Indri Lemurs Use a Soprano-Like Singing Trick
Monday, September 28, 2026219 words3 minutes1379 reads
A rainforest song has given scientists a comparison with opera. Indris, the only lemurs known for singing, make structured canopy calls. Their songs help groups communicate and mark territory in dense vegetation.
Researchers analysed 83 video recordings of 19 wild indris from the Maromizaha forest and Mitsinjo reserve. They tracked facial landmarks frame by frame and matched them with audio. As pitch rose, mouth opening increased. The pattern was robust and is consistent with formant tuning, a technique associated with trained singers.
Formants are resonance frequencies shaped by the vocal tract: the mouth and throat. When an indri opens its mouth wider on a high note, it changes that tube-like space. This can bring a resonance closer to the sound being produced, which can increase vocal power and help a call carry farther. The study describes a link between mouth opening and pitch; it does not mean that every indri song works exactly like a human performance.
The comparison is useful because both species face a physical problem: how to be heard at a distance. Human and lemur lineages split roughly 70 million years ago, Reuters reported. Similar solutions can evolve when clear long-distance communication matters. For indris, that ability may be especially important in forests where habitat loss and fragmentation are putting pressure on a critically endangered animal.
