Nobody taught Ayumu to make a drum. Nobody taught him to keep a beat. Yet for more than two years, the 23-year-old chimpanzee living at a research center in Japan has been prying wooden floorboards off a walkway, repurposing them as percussion instruments, and staging structured, multi-part rhythmic performances. He is, as far as researchers know, part of a rare documented case of a chimpanzee repurposing objects as instruments and using them in extended, organized displays, and what he does with that instrument may offer clues about how human music evolved.
Where music came from is one of the more genuinely open questions in human evolutionary science. One leading theory holds that rhythmic sound-making grew out of older, emotion-driven vocal behaviors common across primates, a kind of ancient shared root between calling out and playing music. Ayumu’s behavior, spontaneous and untrained, offers a behavioral case that, for the first time, offers a behavioral case that brings together tool use, rhythm, and emotional expression in a way rarely documented in non-human animals.
Researchers at Kyoto University’s Center for the Evolutionary Origins of Human Behavior documented his performances over more than two years and published their findings in the Annals of the New York Academy of Sciences.
How Ayumu Invented His Own Chimpanzee Drumming Tool
Observations ran from February 2023 to March 2025. Whenever Ayumu’s displays could be heard, researchers filmed the sessions. Over the study period, they captured 89 distinct sequences across 37 observation days.
At least twice, Ayumu was filmed removing floorboards from the corridor walkway himself, meeting the scientific definition of tool-making. No other chimpanzee in the group consistently did the same. He had prior experience with electronic keyboards and touch panels at the center, but had never received any training in drumming or rhythm production. He arrived at this behavior entirely on his own.
Each recorded sequence was broken down into its parts: tool-assisted drumming, bodily drumming against a wire fence, object dragging, object rocking, walkway running, and object throwing. Two trained observers coded the footage independently and reached a strong reliability score. Statistical analyses then asked a simple question: was the order in which Ayumu moved through those behaviors random, or did it follow a pattern?
What Researchers Found in Ayumu’s Chimpanzee Drumming Displays
Ayumu’s sequences were not random. Two transitions occurred far more often than chance would predict: drumming consistently led to dragging, and dragging consistently led to throwing. That progression, from slow heavy percussion to rapid scraping to a climactic throw, resembles the introduction-development-climax structure of the pant-hoot, the chimpanzee’s signature long-distance call. In wild chimpanzees, object throwing is typically associated with the vocal peak of a pant-hoot, and the same pattern appeared here. Ayumu’s sequence closely resembled what pant-hoots do vocally.
His rhythm also held up under scrutiny. Analysis of the timing between drum hits showed that Ayumu favored a steady, even beat rather than random or erratic intervals. A regular beat is one of the most consistently documented features of human music across every culture ever studied. His sequences ran between two and fourteen distinct components each, with the whole performance sometimes lasting several minutes, far longer than the few seconds of drumming typically observed in wild chimpanzees.
When Ayumu drummed with the fabricated floorboard rather than his bare hands and feet, his rhythm was measurably more consistent. Studies of human drummers have found similar patterns. Tapping with sticks produces a more stable rhythm than tapping with fingers alone.
A Drummer Who Grins While He Plays
Perhaps the most unexpected detail was what was happening on Ayumu’s face. During many sessions, he displayed what primatologists call a play face, a relaxed open-mouthed expression associated with positive, non-aggressive arousal. On a handful of occasions, he also showed a silent bared teeth expression, typically linked to friendly, tension-reducing social signals. Neither expression had previously been documented during pant-hoot displays.
Researchers noted that “Ayumu’s drumming suggests not only a display, but also the experience of intrinsically positive emotions associated with the production of sounds, similar to human musical performance.” Research on human music across cultures has found that musical performance frequently expresses high-arousal, positive emotional states. Ayumu’s face during his performances fits that same profile.
Ayumu is the alpha male of his group of 11 adult chimpanzees, a social position researchers note may have contributed to his repeated use of loud, conspicuous drumming as a display. No other chimpanzee in the group adopted the same behavior consistently throughout the study.