55 research outputs found

    Bat Conservation Management in Exploited European Temperate Forests

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    Forests offer important refuge to bats by providing attractive roosting and foraging habitats. Their conservation is a major responsibility of forest managers. The use of tree cavities by bats in forests depends on the specific demands of each species, with a large range of different types of microhabitats utilised, from degraded cavities such as peeling bark to healthy hollows in live trees ensuring the temporal stability of the habitat. The conservation of tree-dwelling bats should not be dissociated from their fission-fusion behaviour which involves the use of many different roosts. Conservation measures must therefore take into account forest habitats suitable for feeding and in particular, forest parameters such as structure, composition, vegetation and foliage, among other elements such as deadwood, all upon which the forest manager can intervene. Acting in favour of bats requires close consideration of their complex individual responses concerning roost selection and foraging habitat selection, which is largely dictated by the reproductive status of individuals. Thereafter it is possible to evaluate the impact of wood harvesting on bats and to infer silvicultural conservation measures. The implementation of recommendations must then subsequently be based on a strong involvement on the part of the forest manager

    Annual activity cycle of bats in Bou-Hedma National Park (Tunisia)

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    La capture mensuelle des ChiroptĂšres dans six des principaux habitats du Parc National de Bou-Hedma sur une pĂ©riode de 26 mois a permis d’inventorier sept espĂšces, assez largement rĂ©pandues au Maghreb, Ă  l’exception de la saharienne Otonycteris hemprichii. Les bassins du Bordj et de Nouh sont les plus attractifs, surtout au dĂ©but de l’étĂ©, l’oued Bou-Hedma est beaucoup moins frĂ©quentĂ©, surtout en hiver. Aucune capture n’a Ă©tĂ© rĂ©alisĂ©e dans la steppe et dans les forĂȘts claire et dense d’acacias, ce qui confirme l’attractivitĂ© des plans d’eau pour toutes les espĂšces dans la rĂ©gion mĂ©diterranĂ©enne. Une activitĂ© hivernale a Ă©tĂ© mise en Ă©vidence et la pĂ©riode de reproduction de Pipistrellus kuhlii et Eptesicus isabellinus, qui correspond au pic de captures, a Ă©tĂ© prĂ©cisĂ©e.Bats were mist-netted in six main habitats of the Bou-Hedma National Park over two years. Most of the seven recorded species are widely distributed in northwestern Africa, except the Saharan Otonycteris hemprichii. Basins of Bordj and Nouh were the most attractive for bats, mainly in early summer. Oued Bou-Hedma was less attractive, particularly in winter. No bat was mist-netted in the steppe and the two types of Acacia forest, which supports the major role of water bodies in the Mediterranean area. Winter activity of bats was detected and tentatively quantified. Also informative is the fact that captures peaked when most Pipistrellus kuhlii and Eptesicus isabellinus were pregnant or lactating

    Évaluation des dĂ©penses Ă©nergĂ©tiques au quotidien chez les ongulĂ©s sauvages in natura : analyse bibliographique des Ă©lĂ©ments disponibles pour une approche additive

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    Les dĂ©penses Ă©nergĂ©tiques des ongulĂ©s sauvages in natura doivent souvent ĂȘtre quantifiĂ©es par une approche indirecte qui les dĂ©compose en coĂ»ts : (i) de base, (ii) de thermorĂ©gulation, (iii) d'alimentation, (iv) de posture debout et d'activitĂ©, (v) de croissance et de reproduction. Les dĂ©penses « au quotidien », objet de cette synthĂšse, correspondent aux quatre premiers compartiments; les donnĂ©es bibliographiques correspondantes, mesures, estimations et prĂ©dictions, sont rapportĂ©es et comparĂ©es; leurs conditions et limites d'utilisation sont discutĂ©es. Le niveau de base (sans thermorĂ©gulation, ni activitĂ©) devrait ĂȘtre estimĂ© par le mĂ©tabolisme dit « Standard » ou « de Base », dĂ©licat Ă  mesurer, mĂȘme en laboratoire, sur les animaux sauvages. C'est pourquoi d'autres estimations, plus ou moins assimilables Ă  un mĂ©tabolisme dit « de Repos », sont habituellement utilisĂ©es, bien que cette approche puisse ĂȘtre considĂ©rĂ©e comme moins rigoureuse. La formule de Kleiber (1961) prĂ©dit le mĂ©tabolisme standard d'animaux adultes, MammifĂšres et Oiseaux principalement, en fonction de leur masse corporelles; des prĂ©dictions plus prĂ©cises ont Ă©tĂ© mises au point, mais pour des catĂ©gories (d'espĂšce, d'Ăąge, de sexe,...) particuliĂšres. La thermorĂ©gulation est le rĂ©sultat d'interactions complexes entre diverses caractĂ©ristiques environnementales (tempĂ©rature ambiante, humiditĂ©, vitesse du vent, rayonnement solaire) et de multiples paramĂštres relatifs Ă  l'animal (surface offerte, isolation corporelle, Ă©tat physiologique...). Si son coĂ»t peut ĂȘtre considĂ©rĂ© comme nul Ă  l'intĂ©rieur de ce qu'on appelle « zone de neutralitĂ© thermique » (ZNT), il augmente de part et d'autre, via la mise en Ɠuvre de mĂ©canismes physiologiques, chimiques et comportementaux trĂšs divers qui interviennent pour maintenir une tempĂ©rature corporelle acceptable. Les expĂ©rimentations permettant de dĂ©terminer la nature et le coĂ»t des mĂ©canismes mis en oeuvre exigent des sujets entraĂźnĂ©s et un dispositif expĂ©rimental assez lourd; la transposition qualitative aux animaux libres en nature est, dans une certaine mesure, possible, la transposition quantitative est difficile. Le coĂ»t total d'alimentation inclut les coĂ»ts de posture debout et de recherche alimentaire, ainsi que ceux, plus spĂ©cifiques, de prise alimentaire (i.e. prĂ©lĂšvement, mastication, dĂ©glutition), de digestion et Ă©ventuellement de rumination. La nature de l'aliment peut certes, chez tous les ongulĂ©s, influer assez fortement sur le coĂ»t de prise alimentaire, mais ce sont les dĂ©placements liĂ©s Ă  la recherche alimentaire qui gĂ©nĂšrent les dĂ©penses les plus importantes chez les animaux sauvages en nature. Les coĂ»ts de posture debout et de locomotion (composantes essentielles de l'activitĂ©) ont Ă©tĂ© quantifiĂ©s chez de nombreuses espĂšces en comparant le mĂ©tabolisme d'animaux debout et/ou en dĂ©placement Ă  celui d'animaux couchĂ©s. A partir de ces mesures, certains auteurs, Taylor et al. (1982) en particulier, ont proposĂ© des formules prĂ©dictives pour Ă©valuer le coĂ»t de locomotion en fonction de la masse corporelle. Des estimations de surcoĂ»t pour les dĂ©placements en terrain difficile (pente, obstacles, neige, boue) ont Ă©galement Ă©tĂ© rapportĂ©es. L'approche additive reste une modĂ©lisation dont la validitĂ© dĂ©pend largement de la qualitĂ© des estimations de dĂ©penses disponibles et de la prĂ©cision des paramĂštres d'activitĂ© recueillis sur les animaux cibles.Estimating the energy expenditures of wild ungulates in natura often requires an indirect approach splitting them within: (i) basal level, (ii) thermoregulation cast, (iii) feeding cast, (iv) standing and activity cast, (v) growth and reproduction cast. First, each of the costs can be measured (most often through respirometric technics) or estimated (from previously obtained values). Second, these amounts are summed up ("additive" approach) according to the activity budget of the animal. The present bibliographie review only deals with daily expenditures, namely costs (i) to (iv). Various measures (with comparative tables), estimations and [allometric] predictive equations are reported, and their accuracy and limits are discussed. Basal level (without thermoregulation and activity) should be estimated by Standard or Basal Metabolic Rate, but this is difficult to measure on wild animals, even in the laboratory. Other estimations, more or less close to Resting Metabolic Rate (RMR) are therefore often used, although they are Jess relevant. Kleiber' s equation (196 1 ) predicts the standard metabolism of adult animals, mainly mammals and birds, from their body mass; some more accurate models are available but for more limited species, age, sex, ... categories. Thermoregulation is the result of complex interactions between various environmental (air temperature, moisture, wind speed, solar radiation . . . ) and animal (body area, insulation, physiological condition, . . . ) parameters. Therefore, it is not possible to give more or less standardized costs as for other expenditures. Thermoregulation cast can be considered as null in the so called "Thermoneutral Zone, TNZ". It increases outside this zone because of various physiological, chemical and behavioural mechanisms acting to maintain acceptable deep body temperature. Determining the nature and measuring the cast of the involved mechanisms (which vary according to species, season, age and physical condition of animals) require experiments on trained animals and an heavy experimental device. Qualitative extent to ungulates in natura is somewhat possible, but quantitative extent is difficult. Total feeding cast includes standing and moving (food search) costs, and some more typical costs: "eating" (i.e. prehension, mastication and swallowing), digestion and possibly rumination. In all (domestic or wild) ungulates, the type of food consumed can modify the eating cast, but foraging trips (more or Jess inversely related to food availability) can obviously involve the most important incremental costs in wild ungulates. Standing and locomotion costs (the main components of activity costs) were quantified in various species by comparing the metabolism of lying, standing and moving animals. From these measures, some authors (particularly Taylor et al., 1982) modeled locomotion cast from body mass. Some estimations of incremental costs due to a difficult terrain (slope, obstacles, snow caver, mud) are also reported. The relevance of the additive approach in energetic studies mainly relies on the quality of the available measures or estimations of each cost and on the accuracy of the activity parameters that are obtained from target animals. Of the various expenditure components, locomotion appears to be the most suitable for comparative purposes; however, the accurate estimation of its cost requires data adequate to identify the right terrain used by the animals

    Novel insights into the diet of the Pyrenean desman (Galemys pyrenaicus) using next-generation sequencing molecular analyses

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    [Departement_IRSTEA]EauxInternational audienceThe Pyrenean desman, a threatened, semiaquatic mammal, is considered a specialist predator feeding on aquatic benthic invertebrates. This categorization comes from visual identification of prey in scat or gut contents, often based on a limited number of samples and locations. We combined diet analyses using next-generation sequencing methods with an extensive survey to explore the summer diet of Pyrenean desmans across the French Pyrenees. This study thus provides an unprecedented level of detail on the trophic ecology of Pyrenean desmans. Our results revealed a diverse diet containing a high proportion of rare prey and substantial consumption of terrestrial prey, which suggests a more generalist diet than previously understood. Three diet groups were identified, with significant differences in prey composition. These differences were not related to geographic location, but rather to local environmental variables. The spatial variation in diet was likely induced by local abiotic parameters that affect prey availability or use of foraging habitats

    Integrating hydrological features and genetically validated occurrence data in occupancy modeling of an endemic and endangered semi-aquatic mammal species, Galemys pyrenaicus, in a Pyrenean catchment

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    As freshwater habitats are among the most endangered, there is an urgent need to identify critical areas for conservation, especially those that are home to endangered species. The Pyrenean desman (Galemys pyrenaicus) is a semi-aquatic mammal whose basic ecological requirements are largely unknown, hindering adequate conservation planning even though it is considered as a threatened species. Species distribution modelling is challenging for freshwater species. Indeed, the complexity of aquatic ecosystems (e.g., linear and hierarchical ordering) must be taken into account as well as imperfect sampling. High-quality and relevant hydrological descriptors should also be used. To understand the influence of environmental covariates on the occupancy and detection of the Pyrenean desman, we combine both a robust sign-survey data set (i.e. with genetic validation ensuring true presence information) and a hydrological model to simulate the flow regime across a whole catchment. Markovian site-occupancy analysis, taking into account sign detection and based on spatially adjacent replicates, indicated a positive influence of heterogeneity of substrate and shelters, and a negative influence of flow variability on Pyrenean desman detection. This valuable information should help to improve monitoring programs for this endangered species. Our results also highlighted a spatially clustered distribution and a positive influence of stream flow and number of tributaries on occupancy. Hence, modifications of flow regime (e.g. hydropower production, irrigation, climate change) and habitat fragmentation appear to be major threats for this species, altering the connectivity between tributaries and the mainstream river as well as between adjacent sub-catchments

    Conservation du Cerf de Corse (Cervus elaphus corsicanus) : caractérisation biologique et étude des populations captives

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    The Corsican red deer (Cervus elaphus corsicanus) has been extirpated from Corsica in the late sixties. In 1985, the Regional Natural Park of Corsica implemented the reintroduction of this threatened taxon, through a conservation action plan, including three steps: (1) importing animals (13) from Sardinia to be the founder population, (2) captive breeding of three populations in enclosures in order to provide animals to be released in the wild, and (3) releasing of groups of deer in suitable Corsican habitats.We carried on simultaneous different studies on the three captive populations in order to: (1) analyse their phenotypic, genetic and health status, (2) investigate factors influencing population dynamics and social organization, and (3) optimise the management of captive breeding thanks to convenient results.From 2002 to 2006, we have been trapping deer in the enclosures in order to monitor morphometrics and take suitable samples for genetic and parasite surveys. Animals were then individually tagged (necklace and eartag) for subsequent observations according to a standardised protocol.Deer reintroduced in Corsica are smaller than Red deer from the continent, and males emit deeper vocalizations during the rutting period. Investigations for pathogens and parasites revealed animals in good health condition. The genetic study showed a low level of allelic polymorphism (microsatellites), but no noticeable inbreeding depression in any population. We observed a social organization very similar to that is reported for the continental deer with a sexual segregation out of the rutting period. However the different grouping pattern of females in the enclosures of Quenza and Casabianda leads to different mating and siring success of individual males of these populations.Based on these results and previous knowledge, updated guidelines are proposed for improving the captive breading programme as well as preparing new reintroduction in the wild.Les derniers cerfs de Corse (Cervus elaphus corsicanus) ayant disparu de l’üle vers 1968, le Parc Naturel RĂ©gional Corse a entrepris sa rĂ©introduction en 1985. Le programme de conservation de ce taxon menacĂ© comporte trois phases : (1) la constitution d’une population souche Ă  partir de 13 individus provenant de Sardaigne, (2) le dĂ©veloppement de trois populations en enclos pour produire des animaux Ă  relĂącher en nature et (3) le lĂącher de groupes d’individus sur diffĂ©rents sites propices.Par une approche pluridisciplinaire, en Ă©tudiant les trois populations captives, nous avions pour objectifs de : (1) caractĂ©riser d’un point de vue phĂ©notypique, gĂ©nĂ©tique et sanitaire les populations captives, (2) analyser les facteurs influant sur la dynamique dĂ©mographique et l’organisation sociale de ces populations et (3) en tirer des enseignements pratiques permettant d’optimiser le fonctionnement des enclos de reproduction.Entre 2002 et 2006, nous avons capturĂ© les animaux dans les enclos afin de les mesurer et d’effectuer des prĂ©lĂšvements pour des Ă©tudes gĂ©nĂ©tiques, parasitologiques... Les animaux Ă©taient alors marquĂ©s individuellement (collier et boucle) pour des observations rĂ©guliĂšres selon un protocole standardisĂ©. Les cerfs rĂ©introduits en Corse prĂ©sentent deux particularitĂ©s phĂ©notypiques : une taille plus petite et des vocalisations plus graves que celles du cerf Ă©laphe. Le suivi des principales pathogĂšnes et parasites a montrĂ© les bonnes conditions sanitaires des Ă©levages. L’étude du polymorphisme gĂ©nĂ©tique n’a pas rĂ©vĂ©lĂ© de consanguinitĂ© notable dans les trois populations. La structure sociale est identique Ă  celle du cerf Ă©laphe avec une sĂ©grĂ©gation des sexes hors pĂ©riode de rut. Cependant, il ressort que l’organisation sociale des femelles, diffĂ©rente dans les enclos de Quenza et de Casabianda, influe sur le taux de participation des mĂąles Ă  la reproduction.A l’issue de cette Ă©tude, un certain nombre de recommandations sont Ă©mises pour la gestion des enclos de reproduction et la poursuite du programme de rĂ©introduction

    Comportement et systématique (le cas des Cervidae (Ruminantia, Pecora))

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    TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

    Cycle annuel d’activitĂ© des ChiroptĂšres du Parc national de Bou-Hedma (Tunisie)

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    Annual activity cycle of bats in Bou-Hedma National Park (Tunisia). Bats were mist-netted in six main habitats of the Bou-Hedma National Park over two years. Most of the seven recorded species are widely distributed in northwestern Africa, except the Saharan Otonycteris hemprichii. Basins of Bordj and Nouh were the most attractive for bats, mainly in early summer. Oued Bou-Hedma was less attractive, particularly in winter. No bat was mist-netted in the steppe and the two types of Acacia forest, which supports the major role of water bodies in the Mediterranean area. Winter activity of bats was detected and tentatively quantified. Also informative is the fact that captures peaked when most Pipistrellus kuhlii and Eptesicus isabellinus were pregnant or lactating.La capture mensuelle des ChiroptĂšres dans six des principaux habitats du Parc National de Bou-Hedma sur une pĂ©riode de 26 mois a permis d’inventorier sept espĂšces, assez largement rĂ©pandues au Maghreb, Ă  l’exception de la saharienne Otonycteris hemprichii. Les bassins du Bordj et de Nouh sont les plus attractifs, surtout au dĂ©but de l’étĂ©, l’oued Bou-Hedma est beaucoup moins frĂ©quentĂ©, surtout en hiver. Aucune capture n’a Ă©tĂ© rĂ©alisĂ©e dans la steppe et dans les forĂȘts claire et dense d’acacias, ce qui confirme l’attractivitĂ© des plans d’eau pour toutes les espĂšces dans la rĂ©gion mĂ©diterranĂ©enne. Une activitĂ© hivernale a Ă©tĂ© mise en Ă©vidence et la pĂ©riode de reproduction de Pipistrellus kuhlii et Eptesicus isabellinus, qui correspond au pic de captures, a Ă©tĂ© prĂ©cisĂ©e.Dalhoumi Ridha, Aissa Patricia, Aulagnier StĂ©phane. Cycle annuel d’activitĂ© des ChiroptĂšres du Parc national de Bou-Hedma (Tunisie). In: Revue d'Écologie (La Terre et La Vie), tome 70, n°3, 2015. pp. 261-270
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