title: Population genetic structure and long-distance dispersal among seabird populations: implications for colony persistence.
abstract: Dramatic local population decline brought about by anthropogenic-driven change is an increasingly common threat to biodiversity. Seabird life history traits make them particularly vulnerable to such change; therefore, understanding population connectivity and dispersal dynamics is vital for successful management. Our study used a 357-base pair mitochondrial control region locus sequenced for 103 individuals and 18 nuclear microsatellite loci genotyped for 245 individuals to investigate population structure in the Atlantic and Pacific populations of the pelagic seabird, Leach's storm-petrel Oceanodroma leucorhoa leucorhoa. This species is under intense predation pressure at one regionally important colony on St Kilda, Scotland, where a disparity between population decline and predation rates hints at immigration from other large colonies. AMOVA, F(ST), Φ(ST) and Bayesian cluster analyses revealed no genetic structure among Atlantic colonies (Global Φ(ST) = -0.02 P > 0.05, Global F(ST) = 0.003, P > 0.05, STRUCTURE K = 1), consistent with either contemporary gene flow or strong historical association within the ocean basin. The Pacific and Atlantic populations are genetically distinct (Global Φ(ST) = 0.32 P < 0.0001, Global F(ST) = 0.04, P < 0.0001, STRUCTURE K = 2), but evidence for interocean exchange was found with individual exclusion/assignment and population coalescent analyses. These findings highlight the importance of conserving multiple colonies at a number of different sites and suggest that management of this seabird may be best viewed at an oceanic scale. Moreover, our study provides an illustration of how long-distance movement may ameliorate the potentially deleterious impacts of localized environmental change, although direct measures of dispersal are still required to better understand this process.
authors.affiliation: Marine Biology and Ecology Research Centre, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK. anthony.bicknell@plymouth.ac.uk
authors.forename: A W J
authors.initials: AW
authors.lastname: Bicknell
authors.forename: M E
authors.initials: ME
authors.lastname: Knight
authors.forename: D
authors.initials: D
authors.lastname: Bilton
authors.forename: J B
authors.initials: JB
authors.lastname: Reid
authors.forename: T
authors.initials: T
authors.lastname: Burke
authors.forename: S C
authors.initials: SC
authors.lastname: Votier
mesh_terms: D063147:Animal Distribution; D025041:Animal Migration; D000818:Animals; D001483:Base Sequence; D044822:Biodiversity; D001717:Birds / Q000235:genetics* / Q000502:physiology; D004272:DNA, Mitochondrial / Q000235:genetics; D040342:Genetic Structures; D014644:Genetic Variation; D005838:Genotype; D018895:Microsatellite Repeats / Q000235:genetics; D008928:Mitochondria / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial