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ACTIVITY: Echolocating with Dolphins

NGSS Science and Engineering Practices:

NGSS Crosscutting Concepts:

NGSS Disciplinary Core Ideas:

The activity below draws from the content in the page Information ProcessingRelated information on sound waves can be found in another topic, The Patterns to Transfer Information

<p>Fig. 1. Dolphins use sound to navigate in their everyday life.</p>Phenomenon:

Animals send and receive sounds to communicate and explore their environment (Fig.1).

Inquiry:

How is sound used to communicate information?

Guiding Questions:

  1. How do animals receive information with their senses?
  2. How do animals process information?
  3. How do animals respond to information?
  4. How do dolphins used sound to get and share information?

Activity:

In this activity, you will explore how dolphins use sound and echolocation to find an object!

Materials:

Teacher Recommendations:

Procedure:

  1. Follow along on your worksheet for instructions to model dolphin echolocation.
  2. Discuss and answer these questions with your classmates:
    1. What senses do we, as people, use in our daily lives?
    2. Do animals use these senses differently than humans?
    3. What are some additional senses that marine animals have (different from humans)?
  3. Read the background information below:

    Background Reading

    An animal’s ability to sense and respond to its environment enhances its chance of surviving and reproducing. Animals have senses that are adapted to where they live, including sight, sound, smell, taste, touch, electroreception, and echolocation. Animals communicate by sending out signals and receiving information back. The most effective means of communication in water is sound. Sound actually travels faster in water than it does in air! Animals also use sound for other purposes, such as finding food.

    <p>Fig. 2. A dolphin sends out a sound and interprets the echo to know if the object is a prey item.</p>

     

    Echolocation, or biological sonar, is used by mammals, like bats and toothed whales to process information about their environment. To echolocate, an animal sends out a series of clicks and whistles and then processes the returning echoes that bounce off of the object (Fig. 2). The return signal creates an image that gives information about the distance, shape, and characteristics of the object. This allows the animal to 'see' further than their eyes are able. A dolphin, for example, relies on echolocation to find prey, to identify other dolphins, and to communicate.

  4. Go to the NOAA Fisheries Sounds in the Ocean page and listen to sample dolphin (or other toothed whale) sounds.
  5. In teams of two, choose one person to be the 'dolphin' and the other to be the 'echo.' 
    Note: You will switch roles and each student will get to be both the dolphin and the echo.
    1. The role of the dolphin will be to locate, while blindfolded, the center of the target (and therefore capture the fish) using echolocation. 
    2. The role of the echo will be to respond to the sounds of the dolphin to help guide them to capture the fish.
  6. Come up with your own signature sound or whistle that is unique to you as the dolphin. Write it out: _________________________________________
  7. As a pair, come up with the different echo sounds that signal directions (left, right, forward, backward) to help find your target. Fill in the table below to help you remember:
    SOUND DIRECTION SOUND DESCRIPTION

    Ex. Left

    Two clicks with your tongue
    Left  

    Right

     
    Forward  
    Backward  
  1. Practice making and listening to your sounds.
  2. As the dolphin:
    1. Read the instructions below before you put on the blindfold. You will:

      1. Extend your arm to grab and hold the marker.

      2. Make your signature sound and wait for the echo's response.

      3. Move your arm in the direction indicated by the echo's call.

      4. Repeat for a total of 5 calls.

      5. After the 5th call, lower your arm so the marker tip touches the paper. 

    2. Put on your blindfold and follow steps i-v above. No peeking!

    3. Remove your blindfold and measure how close you were to the center of the target. Record the distance from your mark to the target fish in your table.

    4. Repeat this process for at least three trials. Number each trial position with your marker.

  3. As the echo:
    1. When the dolphin is blindfolded, place their target somewhere on the desk within arm's reach. 
    2. Tell them to extend their arm above the worksheet and hand them the uncapped marker with the tip pointing down. 
    3. Let the dolphin know you are ready and listen for their call.
    4. When they make their call, respond with the appropriate echo that directs them closer to the center of the target.
    5. Continue for five of their calls. 
    6. After the 5th call, they will lower their arm to mark the target.
    7. Repeat the whole process for at least three trials. Be sure to move the target before the next trial.
  4. Switch roles and repeat!

<p>Fig. 3. Use this target to test your echolocation skills! (Note: you can also find this image in the attached worksheet)</p><br />

TRIAL DISTANCE TO THE CENTER OF THE TARGET
Trial #1  
Trial #2  
Trial #3  

Activity Questions:

  1. How well did you and your partner do in guiding each other to the fish?
    1. Did you improve with practice?
    2. How could you have done better?
  2. In order to locate the target when you were the dolphin, how did you:
    1. Receive information:
    2. Process the information:
    3. Respond to the information:
  3. How might dolphins use sound in other ways?
  4. How do you think that communication between dolphins is different than between humans?
  5. What are some challenges that scientists face when studying dolphin echolocation and communication?
Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.