Walrus - Odobenus Rosmarus
Walrus - Odobenus Rosmarus

About the walrus.

The walrus has huge ivory tusks to perform several tasks. They use them (as a lever) to drag their own bodies and climb out of the cold water, to break holes in the ice and be able to breathe under the ice sheets, to defend their territory and their harem of females (in the case of males) and to dig the sea bottom for food.


These animals also have special whiskers that help them detect seafood in the sea bottom where there is almost no light. The tactile sensing of these whiskers equates that of fingers.


Another characteristic is their extremely thick layer of fat, which allows them to live comfortably in regions where temperatures are extremely cold, as well as the ability to lower their heart rate while swimming in freezing water.


Until not long ago, there were three walrus subspecies, even though there are currently only two, separated geographically: in the Atlantic and in the Pacific.


They have relatively small eyes and their eyesight is not good. They detect food through their sense of touch and the eyes have been losing importance at an evolutionary level. These organs have some fat cells that prevents them from freezing in the cold waters.


Males are larger than females, their tusks are longer and wider, and their skin is thicker.


Males are territorial and compete among each other for females. Each male can impregnate an entire group of females and fights against other males to be able to do it. These have normally only one baby they take care of until it is 3 years old and becomes independent. Males never get involved in the raising of their descendants.


Walruses hierarchy is connected to their age. The older a male is, the larger his tusks are (they keep growing their whole lives), which he uses to fight for females and territory during the mating season. Oddly enough, during the non-breeding season, walruses stay on the ground in same sex herds: females and males separated, being very social animals.


In order to get mollusks from the sea bottom, walruses drag their whiskers and tusks stirring up the sand and propelling themselves with their hind flippers. When they detect a bivalve or other type of food with their whiskers, they use suction to bring it to their mouth and open it with the tongue or crush it with their teeth.


An adult walrus needs 25 kg of food per day, which it obtains during their 5-20 min dives in water. They can dive to depths of 70 m and eat around 60 clams per immersion.


The natural predators of the walrus are orcas and polar bears. Most of the times adults can defend themselves using their tusks, so victims are mostly younger and unprotected walruses.


Walruses were endangered in the past due to intensive hunting. The fat, ivory and skin of these animals are very valuable to humans, who hunted them, dramatically reducing their population.

Group of walrus on ice floe in Canadian High Arctic. By outdoorsman | Shutterstock.com
Group of walrus on ice floe in Canadian High Arctic. By outdoorsman | Shutterstock.com
COMMON NAMECONSERVATION STATUS
WalrusVulnerable
SCIENTIFIC NAMESIZE
Odobenus rosmarus2,2 – 3,6 m (7,2 – 11,8 ft)
FAMILYWEIGHT
Odobenidae600 – 2.000 kg (1,300 – 4,400 lb)
ORDERLIFESPAN
Carnivora30 – 40 years
CLASSGESTATION PERIOD
Mammalia15 months
POPULATIONDIET
Estimated to be 112,500 specimensThey usually eat small invertebrates, especially bivalves.
HABITATRANGE
Arctic seas.Arctic regions of the planet: Pacific ocean, especially Bering sea, Beaufort sea and Eastern Siberia, east and west of the Atlantic ocean and Laptev sea.
Walrus family. By Vladimir Melnik | Shutterstock.com
Walrus family. By Vladimir Melnik | Shutterstock.com

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