Modelling Birdsong Evolution

In many bird species, young males learn their songs from their fathers. But learning occurs with error, so songs can change over generations. This culturally transmitted behaviour fascinates the public and has important implications for conservation. Birds use songs to choose mates, so if songs diverge between partly isolated populations, this may prevent those populations from exchanging genes, diminishing genetic diversity and threatening the species viability. Data-driven mechanistic models of the evolution of birdsong could help us understand birdsong evolution, but few such models exist.

Birdsong evolution is in some ways analogous to genome evolution. Notes play the role of nucleotides, and mutations (i.e., errors in copying) can change one note to another. Notes or song segments can be inserted, deleted, or duplicated. Tools from molecular phylogenetics may thus provide a foundation for modelling the generation-to-generation change in birds' songs. There are, however, important differences between genomes and birdsongs. For example, individuals have a single genome, but a bird may sing many different songs. Genomes are comprised of only four nucleotides, but birdsongs typically have many more than four different notes and - at least in principle - entirely new notes can arise. Furthermore, because changes between related birdsongs are more common than genetic changes, aligning birdsongs for study is difficult, and inferences may need to be drawn from multiple possible alignments. Novel mathematical and statistical approaches are needed to overcome these challenges.

The student in this will develop novel mathematical models to describe and predict the evolution of birdsong. These models will help explain how animal cultures evolve and will have applications for in situ and ex situ conservation.

The project will be advised by a team including an applied mathematician, a mathematical ecologist and a linguist at the University fo Manchester as well as an animal behaviourist who is a birdsong expert at the University of Hokkaido.