Genomics of white-tailed eagle (Haliaeetus albicilla) in the
North-Atlantic islands reveal low diversity and substantial inbreeding
in comparison with the mainland populations
Abstract
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 genetic differentiation is observed between samples from the
different countries, with the largest differences between the island and
mainland populations, and indications that the island populations share
the most recent ancestry with the Norwegian population. We find signs of
strong inbreeding in the island populations. Further, temporal
differences are observed in some populations, for example, replacement
of the Danish gene pool following its population’s extinction in the
early 20th century, as well as a change in the genetic diversity of the
Icelandic population following a severe bottleneck during the last
century, all of which could warrant a further conservation effort in
Iceland. More generally, all populations show a decline in effective
population size, which may have been shaped by I) distinct refugia
during the last glacial period, II) population divergence following the
colonization of the deglaciated areas ~10,000 years ago,
III) human population expansion and e.g., settlement in Iceland
~1,100 years ago, and IV) human persecution and toxic
pollutants during the last two centuries.