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Odobenus rosmarus

Walrus

Order: Carnivora
Family: Odobenidae

Click to see adaptations.   
Image of Odobenus rosmarus
Odobenus rosmarus - Pacific male (left) and female (right) on ice floe; Atlantic male (smaller, smoother skin) in water (far right); males fighting (upper left)
Click to enlarge. (78 kb)

Conservation Status: Data Deficient.


Both male and female walruses have tusks, upper canine teeth that continue to grow throughout their lives. Males' tusks are larger and are used for display and as weapons, usually in competition with other males. Walruses occupy the continental shelf rather than deep water, feeding at depths no greater than 100 m. They eat a large variety of bottom-dwelling invertebrates, from tiny crustaceans to octopuses and large crabs. Walruses breed deep in the Arctic pack ice during the darkness of winter. Females begin breeding at 6-7 years of age, and have just one calf after a long, almost 15-month pregnancy. Males are sexually mature at about 9-10 years, but may not be successful in competing for mates until they are about 15 years old. Humans have exploited walruses for years for their ivory tusks, and also for meat, oil, and hides. Their only other predators are polar bears and killer whales, which mostly take the young.

Also known as:
Mores, Avik, Ayveq, Amak

Sexual Dimorphism:
Males are larger than females and have more prominent tusks.

Length:
Range: 2.5-3.5 m males; 2.3-3.1 m females

Weight:
Range: 590-1,656 kg males; 400-1,250 kg females

References:

Linnaeus, C., 1758.  Systema Naturae per regna tria naturae, secundum classis, ordines, genera, species cum characteribus, differentiis, synonymis, locis, p. 38. Tenth Edition, Vol. 1. Laurentii Salvii, Stockholm, 824 pp.

Links:

Mammal Species of the World

Mammalian Species, American Society of Mammalogists' species account

Distribution of Odobenus rosmarus

Image of Odobenus rosmarus
Click to enlarge. (89kb)

Skull of Odobenus rosmarus
Click to enlarge. (18kb)