They are in danger of extinction. But that doesn’t stop them from singing with rhythm. These are the singing lemurs of Madagascar (Indri indri). They have a natural ability to keep rhythm, just like humans. This is proven by research published in the journal Current Biology.
Singing and screeching
These black and white primates have the weight of a small dog. And they look like a cross between a cat and a koala. They make a sound that sounds like the squeak of a balloon rapidly releasing air. Andrea Ravignani is a cognitive biologist at the Institute of Psycholinguistics in the Netherlands. He decided to investigate this characteristic.
The last common ancestor between humans and indris lived more than 77 million years ago. But we are more similar than we think. There’s something surprising about the strange, wailing songs of lemurs. They are universal rhythms, present in human musical cultures.
The song and rhythm of other animals have intrigued scientists for decades. “Only a few primate species sing. They are vital to understanding the evolutionary origins of human musicality.”
Songs of 20 indri groups (39 animals in all) were recorded over 12 years. There are two examples of human rhythm in lemur songs. A 1:1 rhythm (intervals between two sounds have the same duration). And a 1:2 rhythm, (the second interval is twice as long as the first). They also noticed a gradual decrease in tempo. This is the first time these categorical rhythms have been identified in a non-human mammal.
The singing lemurs of Madagascar have a sense of heartbeat. It’s the repetitive pulse that allows us to move to the beat of the music. “It’s so close to human music, it’s quite amazing,” Ravignani said.
It may be a case of common ancestry or convergent evolution. Exploring our similarities with indris is helping to demystify the evolutionary origins of human music. And it is also bringing much-needed attention to these lemurs. Their cultural importance to the Malagasy people is unique and necessary.