This project, supported by an ERC advanced grant that started in January 2026, aims at identifying genes that code for variation of migration patterns (propensity to migrate as well as directions and distances). In willow warblers and chiffchaffs we have found that a repeat rich region in the genome that we have named MARB (Migration Associated Repeat Block), predict their migration direction(SW or SE) with a remarkable precision. We will do detailed studies of these species to find out the genetic mechanisms behind this behavior including multiple long-read genomes to construct a pangenome, single-cell RNA-seq from specific regions in the brain, and whole-genome resequencing from populations across their breeding ranges. To put these results in a wider context we will sequence genomes of all 70 species in the genus Phylloscopus combining long-read and short-read sequencing.