The haunting, musical songs of Madagascar's largest lemur

Nature · Published 24 October 2026 Swipe more like this →

In short: In the dense canopy of Madagascar, a mournful melody rises like a whale song. These are the vocalizations of the indri, the world's largest lemur. But as their forest habitat vanishes, scientists are turning to artificial intelligence to listen for the survivors.

For roughly 88 million years, Madagascar has remained geographically isolated from Africa and Asia, acting as an evolutionary sandbox. This isolation allowed unique wildlife to flourish, including the indri. These primates are known for their complex, resonant songs—a mix of wolf-like howls and whale songs—which they use to claim territory. When groups respond to one another, it creates a 'chorus' that moves through the forest like a stadium cheer. The ancestors of these mammals likely arrived on the island by drifting from the continent on mats of vegetation carried by ocean currents.

However, the indri faces a critical threat from habitat loss. In areas like Maromizaha, the species is pressured by 'tavy'—slash-and-burn agriculture—and the production of charcoal. Additionally, in the north-eastern mountains, the Silky Sifaka is pushed to the brink by illegal logging driven by international demand for rosewood and ebony. Because all attempts to keep indri in captivity have failed, protecting their wild habitat is the only way to ensure their survival. The Silky Sifaka is particularly vulnerable, with fewer than one thousand individuals remaining in the Marojejy–Anjanaharibe-Sud region.

To monitor these elusive animals, researchers like biologist Filippo Carugati and postdoctoral fellow Valeria Ferrario are using Passive Acoustic Monitoring (PAM). In a study involving the Maromizaha Reserve, the team attached 26 autonomous recording units (ARUs) to trees. These devices recorded 10 minutes of audio every half hour to optimize battery and storage. By using an AI model trained to recognize the indri's unique dimorphic duets, scientists can now estimate population density and abundance noninvasively. The research team, which included local Malagasy guides, also noted the direction and origin of the singing to better map the groups. These indri groups typically consist of only two to four individuals.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• The haunting spirits of Madagascar turned out to be primates
• The indri is the largest living lemur, yet it possesses only a stubby tail.
• Millions of years of isolation created a biological laboratory in the ocean
• Until recently, Madagascar was home to a diverse population of giant lemurs.
• Madagascar's unique primates: the lemur's evolutionary isolation
• Can a Japanese budget sports car survive the desert?
• Evolutionary islands: how isolation creates the world's most specialized creatures
• Tracing the journey of plastic waste from the Ganges River to the ocean
• The slow-motion journey through Spain's rugged green north
• The California turret spider builds a camouflaged fortress to launch lightning-fast ambush attacks
• A journey at the speed of earlier centuries through Portugal
• How a 'god of ugly things' survived the arrival of mammals

More in Nature · Latest · A–Z · All topics