Humans and wild birds communicate with each other so that they can seek out honey. The unique relationship between people and the honeyguide bird across much of sub-Saharan Africa was thought to be more of a one-way conversation, but now it seems that both species are listening out for each other.
Flitting from tree to tree, the greater honeyguide (Indicator indicator) leads the humans in the direction of nearby beehives. This is obviously beneficial to the humans as they are shown a delicious house of bees, but also to the bird as it hangs around and waits for them to subdue the bees using smoke, and then break into the hive to get at the sweet honey within. When done, the person will then provide the bird with the wax, in addition to the tasty larvae hidden within. In this relationship both partners benefit, but until now it was only thought that it was the birds that got the humans attention by calling to them.
It has now been found that this the communication between the two species that form this unique relationship is, in fact, two-way: the birds not only recruit the humans, but the humans will recruit the birds. To test this, the researchers recorded a specific call that the hunter-gatherers make to talk with the passerines – a "brrr-hm" noise (which you can hear below) that is learned by children from their fathers – while walking through the bush in Mozambique where the birds live, and compared it with other random noises such as talking.