• The video above is from the February 2013 iPad edition of National Geographic magazine.

     

    River otters are playful animals. But did you know these mammals are also top predators? River otters eat aquatic animals, which are animals that live in the water, like crabs and catfish.

    Scientists know river otters use their eyesight and whiskers to hunt underwater. Their whiskers feel movement in the water—the swish of a fish's tail, for example. But could river otters rely on another sense? Charlie Hamilton James thinks so. He thinks otters can smell underwater.

    Charlie lives near a river in western England. He’s been photographing river otters since he was 16 years old. Charlie wanted to see if an otter could find a dead trout in cloudy water at night. The otter wouldn’t be able to use its whiskers because the fish wouldn’t be moving. It wouldn’t be able to see the fish because the water was too murky.

    Charlie set up night-vision cameras on the riverbank. He also put waterproof cameras in the river near the trout. He saw what was happening in the river from small screens set up in his kitchen. He was lucky. Two otters visited his section of the river. Watch the video to find out if they found the fish!

    1. After watching the video, do you think river otters can smell underwater? Why?

      Answers will vary. Possible answer: I think river otters can smell underwater because one was able to find the fish even though it couldn’t see the fish or feel it moving with its whiskers

    2. If you were the photographer, what would you do next to prove your prediction that otters can smell underwater?

      Answers will vary. Possible answer: I would do the experiment again. I would look to see if another otter also pushes an air bubble out of its nose and sucks it back it. I might also do the experiment with a different animal as bait, like a crab.

    • River otters can stay underwater for up to four minutes.
    • When a river otter dives, its ears close tightly to keep out water.
    • River otters love to play. They slide down snowy or muddy hills into the water.
    • River otter bodies are perfect for swimming.  They have powerful tails to propel them through the water, webbed feet that act like flippers, and water repellent fur to keep them warm and dry.
    • River otters are equally at home on land or in the water. They live in burrows with an underwater entrance.
  • Term Part of Speech Definition Encyclopedic Entry
    aquatic Adjective

    having to do with water.

    mammal Noun

    animal with hair that gives birth to live offspring. Female mammals produce milk to feed their offspring.

    predator Noun

    animal that hunts other animals for food.

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