title: Senescence and age-specific trade-offs between reproduction and survival in female Asian elephants.
abstract: Although studies on laboratory species and natural populations of vertebrates have shown reproduction to impair later performance, little is known of the age-specific associations between reproduction and survival, and how such findings apply to the ageing of large, long-lived species. Herein we develop a framework to examine population-level patterns of reproduction and survival across lifespan in long-lived organisms, and decompose those changes into individual-level effects, and the effects of age-specific trade-offs between fitness components. We apply this to an extensive longitudinal dataset on female semi-captive Asian timber elephants (Elephas maximus) and report the first evidence of age-specific fitness declines that are driven by age-specific associations between fitness components in a long-lived mammal. Associations between reproduction and survival are positive in early life, but negative in later life with up to 71% of later-life survival declines associated with investing in the production of offspring within this population of this critically endangered species.
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK. matthew.r.robinson@sheffield.ac.uk
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Robinson
authors.forename: Khyne U
authors.initials: KU
authors.lastname: Mar
authors.forename: Virpi
authors.initials: V
authors.lastname: Lummaa
mesh_terms: D000367:Age Factors; D000375:Aging; D000818:Animals; D004606:Elephants / Q000502:physiology*; D005260:Female; D008954:Models, Biological; D015233:Models, Statistical; D012098:Reproduction; D015996:Survival Rate