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Sabarros, Philippe S.; Gremillet, David; Demarcq, Herve; Moseley, Christina; Pichegru, Lorien; Mullers, Ralf H. E.; Stenseth, Nils C.; Machu, Eric. |
Oceanic structures such as mesoscale fronts may become hotspots of biological activity through concentration and enrichment processes. These fronts generally attract fish and may therefore be targeted by marine top-predators. In the southern Benguela upwelling system, such fronts might be used as environmental cues by foraging seabirds. In this study we analyzed high-frequency foraging tracks (GPS, 1 s sampling) of Cape gannets Morus capensis from two colonies located on the west and east coast of South Africa in relation to mesoscale fronts detected on daily high-resolution chlorophyll-a maps (MODIS, 1 km). We tested the association of (i) searching behavior and (ii) diving activity of foraging birds with mesoscale fronts. We found that Cape gannets shift... |
Tipo: Text |
Palavras-chave: Seabird; Environmental cue; Behavioral shift; Area-restricted search; Feeding activity; Fractal landscape; Oceanographic fronts; Morus capensis; Southern Benguela; South Africa. |
Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00236/34756/34575.pdf |
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Peron, Clara; Gremillet, David; Prudor, Aurelien; Pettex, Emeline; Saraux, Claire; Soriano-redondo, Andrea; Authier, Matthieu; Fort, Jerome. |
Marine Protected Areas (MPAs) are being established across all marine regions but their validity for the conservation of highly mobile marine vertebrates has been questioned. We tested the hypothesis that French coastal MPAs primarily designed for coastal and benthic biota are also beneficial for the conservation of a pelagic seabird, the Vulnerable yelkouan shearwater (Puffinus yelkouan), an endemic species to the Mediterranean Sea. We used a vast spectrum of electronic devices (GPS, temperature-depth-recorders, satellite transmitters and geolocators) and stable isotopic analyses to study the year-round movements and the trophic status of yelkouan shearwaters from the Hyères archipelago (France). In addition we conducted large-scale ship and aircrafts... |
Tipo: Text |
Palavras-chave: Aerial surveys; At-sea observations; Biotelemetry; Conservation biogeography; Spatial planning; Stable isotope analysis. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00163/27460/26393.pdf |
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Peron, Clara; Authier, Matthieu; Gremillet, David. |
Aim Species distribution models (SDMs) are statistical tools aiming at mapping and predicting species distributions across landscapes. Data acquisition being limited in space and time, SDM are commonly used to predict species distribution in unsampled areas or years, with the expectation that modelled habitat-species relationships will hold across spatial or temporal contexts (i.e., model transferability). This key aspect of habitat modelling has major implications for spatial management, yet it has received limited attention, especially in the dynamic marine realm. Our aims were to test geographical and temporal habitat model transferability and to make recommendations for future population-scale habitat modelling. Location Methods Two contrasted regions... |
Tipo: Text |
Palavras-chave: Biologging; Central-place foragers; Extrapolation; Habitat modelling; Seabirds; Transferability. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00470/58174/75133.pdf |
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Amelineau, Francoise; Gremillet, David; Bonnet, Delphine; Le Bot, Tangi; Fort, Jerme. |
The earth is warming at an alarming rate, especially in the Arctic, where a marked decline in sea ice cover may have far-ranging consequences for endemic species. Little auks, endemic Arctic seabirds, are key bioindicators as they forage in the marginal ice zone and feed preferentially on lipid-rich Arctic copepods and ice-associated amphipods sensitive to the consequences of global warming. We tested how little auks cope with an ice-free foraging environment during the breeding season. To this end, we took advantage of natural variation in sea ice concentration along the east coast of Greenland. We compared foraging and diving behaviour, chick diet and growth and adult body condition between two years, in the presence versus nearby absence of sea ice in... |
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Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00626/73762/74032.pdf |
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Courbin, Nicolas; Besnard, Aurelien; Peron, Clara; Saraux, Claire; Fort, Jerome; Perret, Samuel; Tornos, Jeremy; Gremillet, David. |
Spatio-temporally stable prey distributions coupled with individual foraging site fidelity are predicted to favour individual resource specialisation. Conversely, predators coping with dynamic prey distributions should diversify their individual diet and/or shift foraging areas to increase net intake. We studied individual specialisation in Scopoli’s shearwaters (Calonectris diomedea) from the highly dynamic Western Mediterranean, using daily prey distributions together with resource selection, site fidelity and trophic-level analyses. As hypothesised, we found dietary diversification, low foraging site fidelity and almost no individual specialisation in resource selection. Crucially, shearwaters switched daily foraging tactics, selecting areas with... |
Tipo: Text |
Palavras-chave: Behavioural consistency; Calonectris diomedea; Foraging site fidelity; Resource selection; Scopoli's shearwater; Temporal resource dynamic; Western Mediterranean. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00437/54859/56479.pdf |
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