Greater Honeyguide specimen used in Cornell’s Ornithology course (photo and handling by a teaching assistant)

When I took Cornell’s course in ornithology, we learned about all the bird families in the world to varying extent, often based on the number of species within each family or how interesting they were to our professor. One family that we did not cover with great depth, but which was considered a “cool” example of evolution that could either make for a fascinating science experiment or just good cocktail-party chatting––we were gently reminded that the latter shouldn’t always revolve around weird bird things––was Indicatoridae, or the honeyguides.

While not all members of this family are literally guides to honey, one species in particular, the Greater Honeyguide, is well known for actually showing (or indicating) the way to beehives, where humans can harvest honey and the birds can eat larvae and wax. In this week’s edition of Science, researchers from Cambridge University and University of Cape Town published a paper revealing that the wild birds can actually be better guides when they receive a certain signal from the human honey-hunters. Nicola Davis reports: 

Wild birds and humans can engage in two-way conversation to the benefit of both, researchers have revealed.

A brown bird with a penchant for beeswax, the greater honeyguide is well known for signalling to human honey hunters, issuing a squeaky, chirruping call while darting between trees to indicate the way to a bees’ nest. Once there the honey-hunters collect honey while the birds feast upon leftover wax.

But now researchers have found the communication goes both ways.

“Honey hunters use special calls to signal to honeyguides that they are eager to follow, and then honeyguides in turn use that information to chose partners who are likely to be good collaborators,” said Claire Spottiswoode, lead author of the research from the University of Cambridge and the University of Cape Town.

While such displays of biological teamwork are common between animals that have been domesticated or trained, cases involving free-living animals are rare. “It seems to be a two-way conversation between our own species and a wild animal from which both those partners benefit,” Spottiswoode added.

Writing in the journal Science, Spottiswoode and colleagues describe how they spent time in the Niassa National Reserve in northern Mozambique with honey hunters of the Yao community to unpick the nature of their relationship with the honeyguide.

The researchers found that when the honey hunters special call was used, around 75% of the time the honeyguide successfully led the way to a bees’ nest.

But the question remained whether the honey hunters’ call specifically signalled to the birds that they wanted to be guided, or whether the birds simply turned up because they recognised that humans were in the vicinity.

“This was instantly intriguing: could this really be an example of reciprocal communication between humans and a wild animal?” said Spottiswoode.

To find out, the researchers took part in 72 honey-hunting expeditions. During each of them one of three different sounds was played, one of which was the honey-hunters’ halloo: a long trill followed by a short grunt with a rising inflection known as the “brrrr-hm” call. The other two sounds, spoken words in the local language and the sounds of a common bird, were used as “controls” for comparison.

The researchers found that the honeyguides were more than twice as likely to lead the way when the “brrrr-hm” call was played compared to the other two sounds, prompting the bird to guide the party on 16 out of the 24 occasions it was played.

Read the rest of the article from The Guardian.