Untangling genes and culture: sex-based song traditions in New Zealand bellbirds

One of the most intriguing features of songbirds is their immense song diversity. Bird song is a form of culture; birds learn song components from the songs of parents and neighbours. These cultural units are known as memes and are analogous to genes. How rapidly do memes change and where do they come from? When do young birds learn memes? Bird song dialects have proven to be excellent models for testing cultural evolution theory, as song has evolved due to a range of genetic and cultural influences. The northern New Zealand bellbird meta-population provides a model that will enable us to quantify genetic and cultural contributions to song diversity. Male and female bellbirds sing different repertoires of complex songs but, within a population, share the same genetic history and environmental conditions. We will examine the origins and stability of song diversity using an evolutionary approach. We hypothesise that memes are transferred intra-sexually via learning. Most significantly, bellbird females disperse between populations more frequently than males, thus, the sexes will have independently evolving song diversity. This provides us with the unique opportunity to understand the dynamics of avian cultural change, how dispersal influences song diversity, and how song dialects evolve.