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Chambert T, Pardo D, Choquet R, Staszewski V, McCoy Karen D, Tveraa Torkild, Boulinier Thierry, . (2010). Heterogeneity in detection probability along the breeding season in Black-legged Kittiwakes: implications for sampling design
. J. Ornithol., , 1-10.
Abstract: In wild animal population studies, capture heterogeneity is likely to be prevalent and can reduce the accuracy of vital rate estimates. Here, we test how individual detection probabilities vary through the breeding season in a population of a cliff-nesting colonial seabird, the Black-legged Kittiwake (Rissa tridactyla). Specifically, we expected detection probability to be affected by changes in brooding behavior and nest attendance associated with the breeding phenology and the local breeding performance of individuals. As predicted, we found that strong heterogeneities in detection probability can occur in relation to the breeding performance of individuals, the breeding performance of their neighbors, and the timing of surveys. Detection probability is highest and most homogeneous at the beginning of the breeding season. Later in the season, it is lower and can vary dramatically among groups of breeding individuals. A simulation approach was used to assess the implications of these results for the performance (bias and precision) of different study designs. Clearly, investing sampling effort early in the season is an efficient way to improve the accuracy of parameter estimates in this species. Our findings stress the importance of establishing study designs that take into account the population and behavioral ecology of the focal species.
Keywords: biomedical life sciences,
Programme: 333
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. (2011). Introduced black rats Rattus rattus on Ile de la Possession (Iles Crozet, Subantarctic): diet and trophic position in food webs
. Polar Biol., 34(2), 169–180 -180.
Abstract: Rats introduced on islands can affect ecosystem structure and function by feeding on terrestrial plants and both marine and terrestrial animals. The diet and trophic position of Rattus rattus introduced on Ile de la Possession (Iles Crozet) was assessed from two sites, according to the presence or absence of a king penguin colony. We used three complementary assays: macroanalyses of the stomach, faecal microhistology, and stable isotope analyses of 15N/13C in liver. Near the rookery, spermatophytes contributed on average 50% (confidential interval: 2375) to the diet based on isotopes, mainly consisting in reproductive parts of Poa spp., Agrostis magellanica, and Cerastium fontanum identified in faeces. Terrestrial animal preys were represented by insects that contributed 25% (056) in isotopes, dominated in faeces by caterpillars of Pringleophaga spp. and adult weevils. Bird remains were found in faeces, forming 18% (630) of isotopes. Terrestrial earthworms contributed to 7% (021), with chaetae observed in faeces. On the other site, spermatophytes represented 62% (5173) of assimilated food in rats livers, mainly formed by Poaceae and Acaena magellanica, insects by caterpillars [24% (1039)], and terrestrial earthworms [13% (223)]. Our results suggest that rats, which were found at the top of terrestrial food chains, may have a direct role on a such simplified ecosystem, by preying on the most abundant and largest body-sized terrestrial invertebrates,e.g. the keystone species Pringleophaga spp., and by feeding on both reproductive and vegetative parts of autochthonous and introduced plants. The discrepancies and usefulness of employing both isotopes and faecal analyses are discussed.
Keywords: Biomedical and Life Sciences,
Programme: 136
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Authier Matthieu, Delord Karine, Guinet Christophe, . (2011). Polar Biol., 34(3), 319–328.
Keywords: Biomedical and Life Sciences,
Programme: 109
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Mazzei F, Ghigliotti L, Coutanceau Jean-Pierre, Detrich H, Prirodina V, Ozouf-Costaz C, Pisano E, . (2008). Chromosomal characteristics of the temperate notothenioid fish Eleginops maclovinus (Cuvier)
. Polar Biol., 31(5), 629–634.
Abstract: The Falklands mullet, Eleginops maclovinus , is the only modern representative of the Sub-Antarctic family Eleginopidae, suborder Notothenioidei. Based on specimens from the Falkland Islands/Islas Malvinas, the Magellan Straits, and the southern coast of Chile, we have established the specific karyotype by conventional cytogenetic methods and have mapped the chromosomal loci of the ribosomal genes by fluorescence in situ hybridization (FISH). With respect to the basal notothenioid family Bovichtidae and to the hypothetical basal condition of the suborder (diploid number = 48, fundamental number = 48), E. maclovinus displays a slightly derived karyotype (diploid number = 48, fundamental number = 54). In contrast to the bovichtids, the 45S and 5S ribosomal DNAs are co-localized to a single chromosome pair. Condensation of the ribosomal genes to a single locus is likely to represent an intermediate stage in the evolution of notothenioid karyology. Features unique to E. maclovinus (e.g., morphology of its large, rDNA-bearing chromosome pair) probably result from divergence during the long evolutionary isolation of the family.
Keywords: Biomedical and Life Sciences,
Programme: 1124
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. (2008). Community structure and spatial distribution of benthic fauna in the Bellingshausen Sea (West Antarctica)
. Polar Biol., 31(6), 735–743.
Abstract: The structure and spatial distribution of the macrofauna community of the Bellingshausen Sea in the western sector of Antarctica was studied during the BENTART06 oceanographic expedition. This is one of the least explored Antarctic seas. A total of 20 box cores were sampled at 11 stations ranging from 157 to 3,304 m depth, using an USNEL-type box corer (BC) dredge. Representatives of 25 higher taxa of invertebrates were collected. Deeper sampling sites were less rich in taxa (47 taxa), whereas the figures were higher at shallower sites (up to 17 taxa). Faunal density on the sea bottom revealed a horizontal spatial gradient from the western sites with extremely low figures (90 indiv./m 2 ) towards the eastern ones with the highest figures (1,360 indiv./m 2 ) close to the Antarctic Peninsula. Several abiotic factors (depth, redox, organic matter, carbonates and particle size of surficial sediments) were measured simultaneously on the sea floor to characterise the substrate preferences of the fauna. Positive correlations were found between the faunal distribution and a combination of depth, redox values, and organic matter content of sediments. This indicates decreasing availability of food in the deeper bottoms of the Bellingshausen Sea with a prevalence of depauperated bottoms dominated almost exclusively by a foraminiferans community.
Keywords: Biomedical and Life Sciences,
Programme: 1124
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. (2009). Stomach stones in king penguin chicks
. Polar Biol., 32(4), 593–597.
Abstract: Many animals that possess a gizzard swallow stones or sandy grit, supposedly to aid in the mechanical breakdown of food. While this has been well documented in the literature, our study is the first to report the presence of stones in the gizzard of king penguin chicks. We found stones, so called gastroliths, in the pyloric region of the gizzard, the part of the digestive tract that is specialised for the mechanical breakdown of food. Stones were already present in the gizzard of chicks and, hence, during the first year of the life of king penguins, which is spent on land. Some chicks were found to have more than 130 stones (0.522 mm in size) in their gizzard. The gastroliths we found in king penguins are of the same geological origin as rocks present at the colony, which suggests that birds swallowed them there. The functional role of gastroliths in penguin chicks and adults is still unknown. We discuss the potential roles that these gastroliths might play in king penguins (i.e. aid in digestion, buoyancy control during foraging at sea, adaptation to fasting).
Keywords: Biomedical and Life Sciences,
Programme: 137
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. (2009). Molecular surveillance for avian influenza A virus in king penguins (Aptenodytes patagonicus)
. Polar Biol., 32(4), 663–665.
Abstract: An investigation of the presence of influenza A virus has been conducted in king penguins ( Aptenodytes patagonicus ) at the Possession Island in the Crozet Archipelago, Antarctica, using a rapid molecular diagnostic method based on real-time polymerase chain reaction. No evidence of outbreak or positive viral infection of influenza A virus was found in this study. We however recommend the implementation of long-term surveillance in seabird populations of polar ecosystems to detect the potential introduction of exotic strains and potential existence of a local epidemiological cycle for avian influenza viruses.
Keywords: Biomedical and Life Sciences,
Programme: 137
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. (2010). Fatty acid signature analysis documents the diet of five myctophid fish from the Southern Ocean
. Marine Biology, 157(10), 2303–2316.
Abstract: Fatty acid (FA) and fatty alcohol (FAlc) compositions of both total lipid and neutral lipid fractions were studied for five myctophid species sampled in Kerguelen waters. Both qualitative and quantitative FA signature analyses were then performed to investigate their diet over longer time scales than the conventional stomach content analysis. Regarding their lipid class, FA and FAlc compositions, the five species could be discriminated into two groups: wax-ester-rich species ( Electrona antarctica , Krefftichthys anderssoni ) characterised by large amounts of monounsaturated FAs (>73% of total FAs) and triacylglycerol-rich species ( Electrona carlsbergi , Gymnoscopelus nicholsi , Protomyctophum bolini ) with major amounts of saturated and monounsaturated FAs (>29 and >46% of total FAs, respectively). Qualitative and quantitative FA analyses showed that K. anderssoni mainly preyed upon copepods, E. antarctica upon copepods and more euphausiids and P. bolini and E. carlsbergi mainly upon euphausiids with some copepods, while G. nicholsi had a more diverse diet. This study shows the usefulness of quantitative statistical analysis to determine the diet of Antarctic and sub-Antarctic predators and stresses the need of increasing the lipid and FA analyses of more zooplanktonic and micro-nektonic marine species.
Keywords: Biomedical and Life Sciences,
Programme: 109
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. (2010). Morphology, ontogenesis and mechanics of cervical vertebrae in four species of penguins (Aves: Spheniscidae)
. Polar Biol., 33(6), 807–822.
Abstract: Penguins (Aves: Spheniscidae) are pelagic, flightless seabirds, restricted to the southern hemisphere (Antarctic and sub-Antarctic areas, New Zealand, Australia, and nearby islands, as well as parts of South America and South Africa). They spend much of their life at sea, but return to islands and coasts to breed. Penguins are terrestrial as juveniles and aquatic as adults. To improve hydrodynamics, penguins tuck in their necks while swimming. They thus attain an ichthyosaur or cetacean body shape: characterised by telescoped cervicals. This mechanism is also used on land, associated with the posture of these birds. Our study of neck structure and cervical vertebrae morphology (morphological description, biometry and contour analysis) of the King Penguin ( Aptenodytes patagonicus ), Gentoo Penguin ( Pygoscelis papua ), Macaroni Penguin ( Eudyptes chrysolophus ) and Humboldt Penguin ( Sphensicus humboldti ) shows a highly specialised fitting in adults, which develops during ontogenesis. The growth of penguins proceeds by stages and there are key stages with regard to the design of the neck. Despite a common main structure, some characteristics vary between species. Distribution of cervical vertebrae can be defined by six modules. There are differences in modularity between species and also within species between different ontogenetical phases.
Keywords: Biomedical and Life Sciences,
Programme: 137
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. (2010). Diatom communities in soils influenced by the wandering albatross (Diomedea exulans)
. Polar Biology, 33(2), 241–255.
Keywords: Biomedical and Life Sciences,
Programme: 136
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