10 Apr Do Monkeys Have Names for Each Other? New Research Says Yes!
By Ruth Alexander, UNE Discovery
We humans use names in almost every conversation, whether addressing the person we’re speaking to, recounting what friends and family have been up to, cheering on our favourite athlete or discussing the latest celebrity news. But what if animals could also call each other by ‘name’? It might sound like something out of a movie, or a serious case of anthropomorphising, but new research suggests that some monkeys may be doing exactly that.
Marmoset monkeys live in close-knit family groups and rely heavily on communication to stay connected, especially in dense forest environments where they can’t always see each other. One of the key sounds they make is called a ‘phee call’, a high-pitched call used to keep in touch over distance. Think of it as a ‘Where are you?’ call.
To understand how these calls work, researchers set up experiments where pairs of monkeys were placed out of sight of each other but could still hear one another. By recording thousands of these ‘conversations’ and analysing them, the team looked for patterns in how the calls changed depending on who was listening. What they found was remarkable: monkeys subtly change their calls depending on which individual they are addressing. In the first 20 or so calls, the caller monkey used highly variable calls to try to identify the receiver, then rapidly converged to addressing the receiver monkey by a specific identifying call. In other words, these monkeys seem to be using different ‘names’ for different group members. Interestingly, monkeys from the same family group used similar calls for the same individual on the other side of the barrier, providing evidence that monkeys learn calls from family members, rather than independently inventing ‘names’ for others around them. In another experiment, three monkeys were exposed to recordings of calls made by other monkeys, including some calls of their own unique identifying ‘name’ and some calls addressed to other individuals. These monkeys were more likely to respond when a call was specifically directed at them, suggesting they can recognise their own ‘name’ when they hear it. To add to this, these individuals could also accurately identify the caller and respond with their specific ‘name’.
These kinds of abilities were once thought to be unique to humans, with only a few other animals like dolphins and elephants showing similar behaviour. So, what does this mean for us? At its core, this behaviour shows that marmosets can recognise individuals, learn from each other, and adapt their communication in flexible ways. These are all important building blocks of language. However, unlike humans, who can form an almost infinite combination of vocalisations to form a name, marmosets only modulate the fine acoustic structure of a stereotypical phee call to form a unique label for each receiver. Regardless, this is the first tentative evidence for enduring vocal labels of others in non-human primates, so it may have big implications as we consider how speech evolved. While monkey calls are a long way from human speech, this research hints that the roots of language may go much deeper in the animal kingdom than we once thought.
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