. (2021). Recent Climate Variability around the Kerguelen Islands (Southern Ocean) Seen through Weather Regimes (Vol. 60). Bachelor's thesis, , .
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. (2021). The high diversity of Southern Ocean sea stars (Asteroidea) reveals original evolutionary pathways (Vol. 190). Bachelor's thesis, , .
Abstract: Benthic life in the Southern Ocean (SO) features unique life history traits and species assemblages, but the origin and evolution of many of these taxonomic groups is still unclear. Sea stars (Asteroidea) are a diversified and abundant component of benthic ecosystems in the SO, in which they can play key ecological roles. Former studies suggest that the diversity of the entire class is still poorly known and underestimated, hampering the assessment of the origin and evolution of the class in the SO. In the present study, we analyse spatial patterns of SO sea star diversity using an occurrence database of ~14,000 entries. The biogeographic analysis is coupled with the exploration of an extensive molecular phylogeny based on over 4,400 specimen sequences to inform, support and/or question the observed diversity patterns. We show that the current taxonomy of SO asteroids needs revision and that their diversity has generally been overlooked and misinterpreted. Molecular results highlight the recent diversification of most studied taxa, at genus and species levels, which supports an evolutionary scenario referring to successive invasion and exchange events between the SO and adjacent regions, and clade diversification during periods of rapid environmental changes driven by the succession of glacial cycles. Our work advocates for employing, and endorsing the use of extensive genetic barcode libraries for biodiversity studies.
Keywords: Antarctica Biodiversity COI mtDNA Echinodermata Evolution Phylogeography
Programme: 1044,1124
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. (2021). A dedicated robust instrument for water vapor generation at low humidity for use with a laser water isotope analyzer in cold and dry polar regions (Vol. 14). Bachelor's thesis, , .
Programme: 1110,1169,1205
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. (2021). Spatial segregation in a sexually dimorphic central place forager: Competitive exclusion or niche divergence? (Vol. 90). Bachelor's thesis, , .
Keywords: bio-logging central place foraging ecological niche theory intraspecific competition kernel density estimates resource selection functions sexual segregation wandering albatross
Programme: 109,394
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Viblanc Va, Stier A, Bize P, Schull Q, Criscuolo F, Groscolas R, Robin Jp. (2021). The ecophysiology of king penguins : responses to a fluctuating environment. Bachelor's thesis, , .
Abstract: Penguins are sea...birds. These highly evolved marine predators thrive in the oceanic habitat. Yet, they are conflicted – confronted to the duality of a life spent partly at sea, partly on-land. This life style has them subject to a number of very different ecological pressures. The ECONERGY polar project (IPEV #119) seeks to understand how king penguin cope with the constraints they face while living on-land, and the underlying physiological adaptations that allow them to do so. This includes studies dealing with fasting, parasites, predators, aggressive neighbors, climate and human disturbance. I will present some of the advances our project has made over the past decades, and where we will proceed in the years to come with a new project. We aim to understand bird stress from an integrative perspective, building a long-term observatory of penguin physiological responses to a changing world, and determining how breeding performances on land and foraging performances at sea are related.
Programme: 119
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. (2021). (Vol. 91). Bachelor's thesis, , .
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Mark A. Hindell, Clive R. McMahon, Ian Jonsen, Robert Harcourt, Fernando Arce, Christophe Guinet. (2021). Inter- and intrasex habitat partitioning in the highly dimorphic southern elephant seal (Vol. 11). Bachelor's thesis, , .
Abstract: Partitioning resources is a key mechanism for avoiding intraspecific competition and maximizing individual energy gain. However, in sexually dimorphic species it is difficult to discern if partitioning is due to competition or the different resource needs of morphologically distinct individuals. In the highly dimorphic southern elephant seal, there are intersexual differences in habitat use; at Iles Kerguelen, males predominantly use shelf waters, while females use deeper oceanic waters. There are equally marked intrasexual differences, with some males using the nearby Kerguelen Plateau, and others using the much more distant Antarctic continental shelf ( 2,000 km away). We used this combination of inter and intrasexual behavior to test two hypotheses regarding habitat partitioning in highly dimorphic species. (a) that intersexual differences in habitat use will not appear until the seals diverge in body size and (b) that some habitats have higher rates of energy return than others. In particular, that the Antarctic shelf would provide higher energy returns than the Kerguelen Shelf, to offset the greater cost of travel. We quantified the habitat use of 187 southern elephant seals (102 adult females and 85 subadult males). The seals in the two groups were the same size ( 2.4 m) removing the confounding effect of body size. We found that the intersexual differences in habitat use existed before the divergence in body size. Also, we found that the amount of energy gained was the same in all of the major habitats. This suggests that the use of shelf habitats by males is innate, and a trade-off between the need to access the large benthic prey available on shelf waters, against the higher risk of predation there. Intrasexual differences in habitat use are another trade-off; although there are fewer predators on the Antarctic shelf, it is subject to considerable interannual fluctuations in sea-ice extent. In contrast, the Kerguelen Plateau presents more consistent foraging opportunities, but contains higher levels of predation. Habitat partitioning in this highly dimorphic species is therefore the result of complex interplay of life history strategies, environmental conditions and predation pressure.
Keywords: Antarctic Shelf foraging and diving behavior Kerguelen Plateau mid-year haul out predation risk Southern Ocean
Programme: 109,1201
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Noor Johnson, Matthew L Druckenmiller, Finn Danielsen, Peter L Pulsifer. (2021). The Use of Digital Platforms for Community-Based Monitoring (Vol. 71). Bachelor's thesis, , .
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Hajo Eicken, Finn Danielsen, Josephine-Mary Sam, Maryann Fidel, Noor Johnson, Michael K Poulsen, Olivia A Lee, Katie V Spellman, Lisbeth Iversen, Peter Pulsifer, Martin Enghoff. (2021). Connecting Top-Down and Bottom-Up Approaches in Environmental Observing (Vol. 71). Bachelor's thesis, , .
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. (2021). Multispecies tracking reveals a major seabird hotspot in the North Atlantic (Vol. 14). Bachelor's thesis, , .
Keywords: area beyond national jurisdiction Atlantic biologging conservation high seas marine protected area regional seas convention
Programme: 330,333,388,1036
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