Indri lemurs widen mouths to boost high notes, echoing opera singers' technique
Researchers discovered that indri lemurs open their mouths wider for higher-pitched notes, using a formant-tuning trick that extends the reach of their songs in Madagascar's forest.
A study of 83 recordings of 19 wild indri lemurs in Madagascar's Maromizaha forest and Mitsinjo reserve found that the primates consistently open their mouths wider when producing higher-pitched notes, employing a vocal strategy known as formant tuning. This technique, similar to how opera singers project high notes, boosts the intensity and distance of their haunting duets, which serve territorial, spacing and reunification functions in the thick rainforest.
Filippo Carugati of the University of Turin described the adjustment as reshaping the vocal tract to resonate specific frequencies. Chiara De Gregorio of the University of Warwick stressed the discovery's importance for understanding communication in the critically endangered indri, the only singing lemur. Published in PLOS Computational Biology, the research also notes that habitat loss threatens the species, underscoring urgent conservation needs. Comparable vocal-tract modifications have been documented in gibbons, wolves and grasshopper mice, illustrating convergent evolution across distant animals.
Why it matters
The finding reveals sophisticated vocal adaptation in an endangered species, aiding both scientific insight and conservation efforts.
In this story
