title: Upscaling the niche variation hypothesis from the intra- to the inter-specific level.
abstract: The "niche variation hypothesis" (NVH) predicts that populations with wider niches should display higher among-individual variability. This prediction originally stated at the intra-specific level may be extended to the inter-specific level: individuals of generalist species may differ to a greater extent than individuals of a specialist species. We tested the NVH at intra- and inter-specific levels based on a large diet database of three large herbivore feces collected in the field and analyzed using DNA metabarcoding. The three herbivores (roe deer Capreolus capreolus, chamois Rupicapra rupicapra and mouflon Ovis musimon) are highly contrasted in terms of sociality (solitary to highly gregarious) and diet. The NVH at the intraspecific level was tested by relating, for the same population, diet breadth and inter-individual variation across the four seasons. Compared to null models, our data supported the NVH both at the intra- and inter-specific levels. Inter-individual variation of the diet of solitary species was not larger than in social species, although social individuals feed together and could therefore have more similar diets. Hence, the NVH better explained diet breadth than other factors such as sociality. The expansion of the population niche of the three species was driven by resource availability, and achieved by an increase in inter-individual variation, and the level of inter-individual variability was larger in the generalist species (mouflon) than in the specialist one (roe deer). This mechanism at the base of the NVH appears at play at different levels of biological organization, from populations to communities.
authors.affiliation: Laboratoire d'Ecologie Alpine, CNRS UMR 5553, Université de Savoie, Bâtiment Belledonne Ouest, 73376, Le Bourget-du-Lac, France. marjorie.bison@gmail.com.|Department of Arctic and Marine Biology, UiT The Arctic University of Norway, 9037, Tromsø, Norway. marjorie.bison@gmail.com.
authors.forename: Marjorie
authors.initials: M
authors.lastname: Bison
authors.affiliation: Laboratoire d'Ecologie Alpine, CNRS UMR 5553, Université de Savoie, Bâtiment Belledonne Ouest, 73376, Le Bourget-du-Lac, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Ibanez
authors.affiliation: Laboratoire d'Ecologie Alpine, CNRS UMR 5553, Université de Savoie, Bâtiment Belledonne Ouest, 73376, Le Bourget-du-Lac, France.|Office National de la Chasse et de la Faune Sauvage, Centre National d'Etudes et de Recherche Appliquée Faune de Montagne, 147 Route de Lodève, Les Portes du Soleil, 34990, Juvignac, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Redjadj
authors.affiliation: Laboratoire d'Ecologie Alpine, UMR CNRS 5553, Université J. Fourier, BP 53, 38041, Grenoble Cedex 9, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Boyer
authors.affiliation: Laboratoire d'Ecologie Alpine, UMR CNRS 5553, Université J. Fourier, BP 53, 38041, Grenoble Cedex 9, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Coissac
authors.affiliation: Laboratoire d'Ecologie Alpine, UMR CNRS 5553, Université J. Fourier, BP 53, 38041, Grenoble Cedex 9, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Miquel
authors.affiliation: Laboratoire d'Ecologie Alpine, UMR CNRS 5553, Université J. Fourier, BP 53, 38041, Grenoble Cedex 9, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Rioux
authors.affiliation: Office National de la Chasse et de la Faune Sauvage, Centre National d'Etudes et de Recherche Appliquée Cervidés-Sangliers, Montfort, 01330, Birieux, France.
authors.forename: Sonia
authors.initials: S
authors.lastname: Said
authors.affiliation: Office National de la Chasse et de la Faune Sauvage, Centre National d'Etudes et de Recherche Appliquée Faune de Montagne, 147 Route de Lodève, Les Portes du Soleil, 34990, Juvignac, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Maillard
authors.affiliation: Laboratoire d'Ecologie Alpine, UMR CNRS 5553, Université J. Fourier, BP 53, 38041, Grenoble Cedex 9, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Taberlet
authors.affiliation: Department of Arctic and Marine Biology, UiT The Arctic University of Norway, 9037, Tromsø, Norway.
authors.forename: Nigel Gilles
authors.initials: NG
authors.lastname: Yoccoz
authors.affiliation: Laboratoire d'Ecologie Alpine, CNRS UMR 5553, Université de Savoie, Bâtiment Belledonne Ouest, 73376, Le Bourget-du-Lac, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Loison
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D058893:DNA Barcoding, Taxonomic; D003670:Deer / Q000235:genetics / Q000502:physiology*; D004032:Diet; D017753:Ecosystem; D060434:Herbivory; D011157:Population Dynamics; D048608:Rupicapra / Q000235:genetics / Q000502:physiology*; D012621:Seasons; D034561:Sheep, Domestic / Q000235:genetics / Q000502:physiology*; D012919:Social Behavior; D013045:Species Specificity
keywords: DNA metabarcoding; Individual heterogeneity; Large herbivores; Null models; Sociality