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Nicolas Crouzet, Abdelkrim Agabi, Tristan Guillot, Lyu Abe, François-Xavier Schmider, Djamel Mékarnia, Amaury H. M. J. Triaud, Yves Bresson, Nicolas Mauclert, Christophe Bailet, Dennis Breeveld, Sander Blommaert, Brian Shortt, Jean-Baptiste Daban, Anne-Marie Lagrange, Romain Touzé, Justin Dufour, Valentin Stee, Jocelyn Caruana. (2020). Towards ASTEP+, a two-color photometric telescope at Dome C, Antarctica (Vol. 11447).
Abstract: Dome C, Antarctica is unique in particular for long-duration astronomical observations due to the excellent weather conditions and nearly uninterrupted nights during the Southern winter period. The 40 cm telescope ASTEP has been operating successfully at the Concordia base, at Dome C, since 2010. We describe the new ASTEP+, a major upgrade of its camera box which will allow it to observe simultaneously in two colors. Approximately three times more photons will be collected for science, yielding more sensitive and accurate observations. The southern location of the telescope means that it is ideally located to follow-up exoplanetary targets in preparation for the future JWST and Ariel observations, in particular when located in the southern continuous viewing zones of these space-based telescopes.
Programme: 1066
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Christophe Barbraud, Adrien Chaigne, Maxime Loubon, Olivier Lamy, Fabrice Le Bouard. (2020). An estimate of the South Georgia diving petrel Pelecanoides georgicus population at Ile de la Possession, Crozet archipelago (Vol. 32).
Abstract: Burrow-nesting seabirds constitute an important part of seabird diversity, yet accurate estimates of their abundance are largely lacking, limiting our understanding of their population dynamics and conservation status. We conducted a survey to estimate the number of South Georgia diving petrel (Pelecanoides georgicus) burrows during the 2013–14 breeding season on Ile de la Possession, Crozet archipelago, southern Indian Ocean. We used distance sampling and acoustic playback in order to estimate burrow densities in a priori-selected favourable nesting areas. A total of 855 burrows were detected. The mean altitude of burrows was 601.8 ± 69.4 m. The mean burrow detection distance was 1.77 ± 1.63 m. The burrow density was estimated at 15.649 burrows ha-1 (95% confidence interval (CI): 10.245–23.903) and the slope-corrected total favourable area was 2365.53 ha, which yielded an estimate 37 018 burrows (95% CI: 24 235–56 544). The playback response rate was 15.8 ± 1.3%, and 40.8 ± 1.7% of burrows were occupied or showed signs of occupation. Occupancy rates were low compared to those measured by systematic burrow inspection in other studies. Assuming that laying occurred in 80–93% of the estimated number of burrows, as estimated by previous studies, gives an estimate of 29 614 (95% CI: 19 388–45 235) to 34 426 (95% CI: 22 538–52 585) breeding pairs.
Keywords: acoustic playback burrowing petrel detection probability distance sampling Procellariiformes
Programme: 109
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Fabienne Joliet, Véronique Van Tilbeurgh, Anne Atlan. (2020). La valeur d’existence du monde vivant selon les Inuits du Nunavik et les Occidentaux aux Kerguelen (Vol. 732).
Abstract: Dans le contexte actuel de transition socio-écologique internationale, l’objectif de cet article est d’interroger la relation entre les humains et les autres vivants et choses naturelles dans les derniers espaces de vaste naturalité aux pôles. C’est à travers la notion de valeur d’existence que cette relation sera analysée dans ses retranchements chez les Inuits qui habitent le Nunavik en subarctique et les Occidentaux qui veillent sur les Kerguelen en subantarctique. Plus particulièrement, c’est la nature du lien qu’ils entretiennent avec les vivants non-humains et autres choses naturelles, et ses registres de valeurs qui sont étudiées.Ces enquêtes boréales et australes en zone protégée ou bien à ses abords montrent ainsi que ce qui prédomine, c’est le fait qu’il est attribué aux éléments naturels une valeur d’existence en fonction d’un esprit commun spirituel ou bien d’une enveloppe commune charnelle d’« être vivant ». Selon ces principes, les modalités prises par l’attribution de la valeur d’existence changent : les humains se concevant soit, comme une partie d’un ensemble au même titre que les autres vivants et choses naturelles ayant un esprit ou conscience, soit comme maîtres et protecteurs des autres vivants et choses naturelles, en tant qu’ayant une fonction dominante au sein d’« êtres vivants ». Dans cette perspective, le territoire joue un rôle spécifique favorisant l’existence même de cette valeur au-delà de ses fonctions de régulation couramment retenues.
Programme: 136
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Barbara Delmonte, Holly Winton, Mélanie Baroni, Giovanni Baccolo, Margareta Hansson, Per Andersson, Carlo Baroni, Maria Cristina Salvatore, Luca Lanci, Valter Maggi. (2020). Holocene dust in East Antarctica: Provenance and variability in time and space (Vol. 30).
Abstract: In this paper, we provide a comprehensive overview of the state-of-knowledge of dust flux and variability in time and space in different sectors of East Antarctica during the Holocene. By integrating the literature data with new evidences, we discuss the dust flux and grain-size variability during the current interglacial and its provenance in the innermost part of the East Antarctic plateau as well as in peripheral regions located close to the Transantarctic Mountains. The local importance of aeolian mineral dust aerosol deflated from low-elevation areas of peripheral East Antarctica is also discussed in the light of new data from several coastal, low-elevation sites.
Keywords: East Antarctica ice cores dust dust stratigraphy Holocene provenance
Programme: 1145
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Olivier Gilg, Loïc Bollache, Eve Afonso, Glenn Yannic, Niels Martin Schmidt, Lars Holst Hansen, Jannik Hansen, Benoît Sittler, Johannes Lang, Nicolas Meyer, Brigitte Sabard, Vladimir Gilg, Anita Lang, Mathilde Lebbar, Voitto Haukisalmi, Heikki Henttonen, Jérôme Moreau. (2020). Are gastrointestinal parasites associated with the cyclic population dynamics of their arctic lemming hosts? (Vol. 10).
Abstract: Many rodents, including most populations of arctic lemmings (genus Dicrostonyx and Lemmus), have cyclic population dynamics. Among the numerous hypotheses which have been proposed and tested to explain this typical characteristic of some terrestrial vertebrate communities, trophic interactions have often been presented as the most likely drivers of these periodic fluctuations. The possible role of parasites has, however, only seldom been assessed. In this study, we genetically measured the prevalence of two endoparasite taxa, eimerians and cestodes, in 372 faecal samples from collared lemmings, over a five year period and across three distant sites in Northeast Greenland. Prevalence of cestodes was low (2.7% over all sites and years) and this taxon was only found at one site (although in 4 out of 5 years) in adult hosts. By contrast, we found high prevalence for eimerians (77.7% over all sites and years), which occurred at all sites, in every year, for both age classes (at the Hochstetter Forland site where both adult and juvenile faeces were collected) and regardless of reproductive and social status inferred from the characteristics of the lemming nests where the samples had been collected. Prevalence of eimerians significantly varied among years (not among sites) and was higher for juvenile than for adult lemmings at the Hochstetter Forland site. However, higher prevalence of eimerians (Pt) was only associated with lower lemming density (Nt) at one of the three sites and we found no delayed density dependence between Nt and Pt+1 to support the parasite hypothesis. Our results show that there is no clear relation between lemming density and eimerian faecal prevalence in Northeast Greenland and hence no evidence that eimerians could be driving the cyclic population dynamics of collared lemmings in this region.
Keywords: Cestodes Eimerians Faecal prevalence Greenland Population dynamics Rodent-parasites interactions
Programme: 1036
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Pierre Blévin, Scott A. Shaffer, Paco Bustamante, Frédéric Angelier, Baptiste Picard, Dorte Herzke, Børge Moe, Geir Wing Gabrielsen, Jan Ove Bustnes, Olivier Chastel. (2020). Contaminants, prolactin and parental care in an Arctic seabird: Contrasted associations of perfluoroalkyl substances and organochlorine compounds with egg-turning behavior (Vol. 291).
Abstract: Incubating eggs represents a trade-off for parent birds between spending enough time fasting to take care of the clutch and to get enough nutrients for self-maintenance. It is believed that the pituitary hormone prolactin plays an important role in such allocation processes. Incubation does not solely imply the active warming of the eggs but also the active egg-turning to facilitate absorption of albumen by the embryo, reduce malposition and prevent the embryo from adhering to the inner shell membrane. However, how prolactin secretion is related to egg-turning behaviors is presently poorly addressed. In addition, several environmental contaminants can affect parental care behaviors through their endocrine disrupting properties but the effects of such contaminants on egg-turning behaviors remain so far unexplored. Using artificial eggs equipped with miniaturized data loggers, we investigated the relationships between egg-turning behaviors, prolactin secretion and contaminants burden in Arctic black-legged kittiwakes (Rissa tridactyla). Specifically, we examined the relationships between blood concentrations of poly- and perfluoroalkyl substances (PFASs), organochlorines (OCs), mercury (Hg), plasma prolactin levels and both egg-turning frequency and angular change. We also incorporated baseline corticosterone levels since this glucocorticoid is known to affect parental care. Plasma prolactin levels were positively related to angular change in female kittiwakes while corticosterone was not related to egg-turning behaviors in either sex. Hg was not related to egg-turning behaviors in either sex. We found contrasting associations between OCs and PFASs, since polychlorinated biphenyls (PCBs) were negatively associated with angular change in females, contrary to linear perfluorooctanesulfonate (PFOSlin) and perfluoroalkyl carboxylic acids (PFCAs) which were positively related to egg-turning frequency and angular change in both sexes. Additionally, PFASs concentrations were positively related to prolactin levels in female kittiwake. The possible stimulation of prolactin secretion by PFASs could therefore make adult kittiwakes to allocate more time taking care of their eggs, and thus possibly modify the trade-off between spending enough time caring for the clutch and obtaining enough nutrients at sea.
Keywords: Black-legged kittiwake Corticosterone Egg-loggers Incubation behaviors Mercury Organochlorine compounds Perfluoroalkyl substances Prolactin
Programme: 330
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Eva Fuglei, John-André Henden, Chris T. Callahan, Olivier Gilg, Jannik Hansen, Rolf A. Ims, Arkady P. Isaev, Johannes Lang, Carol L. McIntyre, Richard A. Merizon, Oleg Y. Mineev, Yuri N. Mineev, Dave Mossop, Olafur K. Nielsen, Erlend B. Nilsen, Åshild Ønvik Pedersen, Niels Martin Schmidt, Benoît Sittler, Maria Hørnell Willebrand, Kathy Martin. (2020). Circumpolar status of Arctic ptarmigan: Population dynamics and trends (Vol. 49).
Abstract: Rock ptarmigan (Lagopus muta) and willow ptarmigan (L. lagopus) are Arctic birds with a circumpolar distribution but there is limited knowledge about their status and trends across their circumpolar distribution. Here, we compiled information from 90 ptarmigan study sites from 7 Arctic countries, where almost half of the sites are still monitored. Rock ptarmigan showed an overall negative trend on Iceland and Greenland, while Svalbard and Newfoundland had positive trends, and no significant trends in Alaska. For willow ptarmigan, there was a negative trend in mid-Sweden and eastern Russia, while northern Fennoscandia, North America and Newfoundland had no significant trends. Both species displayed some periods with population cycles (short 3–6 years and long 9–12 years), but cyclicity changed through time for both species. We propose that simple, cost-efficient systematic surveys that capture the main feature of ptarmigan population dynamics can form the basis for citizen science efforts in order to fill knowledge gaps for the many regions that lack systematic ptarmigan monitoring programs.
Programme: 1036
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Stephanie M. Harris, Sébastien Descamps, Lynne U. Sneddon, Philip Bertrand, Olivier Chastel, Samantha C. Patrick. (2020). Personality predicts foraging site fidelity and trip repeatability in a marine predator (Vol. 89).
Abstract: Animal populations are often comprised of both foraging specialists and generalists. For instance, some individuals show higher foraging site fidelity (spatial specialization) than others. Such individual differences in degree of specialization can persist over time-scales of months or even years in long-lived animals, but the mechanisms leading to these different individual strategies are not fully understood. There is accumulating evidence that individual variation in foraging behaviour is shaped by animal personality traits, such as boldness. Despite this, the potential for boldness to drive differences in the degree of specialization is unknown. In this study, we used novel object tests to measure boldness in black-legged kittiwakes (Rissa tridactyla) breeding at four colonies in Svalbard and deployed GPS loggers to examine their at-sea foraging behaviour. We estimated the repeatability of foraging trips and used a hidden Markov model to identify locations of foraging sites in order to quantify individual foraging site fidelity. Across the breeding season, bolder birds were more repeatable than shy individuals in the distance and range of their foraging trips, and during the incubation period (but not chick rearing), bolder individuals were more site-faithful. Birds exhibited these differences while showing high spatial similarity in foraging areas, indicating that site selection was not driven by personality-dependent spatial partitioning. We instead suggest that a relationship between boldness and site fidelity may be driven by differences in behavioural flexibility between bold and shy individuals. Together, these results provide a potential mechanism by which widely reported individual differences in foraging specialization may emerge.
Keywords: biologging boldness foraging niche width foraging specialization marine vertebrate movement ecology personality site fidelity
Programme: 330
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Marion Donat-Magnin, Nicolas C. Jourdain, Hubert Gallée, Charles Amory, Christoph Kittel, Xavier Fettweis, Jonathan D. Wille, Vincent Favier, Amine Drira, Cécile Agosta. (2020). Interannual variability of summer surface mass balance and surface melting in the Amundsen sector, West Antarctica (Vol. 14).
Abstract: Abstract. Understanding the interannual variability of surface mass balance (SMB) and surface melting in Antarctica is key to quantify the signal-to-noise ratio in climate trends, identify opportunities for multi-year climate predictions and assess the ability of climate models to respond to climate variability. Here we simulate summer SMB and surface melting from 1979 to 2017 using the Regional Atmosphere Model (MAR) at 10 km resolution over the drainage basins of the Amundsen Sea glaciers in West Antarctica. Our simulations reproduce the mean present-day climate in terms of near-surface temperature (mean overestimation of 0.10 ∘C), near-surface wind speed (mean underestimation of 0.42 m s−1), and SMB (relative bias <20 % over Thwaites glacier). The simulated interannual variability of SMB and melting is also close to observation-based estimates. For all the Amundsen glacial drainage basins, the interannual variability of summer SMB and surface melting is driven by two distinct mechanisms: high summer SMB tends to occur when the Amundsen Sea Low (ASL) is shifted southward and westward, while high summer melt rates tend to occur when ASL is shallower (i.e. anticyclonic anomaly). Both mechanisms create a northerly flow anomaly that increases moisture convergence and cloud cover over the Amundsen Sea and therefore favors snowfall and downward longwave radiation over the ice sheet. The part of interannual summer SMB variance explained by the ASL longitudinal migrations increases westward and reaches 40 % for Getz. Interannual variation in the ASL relative central pressure is the largest driver of melt rate variability, with 11 % to 21 % of explained variance (increasing westward). While high summer SMB and melt rates are both favored by positive phases of El Niño–Southern Oscillation (ENSO), the Southern Oscillation Index (SOI) only explains 5 % to 16 % of SMB or melt rate interannual variance in our simulations, with moderate statistical significance. However, the part explained by SOI in the previous austral winter is greater, suggesting that at least a part of the ENSO–SMB and ENSO–melt relationships in summer is inherited from the previous austral winter. Possible mechanisms involve sea ice advection from the Ross Sea and intrusions of circumpolar deep water combined with melt-induced ocean overturning circulation in ice shelf cavities. Finally, we do not find any correlation with the Southern Annular Mode (SAM) in summer.
Programme: 411
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Marine Duc. (2020). “You are the Greenlandic one”. Saisir la place de la région d’origine dans la production de l’autochtonie chez les étudiant·e·s groenlandais·e·s au Danemark.
Abstract: En partant des expériences quotidiennes de minorisation rencontrées par des étudiant·e·s groenlandais·e·s au Danemark, je propose de voir comment l’imposition d’un stigmate territorial -comme sa négociation – participent à la production d’une autochtonie en tension. L’objectif de cet article est donc double. D’une part, en montrant comment les représentations de la région d’origine participent aux processus de racialisation, il s’agit de mettre en évidence la manière dont un ordre national chromatisé est performé au quotidien entre Danemark et Groenland. D’autre part, en montrant que la négociation de l’imposition du stigmate n’est pas la même selon les ressources dont disposent les individus, je soulignerai la nécessité de ne pas prendre la catégorie « peuples autochtones » comme un donné, mais au contraire, de penser l’autochtonie comme un positionnement social dynamique, qui se recompose selon les contextes, selon des logiques de race, de classe et de genre, mais également selon les trajectoires des individus.
Programme: 1213
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