Gioca STEMAnimals

Animals · Ice: the Arctic and Antarctica

Walrus

Odobenus rosmarus

Two canine teeth three feet long

An adult male hauls itself onto the ice pack by digging its tusks in inspiring its genus name.
An adult male hauls itself onto the ice pack by digging its tusks in inspiring its genus name.
  • Status: Threatened
  • Pack ice and shallow waters of the Arctic and subarctic seas

Numbers

Weight
2600 lbfrom 1,800 to 3,700 lb, up to 4,400 in the largest males
Length
10 ftfrom 7 to 12 ft
Lifespan
25 yearsfrom 20 to 30 years in the wild
Tusks
3 ftup to 12 lb in weight each
Breath hold
30 minutesfeeding dive on the sea floor
Whisker sensitivity
0,1 inminimum thickness of an object recognized by touch

Ten fun facts

  1. tusks are enlarged canine teeth present in both sexes that can reach three feet in length and weigh twelve pounds.

  2. the genus name Odobenus means tooth walker because the animal uses its long tusks to pull itself onto the ice.

  3. it has four hundred to seven hundred whiskers arranged in thirteen to fifteen rows that grow up to twelve inches long.

  4. each whisker connects to a nerve and blood vessel and can identify objects just one tenth of an inch thick.

  5. it extracts shellfish from their shells by moving its tongue like a piston inside a uniquely shaped palate.

  6. by foraging along the sea floor it stirs up sediment and releases nutrients making it a key Arctic species.

  7. an air sac inside its throat acts as a float allowing the walrus to sleep upright in the open sea.

  8. in freezing water its blood vessels constrict causing the normally brown animal to look almost white while swimming.

  9. females give birth at most once every two years which is the lowest reproductive rate among all pinnipeds.

  10. a fossil dating back twenty-eight thousand years was discovered on the sea floor of San Francisco Bay.

The quiz answers

The first one is the question printed in your book: here is the answer. The other four are extra.

Question 1 of 5★ this one is in your book

What are walrus tusks mainly used for?

Question 2 of 5

How does it find food on the sea floor?

Question 3 of 5

What is its favorite food?

Question 4 of 5

How deep does it dive?

Question 5 of 5

What are its only natural predators?

Try it yourself

Experiment 1

With your eyes closed find a coin at the bottom of a bowl filled with wet sand. That is how whiskers search for clams in total darkness.

Experiment 2

Suck water from a glass with a straw while keeping your tongue still. A walrus creates the same vacuum suction to empty a clam shell.

Experiment 3

Measure three feet with a tape measure and hold it out in front of you. That is the impressive length of a single adult tusk.

Data from Wikidata (Q40994) and Wikipedia (Walrus).