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Author Q Schull, V A Viblanc, A Stier, H Saadaoui, E Lefol, F Criscuolo, P Bize, J-P Robin doi  openurl
  Title The oxidative debt of fasting: evidence for short to medium-term costs of advanced fasting in adult king penguins Type Journal Article
  Year 2016 Publication Journal of experimental biology Abbreviated Journal J. Exp. Biol.  
  Volume 219 Issue 20 Pages 3284-3293  
  Keywords  
  Abstract Skip to Next Section In response to prolonged periods of fasting, animals have evolved metabolic adaptations helping to mobilize body reserves and/or reduce metabolic rate to ensure a longer usage of reserves. However, those metabolic changes can be associated with higher exposure to oxidative stress, raising the question of how species that naturally fast during their life cycle avoid an accumulation of oxidative damage over time. King penguins repeatedly cope with fasting periods of up to several weeks. Here, we investigated how adult male penguins deal with oxidative stress after an experimentally induced moderate fasting period (PII) or an advanced fasting period (PIII). After fasting in captivity, birds were released to forage at sea. We measured plasmatic oxidative stress on the same individuals at the start and end of the fasting period and when they returned from foraging at sea. We found an increase in activity of the antioxidant enzyme superoxide dismutase along with fasting. However, PIII individuals showed higher oxidative damage at the end of the fast compared with PII individuals. When they returned from re-feeding at sea, all birds had recovered their initial body mass and exhibited low levels of oxidative damage. Notably, levels of oxidative damage after the foraging trip were correlated to the rate of mass gain at sea in PIII individuals but not in PII individuals. Altogether, our results suggest that fasting induces a transitory exposure to oxidative stress and that effort to recover in body mass after an advanced fasting period may be a neglected carryover cost of fasting.  
  Programme 119  
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  ISSN 0022-0949 ISBN Medium  
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  Notes Approved yes  
  Call Number Serial 6482  
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Author Cunningham Gregory B, Bonadonna Francesco, doi  openurl
  Title King penguins can detect two odours associated with conspecifics. Type Journal Article
  Year 2015 Publication The Journal of experimental biology Abbreviated Journal  
  Volume 218 Issue Pt 21 Pages 3374-6  
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  Abstract Recent studies on olfaction in penguins have focused on their use of odours while foraging. It has been proposed for some seabirds that an olfactory landscape shaped by odours coming from feeding areas exists. Islands and colonies, however, may also contribute to the olfactory landscape and may act as an orienting map. To test sensitivities to a colony scent we studied whether King penguins (Aptenodytes patagonicus) could detect the smell of sand, feathers or feces by holding presentations beneath their beaks while they naturally slept on the beach. Penguins had a significantly greater response to the feathers and feces presentations than to sand. Although only a first step in exploring a broader role of olfaction in this species, our results raise the possibility of olfaction being used by King penguins in three potential ways: (1) locating the colony from the water or the shore, (2) finding the rendezvous zone within the colony where a chick or partner may be found, or (3) recognizing individuals by scent, as in Humboldt penguins (Spheniscus demersus).
 
  Programme 354  
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  Notes Approved yes  
  Call Number Serial 6253  
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Author doi  openurl
  Title Modulation of heart rate response to acute stressors throughout the breeding season in the king penguin Aptenodytes patagonicus. Type Journal Article
  Year 2015 Publication The Journal of experimental biology Abbreviated Journal  
  Volume 218 Issue Pt 11 Pages 1686-92  
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  Abstract 'Fight-or-flight' stress responses allow animals to cope adaptively to sudden threats by mobilizing energy resources and priming the body for action. Because such responses can be costly and redirect behavior and energy from reproduction to survival, they are likely to be shaped by specific life-history stages, depending on the available energy resources and the commitment to reproduction. Here, we consider how heart rate (HR) responses to acute stressors are affected by the advancing breeding season in a colonial seabird, the king penguin (Aptenodytes patagonicus). We subjected 77 birds (44 males, 33 females) at various stages of incubation and chick-rearing to three experimental stressors (metal sound, distant approach and capture) known to vary both in their intensity and associated risk, and monitored their HR responses. Our results show that HR increase in response to acute stressors was progressively attenuated with the stage of breeding from incubation to chick-rearing. Stress responses did not vary according to nutritional status or seasonal timing (whether breeding was initiated early or late in the season), but were markedly lower during chick-rearing than during incubation. This pattern was obvious for all three stressors. We discuss how 'fight-or-flight' responses may be modulated by considering the energy commitment to breeding, nutritional status and reproductive value of the brood in breeding seabirds.
 
  Programme 119  
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  ISSN 0022-0949 ISBN Medium  
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  Notes Approved yes  
  Call Number Serial 6096  
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Author Monternier Pierre-Axel, Marmillot Vincent, Rouanet Jean-Louis, Roussel Damien, doi  openurl
  Title Mitochondrial phenotypic flexibility enhances energy savings during winter fast in king penguin chicks Type Journal Article
  Year 2014 Publication The Journal of Experimental Biology Abbreviated Journal J. Exp. Biol.  
  Volume 217 Issue 15 Pages 2691 -2697  
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  Programme 131  
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  Notes Approved yes  
  Call Number Serial 5179  
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Author Pierre-Axel Monternier, Vincent Marmillot, Jean-Louis Rouanet, Damien Roussel doi  isbn
openurl 
  Title Mitochondrial phenotypic flexibility enhances energy savings during winter fast in king penguin chicks Type Journal
  Year 2014 Publication Journal of Experimental Biology Abbreviated Journal  
  Volume 217 Issue 15 Pages 2691-2697  
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  Programme 131  
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  ISSN 0022-0949, 1477-9145 ISBN 0022-0949, 1477-9145 Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 7219  
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Author doi  openurl
  Title Variation in body condition during the post-moult foraging trip of southern elephant seals and its consequences on diving behaviour. Type Journal Article
  Year 2014 Publication The Journal of experimental biology Abbreviated Journal J. Exp. Biol.  
  Volume 217 Issue Pt 14 Pages 2609-19  
  Keywords Animals, Behavior, Animal, Behavior, Animal: physiology, Biomechanical Phenomena, Body Composition, Diving, Diving: physiology, Female, Oceans and Seas, Seals, Earless, Seals, Earless: physiology, Swimming, Swimming: physiology, Telemetry,  
  Abstract Mature female southern elephant seals (Mirounga leonina) come ashore only in October to breed and in January to moult, spending the rest of the year foraging at sea. Mature females may lose as much as 50% of their body mass, mostly in lipid stores, during the breeding season due to fasting and lactation. When departing to sea, post-breeding females are negatively buoyant, and the relative change in body condition (i.e. density) during the foraging trip has previously been assessed by monitoring the descent rate during drift dives. However, relatively few drift dives are performed, resulting in low resolution of the temporal reconstruction of body condition change. In this study, six post-breeding females were equipped with time-depth recorders and accelerometers to investigate whether changes in active swimming effort and speed could be used as an alternative method of monitoring density variations throughout the foraging trip. In addition, we assessed the consequences of density change on the swimming efforts of individuals while diving and investigated the effects on dive duration. Both descent swimming speed and ascent swimming effort were found to be strongly correlated to descent rate during drift dives, enabling the fine-scale monitoring of seal density change over the whole trip. Negatively buoyant seals minimized swimming effort during descents, gliding down at slower speeds, and reduced their ascent swimming effort to maintain a nearly constant swimming speed as their buoyancy increased. One per cent of seal density variation over time was found to induce a 20% variation in swimming effort during dives with direct consequences on dive duration.
 
  Programme 109  
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  Notes Approved yes  
  Call Number Serial 5905  
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Author Sachs G, Traugott J, Nesterova A P, Bonadonna F, doi  openurl
  Title Experimental verification of dynamic soaring in albatrosses Type Journal Article
  Year 2013 Publication The Journal of Experimental Biology Abbreviated Journal  
  Volume 216 Issue 22 Pages 4222 -4232  
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  Abstract Dynamic soaring is a small-scale flight manoeuvre which is the basis for the extreme flight performance of albatrosses and other large seabirds to travel huge distances in sustained non-flapping flight. As experimental data with sufficient resolution of these small-scale movements are not available, knowledge is lacking about dynamic soaring and the physical mechanism of the energy gain of the bird from the wind. With new in-house developments of GPS logging units for recording raw phase observations and of a dedicated mathematical method for postprocessing these measurements, it was possible to determine the small-scale flight manoeuvre with the required high precision. Experimental results from tracking 16 wandering albatrosses (Diomedea exulans) in the southern Indian Ocean show the characteristic pattern of dynamic soaring. This pattern consists of four flight phases comprising a windward climb, an upper curve, a leeward descent and a lower curve, which are continually repeated. It is shown that the primary energy gain from the shear wind is attained in the upper curve where the bird changes the flight direction from windward to leeward. As a result, the upper curve is the characteristic flight phase of dynamic soaring for achieving the energy gain necessary for sustained non-flapping flight.  
  Programme 354  
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  ISSN 0022-0949 ISBN Medium  
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  Notes Approved yes  
  Call Number Serial 4740  
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Author doi  openurl
  Title King penguins adjust their diving behaviour with age Type Journal Article
  Year 2012 Publication JOURNAL OF EXPERIMENTAL BIOLOGY Abbreviated Journal J. Exp. Biol.  
  Volume 215 Issue Pt 21 Pages 3685-3692  
  Keywords Aging, Animals, Behavior, Animal, Biomechanical Phenomena, Diving, Energy Metabolism, Female, Male, Motor Activity, Spheniscidae, Swimming,  
  Abstract Increasing experience in long-lived species is fundamental to improving breeding success and ultimately individual fitness. Diving efficiency of marine animals is primarily determined by their physiological and mechanical characteristics. This efficiency may be apparent via examination of biomechanical performance (e.g. stroke frequency and amplitude, change in buoyancy or body angle, etc.), which itself may be modulated according to resource availability, particularly as a function of depth. We investigated how foraging and diving abilities vary with age in a long-lived seabird. During two breeding seasons, small accelerometers were deployed on young (5 year old) and older (8/9 year old) brooding king penguins (Aptenodytes patagonicus) at the Crozet Archipelago, Indian Ocean. We used partial dynamic body acceleration (PDBA) to quantify body movement during dive and estimate diving cost. During the initial part of the descent, older birds exerted more effort for a given speed but younger penguins worked harder in relation to performance at greater depths. Younger birds also worked harder per unit speed for virtually the whole of the ascent. We interpret these differences using a model that takes into account the upthrust and drag to which the birds are subjected during the dive. From this, we suggest that older birds inhale more at the surface but that an increase in the drag coefficient is the factor leading to the increased effort to swim at a given speed by the younger birds at greater depths. We propose that this higher drag may be the result of young birds adopting less hydrodynamic postures or less direct trajectories when swimming or even having a plumage in poorer condition.  
  Programme 137  
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  ISSN 1477-9145 ISBN Medium  
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  Notes Approved yes  
  Call Number Serial 4271  
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Author doi  openurl
  Title Differential muscular myosin heavy chain expression of the pectoral and pelvic girdles during early growth in the king penguin (Aptenodytes patagonicus) chick Type Journal Article
  Year 2011 Publication The Journal of Experimental Biology Abbreviated Journal J. Exp. Biol.  
  Volume 214 Issue 11 Pages 1829 -1835  
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  Abstract Continuous growth, associated with a steady parental food supply, is a general pattern in offspring development. So that young chicks can acquire their locomotor independence, this period is usually marked by a fast maturation of muscles, during which different myosin heavy chain (MyHC) isoforms are expressed. However, parental food provisioning may fluctuate seasonally, and offspring therefore face a challenge to ensure the necessary maturation of their tissues when energy is limited. To address this trade-off we investigated muscle maturation in both the pectoral and pelvic girdles of king penguin chicks. This species has an exceptionally long rearing period (1 year), which is prolonged when parental food provisioning is drastically reduced during the sub-Antarctic winter. Approximately 1 month post hatching, chicks acquire a functional pedestrian locomotion, which uses pelvic muscles, whereas swimming, which uses the pectoral muscles, only occurs 1 year later. We therefore tested the hypothesis that the MyHC content of the leg muscles reaches a mature state before those of the pectoral muscles. We found that leg muscle MyHC composition changed with the progressive acquisition of pedestrian locomotion, whereas pectoral muscle fibres reached their mature MyHC profile as early as hatching. Contrary to our predictions, the acquisition of the adult profile in pectoral muscles could be related to an early maturation of the contractile muscular proteins, presumably associated with early thermoregulatory capacities of chicks, necessary for survival in their cold environment. This differential maturation appears to reconcile both the locomotor and environmental constraints of king penguin chicks during growth.
 
  Programme 119  
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  ISSN 0022-0949 ISBN Medium  
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  Notes Approved yes  
  Call Number Serial 3801  
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Author doi  openurl
  Title Poor flight performance in deep-diving cormorants. Type Journal Article
  Year 2011 Publication The Journal of experimental biology Abbreviated Journal J. Exp. Biol.  
  Volume 214 Issue Pt 3 Pages 412 -21  
  Keywords Animals, Biomechanics, Birds, Birds: physiology, Body Weight, Diving, Diving: physiology, Energy Metabolism, Female, Flight, Animal, Flight, Animal: physiology, Male, Muscle, Skeletal, Muscle, Skeletal: physiology, Respiration, Seawater, Swimming, Swimming: physiology, Water, Wing, Wing: anatomy & histology, Wing: physiology,  
  Abstract Aerial flight and breath-hold diving present conflicting morphological and physiological demands, and hence diving seabirds capable of flight are expected to face evolutionary trade-offs regarding locomotory performances. We tested whether Kerguelen shags Phalacrocorax verrucosus, which are remarkable divers, have poor flight capability using newly developed tags that recorded their flight air speed (the first direct measurement for wild birds) with propeller sensors, flight duration, GPS position and depth during foraging trips. Flight air speed (mean 12.7 m s(-1)) was close to the speed that minimizes power requirement, rather than energy expenditure per distance, when existing aerodynamic models were applied. Flights were short (mean 92 s), with a mean summed duration of only 24 min day(-1). Shags sometimes stayed at the sea surface without diving between flights, even on the way back to the colony, and surface durations increased with the preceding flight durations; these observations suggest that shags rested after flights. Our results indicate that their flight performance is physiologically limited, presumably compromised by their great diving capability (max. depth 94 m, duration 306 s) through their morphological adaptations for diving, including large body mass (enabling a large oxygen store), small flight muscles (to allow for large leg muscles for underwater propulsion) and short wings (to decrease air volume in the feathers and hence buoyancy). The compromise between flight and diving, as well as the local bathymetry, shape the three-dimensional foraging range (<26 km horizontally, <94 m vertically) in this bottom-feeding cormorant.
 
  Programme 394  
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  ISSN 0022-0949 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 2682  
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