Bearded Seal

From Wikipedia, the free encyclopedia

Bearded Seal[1]

Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Phocidae
Genus: Erignathus
Gill, 1866
Species: E. barbatus
Binomial name
Erignathus barbatus
Erxleben, 1777
Distribution of Bearded Seal
Distribution of Bearded Seal
Bearded Seal pup
Bearded Seal pup

The Bearded Seal (Erignathus barbatus), also called the Square Flipper Seal, is a medium-sized pinniped that is found in and near to the Arctic Ocean. It gets its generic name from two Greek words (eri and gnathos) that refer to its heavy jaw. The other part of its Linnean name means bearded and refers to its most characteristic feature, the conspicuous and very abundant whiskers. When dry, these whiskers curl very elegantly, giving the bearded seal a raffish look. Distinguishing features of this earless seal include square fore flippers and thick bristles on its muzzle. Adults are greyish-brown in colour, darker on the back, rarely with a few faint spots on the back or dark spots on the flanks. Occasionally the face and neck are reddish-brown. Bearded Seal pups are born with a greyish-brown natal fur with scattered patches of white on the back and head. The Bearded Seal is unique in the subfamily Phocinae in having two pairs of nipples, a feature it shares with monk seals.

The Bearded Seal reaches about 2.25 m (7.4 ft) to 2.7 m (8.9 ft) in nose-to-tail length and from 275 kg (606 lb) to 340 kg (750 lb) in weight. Both genders are about the same size.

The Bearded Seal is a primary food source for the Polar Bear and for the Inuit of the arctic coast. The Inuktitut name for the seal is Ugyuk or Oogrook. The seal's skin is used to cover a wooden frame boat (Umiak).

The body fat content of a Bearded Seal is 30-40%.

Contents

[edit] Hunting and Diet

Primarily benthic, the Bearded Seal feeds on a variety of small prey found along the ocean floor, including clams, squid, and fish. Its whiskers serve as feelers in the soft bottom sediments. Adults tend not to dive very deep, favoring shallow coastal areas no more than 300 m (984 ft) deep. Pups up to one year old, however, will venture much deeper, diving as deep as 450 m (1,476 ft).

[edit] Reproduction and Lifecycle

The Bearded Seal gives birth in the spring. In the Canadian Arctic, peal pupping occurs in May. Further south, in Alaska, most pups are born in late April. Pups are born on small drifting ice floes in shallow waters, usually weighing around 30-40 kg. They enter the water only hours after they are born, and quickly become proficient divers. Mothers care for the pups for 18-24 days, during which time the pups grow at an average rate of 3.3 kg per day. During this time, pups consume an average of eight liters of milk a day. By the time they are weaned, the pups have grown to about one hundred kilograms.

Just before the pups are weaned, a new mating cycle takes place. Females ovulate at the end of their lactation period, but remain close to their pups, ready to defend them if necessary. During the mating season, male seals will "sing," emitting a long drawn out warbling note that ends in a sort of moan or sigh. This sound may attract females, or may be used by the males to proclaim their territory or their readiness for breeding. Males occupy the same areas from one year to the next.[3]

Like many Arctic mammals, the Bearded Seal employs a reproductive strategy known as delayed implantation. This means that the blastocyst is not implanted for two months after fertilization, most often becoming implanted in July. Thus, the seal's total gestation period is around eleven months, though its active gestation period is nine months.[4]

Bearded Seal on ice, Svalbard
Bearded Seal on ice, Svalbard

[edit] Subspecies

There are two recognized subspecies of this seal:[1]

  • Erignathus barbatus barbatus
  • Erignathus barbatus nautica

[edit] References

  1. ^ a b Wozencraft, W. C. (16 November 2005). in Wilson, D. E., and Reeder, D. M. (eds): Mammal Species of the World, 3rd edition, Johns Hopkins University Press. ISBN 0-801-88221-4. 
  2. ^ Seal Specialist Group (1996). Erignathus barbatus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 12 May 2006.
  3. ^ Nuttal, et al. (2005). Encyclopedia of the Arctic. New York, NY: Routlelege. 
  4. ^ Perry, Judith E. (1983). Seals of the World. Ithaca, NY: Comstock Publishing Associates, p.103. 
 This article about a carnivore is a stub. You can help Wikipedia by expanding it.