title: Feather corticosterone during non-breeding correlates with multiple measures of physiology during subsequent breeding in a migratory seabird.
abstract: Carry-over effects in migratory birds are likely mediated by physiological processes that are activated in response to environmental variation. Such processes affect body condition and/or reproductive success, and can include corticosterone (CORT) because this hormone responds to environmental stressors and influences energy balance. Few studies have considered how CORT levels during non-breeding relate to a broader physiological profile during subsequent breeding, and fewer still have considered measures other than body condition. To explore CORT's potential role in carry-over effects, we investigated the relationship between CORT and foraging ecology of northern gannets (Morus bassanus) during the non-breeding period, and tested for associations between these factors and variation in a suite of physiological and biochemical metrics during subsequent breeding. Northern gannets are the largest seabird top predator in the North Atlantic and were among the hardest hit by the Deepwater Horizon oil blowout in the Gulf of Mexico in 2010. We used light-level geolocators to confirm winter origins of individuals in our study. No interrelationships were found among levels of CORT from feathers grown during non-breeding (CORTf) and variation in foraging ecology, measured by stable isotopes of carbon (δ13C) and nitrogen (δ15N) from the same feathers. CORTfwas correlated negatively with hematocrit and positively with triglyceride measured during subsequent incubation, and explained more variation in these variables than did body mass during incubation. These findings provide support for the hypothesis that energy management, measured using CORTf, during non-breeding carries over to influence physiological measures other than body condition. Gannets that previously wintered within the Gulf of Mexico in the years following the Deepwater Horizon oil blowout had higher levels of CORTfcompared to birds that wintered along the Atlantic coast, suggesting an increased energetic cost associated with visiting the Gulf of Mexico. Our results indicate that CORT during non-breeding is associated with a broader physiological profile during subsequent breeding than previously reported in birds.
authors.affiliation: Department of Veterinary Pathology, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada. Electronic address: graham.fairhurst@usask.ca.
authors.forename: Graham D
authors.initials: GD
authors.lastname: Fairhurst
authors.affiliation: Environment and Climate Change Canada, Québec, QC, G1J 0C3, Canada.
authors.forename: Louise
authors.initials: L
authors.lastname: Champoux
authors.affiliation: Environment and Climate Change Canada, Saskatoon, SK, S7N 3H5, Canada.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Hobson
authors.affiliation: Environment and Climate Change Canada, Québec, QC, G1J 0C3, Canada.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Rail
authors.affiliation: Centre de recherche en toxicologie de l'environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, Montréal, QC, H3C 3P8, Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Verreault
authors.affiliation: Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, QC, G5L 3A1, Canada.
authors.forename: Magella
authors.initials: M
authors.lastname: Guillemette
authors.affiliation: Memorial University of Newfoundland, NL, A1B 3X9, Canada.
authors.forename: William A
authors.initials: WA
authors.lastname: Montevecchi
authors.affiliation: Institut National de la Recherche Scientifique - Institut Armand-Frappier, Laval, QC, H7V 1B7, Canada.
authors.forename: Pauline
authors.initials: P
authors.lastname: Brousseau
authors.affiliation: Department of Veterinary Pathology, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada; Environment and Climate Change Canada, Saskatoon, SK, S7N 0X4, Canada.
authors.forename: Catherine
authors.initials: C
authors.lastname: Soos
mesh_terms: D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001717:Birds; D001947:Breeding; D003345:Corticosterone / Q000378:metabolism*; D004734:Energy Metabolism; D005241:Feathers; D012098:Reproduction / Q000502:physiology*; D012621:Seasons
chemical_list: D003345:Corticosterone
keywords: Carbon-13; Carry-over effects; Deepwater Horizon oil spill; Feather biomarkers; Gulf of Mexico; Hormones; Migration; Nitrogen-15; Stable isotopes; Stress physiology