title: The adaptation of generalist predators' diet in a multi-prey context: insights from new functional responses.
abstract: The ability for a generalist consumer to adapt its foraging strategy (the multi-species functional response, MSFR) is a milestone in ecology as it contributes to the structure of food webs. The trophic interaction between a generalist predator, as the red fox or the barn owl, and its prey community, mainly composed of small mammals, has been empirically and theoretically widely studied. However, the extent to which these predators adapt their diet according to both multi-annual changes in multiple prey species availability (frequency dependence) and the variation of the total prey density (density dependence) is unexplored.We provide a new general model of MSFR disentangling changes in prey preference according to variation of prey frequency (switching) and of total prey density (we propose the new concept of "rank switching"). We apply these models to two large data sets of red fox and barn owl foraging. We show that both frequency-dependent and density-dependent switching are critical properties of these two systems, suggesting that barn owl and red fox have an accurate image of the prey community in terms of frequency and absolute density. Moreover, we show that negative switching, which can lead to prey instability, is a strong property of the two systems.
authors.affiliation: Université Bourgogne Franche-Comté - UMR CNRS 6249 Chrono-environnement, Besançon, 25030, France.
authors.forename: Virgile
authors.initials: V
authors.lastname: Baudrot
authors.affiliation: Université Bourgogne Franche-Comté - UMR CNRS 6249 Chrono-environnement, Besançon, 25030, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Perasso
authors.affiliation: Université Bourgogne Franche-Comté - UMR CNRS 6249 Chrono-environnement, Besançon, 25030, France.
authors.forename: Clémentine
authors.initials: C
authors.lastname: Fritsch
authors.affiliation: Université Bourgogne Franche-Comté - UMR CNRS 6249 Chrono-environnement, Besançon, 25030, France.|Institut Universitaire de France, Paris, 75000, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Giraudoux
authors.affiliation: Université Bourgogne Franche-Comté - UMR CNRS 6249 Chrono-environnement, Besançon, 25030, France.
authors.forename: Francis
authors.initials: F
authors.lastname: Raoul
mesh_terms: D000818:Animals; D004032:Diet; D020387:Food Chain; D011157:Population Dynamics; D011235:Predatory Behavior; D020305:Strigiformes
keywords: 
  Tyto alba
  ; 
  Vulpes vulpes
  ; predation; preference; prey community; rank switching; switching