|
. (2011). From preen secretions to plumage: the chemical trajectory of blue petrels' Halobaena caerulea social scent
. 0908-8857, 42(1), 29–38.
Abstract: Petrel seabirds heavily rely on their olfactory sense and are thus appropriate models for the study of avian chemical communication. The uropygial secretions of blue petrels Halobaena caerulea, for instance, have been shown to encapsulate elaborate sociochemical information including species, gender and identity. Yet, it is the plumage, and not preening secretions per se, which acts as the final substrate of avian scents. Importantly, the chemical relationship between secretions from the uropygial gland, located at the dorsal base of the tail, and plumage lipids has been considered in only a handful of studies which reported large qualitative differences. The emission process of avian scents, and the possible participation of the uropygial gland in particular, are therefore not elucidated. In the present study, we examine the early chemical trajectory of blue petrels' social chemosignals by comparing secretion and feather samples using Gas-Chromatography Mass-Spectrometry (GC/MS) and recently developed multivariate statistics. Our results indicate that (1) 85% of the feather lipids come from the uropygial secretions, (2) chemical differentiation between secretions and feather lipids includes qualitative and quantitative variations, which both have interesting implications for scent production, (3) the sociochemical information contained within the secretions (i.e. a sex-specific signal and individual chemical signatures) are present in very conserved forms on the plumage. In the light of these results, it is apparent that the uropygial gland plays a critical role for chemical communication in petrels and possibly other avian groups.
Programme: 354
|
|
|
Brodier S, Pisanu B, Villers A, Pettex E, Lioret M, Chapuis J-L, Bretagnolle V, . (2011). Responses of seabirds to the rabbit eradication on Ile Verte, sub-Antarctic Kerguelen Archipelago
. 1367-9430, 14(5), 459–465.
Keywords: Oryctolagus cuniculus, invasive mammal, burrowing petrels, brown skua, conservation program, Sub-Antarctic island,
Programme: 136
|
|
|
. (2011). Secular gravity variation at Svalbard (Norway) from ground observations and GRACE satellite data
. 0956-540X, 184(3), 1119–1130.
Keywords: Satellite geodesy, Time variable gravity, Global change from geodesy, Arctic region,
Programme: 337
|
|
|
. (2012). Inter-oceanic variation in patterns of host-associated divergence in a seabird ectoparasite
. J. Biogeogr., 39(3), 545–555.
Abstract: Aim Parasites with global distributions and wide host spectra provide excellent models for exploring the factors that drive parasite diversification. Here, we tested the relative force of host and geography in shaping population structure of a widely distributed and common ectoparasite of colonial seabirds, the tick Ixodes uriae. Location Two natural geographic replicates of the system: numerous seabird colonies of the North Pacific and North Atlantic Ocean basins. Methods Using eight microsatellite markers and tick samples from a suite of multi-specific seabird colonies, we examined tick population structure in the North Pacific and compare patterns of diversity and structure to those in the Atlantic basin. Analyses included population genetic estimations of diversity and population differentiation, exploratory multivariate analyses, and Bayesian clustering approaches. These different analyses explicitly took into account both the geographic distance among colonies and host use by the tick. Results Overall, little geographic structure was observed among Pacific tick populations. However, host-related genetic differentiation was evident, but was variable among host types and lower than in the North Atlantic. Main conclusions Tick population structure is concordant with the genetic structure observed in seabird host species within each ocean basin, where seabird populations tend to be less structured in the North Pacific than in the North Atlantic. Reduced tick genetic structure in the North Pacific suggests that host movement among colonies, and thus tick dispersal, is higher in this region. In addition to information on parasite diversity and gene flow, our findings raise interesting questions about the subtle ways that host behaviour, distribution and phylogeographic history shape the genetics of associated parasites across geographic landscapes.
Keywords: Co-evolution, host race, hostparasite interactions, Ixodes uriae, microsatellite, North Atlantic, North Pacific, tick,
Programme: 333
|
|
|
. (2011). Genetic structure of marine Borrelia garinii and population admixture with the terrestrial cycle of Lyme borreliosis
. Environ. Microbiol., 13(9), 2453–2467.
Abstract: Despite the importance of population structure for the epidemiology of pathogenic bacteria, the spatial and ecological heterogeneity of these populations is often poorly characterized. Here, we investigated the genetic diversity and population structure of the Lyme borreliosis (LB) spirochaete Borrelia garinii in its marine cycle involving colonial seabirds and different host races of the seabird tick Ixodes uriae. Multilocus sequence analyses (MLSA) on eight chromosomal and two plasmid loci (ospA and ospC) indicate that B. garinii circulating in the marine system is highly diverse. Microevolution in marine B. garinii seems to be mainly clonal, but recombination and selection do occur. Sequence types were not evenly distributed among geographic regions, with substantial population subdivision between Atlantic and Pacific Ocean basins. However, no geographic structuring was evident within regions. Results of selection analyses and phylogenetic discordance between chromosomal and plasmid loci indicate adaptive evolution is likely occurring in this system, but no pattern of host or vector-associated divergence was found. Recombination analyses showed evidence for population admixture between terrestrial and marine strains, suggesting that LB spirochaetes are exchanged between these enzootic cycles. Importantly, our results highlight the need to explicitly consider the marine system for a complete understanding of the evolutionary ecology and global epidemiology of Lyme borreliosis.
Programme: 333
|
|
|
Schimmel M, Stutzmann E, Gallart J, . (2011). Using instantaneous phase coherence for signal extraction from ambient noise data at a local to a global scale
. Geophysical Journal International, 184(1), 494–506.
Abstract: Stacks of ambient noise cross-correlations are more and more routinely used to extract empirical Green's functions between station pairs. The success of the cross-correlations is due to waves which are recorded by both stations and that constructively sum at lag times which equal their propagation time between the station pair. Stacking cross-correlograms corresponding to different time spans improves the azimuthal noise coverage and further enhances the signals. Here we show how the instantaneous phase coherence can be used for a more efficient signal extraction from ambient noise cross-correlations. The instantaneous phase coherence is obtained by analytic signal processing and can be employed through the phase cross-correlation and/or through the time-frequency domain phase-weighted stack. The phase cross-correlation is more sensitive to waveform similarity but less sensitive to strong amplitude features than the conventional cross-correlation. The time-frequency domain phase-weighted stack cleans the ambient noise cross-correlograms by attenuating incoherent noise and permits an improved signal identification. We show that both approaches are powerful tools in the recovery of signals from ambient noise data and show examples where they improve the extraction of P and Rayleigh waves by considering local and global scale applications.
Keywords: Time series analysis, Interferometry, Body waves, Surface waves and free oscillations,
Programme: 133
|
|
|
Ritsema J, Deuss A, van Heijst H J, Woodhouse J H, . (2011). S40RTS: a degree-40 shear-velocity model for the mantle from new Rayleigh wave dispersion, teleseismic traveltime and normal-mode splitting function measurements
. 0956-540X, 184(3), 1223–1236.
Keywords: Composition of the mantle, Body waves, Surface waves and free oscillations, Seismic tomography,
Programme: 133
|
|
|
Leki V, Romanowicz B, . (2011). Inferring upper-mantle structure by full waveform tomography with the spectral element method
. 0956-540X, 185(2), 799–831.
Keywords: Inverse theory, Surface waves and free oscillations, Seismic anisotropy, Seismic tomography, Computational seismology, Wave propagation,
Programme: 133
|
|
|
Rains Derek, Weimerskirch Henri, Burg Theresa M, . (2011). Piecing together the global population puzzle of wandering albatrosses: genetic analysis of the Amsterdam albatross Diomedea amsterdamensis
. 0908-8857, 42(1), 69–79.
Abstract: Wandering albatrosses have been subjected to numerous taxonomic revisions due to discoveries of new species, analyses of morphological data and, more recently, the inclusion of genetic data. The small population of albatrosses (170 individuals including 26 pairs breeding annually) on Amsterdam Island in the Indian Ocean, Diomedea amsterdamensis, has been given species status based on plumage and morphometrics, but genetic data published to date provide weak support and its specific status remains controversial for some authors. We used mitochondrial control region sequence data to elucidate the relationship of the Amsterdam albatross within the wandering albatross complex (Diomedea amsterdamensis, D. antipodensis, D. dabbenena and D. exulans). Three novel haplotypes were present in 35 individuals from Amsterdam Island, and were highly divergent (3.67.3%) from haplotypes found in the other three members of the wandering albatross complex. Low levels of genetic variation in Amsterdam albatross likely resulted, at least in part, from a population bottleneck. Geographic isolation in the wandering albatross complex is maintained by high natal philopatry. As Amsterdam Island is the only breeding ground for this critically endangered species, we strongly urge conservation efforts in the area, especially in relation to long line fisheries and other threats such as disease and introduced predators, and it be listed as a distinct species.
Programme: 109
|
|
|
. (2011). The ontogeny of diving abilities in subantarctic fur seal pups: developmental trade-off in response to extreme fasting?
. 0269-8463, 25(4), 818–828.
Keywords: aerobic dive limit, behavioural plasticity, diving behaviour, diving physiology, growth strategy, myoglobin, oxygen stores, weaning,
Programme: 109
|
|