Courbin N., Besnard A., Peron Clara, Saraux C., Fort J., Perret S., Tornos J., Gremillet D. (2018). Short-term prey field lability constrains individual specialisation in resource selection and foraging site fidelity in a marine predator. Ecology Letters, 21 (7), p. 1043-1054. ISSN 1461-023X.
Titre du document
Short-term prey field lability constrains individual specialisation in resource selection and foraging site fidelity in a marine predator
Courbin N., Besnard A., Peron Clara, Saraux C., Fort J., Perret S., Tornos J., Gremillet D.
Source
Ecology Letters, 2018,
21 (7), p. 1043-1054 ISSN 1461-023X
Spatio-temporally stable prey distributions coupled with individual foraging site fidelity are predicted to favour individual resource specialisation. Conversely, predators coping with dynamic prey distributions should diversify their individual diet and/or shift foraging areas to increase net intake. We studied individual specialisation in Scopoli's shearwaters (Calonectris diomedea) from the highly dynamic Western Mediterranean, using daily prey distributions together with resource selection, site fidelity and trophic-level analyses. As hypothesised, we found dietary diversification, low foraging site fidelity and almost no individual specialisation in resource selection. Crucially, shearwaters switched daily foraging tactics, selecting areas with contrasting prey of varying trophic levels. Overall, information use and plastic resource selection of individuals with reduced short-term foraging site fidelity allow predators to overcome prey field lability. Our study is an essential step towards a better understanding of individual responses to enhanced environmental stochasticity driven by global changes, and of pathways favouring population persistence.
