Culture and cultural evolution in birds: a review of the evidence

Social learning from the observation of knowledgeable individuals can allow behaviours, skills and techniques to spread across populations and transmit between generations, potentially leading to emergent cultures. An increasing body of research has not only evidenced the occurrence of cultural behaviour in nonhuman animals, but also hypothesized that such cultures could ‘evolve’ over time in a way that shares key characteristics with biological evolution, including through a process of selection on variance, inheritance and adaptation. Outside of humans, song and contact calls in birds provide by far the most comprehensive evidence for culture and cultural evolution. However, birds have often been considered ‘one-trick cultural ponies’ only exhibiting significant diversity in this single component of their behavioural repertoire. Recent studies have begun to challenge this view. Here, I review the evidence across multiple behavioural domains for wild cultures in birds. I then discuss the evidence in birds for four key concepts of cultural evolution: (1) variation, selection, inheritance, (2) adaptation, (3) geographical and demographic processes and (4) the accumulation of modifications. I incorporate the evidence from birdsong with other behavioural domains for each key concept and identify important gaps in knowledge. Finally, I discuss how taking a cultural evolution perspective can be informative for our understanding of cognitive ecology more broadly.