Successful honey hunters know how to communicate with wild birds searching for honey

In many parts of Africa, humans cooperate with a species of wax-eating bird called a large honey guide, Indicator Indicator, which leads them to the nests of wild bees with a chattering call. By using specialized sounds to communicate with each other, both species can significantly increase their chances of accessing high-calorie honey and beeswax.

Human honey hunters in different parts of Africa use different calls to communicate with honey guides. In a new study, researchers have found that honey guide birds from Tanzania and Mozambique discriminate between the calls of honey hunters, responding much more readily to local calls than to foreign ones.

The study is published in the journal Science.

“We found that honeyguides prefer calls made by their local human partners, over foreign calls and arbitrary human sounds. This benefits both species, because it helps honeyhunters attract a honeyguide to show them hard-to-find bee nests. and helps the honeyguides choose a good partner to help them get the wax,” said Dr Claire Spottiswoode, an evolutionary biologist at the University of Cambridge’s department of zoology. and the University of Cape Town, and co-senior author of the paper.

Hadza honey hunters in Tanzania communicate with honey guides using a melodic whistle, while Yao honey hunters in Mozambique use a trill followed by a grunt.

Experiments have shown that honeyguides in the Kidero Hills, Tanzania, are three times more likely to cooperate with people who whistle the local Hadza than with people who give the trill and the “foreign” Yao growl. And honeyguides in Mozambique’s Niassa Special Reserve are almost twice as likely to cooperate in response to the local Yao trill and growl as they are to the “foreign” Hadza whistle.

The phenomenon appears to be self-reinforcing: Honeyguides learn to recognize that a specific call indicates a good honey-hunting partner, and humans are more successful at attracting birds if they use that call.

People who use a different call are less likely to attract a bird to guide them to the honey. So it is in their best interest to stick to sounds used locally.

“Once these local cultural traditions are established, it pays for everyone – birds and humans – to conform to them, even if the sounds themselves are arbitrary,” said co-lead author, Dr. Brian Wood, an anthropologist at the University of California, Los Angeles. Angeles.

The researchers compare this to different human languages, in which the sounds of words are arbitrary, but everyone agrees on their meaning.

Spottiswoode added: “Just as humans around the world communicate using a range of different local languages, people across Africa communicate with honey guide birds using a range of different local sounds.”

Like language, these culturally determined calls convey an underlying meaning: signaling the desire to partner with the bird to find honey.

It is likely that cultural factors related to the broader hunting practices of different groups helped shape the precise design of their honey hunting calls.

For example, the melodic whistle made by Hadza honey hunters in Tanzania to attract honey guide birds sounds like a bird song. This reduces the risk of spooking prey they are trying to hunt at the same time.

In contrast, the loud trill followed by a growl emitted by Yao honey hunters in Mozambique, sounds distinctly human. This can be a good way for them to scare away large, dangerous animals like elephants and buffalo.

The findings build on work published in 2016 that found Mozambique’s honey guide birds respond to the calls of human honey hunters.

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

“It is such a privilege to witness the cooperation between people and the honeys, these are birds that are specifically coming to look for us. The calls really sound like a conversation between the bird and the honey hunters, while They head together toward a honeycomb,” Spottiswoode said.

Humans are useful collaborators of honeyguides because of our ability to subdue stinging bees with smoke and open the nest, thereby 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 an energy-rich food that can provide up to 20% of honey hunters’ caloric intake. The wax they share or discard is valuable food for the honey guide.

“What is remarkable about the relationship between guides and humans is that it involves free-living wild animals whose interactions with humans have evolved through natural selection, perhaps over hundreds of thousands of years,” Spottiswoode said.

She added: “This ancient and evolved behavior was then refined to local cultural traditions – the different human calling sounds – through learning. »

The research is a collaboration between researchers from the University of Cambridge, the University of Cape Town and the University of California, Los Angeles, as well as many of the honey hunters who inspired and supported the experiments .