This project will continue genomic analyses of differentially migrating populations of the willow warbler with the ultimate goal of identifying genes that underlie variation in migratory traits. Using the latest technologies, we will assemble a new reference genome and improve the annotation of genes and repeats. The new reference genome will be the used to analyze whole-genome resequencing data from a number of samples from different populations, including more than 30 samples for which there is detailed data on their migratory routes.