Walrus

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Walrus

The Walrus is a large member of the pinniped (seal) group. Known for their massive bodies and long tusks, walruses are a unique and instantly recognizable symbol of the frozen environment of the northern Arctic oceans.


Content List

1. Scientific & Common Names

2. Characteristics

a. Breeding

b. Behavior

3. History

4. Present Status

5. References


Scientific & Common Names

Kingdom - Animalia

Phylum - Chordata

Class - Mammalia

Order – Carnivora

Clade - Pinnipedia

Family – Odobenidae

Genus - Odobenus

Species – O. rosmarus

Common Name – Walrus, Atlantic walrus (O. r. rosmarus), Pacific walrus (O. r. divergens), Laptev Sea Walrus (O. r. laptevi)


Characteristics

Walruses share similarities with their relatives in the pinniped group, including flipper-like hands and feet and prominent whiskers. They are, however, much larger than most other seal species (with the exception of the elephant seals), and carry a significant amount of blubber on their bodies. They can weigh over 4000 lbs. and grow to nearly 12 feet long.

They are easily recognizable by their tusks which can grow as long as three feet and protrude from their upper jaw. Both males and females have tusks, though the tusks of females are typically smaller.


Breeding

Walrus gestation lasts around 15 months, and when the calf is born it can be over 100 lbs. Female walruses give birth in the spring, before their yearly migration. The young may stay with their mothers for as long as five years.

During mating season, males will compete for females, often with loud displays of intimidation. Occasionally, they will fight over a female's affections with their tusks.


Behavior

Walruses feed on the sea floor, eating a variety of organisms including mollusks, crabs and shrimp. In addition to using their tusks to fight among other walruses, they also hook them onto the ice in order to pull their large bodies out of the water.

Due to their massive size and formidable tusks, walruses have little to fear from other animals, although polar bears and killer whales do occasionally prey on them.


History

Walruses are the sole surviving members of their family, which once contained a wide variety of species. They are related to both "true" seals in the family Phocidae, and the eared seals of the family Otariidae, sharing characteristics of both although they are more closely related to the eared seals and sea lions.

The walrus features heavily in the culture of indigenous Nothern people, and appears often in legends and folklore.


Present status

In the 1700s and 1800s, walruses were hunted heavily for their skin, the oil from their blubber and their tusks, which were used to make ivory carvings. Though some populations were nearly driven to extinction, they have rebounded since commercial hunting was outlawed. Today, indigenous tribes are allowed to hunt small numbers of walruses.

According to the International Union for Conservation of Nature (IUCN), walruses are considered "Vulnerable". Their population size has not been studied in great detail, but it is thought to be decreasing due to many factors, including climate change.


References

Princeton Field Guide: Whales, Dolphins and Other Marine Mammals of the World, Jarrett & Shirihai, 2006
Guide to Marine Mammals of the World; Reeves, Stewart, Clapham, Powell; 2008
https://en.wikipedia.org/wiki/walrus
http://www.iucnredlist.org/details/15106/0