Living together: Cooperation and conflict in the Sociable Weaver
In animal societies individuals cooperate in order to achieve vital things, such as foraging, avoiding predators or reproducing. But cooperation represents an evolutionary puzzle because natural selection is thought to favour selfish individuals over co-operators, which should lead to conflict and ultimately to the collapse of cooperation. We have been investigating the benefits and costs of cooperation through a long-term study of the Sociable Weaver Philetairus socius at Benfontein Nature Reserve in South Africa. These birds are highly social and cooperate to achieve various tasks – from communally building their massive nest structure to mobbing predators or raising young – providing an excellent model to study cooperation. However, sociable weaver societies can also be rife with conflict, with consequences varying from social exclusion to extreme behaviours such as infanticide. Ultimately our long-term 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 10 years of work and the main results obtained.