Walruses Are Weird! 5 Cool Facts About These Unique Marine Mammals

walrus
Allan Hopkins/MNN Flickr Group

The (not so) secret lives of walruses

  • Walruses are probably best known for their intimidating tusks. In fact, the species' scientific name Odobenus rosmarus is Latin for “tooth-walking sea-horse.” Most of us probably assume that walrus tusks are meant for fighting, and indeed the tusks are wielded as a weapon in fights. But these long teeth, which can grow to as long as 15 inches, also have a much more practical purpose. A walrus uses its continuously growing tusks to create breathing holes in the ice, as well as to help it get a grip on ice when trying to haul out of the water.
  • Walruses are marine mammals, and that means they have special adaptations that veer away from what we might see from similarly sized land mammals. One such adaptation is that walruses have between two and three times more blood than a comparably sized land animal. This is because they have to be able to dive for long periods of time in cold water to reach food, which means storing as much oxygen in their blood and muscles as possible so they can stay under — and that makes having a boat-load of blood beneficial.
  • When you're talking about raising a youngster in the Arctic, animals need to be careful about the timing to make sure that there are enough resources for both mother and young to survive and thrive. During reproductive periods, a female walrus has a "delayed implantation" where the fertilized egg takes three to five months to implant into the uterine wall. This helps the female in making sure that she has the necessary energy and resources to raise a calf, which is already 100 pounds when born and will grow at an astonishing rate. So much energy goes into birthing and raising a calf that a female is intensely defensive of her offspring, which may stay by her side for as long as two years.
  • Walruses look big and tough, but they can be startled quite easily. Sensitive to approaching planes and boats, a walrus herd will sometimes stampede into the water to escape a perceived danger. Even so, walruses are indeed big and tough. They can grow to be 10-12 feet in length and weigh an incredible 3,700 pounds. Other than humans, the walrus only has two natural predators — orca whales in the water and polar bears on the ice. However, usually only calves are vulnerable since adults are more than most any predator can handle.
  • Walruses don't have mustaches. Though humans have named a facial hair style after the walrus mustache, the whiskers on a walrus are not hairs but incredibly sensitive vibrissae, each of which are attached to muscles that are connected to the circulatory and nervous systems. Between 400 to 700 of these tactile organs are lined up in 13 to 15 rows around the nose, and they are used the same way cats, otters, rats and other whiskered animals feel out the world around them. Walruses feed on a variety of items but a staple in their diet is shellfish. They find the shellfish, as well as other prey items, on the dark ocean floor using these vibrissae. The importance of these whiskers can't be understated, since walruses use them to find — get this — as many as 3,000 to 6,000 clams per meal!