Population genetic structure of Mexican Magnificent Frigatebirds: an integrative analysis of the influence of reproductive behavior and sex-biased dispersal

Abstract

The Magnificent Frigatebird (Fregata magnificens) is a monogamous, widespread, neotropical, pelagicseabird with low flight costs, high dispersal capacity, sex-biased dispersal, and female mate choice. Here, we adoptan integrative approach to evaluate the influence of behavior, male-biased philopatry, female choice, and geographicdistance as non-physical barriers to dispersal acting on the genetic structure of magnificent frigatebirds in the 4largest Mexican breeding colonies. We integrate ecological dispersal observations from tagging studies, analyses ofmaternally and biparentally inherited genetic markers, and group-structured population modeling. Mitochondrial DNA(matrilineal) and randomly amplified polymorphic DNA (biparental) data provided evidence of genetic differentiationbetween ocean basins, as well as among Eastern Pacific breeding colonies, and absence of a genetic pattern of isolationby distance. Our ecological, genetic, and modeling results are concordant with the expected effects of sex-biasedphilopatry and female mate choice as non-physical barriers to interbreeding, and suggest that geographic distance doesnot play a significant role in the genetic distinction of breeding colonies. The genetic differentiation found betweenEastern Pacific and Caribbean, as well as that among Eastern Pacific breeding colonies is of consequence for themanagement plans and conservation measures of the Magnificent Frigatebird in the region.