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Auteur Gutowsky, S.E.; Tremblay, Y.; Kappes, M.A.; Flint, E.N.; Klavitter, J.; Laniawe, L.; Costa, D.P.; Naughton, M.B.; Romano, M.D.; Shaffer, S.A. url  doi
openurl 
  Titre Divergent post-breeding distribution and habitat associations of fledgling and adult black-footed Albatrosses Phoebastria nigripes in the North Pacific Type Article scientifique
  Année 2014 Publication Revue Abrégée Ibis  
  Volume (down) 156 Numéro 1 Pages 60-72  
  Mots-Clés dispersal; geolocators; habitat use; Juvenile; Procellariiform; satellite telemetry; seabird  
  Résumé Past tracking studies of marine animals have primarily targeted adults, biasing our understanding of at-sea habitat use toward older life stages. Anthropogenic threats persist throughout the at-sea ranges of all life stages and it is therefore of interest to population ecologists and managers alike to understand spatiotemporal distributions and possible niche differentiation between age-classes. In albatrosses, particularly little is known about the juvenile life stage when fledglings depart the colonies and venture to sea with no prior experience or parental guidance. We compared the dispersal of 22 fledgling Black-footed Albatross Phoebastria nigripes between 2006 and 2008 using satellite telemetry and 16 adults between 2008 and 2009 using geolocaters from Midway Atoll National Wildlife Refuge, Northwest Hawaiian Islands. Following tag deployment, all fledglings spent several days within the calm atoll waters, then travelled northward until reaching 750-900km from the colony. At this point, fledgling distributions approached the productive North Pacific Transition Zone (NPTZ). Rather than reaching the high chlorophyll a densities on the leading edge of this zone, however, fledglings remained in areas of low productivity in the subtropical gyre. In contrast, adult albatrosses from the same breeding colony did not utilize the NPTZ at this time of year but rather ranged throughout the highly productive northern periphery of the Pacific Ocean Basin among the shelf regions off Japan and the Aleutian Islands. The dichotomy in habitat use between fledglings and adults from Midway Atoll results in complete spatial segregation between age-classes and suggests ontogenetic niche separation in this species. This research fills a large knowledge gap in at-sea habitat use during a little known yet critical life stage of albatrosses, and contributes to a more comprehensive understanding of differential mortality pressure between age-classes and overall conservation status for the vulnerable Black-footed Albatross.  
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  Editeur Lieu de Publication Éditeur  
  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0019-1019 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel LL @ pixluser @ collection 329  
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Auteur Boyd, C.; Castillo, R.; Hunt, G.L.; Punt, A.E.; VanBlaricom, G.R.; Weimerskirch, H.; Bertrand, S. url  doi
openurl 
  Titre Predictive modelling of habitat selection by marine predators with respect to the abundance and depth distribution of pelagic prey Type Article scientifique
  Année 2015 Publication Revue Abrégée J Anim Ecol  
  Volume (down) 84 Numéro 6 Pages 1575-1588  
  Mots-Clés central place foragers; Foraging ecology; habitat use; Humboldt Current system; predator–prey interactions; spatial distribution  
  Résumé * Understanding the ecological processes that underpin species distribution patterns is a fundamental goal in spatial ecology. However, developing predictive models of habitat use is challenging for species that forage in marine environments, as both predators and prey are often highly mobile and difficult to monitor. Consequently, few studies have developed resource selection functions for marine predators based directly on the abundance and distribution of their prey. * We analysed contemporaneous data on the diving locations of two seabird species, the shallow-diving Peruvian Booby (Sula variegata) and deeper diving Guanay Cormorant (Phalacrocorax bougainvilliorum), and the abundance and depth distribution of their main prey, Peruvian anchoveta (Engraulis ringens). Based on this unique data set, we developed resource selection functions to test the hypothesis that the probability of seabird diving behaviour at a given location is a function of the relative abundance of prey in the upper water column. * For both species, we show that the probability of diving behaviour is mostly explained by the distribution of prey at shallow depths. While the probability of diving behaviour increases sharply with prey abundance at relatively low levels of abundance, support for including abundance in addition to the depth distribution of prey is weak, suggesting that prey abundance was not a major factor determining the location of diving behaviour during the study period. * The study thus highlights the importance of the depth distribution of prey for two species of seabird with different diving capabilities. The results complement previous research that points towards the importance of oceanographic processes that enhance the accessibility of prey to seabirds. The implications are that locations where prey is predictably found at accessible depths may be more important for surface foragers, such as seabirds, than locations where prey is predictably abundant. * Analysis of the relative importance of abundance and accessibility is essential for the design and evaluation of effective management responses to reduced prey availability for seabirds and other top predators in marine systems.  
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  Langue en Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1365-2656 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1349  
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Auteur Carpentier, A.S.; Berthe, C.; Ender, I.; Jaine, F.R.A.; Mourier, J.; Stevens, G.; De Rosemont, M.; Clua, E. doi  openurl
  Titre Preliminary insights into the population characteristics and distribution of reef (Mobula alfredi) and oceanic (M. birostris) manta rays in French Polynesia Type Article scientifique
  Année 2019 Publication Revue Abrégée Coral Reefs  
  Volume (down) 38 Numéro 6 Pages 1197-1210  
  Mots-Clés aggregation; australia; bottle-nosed dolphins; california; Citizen science; conservation; Ecotourism management; habitat use; identification; marine park; movements; sharks; Site fidelity; Spatial connectivity; Sympatry  
  Résumé In French Polynesia, both currently recognized manta ray species, Mobula alfredi and M. birostris, are observed. Despite being an important cultural asset and generating significant economic benefits through manta ray watching tourism, published data on the ecology and threats to these species in the region are scarce. Based on an 18-year dataset of sighting records collected by citizen scientists and during two scientific expeditions, this study provides the first insights into the population characteristics and regional distribution of the two manta ray species in French Polynesia. A total of 1347 manta ray photographs (1337 for M. alfredi and 10 for M. birostris) were examined for the period January 2001-December 2017, with photo-identification techniques leading to the successful identification of 317 individual M. alfredi and 10 individual M. birostris throughout the Society, Tuamotu and Marquesas Islands. We provide the first confirmation of sympatric distribution of both species in the Society Islands. Our results highlight strong and long-term site fidelity of M. alfredi individuals to certain aggregation sites (> 9 years for 16 individuals) and reveal some degree of connectivity between populations, with 10 individuals recorded moving between islands located up to 50 km apart. Analysis of photographs of individuals bearing sub-lethal injuries (n = 68) suggests that M. alfredi are more likely to be injured at inhabited islands (Maupiti or Bora Bora; 75% of all injured individuals) than at uninhabited islands, with 75% of injuries related to boat propeller strikes and fishing gear entanglements. Our findings emphasize the need for further research to allow for a comprehensive evaluation of population structure, size and threats to manta rays in this region.  
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  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0722-4028 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000496024100010 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2658  
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Auteur Manna, L.R.; Villeger, S.; Rezende, C.F.; Mazzoni, R. doi  openurl
  Titre High intraspecific variability in morphology and diet in tropical stream fish communities Type Article scientifique
  Année 2019 Publication Revue Abrégée Ecol. Freshw. Fish  
  Volume (down) 28 Numéro 1 Pages 41-52  
  Mots-Clés approach reveals; assemblages; body-size; community ecology; competition; ecology; functional diversity; functional traits; habitat use; originality; plasticity; rainforest stream; savannah stream; specialisation; specialization; traits  
  Résumé Functional diversity of fish communities has been measured according to (a) interspecific variability, assuming that intraspecific variability is negligible, or (b) morphological differences, as good descriptors of complex functions, such as diet. These two assumptions have been scarcely tested on the individual level, especially in species-rich tropical ecosystems. Here, we adapted intraspecific specialisation (ISpe) and intraspecific originality indices (IOri) to assess complementary components of intraspecific variability. Next, we applied these indices to evaluate the intra- and interspecific variability of morphological and diet traits in two contrasting Brazilian stream-dwelling fish assemblages (rainforest and savannah). We also compared correlations between morphology and diet at the individual and species level to test whether accounting for intraspecific variability increases the predictability of diet due to morphological differences. Significant contributions of intraspecific variability to differences between fish were revealed for morphology and diet. Intraspecific variability in the diet was higher than that in morphology in both assemblages. The ISpe was positively correlated to IOri in the diet of both ecosystems. The morphological-dietary relationships were significant but weak at both individual and species levels. Our findings highlight the importance of measuring individual variability and accounting for complementary components of the intraspecific variability (ISpe and IOri). Importantly, we showed that the variability in morphology does not predict diet variability at both intra- and interspecific levels. Thus, high intraspecific variability in morphology and diet challenges the use of functional traits measured at the species level to describe the functional diversity of different fish assemblages.  
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  Editeur Lieu de Publication Éditeur  
  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0906-6691 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2472  
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Auteur Bauer, R.K.; Fromentin, J.-M.; Demarcq, H.; Bonhommeau, S. url  doi
openurl 
  Titre Habitat use, vertical and horizontal behaviour of Atlantic bluefin tuna (Thunnus thynnus) in the Northwestern Mediterranean Sea in relation to oceanographic conditions Type Article scientifique
  Année 2017 Publication Revue Abrégée Deep Sea Research Part II: Topical Studies in Oceanography  
  Volume (down) Numéro Pages 248-261  
  Mots-Clés Archival tags; Fronts; habitat use; Spike dives; Thermal stratification; Thunnus thynnus  
  Résumé We investigated the habitat utilization, vertical and horizontal behaviour of Atlantic bluefin tuna Thunnus thynnus (ABFT) in relation to oceanographic conditions in the northwestern Mediterranean Sea, based on 36 pop-up archival tags and different environmental data sets. Tags were deployed on early mature ABFT (127–255cm) between July and November in 2007-2014, on the shelf area off Marseille, France. The data obtained from these tags provided 1643 daily summaries of ABFT vertical behaviour over 8years of tag deployment. Based on a hierarchical clustering of this data, we could identify four principle daily vertical behaviour types, representing surface (≦10m) and subsurface (10–100m) orientation, moderate (50–200m) and deep (≧200m) diving behaviour. These vertical behaviour types showed seasonal variations with partly opposing trends in their frequencies. Accordingly, ABFT were more surface orientated during summer, while moderate diving behaviour was more common during winter. Depth time series data further revealed inverted day-night patterns for both of these periods. Tagged ABFT frequented the surface waters more regularly during daytime and deeper waters during the night in summer, while the opposite pattern was found in winter. Seasonal changes in the vertical behaviour of ABFT were accompanied by simultaneous changes in environmental conditions (SST, chla, thermal stratification). Accordingly, surface orientation and moderate diving behaviour appeared to be triggered by the thermal stratification of the water column, though less pronounced than previously reported for ABFT in the North Atlantic, probably indicating adaptive vertical behaviour related to the availability of epipelagic food resources (anchovies and sardines). Deep diving behaviour was particularly frequent during months of high biological productivity (February-May), although one recovered tag showed periodic and unusual long spike dives during summer-autumn, in relation to thermal fronts. Regional effects on the vertical behaviour of ABFT were identified through GAMs, with surface orientation being particularly pronounced in the Gulf of Lions, highlighting its suitability for an ongoing annual aerial survey program to estimate ABFT abundance in this region. In addition, increased levels of mesoscale activity/productivity (e.g. related to oceanic fronts) were detected in an area regularly utilized by ABFT, south of the Gulf of Lions, underlining its attractiveness as foraging ground. Kernel densities of geolocation estimates showed a seasonal shift in the horizontal distribution of ABFT from this “high-use” area towards the Gulf of Lions during summer, probably linked to the enhanced availability of epipelagic food resources at this time.  
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  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Abundance, distribution and habitats of Atlantic and Mediterranean marine megafauna Titre de collection Abrégé  
  Volume de collection 141 Numéro de collection Edition  
  ISSN 0967-0645 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2166  
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