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Avis sur la proposition d'inscription du site "La Loire des confluences" au titre de la convention internationale dite de "Ramsar" sur les zones humides
No full textÀ propos de Cilix hispanica : présence en Indre-et-Loire et façon de le reconnaître plus facilement sur le terrain (Lepidoptera Drepanidae Drepaninae)
No full textInternational audienceThe presence of Cilix hispanica is reported for the first time in the Department of Indre-et-Loire. In addition, the authors reveal a new morphological feature that makes it possible to differentiate hispanica from the clear forms of glaucata without having to examine the genitalia or DNA barcodes. Moreover, a figure is provided for the holotype and the two paratypes of Cilix algirica.La présence de Cilix hispanica est signalée pour la première fois dans le département de l’Indre-et-Loire. En outre, les auteurs dévoilent un caractère morphologique inédit permettant de différencier de manière certaine hispanica des formes claires de glaucata sans avoir recours à l’examen des genitalia ni des codes-barres ADN. Par ailleurs, l’holotype et les deux paratypes de Cilix algirica sont figurés
L’empreinte carbone des méthodes d’inventaire de diatomées : la microscopie plus durable que le métabarcoding
No full textL’impact environnemental de la recherche scientifique est une question peu abordée, en particulier à l’échelle des processus. Dans ce travail, nous comparons le bilan carbone de deux méthodes utilisées pour réaliser des inventaires en fréquence relative de taxons de diatomées, à des fins de recherche en écologie ou d’évaluation environnementale. La première méthode repose sur la microscopie optique et la seconde méthode sur le métabarcoding de l’ADN environnemental. Les bilans carbones des deux processus ont été réalisés selon le principe de la méthode Bilan Carbone développée par l’ADEME. Celle-ci est conçue à la base pour réaliser le décompte des émissions de structures entières (entreprise, associations, régions, etc.), aussi, elle a été adaptée afin de permettre le comptage des émissions à l’échelle de l’échantillon, de son prélèvement jusqu’au résultat d’inventaire. Cinq postes d’émissions sont pris en compte : les déplacements, l’énergie consommée, le traitement des déchets, l’achat de réactifs et composants à usage unique, et l’utilisation d’équipement réutilisable (immobilisation). Les résultats montrent que les émissions de GES de l’approche par ADNe sont pratiquement 10 fois plus importantes que pour la microscopie. Ces résultats sont à conforter sur un jeu de données plus important, après correction d’erreurs résiduelles dans l’outil de calcul
Acoustic detection of a nocturnal bird with deep learning: the challenge of low signal-to-noise ratio
No full textInternational audienc
When invasion is faster than science: the long story of the flatworm who travelled across oceans
No full textInternational audienceBoth scientific and policy recommendations on marine non-indigenous species agree on the importance of a rapid detection and identification of species, for a rapid action. But sometimes, detection can just be the beginning of a long investigation, longer than the invasion of the species. In 2020, oyster farmers of the Arcachon Bay (France) noted the presence of a polyclad in cultivated oysters (Magallana gigas). Rapidly, special attention was paid to it because of its potential predatory behavior on bivalves. Because of its absence from public barcode databases until 2023 and from available identification keys, it was described as a new species (Idiostylochus tortuosus) while keeping in mind the high probability to be an introduced non-indigenous species. After several months of investigation, mainly based on molecular markers, the presence of this polyclad in Pacific areas (Australia and Japan)supported this status and finally allowed its identification as Postenterogonia orbicularis described from New-Zealand. Meanwhile, the species took the opportunity to proliferate both in terms of spatial expansion and population densities.This poster aimed to detail the investigation about this traveler polyclad and first results of population dynamic in the Arcachon Bay, acquired during two successive projects, RAPSODI (IFREMER) and VISQUEUX (FEAMPA-OFB)
Soft Range Limits Shape Sensitivity to Forest Cover More Strongly Than Hard Range Limits
No full textInternational audienceLand-use change is a major threat to biodiversity, yet there remains considerable unexplained variation in how it affects different populations of the same species. Here, we examine how sensitivity to forest cover changes depending on proximity to different limits of a species' range. By comparing responses as species approach their coastal ('hard') and inland ('soft') range limits, we aim to provide insight into the relative influence of mass effects, as compared to abiotic and biotic environmental suitability in shaping population sensitivity
Faut-il maximiser la diversité des espèces de couverts pour améliorer la régulation des adventices ?
No full textNational audienc
Female Embryos Are More Likely to Die than Males in a Wild Mammal
No full textInternational audienceBiased birth sex ratios have been documented in many mammalian populations, but it is often difficult to know whether they result from biases in the sex ratio at conception and/or sex differences in prenatal mortality. It is generally admitted that there is an excess of males at conception and a higher level of mortality during gestation for males because of a positive relationship between size and vulnerability. Here, we challenge this classical prediction in a wild boar (Sus scrofa) population facing highly variable food resources (mast seeding) and in which male fetuses are heavier than females. Using long-term hunting and mast seeding data, we show that sex ratio at conception is balanced and that females suffer from higher embryonic mortality particularly in large litters, whatever the level and the type of food resources. One possible explanation is that a female embryo is ready for implantation later than an identically aged male because of slower development and is more likely to miss the implantation window. To what extent a lower survival of female embryos is a common feature in mammals remains to be carefully explored
Functionalities of protected areas for wintering and migratory shorebirds (FONPAL)
No full textInternational audienceMetropolitan France is known for hosting many waterbirds – especially shorebirds - during migration and wintering. Preserving the disturbance-free habitats for these species is of primary importance. Protected areas play a key role. The regulations for these areas protect these species during this particular period of their biological cycle. Nevertheless, limits have been identified in the network of protected areas regarding their ability to cover all the functional needs of birds (resting, feeding), and more generally regarding their effectiveness, particularly at the periphery. The FONPAL programme was therefore set up to help managers understand how to use their area