Data from: Female-biased dispersal and non-random gene flow of MC1R variants do not result in a migration load in barn owls

Non-random gene flow is a widely neglected force in evolution and ecology. This genotype-dependent dispersal is difficult to assess, yet can impact the genetic variation of natural populations and their fitness. In this work, we demonstrate a high immigration rate of barn owls (Tyto alba) inside a Swiss population surveyed during 15 years. Using 10 microsatellite loci as an indirect method to characterize dispersal, two third of the genetic tests failed to detect a female-biased dispersal, and Monte-Carlo simulations confirmed a low statistical power to detect sex-biased dispersal in case of high dispersal rate of both sexes. The capture-recapture data revealed a female-biased dispersal associated with an excess of heterozygote for the melanocortin-1 receptor gene (MC1R), which is responsible for their ventral rufous coloration. Thus, female homozygotes for the MC1R_white allele might be negatively selected during dispersal. Despite the higher immigration of females that are heterozygote at MC1R, non-random gene flow should not lead to a migration load regarding this gene because we did not detect an effect of MC1R on survival and reproductive success in our local population. The present study highlights the usefulness of using multiple methods to correctly decrypt dispersal and gene flow. Moreover, despite theoretical expectations, we show that non-random dispersal of particular genotypes does not necessarily lead to migration load in recipient populations.Input Fitness dataFitness data used for the reproductive success analysis. Columns: BroodID (ID of the brood = the same ID is attributed to the father and mother of the brood); SiteID (ID of the site); Year (1998 to 2016); Laying date (julian date); Clutch size (clutch size before crossfostering if there is crossfostering); Clutch sizeII (can be different from clutchsize if there is crossfostering and if the number of crossfostered eggs between clutches is different; this variable was used for the fledging success); Cross (crossfostering, yes or no); Fledglings (number of fledglings); Deadnestlings (number of dead nestlings); Ring (ring of the mother or father); sex (1 = male/father; 2 = female/mother); MC1R (II = homozygote for the rufous allele; VI = heterozygote; VV = homozygote for the white allele); MC1R.2 (II and VI genotypes are grouped and II genotypes are renamed VI); Status (Imm = immigrant/born outstide the study area; Res = resident/born inside the study area).Input_Fitness.txtInput Genetic dataGenetic data used for the genetic analyses. Columns: year (1998 to 2012); bird ring (ID); sex (1 = male; 2 = female), immigrant status (1 = immigrant/born oustide the study area; 0 = resident/born inside the study area); V126I (MC1R, II = ho for the rufous allele; VI = he; VV = ho for the white allele); 10 microsatellites (diploid).Input_hierfstat.txtCensusData Survival AnalysisCensus data used for the survival analysis. Columns: ID (bird ring); Birth (birth year); census data; sex (F = female; M = male); MC1R (II = ho for the rufous allele; VI = he; VV = ho for the white allele); status (Res = resident/born inside the study area; Imm = immigrant/born outside the study area).CensusData_SurvivalAnalysis.tx