It is likely that cultural factors relating to the wider hunting practices of different groups have helped to shape the precise design of their honey-hunting calls.

For example, the melodic whistle made by Hadza honey-hunters in Tanzania to attract honeyguide birds sounds like a bird call. This reduces the risk of frightening away the prey animals they’re trying to hunt at the same time.

In contrast, the loud trill followed by a grunt made by Yao honey-hunters in Mozambique, sounds distinctively human. This may be a good way for them to frighten away dangerous large animals like elephants and buffalo.

The findings build on work published in 2016, which found that honeyguide birds in Mozambique respond to the calls of human honey hunters.

The researchers work closely with the Yao and Hadza honey-hunting communities in Africa, whose guidance they have relied on for over a decade.

“It’s such a privilege to witness cooperation between people and honeyguides – these are birds who specifically come to seek us out. The calls really sound like a conversation between the bird and the honey-hunters, as they move together towards a bees’ nest.”

Spottiswoode

Humans are useful collaborators to honeyguides because of our ability to subdue stinging bees with smoke and chop open the nest, providing wax for the honeyguide and honey for ourselves.

This relationship is a rare example of cooperation between humans and wild animals. Wild honey is a high-energy food that can provide up to 20% of the calorie intake for honey-hunters – and the wax they share or discard is a valuable food for the honeyguide.

“What’s remarkable about the honeyguide-human relationship is that it involves free-living wild animals whose interactions with humans have evolved through natural selection, possibly over the course of hundreds of thousands of years,” said Spottiswoode.

She added: “This ancient, evolved behaviour has then been refined to local cultural traditions – the different human call sounds – through learning.”