Scientists Say Lemurs Sing With an Opera Singer's Trick

Researchers at Warwick and Turin report that indri lemurs open their mouths wider on high notes, using the same formant tuning as trained opera singers.

A new study published in PLOS Computational Biology reports that wild indri lemurs — the world's only known singing lemur — coordinate their mouth opening with the pitch of their songs, opening wider to reach higher notes. According to BBC, researchers from the University of Warwick, the University of Turin and Madagascar spent years observing the species and describe the behaviour as similar to a trained soprano. Dr Chiara De Gregorio of Warwick said the animals showed "the kind of fine-tuned coordination between voice and body that we usually associate with trained human singers, not with a lemur singing from the forest canopy."

According to BBC, this is the first direct evidence of this kind of vocal-tract coordination in a non-human primate. Filippo Carugati, the University of Turin researcher who led the study, told Good Morning America that "the same phenomenon we hear in an opera house, when a trained singer opens their mouth wider to project a high note, appears to be happening in a lemur whose lineage split from ours something like 70 million years ago." Good Morning America notes the lemurs' calls project more like a deflating balloon than Bizet, yet still carry through dense forest.

The team analysed 83 video recordings of 19 wild indris, combining field audio with markerless motion-tracking technology that followed upper and lower lip positions frame by frame, as Popular Science reports. They found that mouth opening consistently tracked pitch specifically, note by note, rather than volume or excitement. Good Morning America reports no significant differences between male and female songs, which Carugati said suggests the trait is "a species-level feature rather than an idiosyncrasy of one or two animals." Carugati acknowledged to GMA that data varied between subjects because only frames showing the relevant facial landmarks could be used.

The technique, known as formant tuning, is widely used by professional singers to maximise the power of their voices, and BBC reports the researchers believe the indris may use it for a similar purpose: making their songs carry further through thick Madagascan forest. Popular Science notes the lemurs' haunting songs can strengthen social bonds and warn neighbouring groups to keep their distance, so any boost in how far the signal travels has real value. Carugati told Good Morning America that anything increasing how far and clearly the signal carries has "a real, plausible benefit" for animals holding territory in dense rainforest.

Humans and indris last shared a common ancestor roughly 74 million years ago, and both the BBC and Popular Science report that the researchers believe the two species developed these sound-projection techniques independently — a case of convergent evolution, in which unrelated species evolve similar traits to solve the same problem. Carugati explained to Good Morning America that the shared problem here is how to send an acoustic signal over a long distance. He told GMA the team has not yet found a genetic or mechanistic explanation for the convergence, leaving that question open for future work.

For vocal enthusiasts, the study suggests the mechanics behind operatic projection — reshaping the vocal tract so resonances align with pitch — may be a general solution to the problem of being heard over distance, not a human invention. The Warwick and Turin team has previously suggested their indri work could offer insight into how humans evolved to create music, BBC reports, and a 2025 study found young lemurs learn to sing in a manner similar to human children. Carugati cautioned to Good Morning America that researchers cannot prove the animals sing this way "on purpose," only that the physical result matches the strategy of trained singers.