Barbraud, C., Weimerskirch, H., Bost, C.A., Forcada, J., Trathan, P., Ainley, D. (2008). Are king penguin populations threatened by Southern Ocean warming? Proc. Natl. Acad. Sci. U.S.A., 105(26), E38.
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White, J. F., Wagner, R. H., Helfenstein, F., Hatch, S. A., Mulard, H., Naves, L. C. and Danchin, E. (2008). Multiple deleterious effects of experimentally aged sperm in a monogamous bird. Proc. Natl. Acad. Sci. U.S.A., 105, 13947–13952.
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Jenouvrier S., Caswell H., Barbraud C., Holland M., Str Oelig VE J., Weimerskirch H. (2009). Demographic models and IPCC climate projections predict the decline of an emperor penguin population. Proc. Natl. Acad. Sci. U.S.A., 106, 1844–1847.
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Fraser C.I., Nikula R., Spencer H.G. & Waters J.M. (2009). Kelp genes reveal effects of subantarctic sea ice during the Last Glacial Maximum. Proc. Natl. Acad. Sci. U.S.A., 106, 3249–3253.
Abstract: Ce travail, qui n'est pas issu du programme 136, utilise des prélèvements d'algues et de crustacés marins collectés par des membres du 136 à Crozet et Kerguelen
Programme: 136
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Lecomte Vincent Julien, Sorci Gabriele, Cornet Stéphane, Jaeger Audrey, Faivre Bruno, Arnoux Emilie, Gaillard Maria, Trouvé Colette, Besson Dominique, Chastel Olivier, Weimerskirch Henri, . (2010). Patterns of aging in the long-lived wandering albatross.
. Proc. Natl. Acad. Sci. U.S.A., 107(14), 6370–5.
Abstract: How does an animal age in natural conditions? Given the multifaceted nature of senescence, identifying the effects of age on physiology and behavior remains challenging. We investigated the effects of age on a broad array of phenotypic traits in a wild, long-lived animal, the wandering albatross. We studied foraging behavior using satellite tracking and activity loggers in males and females (age 6-48+ years), and monitored reproductive performance and nine markers of baseline physiology known to reflect senescence in vertebrates (humoral immunity, oxidative stress, antioxidant defenses, and hormone levels). Age strongly affected foraging behavior and reproductive performance, but not baseline physiology. Consistent with results of mammal and human studies, age affected males and females differently. Overall, our findings demonstrate that age, sex, and foraging ability interact in shaping aging patterns in natural conditions. Specifically, we found an unexpected pattern of spatial segregation by age; old males foraged in remote Antarctica waters, whereas young and middle-aged males never foraged south of the Polar Front. Old males traveled a greater distance but were less active at the sea surface, and returned from sea with elevated levels of stress hormone (corticosterone), mirroring a low foraging efficiency. In contrast to findings in captive animals and short-lived birds, and consistent with disposable soma theory, we found no detectable age-related deterioration of baseline physiology in albatrosses. We propose that foraging efficiency (i.e., the ability of individuals to extract energy from their environment) might play a central role in shaping aging patterns in natural conditions.
Keywords: Aging, Animal Migration, Animals, Birds, Birds: physiology, Feeding Behavior, Female, Male, Sex Characteristics, Sexual Behavior, Animal,
Programme: 109
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Masson-Delmotte V, Stenni B, Blunier T, Cattani O, Chappellaz J, Cheng H, Dreyfus G, Edwards R L, Falourd S, Govin A, Kawamura K, Johnsen S J, Jouzel J, Landais A, Lemieux-Dudon B, Lourantou A, Marshall G, Minster B, Mudelsee M, Pol K, Röthlisberger R, Selmo E, Waelbroeck C, . (2010). Abrupt change of Antarctic moisture origin at the end of Termination II
. Proc. Natl. Acad. Sci. U.S.A., 107(27), 12091–12094.
Abstract: The deuterium excess of polar ice cores documents past changes in evaporation conditions and moisture origin. New data obtained from the European Project for Ice Coring in Antarctica Dome C East Antarctic ice core provide new insights on the sequence of events involved in Termination II, the transition between the penultimate glacial and interglacial periods. This termination is marked by a northsouth seesaw behavior, with first a slow methane concentration rise associated with a strong Antarctic temperature warming and a slow deuterium excess rise. This first step is followed by an abrupt north Atlantic warming, an abrupt resumption of the East Asian summer monsoon, a sharp methane rise, and a CO2 overshoot, which coincide within dating uncertainties with the end of Antarctic optimum. Here, we show that this second phase is marked by a very sharp Dome C centennial deuterium excess rise, revealing abrupt reorganization of atmospheric circulation in the southern Indian Ocean sector.
Programme: 458
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Humphries Nicolas E, Weimerskirch Henri, Queiroz Nuno, Southall Emily J, Sims David W, . (2012). Foraging success of biological Lévy flights recorded in situ
. Proc. Natl. Acad. Sci. U.S.A., 109 (19 ), 7169–7174 .
Abstract: It is an open question how animals find food in dynamic natural environments where they possess little or no knowledge of where resources are located. Foraging theory predicts that in environments with sparsely distributed target resources, where forager knowledge about resources locations is incomplete, Lévy flight movements optimize the success of random searches. However, the putative success of Lévy foraging has been demonstrated only in model simulations. Here, we use high-temporal-resolution Global Positioning System (GPS) tracking of wandering (Diomedea exulans) and black-browed albatrosses (Thalassarche melanophrys) with simultaneous recording of prey captures, to show that both species exhibit Lévy and Brownian movement patterns. We find that total prey masses captured by wandering albatrosses during Lévy movements exceed daily energy requirements by nearly fourfold, and approached yields by Brownian movements in other habitats. These results, together with our reanalysis of previously published albatross data, overturn the notion that albatrosses do not exhibit Lévy patterns during foraging, and demonstrate that Lévy flights of predators in dynamic natural environments present a beneficial alternative strategy to simple, spatially intensive behaviors. Our findings add support to the possibility that biological Lévy flight may have naturally evolved as a search strategy in response to sparse resources and scant information.
Programme: 109
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Geng Lei, Alexander Becky, Cole-Dai Jihong, Steig Eric J, Savarino Joël, Sofen Eric D, Schauer Andrew J, . (2014). Nitrogen isotopes in ice core nitrate linked to anthropogenic atmospheric acidity change
. Proc. Natl. Acad. Sci. U.S.A., 111 (16 ), 5808–5812 .
Abstract: Nitrogen stable isotope ratio (δ15N) in Greenland snow nitrate and in North American remote lake sediments has decreased gradually beginning as early as ∼1850 Christian Era. This decrease was attributed to increasing atmospheric deposition of anthropogenic nitrate, reflecting an anthropogenic impact on the global nitrogen cycle, and the impact was thought to be amplified ∼1970. However, our subannually resolved ice core records of δ15N and major ions (e.g., Graphic, Graphic) over the last ∼200 y show that the decrease in δ15N is not always associated with increasing Graphic concentrations, and the decreasing trend actually leveled off ∼1970. Correlation of δ15N with H+, Graphic, and HNO3 concentrations, combined with nitrogen isotope fractionation models, suggests that the δ15N decrease from ∼1850–1970 was mainly caused by an anthropogenic-driven increase in atmospheric acidity through alteration of the gas−particle partitioning of atmospheric nitrate. The concentrations of Graphic and Graphic also leveled off ∼1970, reflecting the effect of air pollution mitigation strategies in North America on anthropogenic NOx and SO2 emissions. The consequent atmospheric acidity change, as reflected in the ice core record of H+ concentrations, is likely responsible for the leveling off of δ15N ∼1970, which, together with the leveling off of Graphic concentrations, suggests a regional mitigation of anthropogenic impact on the nitrogen cycle. Our results highlight the importance of atmospheric processes in controlling δ15N of nitrate and should be considered when using δ15N as a source indicator to study atmospheric flux of nitrate to land surface/ecosystems.
Programme: 1011
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Librado Pablo, Der Sarkissian Clio, Ermini Luca, Schubert Mikkel, Jónsson Hákon, Albrechtsen Anders, Fumagalli Matteo, Yang Melinda A, Gamba Cristina, Seguin-Orlando Andaine, Mortensen Cecilie D, Petersen Bent, Hoover Cindi A, Lorente-Galdos Belen, Nedoluzhko Artem, Boulygina Eugenia, Tsygankova Svetlana, Neuditschko Markus, Jagannathan Vidhya, Thèves Catherine, Alfarhan Ahmed H, Alquraishi Saleh A, Al-Rasheid Khaled A S, Sicheritz-Ponten Thomas, Popov Ruslan, Grigoriev Semyon, Alekseev Anatoly N, Rubin Edward M, McCue Molly, Rieder Stefan, Leeb Tosso, Tikhonov Alexei, Crubézy Eric, Slatkin Montgomery, Marques-Bonet Tomas, Nielsen Rasmus, Willerslev Eske, Kantanen Juha, Prokhortchouk Egor, Orlando Ludovic, . (2015). Tracking the origins of Yakutian horses and the genetic basis for their fast adaptation to subarctic environments
. Proc. Natl. Acad. Sci. U.S.A., 112(50), 201513696.
Abstract: Yakutia, Sakha Republic, in the Siberian Far East, represents one of the coldest places on Earth, with winter record temperatures dropping below -70 °C. Nevertheless, Yakutian horses survive all year round in the open air due to striking phenotypic adaptations, including compact body conformations, extremely hairy winter coats, and acute seasonal differences in metabolic activities. The evolutionary origins of Yakutian horses and the genetic basis of their adaptations remain, however, contentious. Here, we present the complete genomes of nine present-day Yakutian horses and two ancient specimens dating from the early 19th century and ∼5,200 y ago. By comparing these genomes with the genomes of two Late Pleistocene, 27 domesticated, and three wild Przewalski's horses, we find that contemporary Yakutian horses do not descend from the native horses that populated the region until the mid-Holocene, but were most likely introduced following the migration of the Yakut people a few centuries ago. Thus, they represent one of the fastest cases of adaptation to the extreme temperatures of the Arctic. We find cis-regulatory mutations to have contributed more than nonsynonymous changes to their adaptation, likely due to the comparatively limited standing variation within gene bodies at the time the population was founded. Genes involved in hair development, body size, and metabolic and hormone signaling pathways represent an essential part of the Yakutian horse adaptive genetic toolkit. Finally, we find evidence for convergent evolution with native human populations and woolly mammoths, suggesting that only a few evolutionary strategies are compatible with survival in extremely cold environments.
Programme: 1038
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Librado P, Der Sarkissian C, Ermini L, Schubert M, Jónsson H, Albrechtsen A, Fumagalli M, Yang MA, Gamba C, Seguin-Orlando A, Mortensen CD, Petersen B, Hoover CA, Lorente-Galdos B, Nedoluzhko A, Boulygina E, Tsygankova S, Neuditschko M, Jagannathan V, Thèves C, Alfarhan AH, Alquraishi SA, Al-Rasheid KA, Sicheritz-Ponten T, Popov R, Grigoriev S, Alekseev AN, Rubin EM, McCue M, Rieder S, Leeb T, Tikhonov A, Crubézy E, Slatkin M, Marques-Bonet T, Nielsen R, Willerslev E, Kantanen J, Prokhortchouk E, Orlando L. (2015). Tracking the origins of Yakutian horses and the genetic basis for their fast adaptation to subarctic environments. Proc. Natl. Acad. Sci. U.S.A., 112(50), 6889–97.
Abstract: Yakutia, Sakha Republic, in the Siberian Far East, represents one of the coldest places on Earth, with winter record temperatures dropping below -70 °C. Nevertheless, Yakutian horses survive all year round in the open air due to striking phenotypic adaptations, including compact body conformations, extremely hairy winter coats, and acute seasonal differences in metabolic activities. The evolutionary origins of Yakutian horses and the genetic basis of their adaptations remain, however, contentious. Here, we present the complete genomes of nine present-day Yakutian horses and two ancient specimens dating from the early 19th century and ∼5,200 y ago. By comparing these genomes with the genomes of two Late Pleistocene, 27 domesticated, and three wild Przewalski's horses, we find that contemporary Yakutian horses do not descend from the native horses that populated the region until the mid-Holocene, but were most likely introduced following the migration of the Yakut people a few centuries ago. Thus, they represent one of the fastest cases of adaptation to the extreme temperatures of the Arctic. We find cis-regulatory mutations to have contributed more than nonsynonymous changes to their adaptation, likely due to the comparatively limited standing variation within gene bodies at the time the population was founded. Genes involved in hair development, body size, and metabolic and hormone signaling pathways represent an essential part of the Yakutian horse adaptive genetic toolkit. Finally, we find evidence for convergent evolution with native human populations and woolly mammoths, suggesting that only a few evolutionary strategies are compatible with survival in extremely cold environments.
Programme: 1038
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