title: How does climate change influence demographic processes of widespread species? Lessons from the comparative analysis of contrasted populations of roe deer.
abstract: How populations respond to climate change depends on the interplay between life history, resource availability, and the intensity of the change. Roe deer are income breeders, with high levels of allocation to reproduction, and are hence strongly constrained by the availability of high quality resources during spring. We investigated how recent climate change has influenced demographic processes in two populations of this widespread species. Spring began increasingly earlier over the study, allowing us to identify 2 periods with contrasting onset of spring. Both populations grew more slowly when spring was early. As expected for a long-lived and iteroparous species, adult survival had the greatest potential impact on population growth. Using perturbation analyses, we measured the relative contribution of the demographic parameters to observed variation in population growth, both within and between periods and populations. Within periods, the identity of the critical parameter depended on the variance in growth rate, but variation in recruitment was the main driver of observed demographic change between periods of contrasting spring earliness. Our results indicate that roe deer in forest habitats cannot currently cope with increasingly early springs. We hypothesise that they should shift their distribution to richer, more heterogeneous landscapes to offset energetic requirements during the critical rearing stage.
authors.affiliation: UMR 5558, Biométrie et Biologie Evolutive, Université Claude Bernard Lyon 1, 43 boulevard du 11 novembre 1918, Villeurbanne Cedex, France. jean-michel.gaillard@univ-lyon1.fr
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Gaillard
authors.forename: A J Mark
authors.initials: AJ
authors.lastname: Hewison
authors.forename: François
authors.initials: F
authors.lastname: Klein
authors.forename: Floriane
authors.initials: F
authors.lastname: Plard
authors.forename: Mathieu
authors.initials: M
authors.lastname: Douhard
authors.forename: Raziel
authors.initials: R
authors.lastname: Davison
authors.forename: Christophe
authors.initials: C
authors.lastname: Bonenfant
mesh_terms: D000367:Age Factors; D000818:Animals; D057231:Climate Change; D003670:Deer / Q000502:physiology; D017753:Ecosystem; D005602:France; D011157:Population Dynamics; D011158:Population Growth; D012098:Reproduction; D012621:Seasons; D014197:Trees