In the woodlands of northern Mozambique, a unique conversation has been taking place for generations. It doesn’t happen between people, but between people and wild birds, a new study says.
The research, published in People and Nature, shows that these conversations even have regional accents and the birds can keep up.
The study focuses on cooperation between humans and greater honeyguides, small wild birds that lead honey-hunters to bees’ nests. After humans harvest the honey, they leave behind beeswax, which the birds eat. To begin this partnership, people make special calls–whistles, trills, or grunts–to attract a honeyguide and signal their willingness to cooperate.
What surprised scientists is how much these calls vary from place to place.
“Human-wildlife cooperation allows us to investigate whether human signals directed at untrained, wild animals exhibit regional variation, akin to dialects in human language,” the researchers write.
By recording honey-hunting calls from 13 villages across northern Mozambique, the team found that people living closer together used more similar calls, while those farther apart sounded increasingly different. In other words, the calls formed local dialects, much like human accents.
“Our analyses showed that trills, grunts, whoops, and whistles used while cooperating with honeyguides consistently varied with spatial distance between villages,” the authors report. People from the same village sounded more alike than people from different villages.
At first glance, it might seem obvious that the environment–dense forest versus open woodland–could shape how people call. But the data told a different story. “Calls varied irrespective of the local habitat,” the study found. Even after accounting for vegetation and sound-carrying conditions, the differences remained.
Instead, culture appears to be the driving force. Most honey-hunters learn their calls from older relatives or fellow villagers, passing them down through generations. Over time, this social learning creates local traditions–dialects meant not for other humans, but for birds.
Even more striking, hunters who moved to new villages did not keep their old calling style. “Immigrant honey-hunters appear to adapt to the calls in their new village of residence, rather than retaining the calls they learnt in their village of origin,” the researchers write. Just like people adjusting their accents after moving, honey-hunters quickly adopt the local “bird language.”
But perhaps the most remarkable finding is that the honeyguides themselves make all this work. Despite the patchwork of human dialects, cooperation continues successfully everywhere.
“Honeyguides cooperate effectively with honey-hunters throughout this landscape, suggesting that they accommodate (and likely reinforce) cultural differences by learning the local interspecies dialect,” the authors note.
Previous experiments have already shown that honeyguides respond more strongly to familiar local calls than to unfamiliar ones. This suggests the birds are not just following instinct–they are learning.
Taken together, the findings reveal something profound about communication and intelligence across species boundaries. “Human dialects can emerge even in signals intended for wild, untrained animal partners,” the researchers conclude.
In a world where human influence often disrupts wildlife, this ancient partnership offers a rare counterpoint: a shared language, shaped by culture, learned across species, and refined over generations–one whistle at a time.
Photo credit: Claire Spottiswoode, accessed from AAAS