title: Early and adult social environments have independent effects on individual fitness in a social vertebrate.
abstract: Evidence that the social environment at critical stages of life-history shapes individual trajectories is accumulating. Previous studies have identified either current or delayed effects of social environments on fitness components, but no study has yet analysed fitness consequences of social environments at different life stages simultaneously. To fill the gap, we use an extensive dataset collected during a 24-year intensive monitoring of a population of Alpine marmots (Marmota marmota), a long-lived social rodent. We test whether the number of helpers in early life and over the dominance tenure length has an impact on litter size at weaning, juvenile survival, longevity and lifetime reproductive success (LRS) of dominant females. Dominant females, who were born into a group containing many helpers and experiencing a high number of accumulated helpers over dominance tenure length showed an increased LRS through an increased longevity. We provide evidence that in a wild vertebrate, both early and adult social environments influence individual fitness, acting additionally and independently. These findings demonstrate that helpers have both short- and long-term effects on dominant female Alpine marmots and that the social environment at the time of birth can play a key role in shaping individual fitness in social vertebrates.
authors.affiliation: Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, F-69622, Villeurbanne, France.
authors.forename: Vérane
authors.initials: V
authors.lastname: Berger
authors.affiliation: Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, F-69622, Villeurbanne, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Lemaître
authors.affiliation: Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, F-69622, Villeurbanne, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Allainé
authors.affiliation: Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, F-69622, Villeurbanne, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Gaillard
authors.affiliation: Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, F-69622, Villeurbanne, France aurelie.cohas@univ-lyon1.fr.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Cohas
mesh_terms: D000818:Animals; D005260:Female; D005602:France; D056084:Genetic Fitness; D008098:Litter Size; D008136:Longevity; D008297:Male; D008392:Marmota / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D012621:Seasons; D012931:Social Environment
keywords: Marmota marmota; cooperative breeding; lifetime reproductive success; longevity; sociality; subordinate