Direction des Etudes et de la Recherche

Nantes, France

Direction des Etudes et de la Recherche

Nantes, France
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Peron G.,CNRS Center of Evolutionary and Functional Ecology | Peron G.,Utah State University | Ferrand Y.,Direction des Etudes et de la Recherche | Gossmann F.,Office National de la Chasse et de la Faune Sauvage | And 3 more authors.
Behavioral Ecology and Sociobiology | Year: 2011

During unpredictable adverse conditions, endotherms can engage in emergency behaviors (movement, torpor, hyperphagia) to maintain energy balance and reduce mortality hazards. Bird "escape migration" is one of the most visible of these behaviors. In this study, we focus on a Eurasian Woodcock Scolopax rusticola population. Seasonal migrations bring this population from its breeding grounds in Eastern and Northern Europe to its wintering grounds in France. A varying number of these birds are also regularly reported from Spain, supposedly during additional escape movements that occur in winter. Using models that account for the imperfect detection rate of individuals and a large (>44,000 individuals) dataset combining information from the wintering and breeding ranges, we show that severe winters significantly reduced survival probability, but that migration to Spain increased only during the most intense cold spell that occurred over the 20-year study period. This suggests that the decision to resume migration during the winter is submitted to a threshold mechanism, which we discuss in the light of current models of migratory behavior. © 2011 Springer-Verlag.

Beral M.,French National Institute for Agricultural Research | Rossi S.,Direction des Etudes et de la Recherche | Aubert D.,University of Reims Champagne Ardenne | Gasqui P.,French National Institute for Agricultural Research | And 9 more authors.
EcoHealth | Year: 2012

Toxoplasma gondii is a protozoan parasite infecting humans and animals. Wild boars Sus scrofa are a potential source of human infection and an appropriate biological model for analyzing T. gondii dynamics in the environment. Here, we aimed to identify environmental factors explaining the seroprevalence of toxoplasmosis in French wild boar populations. Considering 938 individuals sampled from 377 'communes', overall seroprevalence was 23% (95% confidence interval: [22-24]). Using a Poisson regression, we found that the number of seropositive wild boars detected per 'commune' was positively associated with the presence of European wildcats (Felis silvestris) and moderate winter temperatures.

Peron G.,CNRS Center of Evolutionary and Functional Ecology | Peron G.,Utah State University | Ferrand Y.,Direction des Etudes et de la Recherche | Choquet R.,CNRS Center of Evolutionary and Functional Ecology | And 7 more authors.
Population Ecology | Year: 2012

Spatial heterogeneity, especially in mortality risk, is a major factor shaping population dynamics. Here we study the impacts of spatial heterogeneity in hunting pressure on the demography of Eurasian woodcock Scolopax rusticola, a relatively long-lived migratory game bird. We develop capture-recapture-recovery models in which both seasonality and spatial variation in hunting pressure are accounted for, and fit them to individual-based data collected across the French wintering range (>44000 banded individuals) as well as recoveries from spring stopovers and breeding grounds in Europe. Our results quantify spatial variation in survival probability in the wintering areas. They highlight the role of source-sink dynamics involving juvenile settlement decisions, as well as the importance of mortality outside the winter quarters. We also discuss the impact of spatial heterogeneity for demographic parameter estimation and data collection at the range scale. © 2012 The Society of Population Ecology and Springer.

Dray S.,CNRS Biometry and Evolutionary Biology Laboratory | Royer-Carenzi M.,French National Center for Scientific Research | Calenge C.,Direction des etudes et de la recherche
Ecological Research | Year: 2010

Studies of animal movements have been popularized for many large and shy species by the increasing use of radio telemetry methods (VHF and GPS technologies). Data are collected with high sampling frequency, and consist of successive observations of the position of an individual animal. The statistical analysis of such data poses several problems due to the lack of independence of successive observations. However, the statistical description of the temporal autocorrelation between successive steps is rarely performed by ecologists studying the patterns of animals movements. The aim of this paper is to warn ecologists against the consequences of failing to consider this aspect. We discuss the various issues related to analyzing autocorrelated data, and show how the exploratory analysis of autocorrelation can both reveal important biological insights and help to improve the accuracy of movement models. We suggest some tools that can be used to measure, test, and adjust for temporal autocorrelation. A short ecological illustration is presented. © 2010 The Ecological Society of Japan.

Broyer J.,Direction des Etudes et de la Recherche | Curtet L.,Direction des Etudes et de la Recherche | Boissenin M.,Direction des Etudes et de la Recherche
Journal of Ornithology | Year: 2012

Agri-environment schemes usually assume that suitable management in patches of grassland habitat may benefit bird populations in improving the overall demographic balance. In this study, we investigate the hypothesis that nesting site fidelity after previous breeding success might lead meadow birds to select late mown fields where the risk of breeding failure is lower. It was carried out in 4 study areas of the Mézenc volcanic massif (south-east of France) within the altitude range 1,150-1,350 m. Meadow passerine territories were defined by the territory mapping method, and reproductive success in Whinchat Saxicola rubetra territories was assessed by the observation of prey carrying and juveniles just leaving nests. A comparison of models led us to consider that territorial birds selected hay fields under the influence of grass structure rather than through a theoretical successful experience of late mowing. Higher territory density was observed in fields with dense grass cover ≥50 cm which were usually more fertilized (>75 kg ha -1 nitrogen per year) and mown earlier. In 3 study sites, however, the rate of nesting failure due to mowing was lower than expected under the hypothesis of randomly distributed nesting sites, suggesting that the risk was not ignored by territorial birds. Within each study site, we also observed higher invertebrate abundance during the chick feeding period in fields with high bird territory density. © Dt. Ornithologen-Gesellschaft e.V. 2012.

Marchandeau S.,Direction des Etudes et de la Recherche | Bertagnoli S.,University Paul Sabatier | Leonard Y.,Direction des Etudes et de la Recherche | Santin-Janin H.,University of Lyon | And 3 more authors.
Polar Biology | Year: 2010

Antibodies raised against a Lagovirus were found in healthy rabbits Oryctolagus cuniculus sampled in 2003 and 2004 in the Kerguelen archipelago. The serological test we used enabled the detection of antibodies due to both pathogenic and non-pathogenic viruses related to the rabbit haemorrhagic disease virus (RHDV). The overall proportion of seropositive rabbits was 35% and differed between sites. Since previous studies have failed to detect antibodies raised against pathogenic RHDV strains, the antibodies detected in the present study were likely due to non-pathogenic strains. The interest of these strains circulating in the Kerguelen archipelago is that they have evolved independently of those detected in the other parts of the world and should derive from an ancestral RHDV precursor. Their characterization may help understanding the evolution of the virus and the emergence of the disease. © 2010 Springer-Verlag.

Lesage C.,University of Reims Champagne Ardenne | Jouet D.,University of Reims Champagne Ardenne | Patrelle C.,University of Reims Champagne Ardenne | Guitton J.-S.,Office National de la Chasse et de la Faune Sauvage | And 2 more authors.
Parasitology Research | Year: 2014

Pulmonary protostrongyliasis of hare is a parasitic disease caused by nematodes belonging to the genus Protostrongylus (Nematoda, Protostrongylidae). During survey of wildlife disease in the South-East of France, pathologic examination of lungs from European hares found dead or hunter-killed between 2009 and 2012 was performed. Adult male worms were morphologically characterized and the identification confirmed by molecular biology (D2 domain of the 28S and ITS2 of rDNA). Two different species were identified: the first one, Protostrongylus pulmonalis, is identical with the haplotype previously deposited in GenBank. Based on morphological criteria of copulatory bursa of adult male worms (especially length of spicules and gubernaculum structure), we identified a second species found in France as Protostrongylus oryctolagi. This is the first report of P. oryctolagi in France from European hare and rabbit. P. oryctolagi was isolated from 248 hares and 3 rabbits in the South of France. P. pulmonalis was isolated from four hares found dead in the Northern France and from one hare in the South, which was co-parasitized by P. oryctolagi and P. pulmonalis. It's the first coinfection observed with these two species from a lung of hare in France. © 2014 Springer-Verlag.

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