Parasitic infection is associated with reduced latency to socially learn a novel foraging task

Abstract Social learning, whereby individuals use social information to explore and exploit the environment, is widespread among animals. It enables individuals to have greater efficiency in extracting resources and better adapt to changing environments. At the same time, animals can host numerous parasites that have been found to affect behaviour, including individual learning. However, little is known about the effects of parasitic infection on social learning. In this study, we use the great tit (Parus major)—a species that readily engages in social learning—to investigate potential effects of two prevalent parasites, coccidia (Isospora sp.) and lungworm (Serratospiculoides amaculata), on the ability to socially learn a novel foraging task. Across 24 replicated experimental groups, we found that coccidia infections were associated with a shorter latency to learn the novel behaviour. By contrast, co-infection with the two parasites had a negative effect on social learning by increasing latency to learn relative to individuals with only a single infection. Our study suggests that endoparasites may have substantial implications for the spread of information and novel behaviours in animal populations by modulating the rate of social learning by their hosts.