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| Barbraud, Christophe; Bertrand, Arnaud; Bouchon, Marilu; Chaigneau, Alexis; Delord, Karine; Demarcq, Herve; Gimenez, Olivier; Gutierrez Torero, Mariano; Gutierrez, Dimitri; Oliveros Ramos, Ricardo; Passuni, Giannina; Tremblay, Yann; Bertrand, Sophie. |
| In marine ecosystems top predator populations are shaped by environmental factors affecting their prey abundance. Coupling top predators' population studies with independent records of prey abundance suggests that prey fluctuations affect fecundity parameters and abundance of their predators. However, prey may be abundant but inaccessible to their predators and a major challenge is to determine the relative importance of prey accessibility in shaping seabird populations. In addition, disentangling the effects of prey abundance and accessibility from the effects of prey removal by fisheries, while accounting for density dependence, remains challenging for marine top predators. Here, we investigate how climate, population density, and the accessibility and... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00450/56117/57647.pdf |
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| Roy, Amedee; Delord, Karine; Tavares Nunes, Guilherme; Barbraud, Christophe; Bugoni, Leandro; Bertrand, Sophie. |
| Background Considerable progress in our understanding of long-distance migration has been achieved thanks to the use of small lightweight geolocator devices. Such global location sensors (GLS) are particularly suitable for studying non-breeding movement and behaviour due to their small size and low energy consumption allowing multiyear deployment. Errors of geolocation are however important, difficult to estimate, have a complex structure leading to poor precision and accuracy. Therefore, understanding movement ecology of short-distance migrants or resident birds during extensive time periods remains challenging. We aimed at elucidating the sex-specific marine space uses of a resident tropical seabird, the masked booby over the full annual life cycle,... |
| Tipo: Text |
Palavras-chave: Activity pattern; Breeding constraints; GLS; Masked boobies; Saltwater immersion; Sexual dimorphism; Sula dactylatra. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79438/82044.pdf |
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| Delord, Karine; Barbraud, Christophe; Pinaud, David; Letournel, Bruno; Jaugeon, Baptiste; Goraguer, Herle; Lazure, Pascal; Lormée, Hervé. |
| Among seabirds, alcids are particularly sensitive to bycatch in fisheries and oil pollution, yet their distribution at sea remains scarcely known in most of their breeding areas. GPS telemetry data of fifteen individuals of alcids (5 Razorbills 6 Common Murres and 4 Puffins) were analyzed to determine their distribution during the breeding period of 2016 at Saint Pierre and Miquelon Archipelago (SPM). Two analytical methods (threshold and a switching state-space model) were used to identify behavioral modes and foraging areas. We compared foraging movements and estimated the overlap between the species. Distribution and foraging covered an area located between SPM and Newfoundland. Our results revealed that the three species headed northward of their... |
| Tipo: Text |
Palavras-chave: Telemetry; Behavioral models; Animal movement; Distribution overlap; Fratercula arctica; Alca torda; Uria aalge. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00588/70038/68016.pdf |
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| Passuni, Giannina; Barbraud, Christophe; Chaigneau, Alexis; Demarcq, Herve; Ledesma, Jesus; Bertrand, Arnaud; Castillo, Ramiro; Perea, Angel; Mori, Julio; Viblanc, Vincent A.; Torres-maita, Jose; Bertrand, Sophie. |
| In fluctuating environments, matching breeding timing to periods of high resource availability is crucial for the fitness of many vertebrate species, and may have major consequences on population health. Yet, our understanding of the proximate environmental cues driving seasonal breeding is limited. This is particularly the case in marine ecosystems, where key environmental factors and prey abundance and availability are seldom quantified. The Northern Humboldt Current System (NHCS) is a highly productive, low-latitude ecosystem of moderate seasonality. In this ecosystem, three tropical seabird species (the Guanay Cormorant Phalacrocorax bougainvillii, the Peruvian Booby Sula variegata, and the Peruvian Pelican Pelecanus thagus) live in sympatry and prey... |
| Tipo: Text |
Palavras-chave: Anchovy; Engraulis ringens; Guanay Cormorant; Northern Humboldt Current System; Occupancy model; Oceanographic variability; Pelecanus thagus; Peru; Peruvian Booby; Peruvian Pelican; Phalacrocorax bougainvillii; Prey abundance; Seasonal breeding; Sula variegata. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00317/42844/74394.pdf |
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| Weimerskirch, Henri; Delord, Karine; Barbraud, Christophe; Le Bouard, Fabrice; Ryan, Peter G.; Fretwell, Peter; Marteau, Cedric. |
| Today albatrosses are threatened worldwide, especially by fishing activities, and many populations are currently in decline. Albatrosses breeding at the French Southern Territories in the south-western Indian Ocean, on the Crozet, Kerguelen and Saint-Paul–Amsterdam island archipelagos, are monitored regularly. This monitoring has been based on a sample of species and sites, and there was a need for an assessment of the population trends for all species at each site. During the past 3 years most populations have been surveyed, allowing an assessment of the trends of albatrosses breeding at the archipelagos of the French Southern Territories over the past 40 years. Wandering Albatrosses show similar trends at all sites within the Crozet and Kerguelen... |
| Tipo: Text |
Palavras-chave: Crozet; Kerguelen; Amsterdam; Fisheries; Monitoring. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00440/55192/83479.pdf |
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