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Author Cottin Manuelle, MacIntosh Andrew J J, Kato Akiko, Takahashi Akinori, Debin Marion, Raclot Thierry, RopertCoudert Yan, doi  openurl
  Title Corticosterone administration leads to a transient alteration of foraging behaviour and complexity in a diving seabird Type Journal Article
  Year 2014 Publication MARINE ECOLOGY-PROGRESS SERIES Abbreviated Journal  
  Volume 496 Issue Pages 249-262  
  Keywords  
  Abstract Hormones are a link between environmental stimuli and the behavioural and/or
physiological responses of organisms. The release of corticosterone (hereafter CORT) has
major effects on both energy mobilization and its allocation among the various requirements
of an individual. However, specific effects of CORT on behaviours related to energy
acquisition and, consequently, its allocation with regards to survival and reproduction, are
complex and remain to be deciphered at a fine scale. We examined here the effects of elevated
baseline CORT levels on this trade-off through a detailed study of foraging behaviour in the
Adélie penguin (Pygoscelis adeliae) during the chick-rearing stage. We monitored the at-sea
behaviour of CORT-implanted and control male birds using time-depth recorders, and
monitored the effects of CORT treatment on their body conditions, as well as their chicks’
body masses and survival. Bio-logged data were examined via both traditional measures of
diving behaviour and fractal analysis as an index of behavioural complexity. At the level of
the foraging trip, CORT administration led to a transient decrease in overall foraging effort
(i.e. reductions in the duration of at-sea trips, the time spent diving and the number of dives
performed) as well as the complexity with which treated birds foraged. In contrast, per-dive
performance indices suggest an increase in both efficiency and prey pursuit rates. These
contrasting results suggest the importance of assessing diving behaviour at scales
encompassing both entire foraging trips, as well as individual dives. Ultimately, however, we
observed no short-term effects of treatment on either adult body condition or on chick body
mass and survival. We conclude that under conditions of energy constraint, as mimicked by
our experimental paradigm, sequences of behaviour may become more structured and
periodic as observed in CORT-treated birds. The increased dive-scale effort observed in
CORT-birds could then be a strategy allowing a reduction in trip-scale effort. Indeed, the
increased CORT levels may have forced treated penguins to revert to mechanisms preserving
their survival by engaging in less costly foraging behaviours. This study highlights the utility
of using both traditional and fractal analyses to better understand the responses of free-living
animals to energetic challenges and various environmental constraints.
 
  Programme 1091  
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  ISSN 0171-8630 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 4465  
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Author Schultner J, Moe B, Chastel O, Tartu S, Bech C, Kitaysky AS, doi  openurl
  Title Corticosterone mediates carry-over effects between breeding and migration in the kittiwake Rissa tridactyla Type Journal Article
  Year 2014 Publication Mar Ecol Prog Ser Abbreviated Journal Mar. Ecol. Prog. Ser.  
  Volume 496 Issue Pages 125-133  
  Keywords  
  Abstract Carry-over effects, i.e. when processes in one season influence processes in the next, are believed to have important effects on behavior and fitness in animals. Despite an increasing interest in the identification of carry-over effects, there are few experimental studies of the underlying mechanisms. We investigated how a short-term experimental elevation of the stress hormone corticosterone (CORT) during breeding influences the migratory behavior of black-legged kittiwakes Rissa tridactyla. We exposed chick-rearing kittiwakes to a 3 d elevation of CORT, which is usually secreted in response to food shortages. The migratory behavior of CORT-treated kittiwakes and a control group was then tracked using geolocators. We found that CORT treatment affected subsequent autumn migration in a sex-specific manner. CORT-treated females left the breeding grounds earlier and spent a longer period at the wintering grounds than control birds and CORT-treated males. The CORT treatment did not affect the timing of spring arrival or total length of migration. Our findings indicated that physiological stress incurred during breeding can carry over to affect key parameters of migratory behavior in autumn. Identifying carry-over mechanisms, such as those described here, is important to understand how performance and fitness in animals are determined by interactions between different parts of their life cycle.  
  Programme 330  
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  ISSN 0171-8630 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 5659  
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Author Jaeger A, Jaquemet S, Phillips RA, Wanless RM, Richard P, Cherel Y, doi  openurl
  Title Stable isotopes document inter- and intra-specific variation in feeding ecology of nine large southern Procellariiformes Type Journal Article
  Year 2013 Publication Mar Ecol Prog Ser Abbreviated Journal Mar. Ecol. Prog. Ser.  
  Volume 490 Issue Pages 255-266  
  Keywords  
  Abstract Investigating the foraging ecology of seabirds is especially challenging given their wide-ranging movements and the practical difficulties of obtaining unbiased information on their feeding behavior. Despite the development of animal-borne tracking devices, several limitations preclude investigations at the scale of a whole community in a given season or year, and, until recently, during the non-breeding period. Here we analyzed δ13C and δ15N in feathers of chicks and adults to investigate inter- and intra-specific variation in the foraging habitat and trophic position of 9 large procellariiform seabirds from 6 southern breeding localities during the breeding and non-breeding periods. Isotopic ratios of each species were generally consistent among different breeding populations, despite the large geographical scale and potential variation in oceanography in surrounding waters. Both spatial and trophic segregation apparently allowed the co-existence of sympatric species in most breeding localities, except at South Georgia, where both δ13C and δ15N in chicks showed high overlap among species, probably resulting from the superabundance of alternative food resources during the summer. Low variance in stable isotope ratios among adults in several species indicated high overlap between individuals in feeding habits and trophic levels (i.e. isotopic specialist populations) during the non-breeding period. By contrast, large isotopic variances and the high within- and between-individual components of the trophic niche width suggested that grey-headed and light-mantled sooty albatrosses are generalists. Based on δ13C, the species that breed in the Southern Ocean can be categorized as residents or subtropical migrants, with the latter including oceanic and neritic subtropical migrants. Albatrosses meet the high energetic challenge of feather synthesis by foraging in different habitats, depending on the length of the non-breeding period. Annual breeders renew their plumage in productive neritic waters in ~4 mo, whereas biennially breeding species moult in less productive oceanic waters over much longer periods (~12 to 16 mo).  
  Programme 109  
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  Notes Approved yes  
  Call Number Serial 4751  
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Author Flores H, Atkinson A, Kawaguchi S, Krafft B A, Milinevsky G, Nicol S, Reiss C, Tarling G A, Werner R, Rebolledo E Bravo, Cirelli V, CuzinRoudy J, Fielding S, Groeneveld J J, Haraldsson M, Lombana A, Marschoff E, Meyer B, Pakhomov E A, Rombol E, Schmidt K, Siegel V, Teschke M, Tonkes H, Toullec J Y, Trathan P N, Tremblay N, Putte A P Van de, Franeker J A van, Werner T, doi  openurl
  Title Impact of climate change on Antarctic krill Type Journal Article
  Year 2012 Publication MARINE ECOLOGY-PROGRESS SERIES Abbreviated Journal 0171-8630  
  Volume 458 Issue Pages 1-19  
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  Programme 1039  
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  ISSN 0171-8630 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 4294  
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Author McCoy K D, Beis P, Barbosa A, Cuervo J J, Fraser W R, GonzlezSols J, Jourdain E, Poisbleau M, Quillfeldt P, Lger E, Dietrich M, doi  openurl
  Title Population genetic structure and colonisation of the western Antarctic Peninsula by the seabird tick Ixodes uriae Type Journal Article
  Year 2012 Publication MARINE ECOLOGY-PROGRESS SERIES Abbreviated Journal 0171-8630  
  Volume 459 Issue Pages 109-120  
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  Abstract ABSTRACT: Recent observations on the western Antarctic Peninsula have suggested that changing climatic conditions may be increasing pressure on breeding seabirds due to higher exploitation rates by the tick Ixodes uriae. Using data from 8 microsatellite markers and ticks from 6 Pygoscelis spp. colonies, we employed a population genetics approach to specifically test the hypothesis that I. uriae is expanding south-westward along the peninsula from the Subantarctic region. Contrary to expectations, tick genetic diversity was high within all colonies, and no remaining signal of colonisation events was evident. Although significant geographic genetic structure occurred among ticks from different colonies, these ectoparasites tended to belong to 2 major genetic groups, one found principally in south-western locations (Palmer Station area) and the other in more north-eastern areas (South Shetland Islands). More central colonies showed a mixture of ticks from each genetic group, suggesting that this area represents a hybridisation zone of ticks from 2 distinct origins. A subsequent clustering analysis, including ticks from 2 Subantarctic locations, did not reveal the source population for the northern peninsula group. Overall, our data refute the hypothesis of a recent south-westward expansion of I. uriae along the peninsula and suggest that this tick has been present at more southern latitudes for an extended period of time. Further studies on the distribution and genetic characteristics of this ectoparasite around Antarctica are now required to better understand the colonisation process and predict how changing environmental conditions may affect its presence and diversity in seabird colonies.  
  Programme 333  
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  Notes Approved yes  
  Call Number Serial 4255  
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Author Dragon AC, Bar-Hen A, Monestiez P, Guinet C, doi  openurl
  Title Comparative analysis of methods for inferring successful foraging areas from Argos and GPS tracking data Type Journal Article
  Year 2012 Publication Mar Ecol Prog Ser Abbreviated Journal 0171-8630  
  Volume 452 Issue Pages 253-267  
  Keywords Area-restricted-search · Drift dive · First bottom time · Mirounga leonine · Movement analysis · State-space modelling  
  Abstract Identifying animals’ successful foraging areas is a major challenge, but such comprehensive knowledge is needed for the management and conservation of wild populations. In recent decades, numerous specific analytic methods have been developed to handle tracking data and to identify preferred foraging areas. In this study, we assessed the efficiency of different track-based methods on Argos and GPS predators’ tracks. We investigated (1) the consistency in the detection of foraging areas between track-based methods applied to 2 tracking data resolutions and (2) the similarity of foraging behaviour identification between track-based methods and an independent index of foraging success. We focused on methods that are commonly used in the literature: empirical descriptors of foraging effort, Hidden Markov Models (HMMs) and first passage time analysis. We applied these methods to satellite tracking data collected on 6 long-ranging elephant seals equipped with both Argos and GPS tags. Seals were also equipped with time depth recorder loggers from which we estimated an independent index, based on the drift rate and the changes in the seals’ body condition, as a proxy for foraging success along the tracks. Favourable foraging zones identified by track-based methods were compared to locations where the body condition of the seals significantly increased. With or without an environmental covariate, HMMs were the most reliable for identifying successful foraging areas on both high (GPS) and low (Argos) resolution data. Areas identified by HMMs as intensively used were congruent with the locations where seals significantly increased their body condition given a 4 d metabolisation lag.  
  Programme 109  
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  ISSN 0171-8630 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 3872  
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Author Barbraud C, Rolland V, Jenouvrier S, Nevoux M, Delord K, Weimerskirch H, doi  openurl
  Title Effects of climate change and fisheries bycatch on Southern Ocean seabirds: a review Type Journal Article
  Year 2012 Publication Mar Ecol Prog Ser Abbreviated Journal  
  Volume 454 Issue Pages 285-307  
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  Abstract Over the last century, major climate changes and intense human exploitation of natural living resources have occurred in the Southern Ocean, potentially affecting its ecosystems up to top marine predators. Fisheries may also directly affect seabirds through bycatch and additional food resources provided by discards. The past 20 yr of research has seen an increasing number of studies investigating the effects of climate change and fisheries activities on Southern Ocean seabirds. Here, we review these studies in order to identify patterns in changes in distribution, phenology, demography and population dynamics in response to changes in climate and fisheries bycatch. Shifts in distribution and breeding phenology were documented in parallel to increases in sea-surface temperatures and changes in sea-ice cover. Above all warm sea-surface temperatures negatively affected demographic parameters, although exceptions were found. Relationships suggest non-linear effects of sea-ice cover on demographic parameters and population dynamics, with optimum sea-ice cover conditions appearing to be the rule. Fishing efforts were mainly negatively related to survival rates, and only for a few species positively related to breeding success. A handful of studies found that chronic mortality of immature birds due to fisheries negatively affected populations. Climate factors and fisheries bycatch may simultaneously affect demographic parameters in a complex way, which can be integrated in population models to project population trajectories under future climate or fisheries scenarios. Needed are studies that integrate other environmental factors, trophic levels, foraging behaviour, climate−fisheries interactions, and the mechanisms underlying phenotypic plasticity, such as some pioneering studies conducted elsewhere.  
  Programme 109  
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  ISSN 0171-8630 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 3868  
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Author Grmillet D, Welcker J, Karnovsky NJ, Walkusz W, Hall ME, Fort J, Brown ZW, Speakman JR, Harding AMA, doi  openurl
  Title Little auks buffer the impact of current Arctic climate change Type Journal Article
  Year 2012 Publication Mar Ecol Prog Ser Abbreviated Journal Mar. Ecol. Prog. Ser.  
  Volume 454 Issue Pages 197-206  
  Keywords Behavioural plasticity · Envelope models · Global warming · North Atlantic · Pelagic food web · Zooplankton  
  Abstract Climate models predict a multi-degree warming of the North Atlantic in the 21st century. A research priority is to understand the effect of such changes upon marine organisms. With 40 to 80 million individuals, planktivorous little auks Alle alle are an essential component of pelagic food webs in this region that is potentially highly susceptible to climatic effects. Using an integrative study of their behaviour, physiology and fitness at 3 study sites, we evaluated the effect of ocean warming on little auks across the Greenland Sea in 2005 to 2007. Contrary to our hypothesis, the birds responded to a wide range of sea surface temperatures via plasticity of their foraging behaviour, allowing them to maintain their fitness levels. Predicted effects of climate change are significantly attenuated by such plasticity, confounding attempts to forecast future effects of climate change using envelope models.  
  Programme 388  
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  Notes Approved yes  
  Call Number Serial 4082  
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Author Dragon AC, Bar-Hen A, Monestiez P, Guinet C, doi  openurl
  Title Horizontal and vertical movements as predictors of foraging success in a marine predator Type Journal Article
  Year 2012 Publication Mar Ecol Prog Ser Abbreviated Journal Mar. Ecol. Prog. Ser.  
  Volume 447 Issue Pages 243-257  
  Keywords Area-restricted search · Dive classification · Drift dive · Fine-scale behaviour · Movement analysis  
  Abstract With technical advances in wildlife telemetry, the study of cryptic predators’ responses to prey distribution has been revolutionised. In the case of marine predators, high resolution tagging devices have been developed recently to collect precise diving datasets covering extended periods of time. In this study, we investigated changes in the horizontal movements and diving patterns of a marine predator, the southern elephant seal, at fine temporal and spatial scales. Satellite tracking data collected for 9 seals were processed with switching state-space models. Seal body condition, as a proxy for foraging success, was estimated through changes in drift rate from Time Depth Recorder (TDR) data. We identified (1) statistically distinct behavioural modes from the tracking data (intensive vs. extensive foraging modes) and (2) distinct dive classes from the TDR diving data (drift, exploratory, shallow active and deep active dives). Active dives, associated with vertical foraging and chasing, were more numerous when the seals were in intensive foraging mode. Improved body condition and mass gain of seals were also associated with the intensive foraging mode and, within the vertical dimension, with sets of highly active dives. In conclusion, proportions of dive classes varied according to seals’ horizontal behaviour. Intensive foraging detected from surface tracking data is a good predictor of diving activity and foraging success occurring in the vertical dimension.  
  Programme 109  
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  Notes Approved yes  
  Call Number Serial 3870  
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Author Karnovsky NJ, Brown ZW, Welcker J, Harding AMA, Walkusz W, Cavalcanti A, Hardin J, Kitaysky A, Gabrielsen G, Grmillet D, doi  openurl
  Title Inter-colony comparison of diving behavior of an Arctic top predator: implications for warming in the Greenland Sea Type Journal Article
  Year 2011 Publication Mar Ecol Prog Ser Abbreviated Journal 0171-8630  
  Volume 440 Issue Pages 229-240  
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  Programme 388  
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  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 3511  
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