Periodic Reporting for period 5 - Honeyguides-Humans (How a mutualism evolves: learning, coevolution, and their ecosystem consequences in human-honeyguide interactions)
Periodo di rendicontazione: 2023-06-01 al 2024-05-31
Species interactions such as mutualism, parasitism, and predation underpin much of life’s diversity. We aimed to understand the role of learnt traits in the origin and maintenance of mutually beneficial interactions between species (mutualisms), and to test their evolutionary and ecological consequences. To do so, we studied a remarkable mutualism: the foraging partnership between an African bird species, the greater honeyguide, and the human honey-hunters whom it guides to bees’ nests. Honeyguides know where bees’ nests are located and like to eat beeswax; humans have the ability to subdue the bees and open the nest, thus exposing beeswax for the honeyguides and honey for the humans. This rare example of cooperation between humans and wild animals gives us a wonderful opportunity to study mutualisms, because local human and honeyguide populations vary strikingly in whether and how they interact, and because we can readily manipulate these interactions experimentally. We carried out research in close cooperation with rural honey-hunting communities, particularly in northern Mozambique. Here, and at other locations in south-eastern Africa, we asked how learning is involved in maintaining a geographical mosaic of honeyguide adaptation to different human cultures. We asked how reciprocal communication between humans and honeyguides mediates their interactions, and in so doing tested for the first time the hypothesis that reciprocal learning can give rise to matching cultural traits between interacting species. We asked how the mutualism both maintains, and is maintained by, other species in the ecosystem, and investigated how it helps to shape ecosystem processes (such as wildfires) in its wider environment . Understanding the role of such behavioural adaptations is crucial to explaining 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 project principally involved field research, carried out in particularly in Mozambique in close collaboration with a honey-hunting community in the Niassa Special Reserve, as well as Tanzania, Zambia, and South Africa.
Our research illuminated how cooperation between humans and honeyguides (i) is fine-tuned by learning in both species, particularly learnt communication between species that varies culturally across human societies in Africa; (ii) both supports, and is supported by, its broader ecosystem; (iii) helps to shape the ecosystem processes of African savannah environments.
More broadly, the project has helped to illuminate how cooperation and communication between humans and other animals can evolve and diversify, and is imperilled by human cultural change. It also provides an example of how traditional ecological knowledge can inspire and greatly enhance scientific research.
Our research illuminated how cooperation between humans and honeyguides (i) is fine-tuned by learning in both species, particularly learnt communication between species that varies culturally across human societies in Africa; (ii) both supports, and is supported by, its broader ecosystem; (iii) helps to shape the ecosystem processes of African savannah environments.
More broadly, the project has helped to illuminate how cooperation and communication between humans and other animals can evolve and diversify, and is imperilled by human cultural change. It also provides an example of how traditional ecological knowledge can inspire and greatly enhance scientific research.
The project progressed beyond the state of the art in three ways.
First, it advanced our understanding of how communication between humans and other animals can evolve and diversify. The project showed that honeyguides learn the distinct calls that honey-hunters in different parts of Africa use to communicate with them, facilitating cooperation between species. This suggests that communication between humans and other species can assign meaning to arbitrary sounds in a similar manner to human language. These findings helped to establish the little-studied but potentially powerful concept of cultural coevolution, in which the cultures of interacting species mutually shape and reinforce one another.
Second, it empowered indigenous knowledge. It did so by developing novel methodology that enabled a Mozambican honey-hunting community to allow their deep traditional ecological knowledge to generate a robust scientific dataset. This dataset has, in turn, been crucial to informing local conservation policy and helping to safeguard honey-hunting, and so to the continued persistence of the remarkable honeyguide-human mutualism at its most important remaining hotspot.
Third, it helped to illuminate the rare and threatened cases of cooperation between humans and wild animals, a precious part of our human heritage. This arose from a workshop we organized on Human-Wildlife Mutualism, involving a broad team of collaborators including anthropologists, linguists, conservation practitioners, honey-hunters who cooperate with honeyguides, and fishermen who cooperate with dolphins. This diverse expertise led to insights on how these remarkable relationships evolved, and how they are best safeguarded in those few places where they still thrive.
First, it advanced our understanding of how communication between humans and other animals can evolve and diversify. The project showed that honeyguides learn the distinct calls that honey-hunters in different parts of Africa use to communicate with them, facilitating cooperation between species. This suggests that communication between humans and other species can assign meaning to arbitrary sounds in a similar manner to human language. These findings helped to establish the little-studied but potentially powerful concept of cultural coevolution, in which the cultures of interacting species mutually shape and reinforce one another.
Second, it empowered indigenous knowledge. It did so by developing novel methodology that enabled a Mozambican honey-hunting community to allow their deep traditional ecological knowledge to generate a robust scientific dataset. This dataset has, in turn, been crucial to informing local conservation policy and helping to safeguard honey-hunting, and so to the continued persistence of the remarkable honeyguide-human mutualism at its most important remaining hotspot.
Third, it helped to illuminate the rare and threatened cases of cooperation between humans and wild animals, a precious part of our human heritage. This arose from a workshop we organized on Human-Wildlife Mutualism, involving a broad team of collaborators including anthropologists, linguists, conservation practitioners, honey-hunters who cooperate with honeyguides, and fishermen who cooperate with dolphins. This diverse expertise led to insights on how these remarkable relationships evolved, and how they are best safeguarded in those few places where they still thrive.