Ocean STEMulation: Sea Lion Bobs to a Beat
Focusing on science, technology, engineering, and math (STEM), as they pertain to the ocean.
Dancing is universal in humans, and in the past it was thought to be unique to humans as well. When birds were found to move rhythmically, scientists concluded that their ability to keep a beat must be related to vocal mimicry – their ability to imitate other sounds. New research has changed this.
In new research, scientists studied the relationship between an animal’s ability to mimic sound and its ability to “entrain motor activity to a rhythmic auditory stimulus,” or to move to a beat. Before now, the only animals shown to do this were ones that could also imitate sound, like cockatoos.
In the study, a 3-year-old sea lion named Ronan was trained to bob her head in time with a rhythm. At first, she had to be taught to move with a hand signal, and later to non-musical rhythmic sounds. She improved with practice until she could keep the beat to a song – John Fogerty’s “Down on the Corner.”
Once she was trained, the scientists started the real testing: to see if she had only been doing what she was told, or if she had learned how to interpret a beat.
They had Ronan listen to songs that she had never heard before to see how she would react. When she first heard “Everybody” by the Backstreet Boys and “Boogie Wonderland” by Earth Wind & Fire, Ronan was able to bob her head to the beat of the new music demonstrating that she was able to pick out a new and different beat. They also changed the tempo of the songs to see if she would change her reaction and she was successfully able to follow along to “Boogie Wonderland” at five different speeds.
You can watch her here:
The scientists also wanted to make sure that she was in fact understanding the rhythm and anticipating it – not just following it by bobbing in response to the previous beat. Changing the songs and speeds was one way to test that. The researchers also had her bob to a rhythmic ticking sound; they found that even when the computer-generated sound missed a beat, Ronan kept the beat going.
Not only did she learn to follow new rhythms and improve over time, she also was able to retain that knowledge after the study ended. A few weeks after it was over, a follow up test showed that Ronan could still keep the beat with the rhythms and songs she’d learned before.
Since sea lions don’t have the vocal ability to imitate other sounds or songs, then based on past theory, they shouldn’t be able to keep a musical rhythm. Because the scientists showed that Ronan could learn step-by-step how to keep a beat, we now know that vocal mimicry skills aren’t a requirement for this type of comprehension, and that perhaps there are many more animals out there than we thought that do this.
Photo by Todd Ryburn via Flickr, Creative Commons License.