Carravieri Alice, Weimerskirch Henri, Bustamante Paco, Cherel Yves. (2017). Progressive ontogenetic niche shift over the prolonged immaturity period of wandering albatrosses (Vol. 4).
Abstract: Very little is known about trophic ontogenetic changes over the prolonged immaturity period of long-lived, wide-ranging seabirds. By using blood and feather trophic tracers (?13C and ?15N, and mercury, Hg), we studied age-related changes in feeding ecology during the immature phase of wandering albatrosses Diomedea exulans when they gradually change from a pure oceanic life to visits to their future breeding grounds. Immatures fed in subtropical waters at high trophic positions during moult. Between- and within-individual variations in isotopic niche were very high, irrespective of age, highlighting wide-ranging exploratory behaviours. In summer, while acting as central-place foragers from their future breeding colony, individuals progressively relied on lower trophic level prey and/or southern latitudes as they aged, until occupying a similar isotopic niche to that of adults. Immatures had exceptionally high Hg burdens, with males having lower Hg concentrations than females, suggesting that they foraged more in subantarctic waters. Our findings suggest a progressive ontogenetic niche shift during central-place foraging of this long-lived species.
Programme: 109
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. (2010). Cryptic vector divergence masks vector-specific patterns of infection: an example from the marine cycle of Lyme borreliosis
. Evol Appl, 3(4), 391–401.
Abstract: Vector organisms are implicated in the transmission of close to a third of all infectious diseases. In many cases, multiple vectors (species or populations) can participate in transmission but may contribute differently to disease ecology and evolution. The presence of cryptic vector populations can be particularly problematic as differences in infection can be difficult to evaluate and may lead to erroneous evolutionary and epidemiological inferences. Here, we combine site-occupancy modeling and molecular assays to evaluate patterns of infection in the marine cycle of Lyme borreliosis, involving colonial seabirds, the tick Ixodes uriae, and bacteria of the Borrelia burgdorferi s.l. complex. In this cycle, the tick vector consists of multiple, cryptic (phenotypically undistinguishable but genetically distinct) host races that are frequently found in sympatry. Our results show that bacterial detection varies strongly among tick races leading to vector-specific biases if raw counts are used to calculate Borrelia prevalence. These differences are largely explained by differences in infection intensity among tick races. After accounting for detection probabilities, we found that overall prevalence in this system is higher than previously suspected and that certain vector-host combinations likely contribute more than others to the local dynamics and large-scale dispersal of Borrelia spirochetes. These results highlight the importance of evaluating vector population structure and accounting for detection probability when trying to understand the evolutionary ecology of vector-borne diseases.
Keywords: lyme disease bacteria, pathogen detection, seabirds, site occupancy models, transmission,
Programme: 333
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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).
Keywords: Biologging GPS Indian Ocean Ocean observation Ocean waves Seabird
Programme: 109
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Vare L L, Masse G, Belt S T, . (2010). A biomarker-based reconstruction of sea ice conditions for the Barents Sea in recent centuries
. The Holocene, 20(4), 637–643.
Abstract: Variations in sea ice occurrence for the Barents Sea since c. AD 1700 have been determined by analysis of the abundance of the sea ice biomarker IP25 in three marine sediment box cores obtained from locations in the north, southeast and southwest parts of the region. Depth/age models for each core were established using excess 210Pb activity profiles. Comparisons between these depth/age models with those reported previously for the Barents Sea, suggest that the proxy sea ice record may, alternatively, extend back to c. AD 1500--1600. Sedimentation accumulation rates and bulk densities were combined with IP 25 concentrations, resulting in temporal changes to IP25 fluxes, which have been interpreted in terms of sea ice variability. The IP25 sea ice proxy data are also compared with other bulk organic geochemical parameters (total organic carbon and C/N ratios) and with sediment particle size distributions. The data indicate ice-free conditions for the southwest Barents Sea for the past c. 300 yr, consistent with previous reports based on historical sea ice records. In contrast, the combined proxy data from the southeast and north Barents Sea suggest variable spring sea ice occurrence on a c. 10--50 yr timescale, with reduced sea ice over the last c. 40--100 yr. In the early record, an enhanced sea ice occurrence is observed for the southeast Barents Sea during the mid--late nineteenth century, but as early as c. AD 1780 for the northern region. The outcomes of this study are broadly consistent with those obtained from ice edge position determinations derived previously from observational records. The study also demonstrates the potential of using IP25 as a sea ice proxy for longer-term palaeo sea ice determinations (e.g. the Holocene) for the Barents Sea.
Programme: 452
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Fay Rémi, Barbraud Christophe, Delord Karine, Weimerskirch Henri. (2016). Paternal but not maternal age influences early-life performance of offspring in a long-lived seabird. Proc. Biol. Sci., 283(1828), 20152318.
Abstract: Variability in demographic traits between individuals within populations has profound implications for both evolutionary processes and population dynamics. Parental effects as a source of non-genetic inheritance are important processes to consider to understand the causes of individual variation. In iteroparous species, parental age is known to influence strongly reproductive success and offspring quality, but consequences on an offspring fitness component after independence are much less studied. Based on 37 years longitudinal monitoring of a long-lived seabird, the wandering albatross, we investigate delayed effects of parental age on offspring fitness components. We provide evidence that parental age influences offspring performance beyond the age of independence. By distinguishing maternal and paternal age effects, we demonstrate that paternal age, but not maternal age, impacts negatively post-fledging offspring performance.
Programme: 109
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Cagnati A., Dicasillati R., Salvietti E., Udisti R. (2005). Snow crystals observations at Dome C, Antarctica..
Abstract: V Convegno Nazionale di Glaciologia Antartica (CONGA 05), Milano (Italy), 19-21 Ottobre 2005. Conference proceedings, p. 9.
Programme: 1181
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Udisti R., S. Becagli, E. Castellano, O. Cerri, I. Fattori, M. Innocenti, A. Mannini, F. Marino, E. Salvietti, R. Traversi. (2005). Dome C 2004/05 first winterover campaign: understanding today snow-atmosphere relationships to reliably interpret ice core data..
Abstract: V Convegno Nazionale di Glaciologia Antartica (CONGA 05), Milano (Italy), 19-21 Ottobre 2005. Conference proceedings, p. 71.
Programme: 1181
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Marino F., S. Becagli, E. Castellano, A. Mannini, E. Salvietti, I. Fattori, M. Innocenti, O. Cerri, R. Traversi, B. Delmonte, V. Maggi, R. Udisti. (2005). Geochemical characterization of present-day dust by all-year-round high-volume aerosol sampling: planned activity for the 2005-2006 Dome C campaign..
Abstract: V Convegno Nazionale di Glaciologia Antartica (CONGA 05), Milano (Italy), 19-21 Ottobre 2005. Conference proceedings, p. 40.
Programme: 1181
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Amory, C., A. Trouvilliez, H. Gallée, F. Naaim-Bouvet, C. Genthon, V. favier, C. Agosta, L. Piard, and H. bellot. (2015). Comparison of aeolian snow transport events and snow mass fluxes between observations and simulations made by the regional climate model MAR in Adélie Land, East Antarctica. TC, 9, 1373–1383.
Abstract: Using the original setup described in Gallée et al. (2013), the MAR regional climate model including a coupled snowpack/aeolian snow transport parameterization, was run at a fine spatial (5 km horizontal and 2 m vertical) resolution over 1 summer month in coastal Adélie Land. Different types of feedback were taken into account in MAR including drag partitioning caused by surface roughness elements. Model outputs are compared with observations made at two coastal locations, D17 and D47, situated respectively 10 and 100 km inland. Wind speed was correctly simulated with positive values of the Nash test (0.60 for D17 and 0.37 for D47) but wind velocities above 10 m s−1 were underestimated at both D17 and D47; at D47, the model consistently underestimated wind velocity by 2 m s−1. Aeolian snow transport events were correctly reproduced with the right timing and a good temporal resolution at both locations except when the maximum particle height was less than 1 m. The threshold friction velocity, evaluated only at D17 for a 7-day period without snowfall, was overestimated. The simulated aeolian snow mass fluxes between 0 and 2 m at D47 displayed the same variations but were underestimated compared to the second-generation FlowCaptTM values, as was the simulated relative humidity at 2 m above the surface. As a result, MAR underestimated the total aeolian horizontal snow transport for the first 2 m above the ground by a factor of 10 compared to estimations by the second-generation FlowCaptTM. The simulation was significantly improved at D47 if a 1-order decrease in the magnitude of z0 was accounted for, but agreement with observations was reduced at D17. Our results suggest that z0 may vary regionally depending on snowpack properties, which are involved in different types of feedback between aeolian transport of snow and z0.
Programme: 1013
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. (2009). Full Stokes modeling of marine ice sheets: influence of the grid size (Vol. 50).
Abstract: Using the finite-element code Elmer, we show that the full Stokes modeling of the ice-sheet/ice-shelf transition we propose can give consistent predictions of grounding-line migration. Like other marine ice-sheet models our approach is highly sensitive to the chosen mesh resolution. However, with a grid size down to <5 km in the vicinity of the grounding line, predictions start to be robust because: (1) whatever the grid size (<5 km) the steady-state grounding-line position is sensibly the same (6 km standard deviation), and (2) with a grid-size refinement in the vicinity of the grounding line (200 m), the steady-state solution is independent of the applied perturbation in fluidity, provided this perturbation remains monotonic.
Programme: 1053
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