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Eckbo, N., Le Bohec, C., Planas-Bielsa, V., Warner, N. A., Schull, Q., Herzke, D., et al. (2019). Individual variability in contaminants and physiological status in a resident Arctic seabird species. Environ. Pollut., 249, 191–199.
Résumé: While migratory seabirds dominate ecotoxicological studies within the Arctic, there is limited knowledge about exposure and potential effects from circulating legacy and emerging contaminants in species who reside in the high-Arctic all year round. Here, we focus on the case of the Mandt's Black guillemot (Cepphus grylle mandril) breeding at Kongsfjorden, Svalbard (79.00 degrees N, 11.66 degrees E) and investigate exposure to legacy and emerging contaminants in relation to individual physiological status, i.e. body condition, oxidative stress and relative telomere length. Despite its benthic-inshore foraging strategy, the Black guillemot displayed overall similar contaminant concentrations in blood during incubation (Sigma PCB11(15.7 ng/g w.w.) > Sigma PFAS(5) (9.9 ng/g w.w.)> Sigma Pesticides(9) (6.7 ng/g w.w.) > Sigma PBDE4 (2.7 ng/g w.w.), and Hg (0.3 mu g/g d.w.) compared to an Arctic migratory seabird in which several contaminant-related stress responses have been observed. Black guillemots in poorer condition tended to display higher levels of contaminants, higher levels of reactive oxygen metabolites, lower plasmatic antioxidant capacity, and shorter telomere lengths; however the low sample size restrict any strong conclusions. Nevertheless, our data suggests that nonlinear relationships with a threshold may exist between accumulated contaminant concentrations and physiological status of the birds. These findings were used to build a hypothesis to be applied in future modelling for describing how chronic exposure to contaminants may be linked to telomere dynamics. (C) 2019 Published by Elsevier Ltd.
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Stier, A., Viblanc, V. A., Massemin-Challet, S., Handrich, Y., Zahn, S., Rojas, E. R., et al. (2014). Starting with a handicap: phenotypic differences between early- and late-born king penguin chicks and their survival correlates. Functional Ecology, .
Résumé: * The exceptionally long (c. 11 months) growth period of king penguin chicks (Aptenodytes patagonicus) is interrupted by the Austral winter. As a consequence, penguin chicks born late in the breeding season have little time to build-up their energy reserves before the drastic energy bottleneck they experience during winter and face greater risks of mortality than early-born chicks. * Whereas it is well known that breeding adults alternate between early- and late-breeding attempts, little is known on the phenotype of early- and late-chicks, and on the potential existence of specific adaptive phenotypic responses in late-born individuals. * We investigated phenotypic differences between early- and late-chicks and tested their survival correlates both before the winter and at fledgling. Chicks were sampled 10 days after hatching to measure body mass, plasma corticosterone levels, oxidative stress parameters and telomere length. * Late-chicks were heavier than early-chicks at day 10. Late-chicks also had higher corticosterone and oxidative stress levels, shorter telomere lengths and suffered from higher mortality rates than early-chicks. For both early- and late-chicks, high body mass close to hatching was a strong predictor of survival up to, and over, the winter period. * In late but not early-chicks, high corticosterone levels and long telomeres were significant predictors of survival up to winter and fledging, respectively. * Our study provides evidence that late- and early-king penguin chicks showed marked phenotypic differences 10 days after hatching. We provide an integrative discussion on whether these differences may be adaptive or not, and to what extent they may be driven by active maternal effects, indirectly induced by environmental effects, or stem from individual differences in parental quality.
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Viblanc, V. A., Schull, Q., Stier, A., Durand, L., Lefol, E., Robin, J. - P., et al. (2020). Foster rather than biological parental telomere length predicts offspring survival and telomere length in king penguins. Mol. Ecol., .
Résumé: Because telomere length and dynamics relate to individual growth, reproductive investment and survival, telomeres have emerged as possible markers of individual quality. Here, we tested the hypothesis that, in species with parental care, parental telomere length can be a marker of parental quality that predicts offspring phenotype and survival. In king penguins (Aptenodytes patagonicus), we experimentally swapped the single egg of 66 breeding pairs just after egg laying to disentangle the contribution of prelaying parental quality (e.g., genetics, investment in the egg) and/or postlaying parental quality (e.g., incubation, postnatal feeding rate) on offspring growth, telomere length and survival. Parental quality was estimated through the joint effects of biological and foster parent telomere length on offspring traits, both soon after hatching (day 10) and at the end of the prewinter growth period (day 105). We expected that offspring traits would be mostly related to the telomere lengths (i.e., quality) of biological parents at day 10 and to the telomere lengths of foster parents at day 105. Results show that chick survival up to 10 days was negatively related to biological fathers' telomere length, whereas survival up to 105 days was positively related to foster fathers' telomere lengths. Chick growth was not related to either biological or foster parents' telomere length. Chick telomere length was positively related to foster mothers' telomere length at both 10 and 105 days. Overall, our study shows that, in a species with biparental care, parents' telomere length is foremost a proxy of postlaying parental care quality, supporting the “telomere – parental quality hypothesis.”
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