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Héloïg Barbel Le Page, Dominique Todisco, James Woollett. (2022). (Re)penser la relation au territoire : vers une archéologie de l’habiter.
Abstract: La posture endossée par les chercheur.es structure les problématiques qu’il.elle.s abordent et leurs choix quant aux approches employées pour les étudier. Cet article offre une réflexion sur l’importance de questionner nos postures paradigmatiques, qui structurent notre rapport à la recherche. Elle a émergé de recherches menées en collaboration avec le Gouvernement du Nunatsiavut et la communauté de Nain (Nunatsiavut, Labrador, Canada). Celles-ci contribuent à pluraliser les narrations historiques sur la période coloniale, en s’intéressant à la diversité des choix des Nunatsiavummiut concernant leurs relations avec le système missionnaire. Cette discussion, articulant archéologie et géographie, développe une approche relationnelle du territoire par l’habiter et questionne la trace laissée par les systèmes d’activités quotidiennes à travers le temps et l’espace. Une réflexion sur les façons d’appréhender la complexité des relations aux lieux, au paysage et aux artefacts nous amène à aborder la diversité des vestiges mis au jour, et la nécessité d’une mise en dialogue des disciplines pour étudier les systèmes d’activités passés à partir de leurs traces.
Programme: 1080
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Ruijiao Sun, Christophe Barbraud, Henri Weimerskirch, Karine Delord, Samantha C. Patrick, Hal Caswell, Stephanie Jenouvrier. (2022). Causes and consequences of pair-bond disruption in a sex-skewed population of a long-lived monogamous seabird (Vol. 92).
Abstract: Many animals form long-term monogamous pair bonds, and the disruption of a pair bond (through either divorce or widowhood) can have significant consequences for individual vital rates (survival, breeding, and breeding success probabilities) and life-history outcomes (lifetime reproductive success [LRS], life expectancy). Here, we investigated the causes and consequences of pair-bond disruption in wandering albatross (Diomedea exulans). State-of-the-art statistical and mathematical approaches were developed to estimate divorce and widowhood rates and their impacts on vital rates and life-history outcomes. In this population, females incur a higher mortality rate due to incidental fishery bycatch, so the population is male-skewed. Therefore, we first posited that males would show higher widowhood rates negatively correlated with fishing effort and females would have higher divorce rates because they have more mating opportunities. Furthermore, we expected that divorce could be an adaptive strategy, whereby individuals improved breeding success by breeding with a new partner of better quality. Finally, we posited that pair-bond disruptions could reduce survival and breeding probabilities owing to the cost of remating processes, with important consequences for life-history outcomes. As expected, we showed that males had higher widowhood rates than females and females had higher divorce rates in this male-skewed population. However, no correlation was found between fishing effort and male widowhood. Secondly, contrary to our expectation, we found that divorce was likely nonadaptive in this population. We propose that divorce in this population is caused by an intruder who outcompetes the original partner in line with the so-called forced divorce hypothesis. Furthermore, we found a 16.7% and 18.0% reduction in LRS only for divorced and widowed males, respectively, owing to missing breeding seasons after a pair-bond disruption. Finally, we found that divorced individuals were more likely to divorce again, but whether this is related to specific individual characteristics remains an important area of investigation.
Keywords: bycatch capture–mark–recapture divorce life-history outcomes Markov chain models sex-biased vital rates wandering albatross widowhood
Programme: 109
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Khouloud El Hanafi, Zoyne Pedrero, Laurent Ouerdane, Claudia Marchán Moreno, Silvia Queipo-Abad, Maite Bueno, Florence Pannier, Warren T. Corns, Yves Cherel, Paco Bustamante, David Amouroux. (2022). First Time Identification of Selenoneine in Seabirds and Its Potential Role in Mercury Detoxification (Vol. 56).
Abstract: Birds are principally exposed to selenium (Se) through their diet. In long-lived and top predator seabirds, such as the giant petrel, extremely high concentrations of Se are found. Selenium speciation in biota has aroused great interest in recent years; however, there is a lack of information about the chemical form of Se in (sea)birds. The majority of publications focus on the growth performance and antioxidant status in broilers in relation to Se dietary supplementation. The present work combines elemental and molecular mass spectrometry for the characterization of Se species in wild (sea)birds. A set of eight giant petrels (Macronectes sp.) with a broad age range from the Southern Ocean were studied. Selenoneine, a Se-analogue of ergothioneine, was identified for the first time in wild avian species. This novel Se-compound, previously reported in fish, constitutes the major Se species in the water-soluble fraction of all of the internal tissues and blood samples analyzed. The levels of selenoneine found in giant petrels are the highest reported in animal tissues until now, supporting the trophic transfer in the marine food web. The characterization of selenoneine in the brain, representing between 78 and 88% of the total Se, suggests a crucial role in the nervous system. The dramatic decrease of selenoneine (from 68 to 3%) with an increase of Hg concentrations in the liver strongly supports the hypothesis of its key role in Hg detoxification.
Programme: 109
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Yves Cherel, Antoine Carrouée. (2022). Assessing marine ecosystem complexity: isotopic integration of the trophic structure of seabird communities from the Southern Ocean (Vol. 694).
Abstract: Understanding the processes structuring communities is a fundamental goal in ecology and conservation biology. Seabirds are commonly used as sentinels of marine ecosystems, but there is a lack of quantitative information providing a synoptic view of their community structure and of its underlying mechanisms. We used stable isotope analysis of chick feathers to investigate the structure of 2 communities that are representative of the subantarctic (Kerguelen) and Antarctic (Adélie Land) seabird diversity. Total area of the convex hull (a measure of the total δ13C-δ15N niche space) was 8.4-fold higher at the Kerguelen Islands than in Adélie Land, a consequence of the higher seabird diversity at the former locality. Kerguelen seabirds grouped into 2 clusters of oceanic and inshore species, with the latter group not represented in Adélie Land. Communities are primarily structured by the availability of foraging habitats (δ13C) and then of trophic resources (δ15N), with body size being a major driving force of trophic position. Ecological characteristics are more important than phylogeny to shape seabird isotopic niche breadth (standard ellipse area corrected for small sample size, SEAc), with no significant differences between Sphenisciformes, Procellariiformes, and Charadriiformes. By contrast, SEAc varies according to foraging guilds, diet, and a specialist-generalist gradient, with ubiquitous seabirds having a 10-fold larger mean SEAc than pelagic divers. This study sets a baseline against which the effects of long-term environmental changes on seabird community structure can be studied across years and conditions, and provides a relevant starting point for the investigation into the effect of climate change on Southern Ocean ecosystems.
Keywords: Antarctica Body size Habitat Penguins Procellariiformes Stable isotopes Trophic position
Programme: 109
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Laura Andrea Alfaro Garcia, Sébastien Descamps, Dorte Herzke, Olivier Chastel, Alice Carravieri, Yves Cherel, Pierre Labadie, Hélène Budzinski, Gabriel Munoz, Paco Bustamante, Anuschka Polder, Geir Wing Gabrielsen, Jan Ove Bustnes, Katrine Borgå. (2022). Bioaccumulation of Per and Polyfluoroalkyl Substances in Antarctic Breeding South Polar Skuas (Catharacta maccormicki) and Their Prey (Vol. 9).
Abstract: Per and polyfluoroalkyl substances (PFASs) are found in Antarctic wildlife, with high levels in the avian top predator south polar skua (Catharacta maccormicki). As increasing PFAS concentrations were found in the south polar skua during the breeding season in Antarctica, we hypothesised that available prey during the breeding period contributes significantly to the PFAS contamination in skuas. To test this, we compared PFAS in south polar skuas and their main prey from two breeding sites on opposite sides of the Antarctic continent: Antarctic petrel (Thalassoica antarctica) stomach content, eggs, chicks, and adults from Svarthamaren in Dronning Maud Land and Adélie penguin chicks (Pygoscelis adeliae) from Dumont d’Urville in Adélie Land. Of the 22 PFAS analysed, seven were present in the majority of samples, except petrel stomach content [only perfluoroundecanoate (PFUnA) present] and Adélie penguins (only four compounds present), with increasing concentrations from the prey to the skuas. The biomagnification factors (BMFs) were higher at Dumont d’Urville than Svarthamaren. When adjusted to reflect one trophic level difference, the BMFs at Svarthamaren remained the same, whereas the ones at Dumont d’Urville doubled. At both the colonies, the skua PFAS pattern was dominated by perfluorooctanesulfonic acid (PFOS), followed by PFUnA, but differed with the presence of branched PFOS and perfluorotetradecanoate (PFTeA) and lack of perfluorononanoate (PFNA) and perfluorodecanoate (PFDA) at Dumont d’Urville. At Svarthamaren, the pattern in the prey was comparable to the skuas, but with a higher relative contribution of PFTeA in prey. At Dumont d’Urville, the pattern in the prey differed from the skuas, with the domination of PFUnA and the general lack of PFOS in prey. Even though the PFAS levels are low in Antarctic year-round resident prey, the three lines of evidence (pattern, BMF difference, and BMF adjusted to one trophic level) suggest that the Antarctic petrel are the significant source of PFAS in the Svarthamaren skuas, whereas the skuas in Dumont d’Urville have other important sources to PFAS than Adélie penguin, either in the continent or external on the inter-breeding foraging grounds far from Antarctica.
Programme: 109
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Yves Cherel, Pierrick Bocher. (2022). Diet of the soft-plumaged petrel (Pterodroma mollis) at Kerguelen Islands and a review of the food of gadfly petrels (Pterodroma spp.) worldwide (Vol. 169).
Abstract: Little is known on the food and feeding ecology of the soft-plumaged petrel Pterodroma mollis, which is the single gadfly petrel Pterodroma spp. with a circumpolar breeding distribution within the Southern Ocean. Our primary goal was to describe its diet at Kerguelen Islands, which is the southernmost breeding locality of the species. Soft-plumaged petrels fed on fish (71% by mass), and secondarily on crustaceans (22%), while cephalopods (7%) and other items (< 1%) were minor dietary components. Eight-hundred and sixty prey were identified from the pooled 33 food samples, with the 2 hyperiid amphipods Cyllopus magellanicus (48%) and Themisto gaudichaudii (35%) being the main food items by number. Owing to their larger size than crustaceans, mesopelagic fishes were the main prey by mass, with myctophids being the most important fish family in terms of both abundance (68% of the fish) and diversity (10 species). Prey distribution indicated that soft-plumaged petrels foraged primarily in oceanic subantarctic waters to feed their chicks. The oceanic life style of gadfly petrels was then highlighted by a review of their diet worldwide (20 species, 26 studies). Gadfly petrels prey mainly upon mesopelagic fishes (chiefly myctophids) and squids with their relative proportions depending on species and localities. Crustaceans are minor food items for tropical species, but they form a significant part of the food of the small- and medium-sized petrels that live in temperate and cold waters. The review underlines the need for more well-designed investigations on this globally endangered group of seabirds, since dietary information is available for only 57% of the 35 species of gadfly petrels.
Keywords: Fish Food Myctophidae Procellariiformes Seabirds Southern Ocean Squid Tropics
Programme: 109
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Karine Delord, Timothée Poupart, Nicolas Gasco, Henri Weimerskirch, Christophe Barbraud. (2022). First evidence of migration across the South Pacific in endangered Amsterdam albatross and conservation implications (Vol. 136).
Abstract: Albatrosses are amongst the most globally-threatened species and fisheries bycatch is one of the major conservation issues worldwide. Among the albatrosses the Amsterdam albatross is listed as one of the most endangered species. Within the current National Plan of Actions framework, the present study outlines the first results of a multi-year survey evaluating juvenile dispersal and immature at sea distribution using geolocation and conservation implications. Here we report the first evidence of an Amsterdam albatross wandering for extensive periods outside the Indian Ocean, in the Pacific Ocean. This unprecedented and novel finding is discussed in terms of overlaps with fisheries and conservations issues. This study brings new insights on movements of vagrant stages of an endangered species, paving the way for refined assessments updates of species vulnerability to ongoing anthropogenic threats while providing basic conservation guidance. This makes it possible to point out the responsibility of the various management bodies both for the high seas regional fisheries management organisations and for exclusive economic zones.
Keywords: Immature at sea distribution International conservation responsibility Juvenile dispersal National Plan of Actions
Programme: 109
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Morgane Amelot, Floriane Plard, Christophe Guinet, John P. Y. Arnould, Nicolas Gasco, Paul Tixier. (2022). Increasing numbers of killer whale individuals use fisheries as feeding opportunities within subantarctic populations (Vol. 18).
Abstract: Fisheries can generate feeding opportunities for large marine predators in the form of discards or accessible catch. How the use of this anthropogenic food may spread as a new behaviour, across individuals within populations over time, is poorly understood. This study used a 16-year (2003–2018) monitoring of two killer whale Orcinus orca subantarctic populations (regular and Type-D at Crozet), and Bayesian multistate capture–mark–recapture models, to assess temporal changes in the number of individuals feeding on fish caught on hooks (‘depredation’ behaviour) of a fishery started in 1996. For both populations, the number of depredating individuals increased during the study period (34 to 94 for regular; 17 to 43 for Type-D). Increasing abundance is unlikely to account for this and, rather, the results suggest depredation was acquired by increasing numbers of existing individuals. For regular killer whales, a plateau reached from 2014 suggests that it took 18 years for the behaviour to spread across the whole population. A more recent plateau was apparent for Type-Ds but additional years are needed to confirm this. These findings show how changes in prey availability caused by human activities lead to rapid, yet progressive, innovations in killer whales, likely altering the ecological role of this top-predator.
Keywords: capture–mark–recapture depredation killer whales
Programme: 109
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Silvia Queipo-Abad, Zoyne Pedrero, Claudia Marchán-Moreno, Khouloud El Hanafi, Sylvain Bérail, Warren T. Corns, Yves Cherel, Paco Bustamante, David Amouroux. (2022). New insights into the biomineralization of mercury selenide nanoparticles through stable isotope analysis in giant petrel tissues (Vol. 425).
Abstract: Tiemannite (HgSe) is considered the end-product of methylmercury (MeHg) demethylation in vertebrates. The biomineralization of HgSe nanoparticles (NPs) is understood to be an efficient MeHg detoxification mechanism; however, the process has not yet been fully elucidated. In order to contribute to the understanding of complex Hg metabolism and HgSe NPs formation, the Hg isotopic signatures of 40 samples of 11 giant petrels were measured. This seabird species is one of the largest avian scavengers in the Southern Ocean, highly exposed to MeHg through their diet, reaching Hg concentrations in the liver up to more than 900 µg g-1. This work constitutes the first species-specific isotopic measurement (δ202Hg, Δ199Hg) of HgSe NPs in seabirds and the largest characterization of this compound in biota. Similar δ202Hg values specifically associated to HgSe (δ202HgHgSe) and tissues (δ202Hgbulk) dominated by inorganic Hg species were found, suggesting that no isotopic fractionation is induced during the biomineralization step from the precursor (demethylated) species. In contrast, the largest variations between δ202Hgbulk and δ202HgHgSe were observed in muscle and brain tissues. This could be attributed to the higher fraction of Hg present as MeHg in these tissues. Hg-biomolecules screening highlights the importance of the isotopic characterization of these (unknown) complexes.
Keywords: HgSe nanoparticles Isotopic fractionation MeHg demethylation Mercury Seabirds
Programme: 109
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Leo Uesaka, Yusuke Goto, Yoshinari Yonehara, Kosei Komatsu, Masaru Naruoka, Henri Weimerskirch, Katsufumi Sato, Kentaro Q. Sakamoto. (2022). Ocean wave observation utilizing motion records of seabirds (Vol. 200).
Abstract: Various environmental oceanic factors, such as ocean waves, affect seabird ecology; ocean waves are important, as most flying seabirds must land on ocean surfaces for foraging. However, the global ocean wave observation network is spatiotemporally poor compared to other parameters; fine-scale information on wave conditions is limited, and the influence of wave conditions on seabirds has not been quantitatively studied. In this study, a method was developed to estimate ocean waves from the fine-scale motions of seabirds floating on the sea surface, as recorded by a global positioning system (single-point positioning). Ocean wave parameters, estimated from streaked shearwater around the eastern ocean of Japan, strongly corresponded with the observation results of a buoy, with an accuracy of <0.3 m for wave heights of 1.0–2.5 m. Furthermore, wave height estimated from streaked shearwaters and wandering albatrosses around the southern Indian Ocean significantly correlated with hindcast-model values. Bird-based wave observation methods are valuable not only in seabird ecology but also in oceanography as an in-situ observation system. Based on the results of bird-based wave observations, the preferences of wandering albatrosses under various wave conditions were further examined. Anecdotal studies suggest that seabirds prefer low-wave conditions to forage in because of prey visibility; however, wandering albatrosses landed on the sea surface randomly, even on very high waves (5–6 m), revealing their tolerance to ocean surface conditions. Considering the effect of environmental factors on marine animals, increased inclusion of previously ignored parameters in analysis, such as ocean waves, is essential.
Keywords: Biologging GPS Indian Ocean Ocean observation Ocean waves Seabird
Programme: 109
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