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. (2014). Will seabirds survive a sea-ice free Arctic?.
Abstract: Invited talk
Arctic Change 2014 International conference, Ottawa. Dec. 2014
Programme: 388
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Bon, C., Della Penna, A., d'Ovidio, F., Arnould, J.P.Y., Bost C.A. (2014). Foraging strategies of Macaroni penguins at Crozet islands: relation with oceanographic structures . 5th Biologging Congress, 22-26 Septembre 2015, Strasbourg..
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Klein K-L, Masson S, Bouratzis C, Grechnev V, Hillaris A, Preka-Papadema P, . (2014). The relativistic solar particle event of 2005 January 20: origin of delayed particle acceleration
. 0004-6361, 572, A4.
Abstract: The highest energies of solar energetic nucleons detected in space or through gamma-ray emission in the solar atmosphere are in the GeV range. Where and how the particles are accelerated is still controversial. We search for observational evidence on the acceleration region(s) by comparing the timing of relativistic protons detected at Earth and radiative signatures in the solar atmosphere during the particularly well observed 2005 Jan 20 event. This investigation focusses on the post-impulsive flare phase, where a second peak was observed in the relativistic proton time profile by neutron monitors. This time profile is compared in detail with UV imaging and radio spectrography over a broad frequency band from the low corona to interplanetary space.It is shown that the late relativistic proton release to interplanetary space was accompanied by a distinct new episode of energy release and electron acceleration in the corona traced by the radio emission and by brightenings of UV kernels. These signatures are interpreted in terms of magnetic restructuring in the corona after the CME passage. We attribute the delayed relativistic proton acceleration to magnetic reconnection and possibly turbulence in large- scale coronal loops. While type II radio emission was observed in the high corona, no evidence of a temporal relationship with the relativistic proton acceleration was found.
Programme: 227
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Cornet C. (2014). The adaptive capacities of seabirds to face environmental variability: the role of heterogeneity within populations.
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. (2014). First detection of Borrelia burgdorferi sensu lato DNA in king penguins (Aptenodytes patagonicus halli).
. Ticks and tick-borne diseases, 5(6), 939–42.
Abstract: The hard tick Ixodes uriae parasitises a wide range of seabird species in the circumpolar areas of both Northern and Southern hemispheres and has been shown to be infected with Borrelia burgdorferi sensu lato, the bacterial agents of Lyme borreliosis. Although it is assumed that seabirds represent viable reservoir hosts, direct demonstrations of infection are limited to a single study from the Northern hemisphere. Here, the blood of 50 tick-infested adult king penguins (Aptenodytes patagonicus halli) breeding in the Crozet Archipelago (Southern Indian Ocean) was examined for B. burgdorferi sl exposure by serology and for spirochetemia by in vitro DNA amplification. Four birds were found positive by serology, whereas B. burgdorferi sl DNA was detected in two other birds. Our data therefore provide the first direct proof of Borrelia burgdorferi sl spirochetes in seabirds of the Southern hemisphere and indicate a possible reservoir role for king penguins in the natural maintenance of this bacterium. Although the bacterial genetic diversity present in these hosts and the infectious period for tick vectors remain to be elucidated, our results add to a growing body of knowledge on the contribution of seabirds to the complex epizootiology of Lyme disease and the global dissemination of B. burgdorferi sl spirochetes.
Keywords: Borrelia burgdorferi, Crozet Archipelago, Epidemiology, King penguins, Lyme disease, Spirochetemia,
Programme: 394
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. (2014). Starting with a handicap: phenotypic differences between early- and late-born king penguin chicks and their survival correlates
. Functional Ecology, 28(3), 601–611.
Abstract: The exceptionally long (c. 11 months) growth period of king penguin chicks (Aptenodytes patagonicus) is interrupted by the Austral winter. As a consequence, penguin chicks born late in the breeding season have little time to build-up their energy reserves before the drastic energy bottleneck they experience during winter and face greater risks of mortality than early-born chicks.
Whereas it is well known that breeding adults alternate between early- and late-breeding attempts, little is known on the phenotype of early- and late-chicks, and on the potential existence of specific adaptive phenotypic responses in late-born individuals.
We investigated phenotypic differences between early- and late-chicks and tested their survival correlates both before the winter and at fledgling. Chicks were sampled 10 days after hatching to measure body mass, plasma corticosterone levels, oxidative stress parameters and telomere length.
Late-chicks were heavier than early-chicks at day 10. Late-chicks also had higher corticosterone and oxidative stress levels, shorter telomere lengths and suffered from higher mortality rates than early-chicks. For both early- and late-chicks, high body mass close to hatching was a strong predictor of survival up to, and over, the winter period.
In late but not early-chicks, high corticosterone levels and long telomeres were significant predictors of survival up to winter and fledging, respectively.
Our study provides evidence that late- and early-king penguin chicks showed marked phenotypic differences 10 days after hatching. We provide an integrative discussion on whether these differences may be adaptive or not, and to what extent they may be driven by active maternal effects, indirectly induced by environmental effects, or stem from individual differences in parental quality.
Programme: 394
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Lewden A., Bost C., Bost C.-A. & Y. Handrich. (2014). An over-cost of being a pelagic bird: a possible energetic conflict between thermoregulation and digestive processes.
The 5th International Bio-logging Science Symposium. 22-27 September 2014. Strasbourg, France..
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. (2014). Adjustment of pre-moult foraging strategies in Macaroni Penguins Eudyptes chrysolophus according to locality, sex and breeding status
. 0019-1019, 156(3), 511–522.
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. (2014).
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Lavrillier, A., Claud, C., Rojo, M., Gabyshev, S., Chondan, R.M. (2014).
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