Bretagne Vivante SEPNB


Bretagne Vivante SEPNB


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Barbraud C.,CNRS Chizé Center for Biological Studies | Fortin M.,Bretagne Vivante SEPNB | Charbonnier Y.,Bretagne Vivante SEPNB | Charbonnier Y.,French National Institute for Agricultural Research | And 4 more authors.
Ardeola | Year: 2014

We compared the performances of the strip transect count method and the distance sampling method during colony surveys of large gulls to estimate the total number of nests. Ten colonies were surveyed by both methods. Nest detection probabilities varied from 0.519 ± 0.064 to 0.706 ± 0.049 and the average nest detection probability was 0.614 ± 0.015. Nest densities were highly variable, ranging from 77 nests/ha to 717 nests/ha. Estimates of the number of nests obtained by the strip transect count method averaged 9.3% lower than those obtained by distance sampling but by as much as 31% in some colonies. Underestimation by the strip transect counts increased at high nest densities (Kendall t = -0.556, P = 0.032). The strip transect method needed on average 6.5 observers per colony surveyed, whereas the distance sampling method required 1.4 observers per colony. In addition, the mean time spent per colony was 3 hours vs 1.7 hours for the strip transect and distance sampling methods respectively. Combining both these measures of effort, distance sampling required on average 87% less effort in the field than the strip transect method. We strongly advocate the use of distance sampling for surveys of large gull colonies.

Puechmaille S.J.,University College Dublin | Puechmaille S.J.,Conway Institute of Biomolecular and Biomedical Research | Wibbelt G.,Leibniz Institute for Zoo and Wildlife Research | Korn V.,Office for Faunistic and Landscape Ecology | And 25 more authors.
PLoS ONE | Year: 2011

Background: The dramatic mass mortalities amongst hibernating bats in Northeastern America caused by "white nose-syndrome" (WNS) continue to threaten populations of different bat species. The cold-loving fungus, Geomyces destructans, is the most likely causative agent leading to extensive destruction of the skin, particularly the wing membranes. Recent investigations in Europe confirmed the presence of the fungus G. destructans without associated mass mortality in hibernating bats in six countries but its distribution remains poorly known. Methodology/Principal Findings: We collected data on the presence of bats with white fungal growth in 12 countries in Europe between 2003 and 2010 and conducted morphological and genetic analysis to confirm the identity of the fungus as Geomyces destructans. Our results demonstrate the presence of the fungus in eight countries spanning over 2000 km from West to East and provide compelling photographic evidence for its presence in another four countries including Romania, and Turkey. Furthermore, matching prevalence data of a hibernaculum monitored over two consecutive years with data from across Europe show that the temporal occurrence of the fungus, which first becomes visible around February, peaks in March but can still be seen in some torpid bats in May or June, is strikingly similar throughout Europe. Finally, we isolated and cultured G. destructans from a cave wall adjacent to a bat with fungal growth. Conclusions/Significance: G. destructans is widely found over large areas of the European continent without associated mass mortalities in bats, suggesting that the fungus is native to Europe. The characterisation of the temporal variation in G. destructans growth on bats provides reference data for studying the spatio-temporal dynamic of the fungus. Finally, the presence of G. destructans spores on cave walls suggests that hibernacula could act as passive vectors and/or reservoirs for G. destructans and therefore, might play an important role in the transmission process. © 2011 Puechmaille et al.

Jiguet F.,CNRS Science Conservation Center | Chiron F.,CNRS Science Conservation Center | Dehorter O.,CNRS Science Conservation Center | Dugue H.,Association ACROLA | And 9 more authors.
Acta Ornithologica | Year: 2011

The autumn world population of the endangered Aquatic Warbler Acrocephalus paludicola probably numbers between 23 000 and 69 000 individuals, including 5 000 to 44 000 first-year individuals, depending on variation in breeding success and post-fledging survival. After breeding, the species migrates as early as August along a westerly route along French coast to reach its African wintering grounds. In 2009, French ringers have carried out targeted mist-netting to enhance the capture of the species, using tape luring in suitable habitats. Overall, 874 different individuals were captured in France in that year. In 2010 similar ringing effort allowed the capture of 646 different individuals. From this ringing information, we propose a simple method to estimate the number of individuals which stopped in the country during the autumn migration, considering all birds or first-years only. Splitting the country in two parts (northern and southern), the method uses the total number of captures and the number of southern recaptures of birds first ringed in the north. Overall, we estimated that between 24 000 and 30 000 individuals most of them in their first calendar year stop in France each year during the fall migration. These estimates suggest that probably all first-year Aquatic Warblers migrate by this western flyway and stop in France to refuel, while adults may partly use a different flyway or may stop in France, but for shorter times or at fewer sites. The proposed figures highlight the importance of maintaining suitable refuelling habitats for the species all along coastal France.

The worldwide threatened Aquatic Warbler (IUCN red list) has a memorandum of understanding concerning conservation measures since 2003. As nearly the whole population of Aquatic Warbler migrates during postnuptial migration across Western France, this country initiated a National Action Plan for the years 2010 to 2014 in order to preserve and to increase the availability of suitable habitats for this species. The whole Atlantic coastland and the Rhone valley are concerned by this National Action Plan. Most of the areas used by the species are now identified and habitat protection measures are carried out. The improvement of knowledge on the migration patterns are performed by studies on ringed birds. The availability of suitable habitats and their protection deserve a special emphasis.

Alves J.A.,University of East Anglia | Gunnarsson T.G.,University of Iceland | Potts P.M.,Farlington Ringing Group | Gelinaud G.,Bretagne Vivante SEPNB | And 2 more authors.
Oikos | Year: 2012

For many migratory bird species, the latitudinal range of the winter distribution spans thousands of kilometres, thus encompassing considerable variation in individual migration distances. Pressure to winter near breeding areas is thought to be a strong driver of the evolution of migration patterns, as individuals undertaking a shorter migration are generally considered to benefit from earlier arrival on the breeding grounds. However, the influence of migration distance on timing of arrival is difficult to quantify because of the large scales over which individuals must be tracked. Using a unique dataset of individually-marked Icelandic black-tailed godwits Limosa limosa islandica tracked throughout the migratory range by a network of hundreds of volunteer observers, we quantify the consequences of migrating different distances for the use of stop-over sites and timing of arrival in Iceland. Modelling of potential flight distances and tracking of individuals from across the winter range shows that individuals wintering further from the breeding grounds must undertake a stop-over during spring migration. However, despite travelling twice the distance and undertaking a stop-over, individuals wintering furthest from the breeding grounds are able to overtake their conspecifics on spring migration and arrive earlier in Iceland. Wintering further from the breeding grounds can therefore be advantageous in migratory species, even when this requires the use of stop-over sites which lengthen the migratory journey. As early arrival on breeding sites confers advantages for breeding success, the capacity of longer distance migrants to overtake conspecifics is likely to influence the fitness consequences of individual migration strategies. Variation in the quality of wintering and stopover sites throughout the range can therefore outweigh the benefits of wintering close to the breeding grounds, and may be a primary driver of the evolution of specific migration routes and patterns. © 2011 The Authors. Oikos © 2012 Nordic Society Oikos.

Cadiou B.,Bretagne Vivante SEPNB | Bioret F.,University of Western Brittany | Chenesseau D.,Bretagne Vivante SEPNB
Journal of Ornithology | Year: 2010

Mainly through trampling and manuring, ground-nesting seabirds induced significant habitat changes both on vegetation cover and soil in one of the largest French colonies of European Storm Petrel Hydrobates pelagicus, Habitat deterioration led to a high level of erosion and the collapse of many former Rabbit Oryctolagus cuniculus burrows previously occupied by breeding Storm Petrels. The loss of burrows accelerated in recent years since Great Cormorants Phalacrocorax carbo bred on the islet with growing numbers. The main consequence of this disturbance was at first shifting of breeding Storm Petrels from burrows to rocky sites, reflecting some behavioral plasticity to buffer environmental variability. But over 18 years, a significant decrease in breeding numbers of Storm Petrels was recorded and attributed to continuous nest site destruction. Thus, other behavioral responses were also suspected, such as temporary non-breeding or emigration of birds that have to find a new nest site. Such a problem of heavy erosion and loss of nesting habitat could induce serious detrimental effects on burrowing seabirds breeding in a limited number of colonies. © 2009 Dt. Ornithologen-Gesellschaft e.V.

Sirot E.,CNRS Ecosystems, Biodiversity, and Evolution Laboratory | Maes P.,University of Southern Brittany | Gelinaud G.,Bretagne Vivante SEPNB
Ethology | Year: 2012

We studied movements and conflicts within a small flock of free-living black-tailed godwits foraging on benthic invertebrates in a brackish lagoon. To interpret our results in the framework of foraging theory, we studied the influence of individual feeding rate on the decisions to move and to attack flock companions. Birds changed their position within the flock more often when their intake rate was low and sometimes attacked conspecifics to supplant them from their feeding place. Aggressors significantly avoided front attacks and were almost always successful. They attacked individuals having higher feeding rates than themselves and their own feeding rate significantly increased after the attack, although victims were not chased off to particularly poor sites. Our results suggest that aggressors could obtain reliable information about the quality of the foraging site they coveted by observing their victim's feeding activity before attacking. Although aggression seemed to be caused by a low intake rate, we show that displacing another bird was more time-consuming than independent foraging. We conclude that it was not the most profitable behaviour in terms of energy intake. Foraging site displacement probably also had social functions, such as reinforcement of social status in a flock of birds preparing for pre-breeding migration. © 2011 Blackwell Verlag GmbH.

The Kentish Plover is usually an open nesting species. But some sheltered nesting sites were already recorded in Brittany particularly on islands. During the breeding season of 2015, we found two sheltered nestings at Mouton Island (Glenan Archipelago, Brittany, France). © La reproduction totale est interdite sans autorisation de l'éditeur. © J. Guillaumot.

Hundreds of Common Eiders winter along the French coast and there is also a small breeding population, these birds being considered as sedentary. After a period of occasional breeding in the Bay of Biscay from the beginning of the 20th century, a marked increase occurred in the early 1990s. A maximum of 24 breeding pairs were recorded in spring 1999 on different islands located in Morbihan, Loire-Atlantique, Vendée and Gironde. The Erika oil spill in December 1999 off Southern Brittany led to heavy pollution of the coast for several months and not any case of breeding was recorded in 2000. The local breeding population was probably killed by oil. Since then, few indices of breeding have been recorded, with a first one in 2003 in Vendée, a second one in Morbihan in 2006 and other suspected or proven cases in recent years. Ten years after the oil spill there is no restoration of the previous local breeding population.

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