title: Sex differences in senescence: the role of intra-sexual competition in early adulthood.
abstract: Males and females frequently differ in their rates of ageing, but the origins of these differences are poorly understood. Sex differences in senescence have been hypothesized to arise, because investment in intra-sexual reproductive competition entails costs to somatic maintenance, leaving the sex that experiences stronger reproductive competition showing higher rates of senescence. However, evidence that sex differences in senescence are attributable to downstream effects of the intensity of intra-sexual reproductive competition experienced during the lifetime remains elusive. Here, we show using a 35 year study of wild European badgers (Meles meles), that (i) males show higher body mass senescence rates than females and (ii) this sex difference is largely attributable to sex-specific downstream effects of the intensity of intra-sexual competition experienced during early adulthood. Our findings provide rare support for the view that somatic maintenance costs arising from intra-sexual competition can cause both individual variation and sex differences in senescence.
authors.affiliation: Centre for Ecology and Conservation, School of Biosciences, University of Exeter, Penryn Campus, Cornwall TR10 9EZ, UK.
authors.forename: Christopher
authors.identifier: http://orcid.org/0000-0003-3988-2031
authors.initials: C
authors.lastname: Beirne
authors.affiliation: National Wildlife Management Centre, Animal Health and Veterinary Laboratories Agency (AHVLA), Woodchester Park, Gloucestershire GL10 3UJ, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Delahay
authors.affiliation: Centre for Ecology and Conservation, School of Biosciences, University of Exeter, Penryn Campus, Cornwall TR10 9EZ, UK a.j.young@exeter.ac.uk.
authors.forename: Andrew
authors.initials: A
authors.lastname: Young
mesh_terms: D000375:Aging; D000818:Animals; D003163:Competitive Behavior; D004739:England; D005260:Female; D008137:Longitudinal Studies; D008297:Male; D045969:Mustelidae / Q000502:physiology*; D012727:Sex Characteristics; D012726:Sexual Behavior, Animal
keywords: ageing; disposable soma; individual variation; mammal; senescence; wild population