Genetic Differences in Purple Finch ( <i>Haemorhous purpureus</i> ) Are Linked With Subspecies and Migratory Behaviour Differences

, we found that populations formed three genetic clusters. Population structure was not strongly associated with resident or migratory behaviour, although we did identify five regions under selection that were distinct between migratory and resident populations. Two of the genes identified in these scans were related to ghrelin hormone and liver fat deposit; Ghrelin is a key component of migratory restlessness, while liver fat deposits are used to fuel migration in birds. Combined our results suggest that population genetic differences between subspecies reflect historical isolation during the Last Glacial Maximum, and indicate that some genetic differences occur between resident and migratory populations. These genetic differences appear to be associated essential for pre-migratory and migratory behaviour in birds.