Movement and conformity interact to establish local behavioural traditions in animal populations

The social transmission of information is critical to the emergence of animal culture. Two processes are predicted to play key roles in how socially-transmitted information spreads in animal populations: the movement of individuals across the landscape and conformist social learning. We develop a model that, for the first time, explicitly integrates these processes to investigate their impacts on the spread of behavioural preferences. Our results reveal a strong interplay between movement and conformity in determining whether locally-variable traditions establish across a landscape or whether a single preference dominates the whole population. The model is able to replicate a real-world cultural diffusion experiment in great tits Parus major, but also allows for a range of predictions for the emergence of animal culture under various initial conditions, habitat structure and strength of conformist bias to be made. Integrating social behaviour with ecological variation will be important for understanding the stability and diversity of culture in animals.Author summary: In many animal species, the social transmission of information is important and can lead to the emergence of behavioural traditions. However, how ecological and social processes together influence information transmission and its consequences for animal culture, particularly across space, remains largely unknown. We developed a spatially-explicit model examining the spread of behavioural preference through a population, which integrates two key processes: the movement of individuals in the landscape, and social learning with conformity (the disproportionate likelihood of adopting the behavioural trait that is most common locally). The model can replicate a real-world cultural diffusion experiment in great tits Parus major. It is also general, and allows us to make predictions about the emergence of animal cultures in a range of different ecological and social scenarios, including habitats with different states of fragmentation, species with varying movement patterns, and different strengths of conformity in the transmission of behaviour. Our results reveal a strong interplay between ecological and social processes (in this case, movement and conformity) for determining whether or not traditions establish within a population. If traditions do emerge, then these can either be local or global, depending on the relative strength of conformity compared to movement.