By investigating interactions between a honey-seeking bird and honey-foraging humans, scientists are studying how mutualisms evolve, and how they can differ due to cultural variation.

Fundamental Research

Organisms interact with each other in countless ways. These interactions, including predation, and symbioses all serve to shape ecosystems and underpin much of the variety of life that exists on the planet. Mutualisms, for example, close partnerships that benefit both species, are seen throughout the natural world although extremely rare between animals and humans. Such interactions are well-documented, though the role of learnt traits in their origin, stability and evolutionary and ecological consequences are less well known. The Honeyguides-Humans project, funded by the European Research Council, is studying a remarkable mutualism between an African bird and human honey-hunters, and the role learnt behaviours play in this interaction. The greater honeyguide, Indicator indicator, likes to eat beeswax but can’t always access it. So it shows humans where bees’ nests are, who subdue the bees and open the nests. The birds get the beeswax, the humans get the honey.

Understanding cultural variation

This specific mutualism is a particularly interesting model to study, as these interactions vary across Africa due to the cultural diversity of humans across the continent. “Cultural and ecological variation shapes how cooperation functions,” explains Claire Spottiswoode, principal research associate in the Department of Zoology at the University of Cambridge and Honeyguides-Humans project coordinator. For example, human populations differ with respect to whether and how they harvest bees’ nests, and whether they intentionally offer wax rewards to honeyguides or withhold the rewards from them. “Most strikingly, different honey-hunting cultures in different parts of Africa use different calls to communicate with honeyguides, to attract honeyguides to come and guide them, and to maintain a honeyguide’s attention as they follow it – sometimes for a kilometre or more – to a bees’ nest,” says Spottiswoode. These culturally derived calls include various distinctive trills, grunts, whoops, songs, whistled melodies and whistles made with instruments such as dried fruits or snail shells. One goal of the project has therefore been to explore how rewarding traditions and reciprocal communication between humans and honeyguides alter their interactions, and reinforce the other species’ traits. Some insights were published in a study in ‘Proceedings of the Royal Society B’ in 2022. The project is ongoing until May 2024, so many of the results and analysis are still being finalised.

A cultural collaboration

Spottiswoode highlights that all her team’s research has been inspired by and carried out with the support and collaboration of honey-hunting communities, particularly that of Mbamba village in the Niassa Special Reserve in Mozambique. “None of this project would have been possible without their inspiration, skill, hospitality, and their own direct data collection,” she notes. Ecologically relevant data from the project is also directly contributing to safeguarding this remarkable example of interspecies cooperation. “To safeguard these unique aspects of our human heritage into the future, we need to ensure that both humans and their wildlife partners remain motivated to cooperate, in an environment that supports their shared activities, and retain their shared interspecies knowledge of how to do so,” says Spottiswoode. “We are continuing our research. Many new questions have been inspired by the diversity of honey-hunting traditions,” adds Spottiswoode. “And by the research techniques that the project has enabled us to develop – for tracking honeyguides, and for enabling traditional honey-hunters to contribute crucially to data collection.”

Keywords

Honeyguides-Humans, bird, honey, human, cultural, interactions, beeswax, traits