title: Neighbouring-group composition and within-group relatedness drive extra-group paternity rate in the European badger (Meles meles).
abstract: Extra-group paternity (EGP) occurs commonly among group-living mammals and plays an important role in mating systems and the dynamics of sexual selection; however, socio-ecological and genetic correlates of EGP have been underexplored. We use 23 years of demographic and genetic data from a high-density European badger (Meles meles) population, to investigate the relationship between the rate of EGP in litters and mate availability, mate incompatibility and mate quality (heterozygosity). Relatedness between within-group assigned mothers and candidate fathers had a negative quadratic effect on EGP, whereas the number of neighbouring-group candidate fathers had a linear positive effect. We detected no effect of mean or maximum heterozygosity of within-group candidate fathers on EGP. Consequently, EGP was associated primarily with mate availability, subject to within-group genetic effects, potentially to mitigate mate incompatibility and inbreeding. In badgers, cryptic female choice, facilitated by superfecundation, superfoetation and delayed implantation, prevents males from monopolizing within-group females. This resonates with a meta-analysis in group-living mammals, which proposed that higher rates of EGP occur when within-group males cannot monopolize within-group females. In contrast to the positive meta-analytic association, however, we found that EGP associated negatively with the number of within-group assigned mothers and the number of within-group candidate fathers; potentially a strategy to counter within-group males committing infanticide. The relationship between the rate of EGP and socio-ecological or genetic factors can therefore be intricate, and the potential for cryptic female choice must be accounted for in comparative studies.
authors.affiliation: Wildlife Conservation Research Unit, Department of Zoology, Recanati-Kaplan Centre, University of Oxford, Tubney, Abingdon, Oxfordshire, UK; NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK; Biology Department, Faculty of Science, University of Putra Malaysia, Selangor Darul Ehsan, Malaysia.
authors.forename: G
authors.initials: G
authors.lastname: Annavi
authors.forename: C
authors.initials: C
authors.lastname: Newman
authors.forename: H L
authors.initials: HL
authors.lastname: Dugdale
authors.forename: C D
authors.initials: CD
authors.lastname: Buesching
authors.forename: Y W
authors.initials: YW
authors.lastname: Sin
authors.forename: T
authors.initials: T
authors.lastname: Burke
authors.forename: D W
authors.initials: DW
authors.lastname: Macdonald
mesh_terms: D000818:Animals; D004739:England; D005260:Female; D005828:Genetics, Population; D005838:Genotype; D006579:Heterozygote; D008297:Male; D045969:Mustelidae / Q000235:genetics*; D010375:Pedigree; D012098:Reproduction; D012726:Sexual Behavior, Animal
keywords: European badger; breeding density; extra-pair paternity; group composition; heterozygosity; inbreeding; mate incompatibility; mating system; promiscuity