Predation risk constrains the plasticity of foraging behaviour in teals, Anas crecca: a flyway-level circumannual approach

• Published in: Animal Behaviour
• Main Authors: Guillemain, Mathieu, Arzel, Céline, Legagneux, Pierre, Elmberg, Johan, Fritz, Hervé, Lepley, Michel, Pin, Christophe, Arnaud, Antoine, Massez, Grégoire
• Other Authors: Office Nationale de la Chasse et de la Faune Sauvage (ONCFS), CNERA Avifaune Migratrice, Laboratoire d'écologie des hydrosystèmes (LEH), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Department of Mathematics and Natural Sciences, Kristianstad University, Office National de la Chasse et de la Faune Sauvage (ONCFS), Centre d'Études Biologiques de Chizé (CEBC), Centre National de la Recherche Scientifique (CNRS), Departmant of Mathematics and natural Sciences, Ecologie quantitative et évolutive des communautés, Département écologie évolutive LBBE, Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Station Biologique de la Tour du Valat, Les amis du Marais du Viguerat
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: feeding efficiency; circumannual; Anas crecca; teal; foraging; flyway; predation risk; trade-off; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.ES]Environmental Sciences/Environment and Society; [SDE.MCG]Environmental Sciences/Global Changes; Northern Sweden
• Online Access: https://hal.science/hal-00182984; https://doi.org/10.1016/j.anbehav.2006.06.019

International audience The trade-off foragers make between predation risk and feeding efficiency is readily studied in dabbling ducks, which have stereotyped feeding methods, some of which prevent predator detection while others do not. Teals forage mostly with only the bill submerged (eyes above the water surface) in winter, but use a broader foraging repertoire in summer. Given the different environments used by teals over the year, it is likely that such a shift is due to changes in diet, but it may also be caused by differences in predation risk between habitats. However, neither predation risk nor teal behaviour has been studied with consistent methods around the year or throughout any of its flyways. Covering wintering, spring-staging, breeding and moulting sites, we combined focal observations of teals and predator flyover data from seven regions ranging from southern France to northern Sweden. Although not apparent at the scale of days within sites, teals indeed relied more on shallow foraging where predation risk was higher, i.e. at wintering sites. Average foraging depth increased gradually from September to August, i.e. from wintering to breeding sites. Foraging bout length of deeply foraging teals did not decrease over the year, suggesting that it is through selection of foraging technique, rather than by the balance between foraging and interruptions, that birds adjust to predation risk. This study highlights behavioural plasticity in response to contrasting selection regimes within a flyway, in dabbling ducks as well as long-distance migrants in general.