. (2020). Evidence of Pathogen-Induced Immunogenetic Selection across the Large Geographic Range of a Wild Seabird (Vol. 37). Bachelor's thesis, , .
Keywords: immunogenetics, positive selection, Toll-like receptors, pathogen-mediated selection, Antarctica and Southern Ocean, Gentoo penguin
Programme: 137,354
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B. Lauer, R. Grandin, Y. Klinger. (2020). Fault Geometry and Slip Distribution of the 2013 Mw 7.7 Balochistan Earthquake From Inversions of SAR and Optical Data (Vol. 125).
Keywords: Balochistan earthquake earthquake rupture modeling earthquake source processes InSAR optical data shallow slip deficit
Programme: 133
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. (2020). Foster rather than biological parental telomere length predicts offspring survival and telomere length in king penguins.
Keywords: gene and early life environmental effects growth penguins reproduction investment telomere
Programme: 119
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. (2020). Health access inequities and magic medicine: the first ancient evidence? (Vol. 395). Bachelor's thesis, Elsevier, .
Abstract: Inequities in access to the latest advances in health care and effective drugs constitute public health problems today,1 but was this also the case in ancient societies when practitioners used traditional medicines with limited means? The excavation of frozen graves in Yakutia (present day eastern Siberia, Russia) dating from 1700 CE2 led to the identification of a woman, buried almost naked, covered with a magnificent robe and with half a horse bit in her mouth (figure). The other half of the horse bit was found in the trunk behind her head with her earrings, bracelets, and signet rings.
Programme: 1038
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Sam L. Cox, Matthieu Authier, Florian Orgeret, Henri Weimerskirch, Christophe Guinet. (2020). High mortality rates in a juvenile free-ranging marine predator and links to dive and forage ability (Vol. 10). Bachelor's thesis, , .
Abstract: High juvenile mortality rates are typical of many long-lived marine vertebrate predators. Insufficient development in dive and forage ability is considered a key driver of this. However, direct links to survival outcome are sparse, particularly in free-ranging marine animals that may not return to land. In this study, we conduct exploratory investigations toward early mortality in juvenile southern elephant seals Mirounga leonina. Twenty postweaning pups were equipped with (a) a new-generation satellite relay data tag, capable of remotely transmitting fine-scale behavioral movements from accelerometers, and (b) a location transmitting only tag (so that mortality events could be distinguished from device failures). Individuals were followed during their first trip at sea (until mortality or return to land). Two analyses were conducted. First, the behavioral movements and encountered environmental conditions of nonsurviving pups were individually compared to temporally concurrent observations from grouped survivors. Second, common causes of mortality were investigated using Cox's proportional hazard regression and penalized shrinkage techniques. Nine individuals died (two females and seven males) and 11 survived (eight females and three males). All but one individual died before the return phase of their first trip at sea, and all but one were negatively buoyant. Causes of death were variable, although common factors included increased horizontal travel speeds and distances, decreased development in dive and forage ability, and habitat type visited (lower sea surface temperatures and decreased total [eddy] kinetic energy). For long-lived marine vertebrate predators, such as the southern elephant seal, the first few months of life following independence represent a critical period, when small deviations in behavior from the norm appear sufficient to increase mortality risk. Survival rates may subsequently be particularly vulnerable to changes in climate and environment, which will have concomitant consequences on the demography and dynamics of populations.
Keywords: bio-logging early life foraging ecology juvenile mortality Mirounga leonina southern elephant seal survival analyses
Programme: 109,1201
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Ross J. Turner, Martin Gal, Mark A. Hemer, Anya M. Reading. (2020). Impacts of the Cryosphere and Atmosphere on Observed Microseisms Generated in the Southern Ocean (Vol. 125).
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. (2020). When do older birds better resist stress? A study of the corticosterone stress response in snow petrels (Vol. 16). Bachelor's thesis, Royal Society, .
Abstract: Life-history theory predicts that, to optimize their fitness, individuals should increase their reproductive effort as their residual reproductive value decreases. Accordingly, several studies have shown that individuals downregulate their glucocorticoid stress response (a proxy of reproductive investment in vertebrates) as they age, and as the subsequent reproductive value decreases. However, and surprisingly, results appear inconsistent, suggesting that the environmental context or the individual state may affect the relationship between age and reproductive effort. Here, we tested for the first time this hypothesis, and more specifically, whether this attenuation of the corticosterone stress response with advancing age depends on the energetic status of individuals. We compared the influence of age on the corticosterone stress response between fasting and non-fasting breeding snow petrels (Pagodroma nivea), an extremely long-lived bird. As expected, we found that the corticosterone stress response was attenuated in old petrels, but only when they were not fasting. Interestingly, this pattern was not apparent in fasting petrels, suggesting that old birds downregulate their corticosterone stress response and increase their parental investment only when they are in good body condition. At the ultimate level, old individuals may maintain a strong corticosterone stress response when fasting because the survival costs of increased stress resistance and parental effort might then outweigh their reproductive benefits.
Programme: 109
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. (2020). Weak effects of geolocators on small birds: A meta-analysis controlled for phylogeny and publication bias (Vol. 89).
Abstract: Currently, the deployment of tracking devices is one of the most frequently used approaches to study movement ecology of birds. Recent miniaturization of light-level geolocators enabled studying small bird species whose migratory patterns were widely unknown. However, geolocators may reduce vital rates in tagged birds and may bias obtained movement data. There is a need for a thorough assessment of the potential tag effects on small birds, as previous meta-analyses did not evaluate unpublished data and impact of multiple life-history traits, focused mainly on large species and the number of published studies tagging small birds has increased substantially. We quantitatively reviewed 549 records extracted from 74 published and 48 unpublished studies on over 7,800 tagged and 17,800 control individuals to examine the effects of geolocator tagging on small bird species (body mass <100 g). We calculated the effect of tagging on apparent survival, condition, phenology and breeding performance and identified the most important predictors of the magnitude of effect sizes. Even though the effects were not statistically significant in phylogenetically controlled models, we found a weak negative impact of geolocators on apparent survival. The negative effect on apparent survival was stronger with increasing relative load of the device and with geolocators attached using elastic harnesses. Moreover, tagging effects were stronger in smaller species. In conclusion, we found a weak effect on apparent survival of tagged birds and managed to pinpoint key aspects and drivers of tagging effects. We provide recommendations for establishing matched control group for proper effect size assessment in future studies and outline various aspects of tagging that need further investigation. Finally, our results encourage further use of geolocators on small bird species but the ethical aspects and scientific benefits should always be considered.
Keywords: condition migration phenology reproduction return rate survival tag effect tracking device
Programme: 1036
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. (2020). Vocal tract anatomy of king penguins: morphological traits of two-voiced sound production (Vol. 17). Bachelor's thesis, , .
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. (2020). Using Component Ratios to Detect Metadata and Instrument Problems of Seismic Stations: Examples from 18 Yr of GEOSCOPE Data (Vol. 91).
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