Hanging out at the club: Breeding status and territoriality affect individual space use, multi‐species overlap and pathogen transmission risk at a seabird colony

1. Wildlife movement ecology often focuses on breeders, whose territorial attachments facilitate trapping and following individuals over time. This leads to incomplete understanding of movements of individuals not actively breeding due to age, breeding failure, subordinance, and other factors. These individuals are often present in breeding populations and contribute to processes such as competition and pathogen spread. Therefore, excluding them from movement ecology studies could bias or mask important spatial dynamics. 2. Loafing areas offer an alternative to breeding sites for capturing and tracking individuals. Such sites may allow for sampling individuals regardless of breeding status, while also avoiding disturbance of sensitive breeding areas. However, little is known about the breeding status of individuals attending loafing sites, or how their movements compare to those of breeders captured at nests. 3. We captured a seabird, the brown skua, attending either nests or loafing areas (‘clubs’) at a multi-species seabird breeding site on Amsterdam Island (southern Indian Ocean). We outfitted skuas with GPS-UHF transmitters and inferred breeding statuses of individuals captured at clubs using movement patterns of breeders captured at nests. We then compared space use and activity patterns between breeders and nonbreeders. 4. Both breeding and nonbreeding skuas attended clubs. Nonbreeders ranged more widely, were more active, and overlapped more with other seabirds and marine mammals than did breeders. Moreover, some nonbreeders occupied fixed territories and displayed more restricted movements than those without territories. Nonbreeders became less active over the breeding season, while activity of breeders remained stable. Nonbreeding skuas were exposed to the agent of avian cholera at similar rates to breeders but were more likely to forage in breeding areas of the endangered endemic Amsterdam albatross, increasing opportunities for interspecific pathogen transmission. 5. Our results show that inference based only on breeders fails to capture important aspects of population-wide movement patterns. Capturing nonbreeders as well as breeders would help to improve population-level representation of movement patterns, elucidate and predict effects of external changes and conservation interventions (e.g. rat eradication) on movement patterns and pathogen spread, and develop strategies to manage outbreaks of diseases such as highly pathogenic avian influenza

The "pied de cuve" as an alternative way to manage indigenous fermentation: impact on the fermentative process and Saccharomyces cerevisiae diversity

Winemakers are increasingly keen to limit the use of commercial yeasts in order to reduce oenological inputs. The preparation of an indigenous winery-made fermentation starter from grapes called 'pied de cuve' (PdC) is becoming popular, especially in organic farming systems. However, the implementation of the PdC method is still empirical and knowledge is lacking regarding the impact of PdC on S. cerevisiae diversity during alcoholic fermentation. In this study, the impact of PdC on S. cerevisiae genetic diversity and wine composition was evaluated at an industrial scale. Despite very low initial population level of S. cerevisiae before inoculation, the use of PdC was as efficient as Active Dry Yeast in terms of fermentation kinetics and chemical analyses on the resulting wines, except for one modality. At mid-fermentation, the diversity of S. cerevisiae strains was different depending on the PdC used, and was also different from that in the spontaneous fermentation with, in some cases, clonal expansion. Our results provide evidence that the use of PdC could secure the fermentation process more efficiently than spontaneous fermentation

Data from: Habitat specialization predicts genetic response to fragmentation in tropical birds

Habitat fragmentation is one of the most severe threats to biodiversity as it may lead to changes in population genetic structure, with ultimate modifications of species evolutionary potential and local extinctions. Nonetheless, fragmentation does not equally affect all species and identifying which ecological traits are related to species sensitivity to habitat fragmentation could help prioritization of conservation efforts. Despite the theoretical link between species ecology and extinction proneness, comparative studies explicitly testing the hypothesis that particular ecological traits underlies species-specific population structure are rare. Here, we used a comparative approach on eight bird species, co-occurring across the same fragmented landscape. For each species, we quantified relative levels of forest specialization and genetic differentiation among populations. To test the link between forest specialization and susceptibility to forest fragmentation, we assessed species responses to fragmentation by comparing levels of genetic differentiation between continuous and fragmented forest landscapes. Our results revealed a significant and substantial population structure at a very small spatial scale for mobile organisms such as birds. More importantly, we found that specialist species are more affected by forest fragmentation than generalist ones. Finally, our results suggest that even a simple habitat specialization index can be a satisfying predictor of genetic and demographic consequences of habitat fragmentation, providing a reliable practical and quantitative tool for conservation biology

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Des outils pour fiabiliser les fermentations des vins et cidres biologiques en utilisant les levures et bactéries indigènes

Ce numéro comprend les articles correspondant aux présentations du Colloque Casdar 2018.With the development of organic wines and ciders, there is a real tendency to carry out spontaneousfermentations, which involve the development of indigenous yeasts and bacteria. Indeed, thesemicroorganisms are sometimes considered as components of the terroir that participate in the typicity ofwines and ciders. However, no scientific knowledge allows us to assert such a specificity, while the lackof control of these microorganisms can lead to difficulties of fermentation, aromatic deviations oralterations. The project CASDAR Levains Bio relied on a network of laboratories, technical institutes andassociations of organic producers to provide the necessary knowledge and practical solutions forcarrying out indigenous fermentations with a good level of control. It has been shown that there is awide diversity of strains of the yeast Saccharomyces cerevisiae and the lactic acid bacteriumOenococcus oeni, that strains are genetically adapted to certain products, but not to regions orproduction sites. Protocols have been developed to allow for the selection of strains from farms or forthe production of "pieds de cuve". Some of the solutions have been successfully transferred toproducers.Avec le développement des vins et cidres bio, on observe une vraie tendance à la réalisation defermentations spontanées, en laissant se développer les levures et bactéries indigènes. En effet, cesmicroorganismes sont parfois considérés comme des éléments du terroir qui participent à la typicité desvins et des cidres. Pourtant, aucune connaissance scientifique ne permet d’affirmer une telle spécificité,alors que la non-maîtrise de ces microorganismes peut conduire à des difficultés de fermentation, desdéviations aromatiques ou des altérations. Le projet Casdar Levains Bio s’est appuyé sur un réseau delaboratoires, instituts techniques et associations de producteurs bio pour apporter les connaissancesnécessaires et des solutions pratiques pour réaliser des fermentations indigènes avec un bon niveau demaîtrise. Il a été montré qu’il existe une grande diversité de souches de la levure Saccharomycescerevisiae et de la bactérie lactique Oenococcus oeni, que des souches sont génétiquement adaptées àcertains produits, mais pas à des régions ou à des sites de production. Des protocoles ont été mis aupoint pour permettre de sélectionner des souches issues des exploitations ou pour réaliser des pieds decuve de microorganismes indigènes. Certaines des solutions ont été transférées avec succès auprèsdes producteurs

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Avec le développement des vins et cidres bio, on observe une vraie tendance à la réalisation de fermentations spontanées, en laissant se développer les levures et bactéries indigènes. En effet, ces microorganismes sont parfois considérés comme des éléments du terroir qui participent à la typicité des vins et des cidres. Pourtant, aucune connaissance scientifique ne permet d’affirmer une telle spécificité, alors que la non-maîtrise de ces microorganismes peut conduire à des difficultés de fermentation, des déviations aromatiques ou des altérations. Le projet Casdar Levains Bio s’est appuyé sur un réseau de laboratoires, instituts techniques et associations de producteurs bio pour apporter les connaissances nécessaires et des solutions pratiques pour réaliser des fermentations indigènes avec un bon niveau de maîtrise. Il a été montré qu’il existe une grande diversité de souches de la levure Saccharomyces cerevisiae et de la bactérie lactique Oenococcus oeni, que des souches sont génétiquement adaptées à certains produits, mais pas à des régions ou à des sites de production. Des protocoles ont été mis au point pour permettre de sélectionner des souches issues des exploitations ou pour réaliser des pieds de cuve de microorganismes indigènes. Certaines des solutions ont été transférées avec succès auprès des producteurs. | With the development of organic wines and ciders, there is a real tendency to carry out spontaneous fermentations, which involve the development of indigenous yeasts and bacteria. Indeed, these microorganisms are sometimes considered as components of the terroir that participate in the typicity of wines and ciders. However, no scientific knowledge allows us to assert such a specificity, while the lack[br/] of control of these microorganisms can lead to difficulties of fermentation, aromatic deviations or alterations. The project CASDAR Levains Bio relied on a network of laboratories, technical institutes and associations of organic producers to provide the necessary knowledge and practical solutions for carrying out indigenous fermentations with a good level of control. It has been shown that there is a wide diversity of strains of the yeast Saccharomyces cerevisiae and the lactic acid bacterium Oenococcus oeni, that strains are genetically adapted to certain products, but not to regions or production sites. Protocols have been developed to allow for the selection of strains from farms or for the production of "pieds de cuve". Some of the solutions have been successfully transferred to producers

Wine yeast phenomics: A standardized fermentation method for assessing quantitative traits of Saccharomyces cerevisiae strains in enological conditions

This work describes the set up of a small scale fermentation methodology for measuring quantitative traits of hundreds of samples in an enological context. By using standardized screw cap vessels, the alcoholic fermentation kinetics of Saccharomyces cerevisiae strains were measured by following their weight loss over the time. This dispositive was coupled with robotized enzymatic assays for measuring metabolites of enological interest in natural grape juices. Despite the small volume used, kinetic parameters and fermentation end products measured are similar with those observed in larger scale vats. The vessel used also offers the possibility to assay 32 volatiles compounds using a headspace solid-phase micro-extraction coupled to gas chromatography and mass spectrometry. The vessel shaking applied strongly impacted most of the phenotypes investigated due to oxygen transfer occuring in the first hours of the alcoholic fermentation. The impact of grape must and micro-oxygenation was investigated illustrating some relevant genetic x environmental interactions. By phenotyping a wide panel of commercial wine starters in five grape juices, broad phenotypic correlations between kinetics and metabolic end products were evidentiated. Moreover, a multivariate analysis illustrates that some grape musts are more able than others to discriminate commercial strains since some are less robust to environmental changes