gray Seal is 220 pounds.
  • Color- A gray seal has 3 different colors they can be grey, brown ,and silver. A pup has this creamy white fur and a light stomach for the first three weeks of their life. A male Gray seal has a dark grey color with silver grey dots. The female seal has a silver/grey color with small dark spots. The difference between female and male seals are that the male seals have darker fur with lighter spots, and the female have lighter fur with dark spots.
  • Natural Range- The gray seal usually lives in the Western Atlantic and the eastern Atlantic, sub-arctic waters. This seal also lives in the Baltic Sea.
  • Diet- The Gray seals diet is about about 15 species, so here are the main things they eat. When baby pups first start feeding they start with shrimp and small fish. Then they slowly start eating things like Cod,Salmon,Saithe,Herring,Halibut,Conger eels, Lumpsuckers, Crustaceans, and Mollusks.
  • Habitat Description- These seals Live on rocky continental coasts,icebergs, ice shelves and isolated islands.
  • Predators- The Gray seal has been hunted for more than 10,000 years. Humans used to kill and harvest the seals skin on a big commercial scale. Some other predators are the killer whale and the Atlantic shark species.

Behavioral Adaptations

Gray seals hunt for food underwater then come up out of the water and spend the rest of their time on the coastlines. This is an adaptation because they use this as a method to get food and it's probably something they learn to do on their own. Another adaptation is that seals do not migrate, but they move to a lot of different places after breeding season is over. This is an adaptation because this is something they do every time breeding season ends. Mothers of these seals abandon them at a certain age, and they go hang out by rock pools. The seals teach themselves how to swim and feed themselves before going out to sea. This helps them in a few ways one of them is that they learn how to feed so they won't starve. The second way is that they need to learn how to swim to survive in the ocean. Gray seals are natatorial, which means that they are specialized for swimming, this helps them survive when they are in the enormous ocean. Seals are also solitary, which means they live alone, this is a behavior because they started their life living with their mothers. The seals have to get used to being alone and fending for themselves. Gray seals are nomadic which means they wander from place to place, but they stay between a certain range. Another adaptation for the seal is that they are polygamous, during breeding season the males like to compete with each other on how many females they can mate with. This helps there population grow bigger, and this is something they do regularly during the breeding season and that makes it a behavioral adaptation.

Physical Adaptations

Gray seals have super-sensitive whiskers which let them follow their prey. The animal has a streamlined body. This adaptation helps them glide through the sea. Seals are gregarious, this means they have good eyesight, which will help them see their predators. Another explanation for gregarious is that they have amazing hearing. Which helps them when they are out in the sea, so they can take caution if there is a predator nearby. They also have back flippers which helps the seal propel itself in the water. These animals also have a nose that is specialized to help them breath under water and on land. During the first few weeks of a baby seals life they have a thick white coat ( kind of like a winter coat). This protects them from the cold and helps them keep warm.

Reference

Smith, J. 2008. "Halichoerus grypus" (On-line), Animal Diversity Web. Accessed March 11, 2015 at http://animaldiversity.org/accounts/Halichoerus_grypus/

Gray seal. (n.d.). Retrieved from windscreen archive website: http://www.arkive.org/grey-seal-(eastern-atlantic-population)/halichoerus-grypus/image-A4335.html

Burton, M., & Burton, R. (2002). Gray seal. In International wildlife encyclopedia v.1 (AAR-BAR) (3rd ed., Vol. 8, pp. 1049-1051). New York, NY: Marshall Cavendish

Lechner, D. M. E. (1995). Gray seal. In Amazing animals around the world (Vol. 11, pp. 32-33). Grolier Educational.

Thompson, D. & Härkönen, T. (IUCN SSC Pinniped Specialist Group) 2008. Halichoerus grypus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 16 March 2015.

Grey seal. (2014). Retrieved March 17, 2015, from BBC nature website: http://www.bbc.co.uk/nature/life/Gray_Seal

Grey seal. (n.d.). Retrieved March 17, 2015, from Brookfield Zoo website: http://www.czs.org/Brookfield-ZOO/Zoo-Animals/Pinniped-Point/Grey-Seal

Encyclopedia of Life. Available from http://www.eol.org. Accessed 15 Jan 2014.

Bonner, W. N. (1990). The natural history of seals. New York, NY: Facts on File.