title: An experimental test of density-dependent selection on temperament traits of activity, boldness and sociability.
abstract: Temperament traits are seen in many animal species, and recent evolutionary models predict that they could be maintained by heterogeneous selection. We tested this prediction by examining density-dependent selection in juvenile common lizards Zootoca vivipara scored for activity, boldness and sociability at birth and at the age of 1 year. We measured three key life-history traits (juvenile survival, body growth rate and reproduction) and quantified selection in experimental populations at five density levels ranging from low to high values. We observed consistent individual differences for all behaviours on the short term, but only for activity and one boldness measure across the first year of life. At low density, growth selection favoured more sociable lizards, whereas viability selection favoured less active individuals. A significant negative correlational selection on activity and boldness existed for body growth rate irrespective of density. Thus, behavioural traits were characterized by limited ontogenic consistency, and natural selection was heterogeneous between density treatments and fitness traits. This confirms that density-dependent selection plays an important role in the maintenance of individual differences in exploration-activity and sociability.
authors: CNRS, UMR 7618, iEES Paris, Université Pierre et Marie Curie, Paris, France.|CNRS/ENS UMS 3194, CEREEP - Ecotron IleDeFrance, École Normale Supérieure, St-Pierre-lès-Nemours, France.
authors: J-F
authors: JF
authors: Le Galliard
authors: CNRS, UMR 7618, iEES Paris, Université Pierre et Marie Curie, Paris, France.|Percy Fitzpatrick Institute, DST/NRF Centre of Excellence, University of Cape Town, Cape Town, South Africa.
authors: M
authors: M
authors: Paquet
authors: CNRS, UMR 7618, iEES Paris, Université Pierre et Marie Curie, Paris, France.|School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
authors: M
authors: M
authors: Mugabo
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D008116:Lizards / Q000502:physiology*; D012641:Selection, Genetic
keywords: competition; correlational selection; growth-survival trade-off; natural selection; personality