Energetic consequences of contrasting winter migratory strategies in a sympatric Arctic seabird duet

• Published in: Journal of Avian Biology
• Main Authors: Fort, Jérôme, Steen, Harald, Strom, Hallvard, Tremblay, Yann, Grønningsæter, Eirik, Pettex, Emeline, Porter, Warren P, Grémillet, David
• Other Authors: Department of Biological Sciences, Aarhus University, Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut de Recherche pour le Développement (IRD France-Sud ), Norwegian Polar Institute, UMR 212 EME "écosystèmes marins exploités" (EME), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM), Department of Zoology, University of Wisconsin-Madison, DST-NRF Centre of Excellence at the Percy FitzPatrick Institute, University of Cape Town
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: [SDV.EE]Life Sciences [q-bio]/Ecology; environment; Arctic; Bjørnøya; Faroe Islands; Greenland; Svalbard; North Atlantic; Uria aalge; Uria lomvia; uria
• Online Access: https://hal.archives-ouvertes.fr/hal-01100392; https://hal.archives-ouvertes.fr/hal-01100392/document; https://hal.archives-ouvertes.fr/hal-01100392/file/Fort%20et%20al_JAB.pdf; https://doi.org/10.1111/j.1600-048X.2012.00128.x

International audience At the onset of winter, warm-blooded animals inhabiting seasonal environments may remain resident and face poorer climatic conditions, or migrate towards more favourable habitats. While the origins and evolution of migratory choices have been extensively studied, their consequences on avian energy balance and winter survival are poorly understood, especially in species diffi cult to observe such as seabirds. Using miniaturized geolocators, time-depth recorders and a mechanistic model, we investigated the migratory strategies, the activity levels and the energy expenditure of the closelyrelated, sympatrically breeding Brünnich ’ s guillemots Uria lomvia and common guillemots Uria aalge from Bjørnøya, Svalbard. The two guillemot species from this region present contrasting migratory strategies and wintering quarters: Brünnich ’ s guillemots migrate across the North Atlantic to overwinter off southeast Greenland and Faroe Islands, while common guillemots remain resident in the Barents, the Norwegian and the White Seas. Results show that both species display a marked behavioural plasticity to respond to environmental constraint, notably modulating their foraging effor tand diving behaviour. Nevertheless, we provide evidence that the migratory strategy adopted by guillemots can have important consequences for their energy balance. Overall energy expenditure estimated for the non-breeding season is relatively similar between both species, suggesting that both southward migration and high-arctic winter residency are energetically equivalent and suitable strategies. However, we also demonstrate that the migratory strategy adopted by Brünnich’ s guillemots allows them to have reduced daily energy expenditures during the challenging winter period. We therefore speculate that ‘ resident ’ common guillemots are more vulnerable than ‘ migrating ’ Brünnich’ s guillemots to harsh winter environmental conditions.