Razzolini Julia. (2020). Croissance musculaire chez le poussin de manchot royal, liens avec la saisonnalité et la condition corporelle. Bachelor's thesis, , .
Abstract: One of the fundamental principles of life history trait theory is the existence of trade-offs. The amount of energy available to living beings is a limited resource that must be shared among different biological functions. The combination of traits best suited to ecological constraints will be selected.
Growth is a crucial phase during which the future phenotype of the adult is established. This period between birth and the acquisition of independence from parents is characterized by very fast stature and weight growth and tissue maturation, particularly in bone and muscle. This phenomenon is marked by sustained parental nutrition. On an intraspecific scale, variations in individual chick growth may reflect the quality/experience of the parents. In some species, parental dietary intake may, regardless of quality, show wide seasonal fluctuations due to environmental changes and for developing individuals the quantity and quality of nutrients ingested and metabolized may be a limiting factor in growth. There is little information to understand the trade-offs in energy allocation that will be established to ensure survival and growth of the young in the case of inadequate dietary intakes.
The king penguin chick is an atypical animal model for the study of these strategies. This seabird has an unusually long one-year development cycle for a bird and its growth is interrupted by a period of severe food restriction during the 4 months of the southern winter. In addition, exceptionally with a penguin, the period of initiation of reproduction is asynchronous and extends over several months. A direct consequence is a shorter time of accumulation of energy reserves in late-born chicks. We aim to determine whether the particularly long cycle of this chick and the environmental constraints to which it is subjected result in particular adaptations in terms of the relative development of the two muscle belts, pelvic and pectoral, and whether this growth compromise is expressed in the same way in early and late born chicks.
Programme: 119
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Natacha Garcin. (2020). The effects of stress hormones on king penguin's growth, energetics and ageing rate.
Abstract: Stress exposure and stress response are likely to vary according to life history strategies and across environmental contexts. If the release of glucocorticoids (e.g. corticosterone, CORT) in response to acute stress enables animals to rightfully cope with the situation, chronic exposure to high CORT levels can lead to deleterious cascading effects on animal’s physiology, behavior and fitness. Some species may be more adapted to cope with stressful events than others and might exhibit natural adaptations to limit the adverse consequences of prolonged high CORT levels. The aim of this study was to investigate the effects of experimentally elevated CORT levels on the growth, energetics and ageing of king penguin chicks (Aptenodytes patagonicus), using sub-cutaneous CORT implants. We investigated the effects of CORT both on the medium (23 days
after implant) and the long-term (fledging: ~ 200 days after the implant) on morphological (i.e. body mass and size), behavioral (i.e. aggressivity, physical activity) and physiological traits (i.e. heart rate, CORT response to acute stress, oxidative stress, mitochondrial density and telomere length). Although CORT-treated chicks were taller, more aggressive and displayed lower CORT response to acute stress on the medium-term, there was no significant impact of CORT on the body mass and whole-body energetics assessed through heart rate and physical activity. Moreover, CORT chicks displayed lower oxidized glutathione on the medium and long-term, thus indirectly preventing
oxidative damage, while telomere length and mitochondrial density were not influenced by CORT implants. Although chronic elevation of glucocorticoid levels is mostly known to result in negative physiological and behavioral outcomes, our results indicating some positive effects of CORT implants are consistent with the hypothesis that species who encounter several noxious stressors in their environment, could be naturally adapted to cope with them. The growth-enhancing effect of CORT might be mediated by a higher efficiency at which food is assimilated and/or used, and CORT chicks might benefit from aggressive behaviors during competitive interactions or predation
encounters. Through the antioxidant glutathione system, CORT treated chicks seem to have developed a resistance to oxidative stress that could last over time (i.e. possibly through a reduction
of ROS production). While CORT implants did not accelerate ageing or bring short and mediumterm costs, possible long lasting programming effects of CORT should be further investigated.
Programme: 119
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Chelsea Ward. (2020). Examining the effect of experimentally induced stress and the stress response on eye region surface temperature in wild king penguins (Aptenodytes patagonicus) (supervisors P Bize and A Lewden).
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Sara Aoroli. (2020). Calibration and exploitation of an automatic spectral albedometer to estimate near-surface snow SSA time series.
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Tranchant Y.-T., C. Chupin, L. Testut, V. Ballu, O. Laurain, P. Bonnefond. (2020). A new high-resolution coastal model in Kerguelen Island for CAL/VAL operations.
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Jouanneau W, Léandri-Breton DJ, Moe B, Parenteau C, Herzke D, Elliott K, Gabrielsen GW, Chastel O. (2020). Transfert maternel de contaminants et perturbation endocrine chez un oiseau marin Arctique.
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Chastel O. (2020). Des polluants préoccupants : Les substances poly et perfluoroalkylées (PFAS) et leurs effets sur les oiseaux marins polaires.
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Viblanc V.A., Schull Q.; Stier A., Durand L., Lefol E., Robin J.-P., Zahn S., Bize P., Criscuolo F. (2020). Foster rather than biological parental telomere length predicts offspring survival and telomere length in king penguins.
Abstract: Because Telomere Length (Tl) And Dynamics Relate To Growth, Reproductive Investment And Survival, Telomeres Might Be Markers Of Individual Quality. In The King Penguin, We Tested The Hypothesis That Parental Tl Can Be A Marker Of Parental Quality. We Swapped The Egg Of Breeding Pairs To Disentangle The Contribution Of Pre And/or Post -Laying Parental Quality On Chick’s Growth, Tl And Survival. Parental Quality Was Estimated Through The Effects Of Biological And Foster Parent Tl On Offspring Traits, 10 Or 105 Days After Hatching. We Show That Chick Survival Up To 10 Days Was Negatively Related To Biological Fathers’ Tl Whereas Survival Up To 105 Days Was Positively Related To Foster Fathers’ Tl. Chick Growth Was Not Related To Parents’ Tl. Chick Tl Was Positively Related To Foster Mothers’ Tl At Both 10 And 105 Days. Overall, We Show That, In A Species With Bi-parental Care, Parents’ Tl Is Foremost A Proxy Of Parental Care Quality, Supporting The Telomere &Ndash; Parental Quality Hypothesis.
Programme: 119
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Baltzer, A.; Robert, L.; Roussel, O. (2020). Des images pour témoigner du réchauffement climatique au Spitsberg.
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Van Tilbeurgh V., Joliet F., Atlan A. (2020). La valeur d’existence du vivant dans le subpolaire.
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