“Rhythm” is a fundamental element that creates a sense of flow, organization and pulse. It refers to a recurring pattern of movements or sounds found in various aspects of life, such as dance and poetry. In music, rhythm involves the placement of sounds in time.
At the intersection of biology and psychology, there’s a tantalizing field of study called biomusicality, which looks at whether different species are capable of behaving in ways that show that they recognize aspects of music, including beat and rhythm.
For example, female crested gibbons display jerky, almost robotic patterns of movement. Researchers have studied these conspicuous actions, which are comparable to human dances. Recently, they’ve been able to describe the structure of these dances, the contexts in which they occur and their distinct rhythms—and have found that they are intentional.
And a highly trained California sea lion who achieved global fame for her ability to bob her head to a beat is back: she’s starring in a new study that shows her rhythm is just as precise—if not better—than that of humans.
All eight species of crested gibbons (eastern black, western black, Hainan, northern gray, northern white-cheeked, southern white-cheeked, northern yellow-cheeked and southern yellow-cheeked) are endangered due to habitat loss and to hunting for food, traditional medicines and the wildlife trade.
The dances of gibbons
Crested gibbons belong to the family of small apes (or “lesser apes”) called Hylobatidae. Visitors to zoos may have noticed how female crested gibbons perform dramatic sequences of twitching movements involving their arms, legs and rumps. This behavior has also been seen in gibbons living in the wild.
While there has been little scientific interest in these special displays to date, now researchers from Germany’s Heinrich Heine University Dusseldorf, Norway’s University of Oslo and France’s Institut Jean Nicod in Paris have studied these showy movements, which are comparable to human dances. In an article published in the scientific journal Primates in October 2024, they describe the structure of the dances and their contexts.
The scientists focused on the intentionality, rhythms and sequences of the movements and the circumstances in which the gibbons perform them. Video material from various rescue centers and zoos proved that all species of crested gibbons perform such dances. The deliberate use of this visual form of communication was indicated by the fact that during performances, the gibbons often checked to see whether their audiences were paying attention.
There are similarities between the dances of female crested gibbons and humans, but they probably evolved independently of each other since other species of apes do not display this behavior.
It was discovered that only sexually mature females dance. While the dances were primarily used to solicit copulation, they also occurred in a wide range of situations related to nonsexual arousal or frustration and were frequently directed at humans when performed in captivity in zoos. The researchers also observed that the dance movements were often organized in groups of up-down or left-right movements, and they followed a clear rhythm. Depending on the individual, they varied in complexity.
The researchers state that they see similarities between crested gibbon and human dances, but they presume that they evolved independently of each other. This conclusion is based on the fact that other species of apes do not display this type of behavior. Furthermore, gibbon dances are likely to be innate, while human dances are primarily determined by culture and are frequently accompanied by music or songs. This is never the case with gibbons.
The head-bobbing of a California sea lion
Ronan, a highly trained California sea lion at the University of California, Santa Cruz, first shimmied onto the world stage in 2013 when researchers at the school’s Joseph M. Long Marine Laboratory reported that not only could she bob her head to a beat, but she could adjust her nods to music and tempos that she hadn’t heard before. In a new study, published in May 2025 in the nature journal Scientific Reports, Ronan’s research team showed that her synchronization was as good or better than that of humans and that her consistency in performing the beat-keeping task was better than that of humans.
California sea lions are known for their intelligence, noisy barking and playfulness. Their fur color ranges from a male’s chocolate brown to a female’s lighter, golden brown. Male California sea lions can weigh up to 850 pounds, while females might grow to 250 pounds.
Ronan was born in the wild in 2008; but due to malnutrition, she stranded repeatedly. After three such strandings and being spotted walking down Highway 1 in 2009, regulatory agencies finally deemed her to be non-releasable. So, UC Santa Cruz adopted her in 2010, and she became a permanent member of the Pinniped Lab.
The lab uses cooperative training methods to study behavior and physiology in marine mammals. Resident research animals, including Ronan, participate in a wide range of projects that help science teams explore their water-loving subjects’ inner worlds. Examples include studies on diving physiology, learning and memory, and sensory biology.
In other words, Ronan isn’t just working on her rhythm every day in the lab. The team estimates that, over the past 12 years, she has participated in about 2,000 rhythm exercises—each lasting just 10 to 15 seconds. Sometimes, years went by between these sessions while she focused on other areas of research. This means that Ronan wasn’t overtrained. The authors of the study say that if you added up the amount of rhythmic exposure Ronan has had since she’s been at the lab, it is probably dwarfed by what a typical one-year-old child has heard.
California sea lions, such as Ronan, can get stranded due to a variety of factors, usually linked to domoic acid poisoning from harmful algal blooms, more common because of climate change. Diseases, bycatch in fishing gear and changes in water temperatures that disrupt the distribution of prey are also causes.
To conduct the recent study, researchers asked 10 UC Santa Cruz undergraduates to move their preferred arm in a fluid, up-and-down motion to the beat of a percussive metronome, which best matches Ronan’s way of responding to a beat: a head bob. Three tempos were played—at 112, 120 and 128 beats per minute (bpm). Ronan had not previously been exposed to 112 and 128 bpm.
Ronan was found to be incredibly precise; at 120 bpm, Ronan’s most practiced tempo, she, on average, hit within 15 milliseconds of the beat. Ronan’s variability in timing beat-to-beat is also around 15 milliseconds. By contrast, the blink of a human eye takes about 150 milliseconds. Basically, say the scientists, she hits the rhythmic bull’s-eye over and over again.
The UC Santa Cruz researchers emphasize that Ronan is in complete control of her participation. She is not deprived of food nor punished for choosing not to engage; and her training structure reflects this autonomy: she begins each session by climbing onto a designated ramp station, where she relaxes while waiting for the experiment to begin. Once ready, she positions herself and signals her readiness to start. If she chooses to disengage at any point, she is free to return to her pool without any negative consequences.
Snowball is a sulphur-crested cockatoo, a species of parrot, like the one pictured here. Snowball is known for his spontaneous dancing abilities. He was first recognized for his viral videos, particularly his “head-banging” to the musical group Backstreet Boys.
The reliable beats of Ronan and Snowball
Ronan’s original rhythm study was inspired by work involving the intermittent beat-keeping of Snowball, a pet cockatoo who spontaneously “danced” to the Backstreet Boys, an American vocal group formed in 1993. Because cockatoos and humans are both vocal mimics, the investigations involving Snowball led to a theory that brain changes to support vocal learning were required for moving in time to music.
Sea lions haven’t shown the ability to learn new vocalizations, so Ronan’s 2013 study made a huge splash because it challenged the vocal-learning theory of rhythm. But in the study’s wake, some prominent theorists in biomusicality claimed that her performance was not as precise and reliable as human performance.
They suggested that Ronan might not be doing exactly what humans were; and that, therefore, she could not rely on the same biological mechanisms for perceiving and moving in time to rhythm. That prompted the UC Santa Cruz researchers to test Ronan again to see if she had improved and to compare her performance to people executing a similar task with the same sounds.
Scientific studies involving Ronan, the California sea lion, challenge existing beliefs about which animals can perceive and produce rhythms. There have been follow-up explorations of rhythm across various species, including elephants.
What they found, as we now know, is that Ronan was more precise and consistent at every tempo that was tested. And in a head-to-head battle of the beats with the UC Santa Cruz students, she more than held her own. The study’s authors then used the students’ performance to model the theoretical performance of 10,000 humans conducting the same rhythmic behavior. Based on that model, Ronan was in the 99th percentile for beat-keeping reliability.
The ripple effects of rhythm research
Now, at 170 pounds and age 16, Ronan is “a grown-up and in her prime” for a female sea lion in managed care, say the scientists. Being with her day in and day out over more than a decade, the researchers have become extremely attuned to Ronan. They know that she is intelligent and motivated; she wants to perform well. And just like with us, her performance gets better with practice. Her new study shows that experience and maturation matter. More than just a test of rhythmic performance, it reflects her cognition and her ability to refine it over time.
In a similar fashion, Ronan’s story is not just about one sea lion. The research on her progress has had far-reaching impacts in the scientific community. Her journey from a curious and eager orphaned sea lion to a key figure in rhythm-perception studies has exceeded all expectations. Her abilities call into question existing paradigms about which species can perceive and produce rhythms, opening new doors for research on the cognitive capacities of many kinds of animals, including birds, elephants, primates and humans.
The study of biomusicality goes back at least to Charles Darwin. He noted that rhythm is everywhere in the biological world, leading naturally, he thought, to the rise of music. Scientific interest got a boost with recordings of whale songs in the 1960s and has grown dramatically.
Researchers who study biomusicality are adamant that their field of study isn’t about teaching animals cool party tricks for fun. What they seek is to foster a broader understanding of the evolution of cognition and rhythm perception across species, the universality of pattern recognition and the intricate ways in which brains—both human and more-than-human—process the world around them.
I have to admit, though, inviting a bird like Snowball to a dance party could be a lot of fun. Just watch.
Here’s to finding your true places and natural habitats,
Candy
