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Barret M, Dommergue A, Ferrari CP, Magand O, . (2013). (Vol. 1). Bachelor's thesis, , .
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Nesterova Anna P, Chiffard Jules, Couchoux Charline, Bonadonna Francesco, . (2013). The invisible cues that guide king penguin chicks home. The use of magnetic and acoustic cues during orientation and short-range navigation
. J. Exp. Biol., 216, 1491–1500.
Abstract: King penguins (Aptenodytes patagonicus) live in large and densely populated colonies, where navigation can be challenging due to the presence of many conspecifics that could obstruct locally available cues. Our previous experiments demonstrated that visual cues were important but not essential for king penguin chicks' homing. The main objective of this study was to investigate the importance of non-visual cues, such as magnetic and acoustic cues, for chicks' orientation and short-range navigation. In a series of experiments, the chicks were individually displaced from the colony to an experimental arena where they were released under different conditions. In the magnetic experiments, a strong magnet was attached to the chicks' heads. Trials were conducted in daylight and at night to test the relative importance of visual and magnetic cues. Our results showed that when the geomagnetic field around chicks was modified, their orientation in the arena and the overall ability to home was not affected. In the low sound experiment we limited the acoustic cues available to the chicks by putting ear pads over their ears, and in the loud sound experiment we provided additional acoustic cues by broadcasting colony sounds on the opposite side of the arena to the real colony. In the low sound experiment, the behavior of the chicks was not affected by the limited sound input. In the loud sound experiment, the chicks reacted strongly to the colony sound. These results suggest that king penguin chicks may use the sound of the colony while orienting towards their home.
Programme: 354
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. (2014). Bachelor's thesis, , .
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Robin JP et J Labonne. (2019). Zone Atelier Antarctique et Terres Australes : Bilan et Perspectives. Bachelor's thesis, , .
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. (2013). Estimating transitions between states using measurements with imperfect detection: application to serological data
. Ecology, 94(10), 2160–2165.
Abstract: Classifying the states of an individual and quantifying transitions between states are crucial while modeling animal behavior, movement, and physiologic status. When these states are hidden or imperfectly known, it is particularly convenient to relate them to appropriate quantitative measurements taken on the individual. This task is, however, challenging when quantitative measurements are not available at each sampling occasion. For capture?recapture data, various ways of incorporating such non-discrete information have been used, but they are either ad hoc and/or use a fraction of the available information by relying on a priori thresholds to assign individual states. Here we propose assigning discrete states based on a continuous measurement, and then modeled survival and transition probabilities based on these assignments. The main advantage of this new approach is that a more informative use of the non-discrete information is done. As an illustrative working example, we applied this approach to eco-epidemiological data collected across a series of years in which individuals of a long-lived seabird, the Black-legged Kittiwake (Rissa tridactyla), could either be visually detected or physically recaptured and blood sampled for subsequent immunological analyses. We discuss how this approach opens many perspectives in eco-epidemiology, but also more broadly, in population ecology.
Programme: 333
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. (2013). AJP Regulatory, Integrative and Comparative Physiology, 305(9), R1065–R1075.
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Toscani C., Gallon S, Mccafferty D.j., Ancel A. & Gilbert C. (2013). Energetics of huddling and moult in southern elephant seals. Colloque d'Ecophysiologie Animale, Lyon, France, 7-9 Novembre 2013. Bachelor's thesis, , .
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Thierry Anne-Mathilde, Brajon Sophie, Massemin Sylvie, Handrich Yves, Chastel Olivier, Raclot Thierry, . (2013). Decreased prolactin levels reduce parental commitment, egg temperatures, and breeding success of incubating male Adélie penguins . Hormones and Behavior, 64(4), 737–747.
Abstract: Hormones regulate many aspects of an individual's phenotype, including various physiological and behavioral traits. Two hormones have been described as important players in the regulation of parental investment in birds: the glucocorticoid hormone corticosterone and prolactin, a pituitary hormone, widely involved in mediating parental behavior. In comparison with corticosterone, the role of prolactin on parental investment remains poorly documented, and most studies so far have been correlative. In this study, the effects of an experimental decrease of prolactin levels on the incubation behavior of a long-lived seabird species were assessed. Male Adelie penguins were treated with self-degradable bromocriptine pellets, inhibiting prolactin secretion. Filming and subsequent video analysis allowed the determination of a behavioral time budget for birds and their position on the nest, while dummy eggs recorded incubation parameters. Incubation duration and breeding success at hatching were also monitored. As expected, bromocriptine-treatment significantly decreased plasma prolactin levels, but did not affect corticosterone levels. The behavioral time budget of penguins was not affected by the treatment. However, treated birds spent significantly more time in an upright position on the nest. These birds also incubated their eggs at lower temperatures and turned their eggs more frequently than controls, resulting in a lengthened incubation period. Despite this, the treatment was insufficient to trigger nest desertion and eggs of treated birds still hatched, indicating that several endocrine signals are required for the induction of nest abandonment. We suggest that the decreased prolactin levels in treated birds offset their timeline of breeding, so that birds displayed behavior typical of early incubation.
Keywords: Bromocriptine, Corticosterone, Egg temperature, Egg rotation rate, Incubation behavior, Parental care, Pygoscelis adeliae, Prolactin, Seabird,
Programme: 394,1091
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Thierry Anne-Mathilde, Massemin Sylvie, Handrich Yves, Raclot Thierry, . (2013). Elevated corticosterone levels and severe weather conditions decrease parental investment of incubating Adélie penguins . Hormones and Behavior, 63(3), 475–483.
Abstract: Corticosterone, the main stress hormone in birds, mediates resource allocation, allowing animals to adjust their physiology and behaviour to changes in the environment. Incubation is a time and energy-consuming phase of the avian reproductive cycle. It may be terminated prematurely, when the parents' energy stores are depleted or when environmental conditions are severe. In this study, the effects of experimentally elevated baseline corticosterone levels on the parental investment of incubating male Adelie penguins were investigated. Incubation duration and reproductive success of 60 penguins were recorded. The clutches of some birds were replaced by dummy eggs, which recorded egg temperatures and rotation rates, enabling a detailed investigation of incubation behaviour. Corticosterone levels of treated birds were 2.4-fold higher than those of controls 18 days post treatment. Exogenous corticosterone triggered nest desertion in 61% of the treated birds; consequently reducing reproductive success, indicating that corticosterone can reduce or disrupt parental investment. Regarding egg temperatures, hypothermic events became more frequent and more pronounced in treated birds, before these birds eventually abandoned their nest. The treatment also significantly decreased incubation temperatures by 1.3 degrees C and lengthened the incubation period by 2.1 days. However, the number of chicks at hatching was similar among successful nests, regardless of treatment. Weather conditions appeared to be particularly important in determining the extent to which corticosterone levels affected the behaviour of penguins, as treated penguins were more sensitive to severe weather conditions. This underlines the importance of considering the interactions of organisms with their environment in studies of animal behaviour and ecophysiology.
Keywords: Egg temperature and rotation rate, Glucocorticoids, Incubation behaviour, Pygoscelis adeliae, Seabird, Weather conditions,
Programme: 394,1091
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. (2013). Tide-induced microseismicity in the Mertz glacier grounding area, East Antarctica
. Geophysical Research Letters, 40(20), 5412–5416.
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