The Pacific walrus, or Odobenus rosmarus divergens, is a subspecies of the walrus, or Odobenus rosmarus – a large marine mammal and the sole member of the Odobenidae family. It is related to sea lions and seals. The animal can grow to weigh 2,000 kg and has tusks that can exceed 1 meter in length.
The Pacific walrus has a bulky body with a small, round head. Sexual dimorphism is present, with males being considerably larger than females. Males are known to reach 2,000 kg, although they usually average between 800 and 1,700 kg. They can grow to be 2.2 to 3.6 meters long, with females being two thirds of the size and weight of males.
Both males and females have long tusks, with males growing tusks that can be 1 meter long and weigh more than 5 kg. The Tusks are used for male display and fighting and by both males and females to drag themselves from water unto ice platforms. Tusks are used to maintain holes in ice and they can also be used as weapons for defense against other animals. Besides the two species of elephant seals, the walrus subspecies in the Pacific is the largest pinniped. They have a large amount of blubber to keep them warm in low temperatures. The tusks are surrounded by bristles or vibrissae which are 30 cm long and can number from 400 to 700.
Just as the name suggests, this walrus subspecies lives in the Pacific. Populations can be found just north from the Bering Strait to the Chukchi Sea in the Arctic Ocean. They can also be seen on the eastern coast of Siberia and in the Beaufort Sea.
Walruses are opportunistic feeders and can consume a wide range of animals, from tube warms, crabs and shrimp to sea cucumbers and mollusks. They have also been found to occasionally prey on smaller seals as well as birds.
Males reach sexual maturity at the age of 7, but they usually start to reproduce only when they develop fully, at 15 years of age. Bulls fight for females and mate with several of them. Gestation lasts for 15 to 16 months. The calves can weigh up to 75 kg when they are born and they will be weaned after two years. The Pacific walrus can live for 20 to 30 years.