Species-specific foraging strategies and segregation mechanisms of sympatric Antarctic fulmarine petrels throughout the annual cycle

• Published in: Ibis
• Main Authors: Delord, Karine, Pinet, Patrick, Pinaud, David, Barbraud, Christophe, de Grissac, Sophie, Lewden, Agnès, Cherel, Yves, Weimerskirch, Henri
• Other Authors: Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), beGraX auto entreprise, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: Fulmarus glacialoides; Daption capense; activity; moult; Pagodroma nivea; seabirds; stable isotopes; tracking; [SDE]Environmental Sciences; Antarctic; East Antarctica; Fulmar; Nivea; Adelie Land; Antarc*; Antarctica; Cape Petrel; Cape Petrels; Snow Petrel; Snow Petrels
• Online Access: https://hal.science/hal-01302388; https://doi.org/10.1111/ibi.12365

International audience Determining the year-round distribution and behaviour of birds is necessary for a betterunderstanding of their ecology and foraging strategies. Petrels form an important componentof the high-latitude seabird assemblages in terms of species and individuals. The distributionand foraging ecology of three sympatric fulmarine petrels (Southern FulmarFulmarus glacialoides, Cape Petrel Daption capense and Snow Petrel Pagodroma nivea)were studied at Adelie Land, East Antarctica, by combining information from miniaturizedsaltwater immersion geolocators and stable isotopes from feathers. During thebreeding season at a large spatial scale (c. 200 km), the three species overlapped in theirforaging areas located in the vicinity of the colonies but were segregated by their dietand trophic level, as indicated by the different chick d15N values that increased in theorder Cape Petrel < Southern Fulmar < Snow Petrel. During the non-breeding season,the three fulmarines showed species-specific migration strategies along a wide latitudinalgradient. Snow Petrels largely remained in ice-associated Antarctic waters, Southern Fulmarstargeted primarily the sub-Antarctic zone and Cape Petrels migrated further north.Overall, birds spent less time in flight during the non-breeding period than during thebreeding season, with the highest percentage of time spent sitting on the water occurringduring the breeding season and at the beginning of the non-breeding period beforemigration. This activity pattern, together with the d13C values of most feathers, stronglysuggests that moult of the three fulmarine petrels occurred at that time in the very productivehigh Antarctic waters, where birds fed on a combination of crustaceans and fish.The study highlights different segregating mechanisms that allow the coexistence of closelyrelated species, specifically, prey partitioning during the breeding season and spatialsegregation at sea during the non-breeding season.