The evolution, ecology and conservation of honeyguide-human mutualism
This project focuses on a unique mutualism: the foraging partnership between the Greater Honeyguide Indicator indicator and 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 nests using axes. By working together, the two species can overcome the bees’ defences, with benefits to both. 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 provides 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.
Claire Spottiswoode and her team have been studying human-honeyguide interactions in the Niassa National Reserve of northern Mozambique since 2013, collaborating with the honey-hunting community of Mbamba village, and receiving crucial support from the Mariri Environmental Centre led by Dr Colleen and Keith Begg of the Niassa Carnivore Project. A key focus to date 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 2016, using a field experiment, we showed 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. So honeyguides use these specialised signals to choose partners who are likely to be good collaborators, in a two-way conversation between humans and a wild animal, from which both partners benefit.
Supported by a Consolidator Grant from the European Research Council, we now ask whether learning is involved in maintaining a geographical mosaic of honeyguide adaptation to local human cultures; how such reciprocal communication between humans and honeyguides mediates their interactions; what the effects of cultural co-extinctions may be on each partner and their ecosystems; and ultimately, how quickly such cultures can be re-ignited following their loss. 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 varies in space and time, and to predict how they will respond to a rapidly changing world.
Our research has the support of the community and traditional chiefs of Mbamba and Nkuti Villages. Our project is known as ‘Projecto Sego’ (sego is greater honeyguide in the Yao language), and heavily involves the local community in independent data collection as well as assistance with our field sampling and experiments.
Activities in 2019
- From May to October MSc student David Lloyd-Jones and local data manager Orlando Ncuela provided ongoing training and support to 20 honey-hunters collecting data. This was enabled by a custom app we developed with HabitatInfo.
- From May to June, David carried out behavioural experiments to test if young honeyguides refine their guiding behaviour through learning.
- Also from May to June, Post-doc Jessica van der Wal studied geographic variation in human honey-hunting culture in collaboration with Celestino Dauda (Niassa Carnivore Project), supported by independent grants from the Association for the Study of Animal Behaviour and the American Ornithological Society.
- From August to October, Dominic Cram, Jessica and David colour-marked honeyguides and conducted experiments in our study area.
- We hosted an intern, Antonio Ngovene. Antonio is a student on the Conservation Biology MSc course at the Edward O. Wilson Biodiversity Laboratory, Gorongosa National Park.
- Twenty Niassa community honey-hunters have collected high-quality data on hundreds of honey-hunting trips, involving thousands of interactions with honeyguides.
- In June, we celebrated our second year of honey-hunter data-collection with a ‘Festa’ at Mariri Environmental Centre, awarding prizes for data and photo quality and care of equipment.
- We have established a colour-ringed population of over 100 Greater Honeyguides, plus smaller numbers of Lesser and Scaly-throated Honeyguides (which eat wax but do not guide humans) in our study area.
- The research team carried out regular outreach activities in Mozambique, giving presentations to school learners from Niassa Province visiting the Mariri Environmental Centre, and sharing our research findings with the Niassa National Reserve management team.
- We assisted a team from National Geographic magazine in the field.
- Dominic Cram was awarded an Early Career Grant by the British Ecological Society.
- Claire presented recent highlights of our honeyguide research at the ‘Frontiers in Behavioural Research’ symposium at the Max Planck Institute for Ornithology, Seewiesen, Germany.
- David presented a talk on honeyguides guiding humans to dangerous animals at the TAWIRI Research Conference in Arusha, Tanzania.
Impact of the project
This project involves rural communities in understanding a unique human-animal relationship. We hope to further our under-standing of how mutualisms evolve, and specifically how learnt traits mediating mutualisms may coevolve with one another. Understanding the evolution of mutualisms is important because it sheds light on the mechanisms that can maintain cooperation among unrelated individuals. It is also important for effective conservation, because mutualisms can have a wide reach in ecological communities. The honeyguide-human mutualism has already died out from large parts of Africa, as the continent develops. It would be a tragedy if it vanished altogether before we fully understood this part of our own evolutionary history.
European Research Council; National Geographic Society; Max Planck Institute for Evolutionary Anthropology; DST-NRF CoE grant; British Ecological Society; Association for the Study of Animal Behaviour; American Ornithological Society.
Research team 2019
Prof. Claire Spottiswoode (FIAO, UCT and, U. Cambridge)
Dr Jessica van der Wal (FIAO, UCT)
Orlando Ncuela (Niassa Carnivore Project)
Dr Dominic Cram (U. Cambridge)
Dr Brian Wood (U. California Los Angeles)
Prof. Timm Hoffman (Biological Sciences, UCT)
Dr Colleen Begg (Niassa Carnivore Project)
Keith Begg (Niassa Carnivore Project)
Student: David Lloyd-Jones (MSc, UCT)
Research Assistants: Musaji Muemede, Carvalho Issa Nanguar, Iahaia Buanachique and Seliano Alberto Rucunua, with data collection by many others.