Genomic diversity and differentiation between island and mainland populations of White‐tailed Eagles (Haliaeetus albicilla)

Using whole genome shotgun sequences from 92 white-tailed eagles (Haliaeetus albicilla) sampled from Greenland, Iceland, Norway, Denmark, Estonia, and Turkey between 1885–1950 and after 1990, we investigate the genomic variation within countries over time, and between countries. Clear signatures of ancient biogeographic substructure across Europe and the North‐East Atlantic are observed. The greatest genomic differentiation was observed between island (Greenland and Iceland) and mainland (Denmark, Norway and Estonia) populations. The two island populations share a common ancestry from a single mainland population, distinct from the other sampled mainland populations, and despite the potential for high connectivity between Iceland and Greenland they are well separated from each other and are characterized by inbreeding and little variation. Temporal differences also highlight a pattern of regional populations persisting despite the potential for admixture. All sampled populations general..., Tissue was obtained from 92 specimens: 63 contemporary and 29 historic, from six different countries. These included 12 contemporary and eight historic individuals from Greenland, 25 contemporary and two historic individuals from Iceland, 12 contemporary and 13 historic individuals from Norway, 11 contemporary and five historic individuals from Denmark, three contemporary individuals from Estonia, and one historic individual from Turkey (Figure 1). The historic specimens were sampled between 1885 and 1950 (all but the two Icelandic individuals were sampled prior to 1937), while all contemporary individuals were sampled post-1990 (full individual information is presented in Table 1).
Muscle tissue and whole blood from contemporary samples from Estonia, Denmark, and Greenland (Table 1) were stored at -20 °C until DNA extraction and were provided by the Department of Ecoscience, Arctic Research Centre, AU, Roskilde, Denmark (Estonian, Danish, and Greenland samples), Natural History Museum ...,