title: Comparing free-ranging and captive populations reveals intra-specific variation in aging rates in large herbivores.
abstract: Although evidence that survival decreases with age in animal species is compelling, the existence of variation in aging rates across different populations of a given species is still questioned. Here, we compared aging rates of 22 pairs of ruminant species living in captive and free-ranging conditions. Based on the recent suggestion that feeding niche is a key factor influencing aging in captivity, we also investigated whether a species' natural diet influences the aging rates of captive ruminants relative to their wild conspecifics. We found that aging rate in a given species was higher under free-ranging conditions than in captivity, which provides the first evidence of consistent aging rate variation within species. Additionally, our study clearly demonstrates that differences in aging rates between captive and free-ranging ruminants increased as species were more specialized on grass diets.
authors.affiliation: Université de Lyon, F-69000, Lyon; Université Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, France. jean-francois.lemaitre@univ-lyon1.fr
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Lemaître
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Gaillard
authors.forename: Laurie Bingaman
authors.initials: LB
authors.lastname: Lackey
authors.forename: Marcus
authors.initials: M
authors.lastname: Clauss
authors.forename: Dennis W H
authors.initials: DW
authors.lastname: Müller
mesh_terms: D000375:Aging; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000835:Animals, Wild / Q000502:physiology*; D000836:Animals, Zoo / Q000502:physiology*; D004032:Diet; D005260:Female; D060434:Herbivory / Q000502:physiology*; D016018:Least-Squares Analysis; D008124:Locomotion; D008297:Male; D015233:Models, Statistical; D010802:Phylogeny; D012418:Ruminants / Q000502:physiology*; D012737:Sex Factors; D013045:Species Specificity