The evolution, ecology and conservation of honeyguide-human mutualism
This project focuses on a unique mutualism: the foraging partnership between an African bird species, the Greater Honeyguide Indicator indicator, and the human honey-hunters whom it guides to bees’ nests. Honeyguides know where bees’ nests are located and like to eat beeswax; humans know how to subdue the bees using fire, and open the nest using axes. By working together, the two species can overcome the bees’ defences, providing beeswax for honeyguides and honey for people. Remarkably, this relationship has evolved through natural selection, rather than through training or domestication which underpins cooperation by other human foraging partners such as dogs or falcons. The honeyguide-human system gives us a wonderful opportunity to study the ecology and evolution of mutualisms in nature, because local human and honeyguide populations vary strikingly in whether and how they interact, and because we can readily manipulate these interactions experimentally.
Since 2013 Claire Spottiswoode has been studying human-honeyguide interactions in the Niassa National Reserve of northern Mozambique in collaboration with the honey-hunting community of Mbamba village, and with the support of Keith and Colleen Begg of the Niassa Carnivore Project. A key focus has been investigating reciprocal communication between the two parties. Not only do honeyguides signal to humans, but in many different cultures humans signal back to honeyguides, giving special calls to attract honeyguides and maintain their attention while following them. Among the Yao honey-hunters of northern Mozambique, this call is a loud trill followed by a grunt: “brrrr-hm!”. In a paper published in the journal Science in 2016, we showed using a field experiment that honeyguides were twice as likely to initiate a cooperative interaction with humans who made this sound compared to humans giving control human and animal sounds, and three times as likely to successfully lead such humans to honey. These results provide experimental evidence that a wild animal in a natural setting correctly attaches meaning and responds appropriately to a human signal.
Next, supported by a newly-awarded Consolidator Grant from the European Research Council, we plan to ask whether learning is involved in maintaining a geographical mosaic of honeyguide adaptation to local human cultures; how reciprocal communication between humans and honeyguides mediate their interactions; what the effects are of cultural co-extinctions on each partner and their ecosystems; and how quickly such cultures can be re-ignited following their loss. This will involve fieldwork in Mozambique, Tanzania, South Africa and Zimbabwe by a team starting work in 2017. In so doing we hope to test for the first time the hypothesis that reciprocal learning can give rise to matching cultural traits between interacting species. Understanding the role of such phenotypic plasticity is crucial to explain how and why the outcome of species interactions vary in space and time, and to predict how such interactions will respond to a rapidly changing world.
Activities in 2016
- In collaboration with Brian Wood from Yale University, Claire carried out fieldwork on the honeyguide-human relationship among the Hadza people of northern Tanzania.
- Claire Spottiswoode conducted a further field experiment for four weeks in northern Mozambique, testing how honeyguides respond to honey-hunting calls from different human cultures in different parts of Africa.
- Paper published demonstrating reciprocal communication between honeyguides and people; it received worldwide attention in the popular press, even briefly displacing Donald Trump from the front page of The New YorkTimes (Spottiswoode et al. 2016. Science 353: 387-389). The research was also featured in The New Yorker, The Times, The Guardian, Nature, National Geographic, the BBC World Service, and many others.
- European Research Council Consolidator Grant to the value of € 2 million awarded to support Claire Spottiswoode’s honeyguide research for the next five years; the grant is held jointly between UCT and the University of Cambridge.
- Claire Spottiswoode and Brian Wood discussed their honeyguide research in depth in a half-hour programme on honeyguides on BBC Radio 4, as part of the “Natural Histories” series.
DST-NRF CoE grant; Biotechnology and Biological Sciences Research Council (BBSRC), UK; from 2017: European Research Council (ERC).
Prof. Claire Spottiswoode (FIAO, UCT and, U. Cambridge)
Dr Brian Wood (Yale University)
Keith Begg (Niassa Carnivore Project)
Dr Colleen Begg (Niassa Carnivore Project)