Singing Lemurs Strike a Chord with Scientists

Do you like to sing in the shower or at karaoke? New research suggests a group of peculiar primates may have played an evolutionary role in your ability to do so.

Published August 9, 2024

By Nick Fetty
Digital Content Manager

Before Beyoncé we had the Beatles. Before the Beatles we had Beethoven. And before Beethoven? Lemurs! …Lemurs???

A new study recently published in Annals of the New York Academy of Sciences reports that these primates frequently use music to communicate with one another, something they’ve likely been doing for generations. The study’s authors even suggest that small, furry tree-dwelling lemurs (Indri indri) may have played a role in how humans evolved to create music.

About the Indris Lemur

Singing lemurs, more formally called “Indris”, are endemic to the island of Madagascar where they generally congregate at mid-to-low elevations. They typically measure between 25 and 28 inches in length and can weigh up to 21 pounds. They subsist on fruits, seeds, flowers, and tree bark, and can live approximately 20 years in the wild.

Indris are classified as Critically Endangered on the International Union for Conservation of Nature’s Red List in large part because of the destruction of their natural habitat through agriculture, logging, and charcoal production. Poaching and political instability on the island have contributed to the threat. This is further complicated by the fact they do not reach reproductive maturity until roughly eight years old. Even then, they only give birth every two to three years.  Efforts are being made to understand these cute creatures in order to better protect them.

Not Missing a Beat

Indris use song to communicate with one another, like birds and ocean creatures such as whales and dolphins. They also use rhythmic vocalizations to alert each other to potential threats, and to keep track of each other when they get lost in the thicket of the forest canopy. What was interesting to the scientists wasn’t the noises themselves (see video below) but that indris are rhythmic in their use of song and other vocalizations.

The researchers recorded songs and calls produced by 51 indris spread across five patches of rainforest over a 15-year period. They then analyzed graphs of the recordings for pitch, tempo, and duration between calls or songs. 

The scientists observed that indris communications have isochrony—that is, “the time between sounds or notes are equal, creating a steady occurrence of events at regular intervals, resulting in a consistent rhythm or beat” — something like the consistent ticking of a clock, or the beat of a metronome.  

Indris surpass other mammals and songbirds with their rhythmic abilities, and instead are more similar to humans.

“The findings highlight the evolutionary roots of musical rhythm, demonstrating that the foundational elements of human music can be traced back to early primate communication systems,” said Daria Valente, a co-author of the paper from the University of Turin.

The Rhythmic Organization of Singing Behavior

While the researchers believe their findings support the hypothesis about the musical connections between lemurs and humans, they also acknowledged some limitations.

“Mechanistic work on singing animals is, with a few notable exceptions (e.g., songbirds, singing mice), almost impossible. Indris are critically endangered and cannot be bred in captivity, so directly tapping the mechanisms behind their singing is unfeasible. This limits our understanding of primates’ song production and perception. Still, fine-grained behavioral studies can highlight factors regulating the rhythmic organization of singing behavior,” the researchers wrote in their conclusion.

This research was published in Annals of the New York Academy of Sciences in June 2024. The team included researchers from Italy, the United Kingdom, Madagascar, the Netherlands, and Denmark. Financial support for the project was provided by the Max Plank Society, the Danish National Research Foundation, and the European Research Council.

This article is open access and publically available because of funding from Projekt DEAL, now called the DEAL Consortium. The organization aims to “negotiate new contractual models with journal publishers that enable the open dissemination of research results from Germany.” Wiley, the publisher of Annals, is one of the partners in the DEAL Consortium.

“DEAL Consortium is one of many so-called Transformational Agreements that journal publishers have established with countries, institutions, and even individual U.S. states,” said Douglas Braaten, PhD, Chief Scientific Officer for The New York Academy of Sciences and Editor-in-Chief of Annals. “These agreements facilitate and ensure Open Access for papers that might otherwise not be available without a subscription.  Annals is working towards being fully Open Access—a goal we hope to achieve in the next two to five years.”