Translator Disclaimer
1 February 2013 Genetic Structure of the Common Eider in the Western Aleutian Islands Prior to Fox Eradication
Author Affiliations +

Since the late 18th century bird populations residing in the Aleutian Archipelago have been greatly reduced by introduced arctic foxes (Alopex lagopus). We analyzed data from microsatellite, nuclear intron, and mitochondrial (mtDNA) loci to examine the spatial genetic structure, demography, and gene flow among four Aleutian Island populations of the Common Eider (Somateria mollissima) much reduced by introduced foxes. In mtDNA, we found high levels of genetic structure within and between island groups (ΦST = 0.643), but we found no population subdivision in microsatellites or nuclear introns. Differences in genetic structure between the mitochondrial and nuclear genomes are consistent with the Common Eider's breeding and winter biology, as females are highly philopatric and males disperse. Nevertheless, significant differences between islands in the mtDNA of males and marginal significance (P = 0.07) in the Z-linked locus Smo 1 suggest that males may also have some level of fidelity to island groups. Severe reduction of populations by the fox, coupled with females' high philopatry, may have left the genetic signature of a bottleneck effect, resulting in the high levels of genetic differentiation observed in mtDNA (ΦST = 0.460–0.807) between islands only 440 km apart. Reestablishment of the Common Eider following the fox's eradication was likely through recruitment from within the islands and bolstered by dispersal from neighboring islands, as suggested by the lack of genetic structure and asymmetry in gene flow between Attu and the other Near Islands.

© 2013 by The Cooper Ornithological Society. All rights reserved. Please direct all requests for permission to photocopy or reproduce article content through the University of California Press's Rights and Permissions website,
Sarah A. Sonsthagen, Sandra L. Talbot, Robert E. Wilson, Margaret R. Petersen, Jeffrey C. Williams, G. Vernon Byrd, and Kevin G. McCracken "Genetic Structure of the Common Eider in the Western Aleutian Islands Prior to Fox Eradication," The Condor 115(1), 28-39, (1 February 2013).
Received: 15 April 2011; Accepted: 1 June 2012; Published: 1 February 2013

Get copyright permission
Back to Top