A dancing sea lion is upending some theories about animals and rhythm.
Three-year-old sea lion Ronan’s ability to shake it to Creedence Clearwater Revival’s “Down on the Corner” and Backstreet Boys' hit “Everybody” is detailed in a new paper from the University of California, Santa Cruz researchers published Monday in the Journal of Comparative Psychology. You can see Ronan cutting a rug in this video from the researchers:
Sound mimicry has long been thought to be one of the required ingredients for an animal’s ability to follow rhythm. Dancing was once thought to be a uniquely human behavior, until some birds showed signs that they could boogie down as well. Cockatoos and parrots have been captured bobbing in time to music, and parakeets can be trained to peck at a target in time with a metronome.
Birds are thought to be naturally inclined toward dancing, thanks to their singing abilities. There are fewer examples of other “non-vocal mimic” animals swaying to the beat, which has led to a theory that a sense for rhythm is mostly dependent on vocal abilities.
Monkeys have been trained to press buttons in time with a beat, but have some trouble keeping up, which seems to reinforce the need for vocal mimicry.
Ronan’s handlers first started her dance training with a simplified version of “Down on the Corner,” rewarding her with fish when she bobbed her head in time to the music. Then, her rhythmic ability was tested with the boy band tune “Everybody” and Earth, Wind and Fire’s “Boogie Wonderland.” Ronan was even able to keep up with “Boogie Wonderland” played at five different tempos: 104 beats per minute, 117 bpm, 124 bpm, 137 bpm and 143 bpm -- and her dancing ability improved over time.
To make sure that Ronan was actually following along, the scientists used different speeds and types of sounds, and also tested her with two computer-generated metronome-like sounds. One metronome program was designed to miss a beat, but Ronan was still able to keep the correct rhythm.
“These findings show that an animal without specialized adaptation for vocal learning or mimicry, a California sea lion, is able to learn to entrain a motoric behavior to regular rhythmic auditory stimuli,” the authors wrote.
In a followup test a few weeks after her last lesson, Ronan could still bob her head in time with the beat – performing better than many monkeys that quickly lost their dancing ability.
"This study is particularly rigorous because it examines, step-by-step, the learning conditions that supported the emergence of this complex behavior,” coauthor and University of California, Santa Cruz scientist Colleen Reichmuth, said in a statement on Monday.
Future studies may reveal that sea lions have some capacity for complex vocal learning, thus reinforcing the vocal mimicry requirement for dancing. Still, until such evidence arises, we might be able to find more unexpected dancers throughout the animal kingdom.
SOURCE: Cook et al. “A California Sea Lion (Zalophus californianus) Can Keep the Beat: Motor Entrainment to Rhythmic Auditory Stimuli in a Non Vocal Mimic.” Journal of Comparative Psychology published online 1 April 2013.