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. (2011). Metabolic rate throughout the annual cycle reveals the demands of an Arctic existence in Great Cormorants
. Ecology, 92(2), 475–486.
Abstract: Aquatic endotherms living in polar regions are faced with a multitude of challenges, including low air and water temperatures and low illumination, especially in winter. Like other endotherms from cold environments, Great Cormorants (Phalacrocorax carbo) living in Arctic waters were hypothesized to respond to these challenges through a combination of high daily rate of energy expenditure (DEE) and high food requirements, which are met by a high rate of catch per unit effort (CPUE). CPUE has previously been shown in Great Cormorants to be the highest of any diving bird. In the present study, we tested this hypothesis by making the first measurements of DEE and foraging activity of Arctic-dwelling Great Cormorants throughout the annual cycle. We demonstrate that, in fact, Great Cormorants have surprisingly low rates of DEE. This low DEE is attributed primarily to very low levels of foraging activity, particularly during winter, when the cormorants spent only 2% of their day submerged. Such a low level of fo...
Keywords: arctic, basal metabolic rate, catch per unit effort, cpue, daily energy expenditure, day length, diving depths, field metabolic rate, foraging efficiency, great cormorant, greenland, phalacrocorax carbo, seasonal variation,
Programme: 388
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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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. (2014). When things go wrong: intra-season dynamics of breeding failure in a seabird
. Ecosphere, 5(1), art4–.
Abstract: During breeding, long-lived species face important time and energy constraints that can lead to breeding failure when food becomes scarce. Despite the potential implications of intra-season dynamics in breeding failure for individual behavior, carry-over effects, dispersal decisions and population dynamics, little information is currently available on these dynamics at fine temporal scales. Here, we monitored the foraging behavior and the proportion of successful black-legged kittiwake pairs from nest construction to chick fledging in a colony of the southern Barents Sea, to relate foraging effort to the dynamics of breeding failure over an entire breeding season, and to infer the environmental conditions leading to this failure. Specifically, we tracked kittiwakes with GPS and satellite tags during incubation and early chick-rearing to document nest attendance, foraging range, time budgets and daily energy expenditures (DEE). We also monitored diet changes over time. We predicted that breeding failure would follow a non-linear trend characterized by a break point after which breeding success would drop abruptly and would be related to a substantial increase in foraging effort. Kittiwakes showed contrasting foraging patterns between incubation and chick-rearing: they extended their foraging range from 20 km during incubation to more than 450 km during chick-rearing and switched diet. They also increased their DEE and readjusted their time budgets by increasing time spent at sea. These changes corresponded to a break point in breeding dynamics beyond which the proportion of successful pairs abruptly dropped. At the end of the season, less than 10% of kittiwake pairs raised chicks in the monitored plots. This integrative study confirms that breeding failure is a non-linear process characterized by a threshold beyond which individuals face an energetic trade-off and cannot simultaneously sustain high reproductive and self-maintenance efforts. In this way, the occurrence of sudden environmental changes complicates our ability to predict population dynamics and poses conservation challenges.
Programme: 333
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Goutte A, Bustamante P, Barbraud C, Delord K, Weimerskirch H, Chastel O, . (2013). Demographic responses to mercury exposure in two closely related Antarctic top predators
. Ecology, 95(4), 1075–1086.
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. (2014). Age, sex, and breeding status shape a complex foraging pattern in an extremely long-lived seabird
. Ecology, 95(8), 2324–2333.
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Nevoux M, Forcada J, Barbraud C, Croxall J, Weimerskirch H, . (2010). Bet-hedging response to environmental variability, an intraspecific comparison
. Ecology, 91(8), 2416–2427.
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Van de Vijver Bart, Moravcova Adela, Kusber Wolf-Henning, Neustupa Jiri, . (2013). Analysis of the type material of Pinnularia divergentissima (Grunow in Van Heurck) Cleve (Bacillariophyceae)
. FOTTEA, 13(1), 1–14.
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David, C.; Keckhut, P.; Armetta, A.; Jumelet, J.; Snels, M.; Marchand, M.; Bekki, S. (2010). Radiosonde stratospheric temperatures at Dumont d'Urville (Antarctica): trends and link with polar stratospheric clouds. ACP, 10(8), 3813–3825.
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Magand, O.; Picard, G.; Brucker, L.; Fily, M.; Genthon, C. (2008). Snow melting bias in microwave mapping of Antarctic snow accumulation. TCD, 2(2), 255–273.
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Masson-Delmotte, V.; Dreyfus, G.; Braconnot, P.; Johnsen, S.; Jouzel, J.; Kageyama, M.; Landais, A.; Loutre, M.-F.; Nouet, J.; Parrenin, F.; Raynaud, D.; Stenni, B.; Tuenter, E. (2006). Past temperature reconstructions from deep ice cores: relevance for future climate change. Climate of the past, 2(2), 145–165.
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