We study the processes of adaptation and speciation using hybrid zones and variation within single species. These systems are ideal for studying evolutionary processes; they allow us to concentrate on the early stages of speciation and work in natural contexts. Our work focuses specifically on the phenotypic and genetic basis of adaptation and speciation and is aided by recent advances in several fields. For example, we are very interested in the role differences in seasonal migration play in speciation and the genetic basis of this behaviour syndrome. Advances in animal movement ecology and genomic are allowing answer questions we never thought possible. Much of our work focuses on single systems but wherever possible we expand out into larger comparative work using data from museum specimens and sequence archives.