Living together: Cooperation and Conflict in the Sociable Weaver

November 1st, 2024 4 PM CET/10 AM EST

Doctor Rita Covas, Principal Researcher at CIBIO, University of Porto (Portugal) and Honorary Research Associate at the FitzPatrick Institute, University of Cape Town (South Africa)

See her webinar at https://youtu.be/rJ57VOMzz14

Cooperative behaviour represents an evolutionary puzzle because natural selection is thought to favour selfish individuals over co-operators, which should lead to the collapse of cooperation. Yet, cooperative behaviour is widespread in nature, from unicellular organisms to humans. To understand how cooperation evolves and persists, it’s important to understand its benefits and costs, and we have been investigating these through a long- term study of a small bird: the Sociable Weaver Philetairus socius at Benfontein Nature Reserve in South Africa. These birds are highly social and cooperate to achieve various tasks, providing an excellent model to study cooperation. Our work has shown that sociable weavers live in societies that are to some extent based on family interactions, and that kin-selection could play a role in explaining cooperative interactions in this species. However, social links and cooperative interactions also take place among non-kin. Theory and studies in humans show us that co-operators are preferred as social and sexual partners, suggesting that partner choice may therefore provide a powerful explanation for the evolution and
stability of cooperation, alongside kin selection, and we are currently assessing the importance of these mechanisms. However, life in animal societies can also be rife with conflict, with consequences varying from social exclusion to extreme behaviours such as infanticide. Ultimately, our study aims to understand the factors that influence the balance between cooperation and conflict, allowing cooperation to be maintained and animal societies to persist. Here I will provide an overview of 15 years of work and the main results obtained.

Biosketch:

Rita is a behavioural ecologist and evolutionary biologist with a strong interest in the evolution and consequences of sociality and a passion for fieldwork. She uses birds as study models and strongly believes in the importance of long-term data to address questions about evolution in the wild. Rita has been working on cooperation using the sociable weaver as a study model since her PhD (2002). After some years studying patterns of adaptation in island birds, Rita returned to South Africa in 2008 to relaunch the Sociable Weaver project, together with long-term collaborator Claire Doutrelant. The project uses these weavers to study the evolution and consequences of sociality and cooperation and the factors that influence the balance between cooperation and conflict. In 2016, Rita became also the coordinator of another study on a cooperative bird, the large and exceptionally long-lived Southern-Ground Hornbill (at the APNR, Hoedspruit, South Africa). The long-term data sets provided by both projects are also used to study how long-term population dynamics is influenced by environmental variation and how this interacts with social behaviour. In addition, Rita has maintained a keen interest in insularity and how species adapt to the island environment, especially on what concerns behavioural adaptations, and this research is currently pursued through comparative studies. Rita is a Principal Researcher at CIBIO, University of Porto (Portugal) and Honorary Research Associate at the FitzPatrick Institute, University of Cape Town (South Africa).

EvoKE webinars are held on the first Friday of every month at 4 PM CET/10 AM EST