Genetic structure among continental and island populations of gyrfalcons

Abstract

Little is known about the possible influence that past glacial events have had on the phylogeography and population structure of avian predators in the Arctic and sub-Arctic. In this study, we use microsatellite and mitochondrial control region DNA variation to investigate the population genetic structure of gyrfalcons (Falco rusticolus) throughout a large portion of their circumpolar distribution. In most locations sampled, the mtDNA data revealed little geographic structure; however, five out of eight mtDNA haplotypes were unique to a particular geographic area (Greenland, Iceland, or Alaska) and the Iceland population differed from others based on haplotype frequency differences (F(ST)). With the microsatellite results, significant population structure (F(ST), principal components analysis, and cluster analysis) was observed identifying Greenland and Iceland as separate populations, while Norway, Alaska and Canada were identified as a single population consistent with contemporary gene flow across Russia. Within Greenland, differing levels of gene flow between western and eastern sampling locations was indicated with apparent asymmetric dispersal in western Greenland from north to south. This dispersal bias is in agreement with the distribution of plumage colour variants with white gyrfalcons in much higher proportion in northern Greenland. Lastly, because the mtDNA control region sequence differed by only one to four nucleotides from a common haplotype among all gyrfalcons, we infer that the observed microsatellite population genetic structure has developed since the last glacial maximum. This conclusion is further supported by our finding that a closely related species, the saker falcon (Falco cherrug), has greater genetic heterogeneity, including mtDNA haplotypes differing by 1-16 nucleotide substitutions from a common gyrfalcon haplotype. This is consistent with gyrfalcons having expanded rapidly from a single glacial-age refugium to their current circumpolar distribution. Additional sampling of gyrfalcons from Fennoscandia and Russia throughout Siberia is necessary to test putative gene flow between Norway and Alaska and Canada as suggested by this study.

Do male and female black‐backed woodpeckers respond differently to gaps in habitat?

“…2000) have patterns of genetic structure consistent with male‐mediated gene flow (i.e., highly structured mtDNA and weakly structured nuclear DNA). Lekking species tend to have the common pattern of female mediated gene flow with high site fidelity by males that is evidenced by mtDNA structure that is weak compared to nuclear structure (Bouzat and Johnson 2004; Johnson et al. 2007).…”

The Use of Genetics for the Management of a Recovering Population: Temporal Assessment of Migratory Peregrine Falcons in North America

“…Blood samples were taken during both autumn and spring migration for each of the following temporal subsets: 1985/86, 1988/89, and 2006/07, with additional samples from spring 2001 migration period (see Table 1 for sample sizes). All samples were kept frozen, and DNA extractions were performed using methods described elsewhere [34]. An additional 349 samples were obtained from the contemporary northern breeding distribution of peregrine falcons throughout Alaska, Canada and western Greenland, of which 168 samples were used in a previous study [35].…”

“…All microsatellite loci were dinucleotide repeats, and protocols used for PCR amplification have been described elsewhere [34], [35], [37]. Genotypic data generated in different laboratories using different procedures were calibrated using a subset of samples (n≥4) for each of the eleven microsatellite loci.…”

Exonic versus intronic SNPs: contrasting roles in revealing the population genetic differentiation of a widespread bird species

“…We also identified Central Eurasian populations as conduits for genetic exchange between the eastern and western saker populations, although we cannot rule out the possibility that their mixed background was due to the low discriminatory power of current exon system. Ancient or occasional recent hybridization has been reported between saker falcons and other falcon species (especially gyrfalcon F. rusticolus; Nittinger et al, 2005Nittinger et al, , 2007Johnson et al, 2007), which may also influence the population history of saker falcons. The efficiency of our SNP system in the examination of this interspecific hybridization warrants future research.…”