Name: Walrus (Odobenus rosmarus)
Average Length: 2-3.5 metres
Average Weight: 800–1,700 kg
Location: The northern reaches of the Atlantic and Pacific Oceans, as well as the Laptev Sea which is part of the Arctic Ocean
Conservation status: Data Deficient (the last global census was taken in 1990)
Diet: Main diet is clams, also eats sea cucumbers, coral, a variety of mollusks, shrimp, crabs, tube worms, tunicates, and other small marine organisms, seals, sea birds, whales and whale carcasses
Appearance: Long tusks (up to a metre in length) with “whiskers”, blubbery skin which is darker brown in youth, growing more pinkish or rusty coloured as they age.
What do walruses eat?
While walruses eat all sorts of small aquatic creatures, their food of choice is the clam. To find clams, walruses dive to shallow sea floors and search with their sensitive vibrissae (whiskers).
Once found, the walrus will seal its lips to the clam’s shell and then quickly withdraw its tongue back into its mouth, which creates a vacuum, sucking the clam right out of its shell.
Walruses will also prey on seals and even narwhals if they’re trapped by ice.
They typically can dive to a depth of about 80-90 metres, and stay underwater for 30 minutes at a time.
Do walruses socialize?
Walruses herd together on ice floes and on shore. Usually the herds are separated by sex.
Relations become less friendly during mating season – males then fight for dominance over a harem of females.
Sunbathing walruses can gather in the hundreds. During mating season, these numbers can go up into the thousands. If startled, a stampede of walrus has been known to crush members of its own herd.
How fast can walruses move?
Walruses can move surprisingly fast on land, matching the running speed of a human being, since they run on all fours like a dog (while some seals can only undulate and drag themselves along with their front flippers).
While swimming walruses become graceful, using full body movements to glide through the waters. On average, they’ll swim at about 7km an hour, and can speed up to 35km per hour.
In the Atlantic and Pacific, thousands of walruses can be seen migrating north for the summer season, when the waters open up from under the ice. The herds in the Laptev Sea area are relatively settled, moving very little.
What are walrus mating rituals like?
Male walruses are sexually mature around age 7, but are usually unable to dominate other males for mating privileges until they reach 15 or so years of age. Females are sexually mature as early as 4 years old.
From January through March males will fight each other for dominance. The more prominent males will then swim around groups of females, emitting vocal calls from the large air sack under its throat.
The pregnancy lasts over a year, for about 15 months. Calving occurs during the spring migration (April through June) of the year following the impregnation.
Calves weigh up to 75kg and are able to immediately swim. Mothers nurse their young for over a year and the young stay with their mothers for up to 5 years.
How long walruses live?
Walruses generally live to be about 20 to 30 years old in the wild.
How many walruses are there today?
Estimates put the worldwide walrus population at approximately 230,000. This number roughly breaks down to:
- Pacific - 200,000
- Atlantic (northeast coasts of North America) - 20,000
- Laptev Sea area – up to 10,000
Do they have any predators?
Because of their size and tusks, walruses only have two natural predators – killer whales and polar bears. However both predators prefer to attack easier prey like seals.
Humanity is historically the greatest hunter of the walrus. During the 1700-1800s the Atlantic population of walruses was hunted to near extinction. The walrus was made up of a range of valuable parts:
- Meat for nutrition.
- Flippers were considered a delicacy.
- Tusks and bones were used for tools, art, and fashion.
- Oil was a source of heat and light.
- The tough hide was used for tarps, boat coverings, and made into rope.
- The guts and intestines were used for waterproof parkas.
Currently walrus hunting is illegal except for indigenous people for whom it still represents a major life resource.
What are a walrus’ tusks for?
A walrus’ tusks are actually two canine teeth that keep growing throughout its lifetime. The tusks are used for:
- Fights between males for dominance over harems.
- Hauling themselves up onto ice.
- Protection against predators.
- Hooking onto ice so they can rest as they float.
8 Wondrous Walrus Facts:
- Walruses spend about 2/3 of their life in the water.
- While underwater, their heart rates slow so they don’t become too cold.
- Odobenus rosmarus, the walrus’ scientific identification, means “tooth-walking sea horse.”
- A walrus’ bellow can be heard over 1.5km away.
- The walrus is a pinniped which means “feather footed,” along with other members of the seal family.
- Female walruses will move away from the herd to give birth. Nobody is sure exactly why, but it has been suggested it may be to move away from the collective walrus scent that attracts predators, or perhaps to keep the calves from being crushed.
- Walrus mothers cuddle calves in the same manner as human mothers.
- The metabolic rate of Walrus requires a 1300 kg specimen to eat some 70 kg of mussels per day on average. This corresponds to some 282 Mars bars!