The taxonomy of Procellariiformes, particularly petrels and shearwaters, is still unresolved. The Manx shearwater Puffinus puffinus is one of the best studied seabirds worldwide. Most of the information known on this seabird is focused on the northern core populations where the species is abundant. However, the species shows a high number of peripheral populations, which are extremely small and difficult to study in comparison to central populations. Using an integrative approach, this...