Distribution in France of a naturalized pel, the Siberian Chipmunk (Tamias sibiricus)

Apparu dans les animaleries de différents pays européens au cours des années 1960, le Tamia de Sibérie (Tamias sibiricus), Sciuridé originaire d'Asie, a été lâché dans la nature à la fin des années 1970. Une enquête nationale lancée en 2000 auprès des agents de l'Office National des Forêts, complétée par diverses autres informations, a permis de recenser sept populations implantées dans des forêts périurbaines et des parcs urbains de la Région Ile-de-France, et trois populations dans des forêts de la Région Picardie. Certaines de ces populations comptent actuellement plusieurs milliers d'individus. Leur présence est liée à l'introduction délibérée d'un nombre inconnu, mais probablement réduit dans chaque cas, d'individus dont la compagnie lassait leurs propriétaires. Seule la population située à Villers-Carbonnel (Picardie) provient d'une trentaine de lamias échappés d'un élevage. Sur certains sites, la vitesse de colonisation est comprise entre 200 et 250 m par an au cours des premières décennies ayant suivi l'introduction. La population de la forêt de Meudon (Hauts-de-Seine) a fait l'objet de dénombrements hebdomadaires, sur itinéraire-échantillon, de mars 2000 à février 2004. En 2002, 15 adultes marqués avec une bague auriculaire identifiable à distance ont été suivis d'avril à octobre. Ces observations et celles provenant de travaux effectués sur son aire d'origine, dans d'autres pays européens ou en captivité, permettent de cerner ses principaux traits d'histoire de vie et de disposer d'éléments permettant d'analyser sa propension à devenir une espèce envahissante en France.The Siberian Chipmunk (Tamias sibiricus) has been sold in pet shops of various European countries since the 1960’s, and voluntarily released in the wild since the 1970’s. In 2000, I held a national inquiry of the wardens of the National Forests Office. The results of this survey, supplemented by other sources, showed the presence of seven populations established in suburban forests and in urban parks of the Région Ile-de-France, and of three populations established in forests of the Région Picardie. Some of these populations number several thousands of individuals. Their origin may be related to deliberate introduction of a presumably low number of individuals, introduced by owners. The only exception is the Villers-Carbonnel (Picardie) population, where about 30 individuals escaped from a pet shop. Some populations seem to spread out at a rate of 200 to 250 m per year, at least during the first decades following their introduction. Weekly censuses on strip-transects were done on one population (Meudon, Hauts-de-Seine), between March 2000 and February 2004. In 2002, 15 adults were marked with ear tags and followed between April and October. These observations, along with observations from other studies in the species native area, in other European countries, or in captivity, allowed me to list the principal features of the life history of T. sibiricus, and to discuss the potential of this introduced squirrel to become an invasive species on the French territory

Une gamme d'îles de référence, un atout majeur pour l'évaluation de programmes de restauration dans l'archipel de Kerguelen

The Kerguelen Archipelago is constituted by a main island (6 500 km2) and about sixty secondary islands (1-200 km2). Somee of these islands are pristine, while some others have been colonized by introduced plants, invertebrate species and, in some cases, by one or several alien mammals. Programs of ecological restoration began in 1992 on three islands, Verte I., Guillou I. and Cochons I. (respectively 150, 145 and 165 ha) damaged by the presence of mammals (rabbits, rabbits-cats-mice, rabbits-mice). The management action was the eradication of rabbits by poisoning. Due to the existence of reference islands (with or without introduced mammals), and of control islands (presence of rabbits), the Kerguelen Archipelago offers an unusual opportunity to distinguish the effects of the management intervention from those of other factors. For example, synchronised vegetation monitoring of habitats on a control island (Cimetière I., colonized by rabbits) has shown the role of this mammal in controlling one introduced Asteraceae (Taraxacum officinale). After rabbit eradication, this plant drastically increased in cover on the three experimental islands. Moreover, results from Mayes I. (without herbivores) and from the 4 other islands studied, emphasized the impact of the present climatic changes on the evolution of plant communities. This factor explains most of the decrease in cover of several native species, especially Acaena magellanica, with the timing of Dandelion's success linked to open land appearance. These observations confirmed the value of contemporary reference sites to analyze the advantages of restoration programs and to conduct future actionsL'archipel de Kerguelen est constitué d'une île principale (6 500 km2) et d'une soixantaine d'îles secondaires (1-200 km2). Certaines sont totalement indemnes d'espèces introduites, d'autres ont été colonisées par des espèces végétales et des invertébrés allochtones, et d'autres encore sont occupées, de plus, par un ou plusieurs mammifères introduits. Un programme de restauration écologique concernant trois îles (145 à 165 ha) dégradées par la présence de mammifères (lapin, lapin-souris, lapin-chat-souris) a été initié en 1992 par éradication du lapin. Par la présence d'îles de référence (sans herbivore introduit) et d'îles témoin (avec lapin), l'archipel de Kerguelen offre une situation exceptionnelle permettant de distinguer les effets de l'intervention de ceux d'autres facteurs. Le suivi synchronique de la végétation de différentes îles a permis de mettre en évidence, par exemple, le rôle du lapin sur le contrôle d'une Astéracée introduite (Taraxacum officinale) et l'importance des changements climatiques sur les trajectoires d'évolution des communautés végétales. Ces observations ont confirmé l'intérêt de disposer de références contemporaines pour analyser les bénéfices d'opérations de restauration et pour orienter les actions à veni

Résilience des communautés insulaires subantarctiques : facteurs influençant la vitesse de restauration écologique après éradication de mammifères introduits

Cattle were introduced to Amsterdam Island in 1871 and rabbits to the Kerguelen Archipelago in 1874. These herbivorous mammals caused severe damage to these terrestrial ecosystems. Two ecological restoration programs were implemented: cattle eradication from the southern part of Amsterdam Island (55 km2) in 1988 and rabbit eradication from three small islands (145 to 165 ha) at Kerguelen from 1992. On Amsterdam Island, in a temperate climate, the recovery of vegetation depended on the degree of damage caused to the environment by cattle. On the Jess eroded organic soils, recovery of native vegetation (e. g. Poa novarae, Blechnum penna-marina) was observed 10 years after cattle eradication. Conversely, on the thin and eroded mineral soils, an irreversible level of disturbance occurred: vegetation recovery was very slow and introduced plant species (e.g. Holcus lanatus) remained dominant while the cover of autochtonous species (Scirpus nodosus, Blechnum penna-marina) increased very slowly. Due to the cooler climate, ecological restoration processes were slower at Kerguelen than at Amsterdam Island. For some autochtonous species, such as Pringlea antiscorbutica and Azorella selago , presence of refuge areas on cliffs inaccessible to rabbits was important for colonization after rabbi! eradication. Vegetation changes depended greatly on the climatic changes recently recorded (characterised by a slight increase in temperature and more frequent summer drought). In contrast to the autochtonous species, most of the alien plants ( Taraxacum officinale, Senecio vulgaris...), originating from temperate regions, were favoured by these climatic changesL'introduction de bovins en 1871 sur l'île Amsterdam et de lapins en 1874 dans l'archipel de Kerguelen a eu un impact considérable sur les écosystèmes terrestres. Deux programmes de restauration écologique ont été mis en place, l'un en 1988 par élimination des bovins de la partie sud de l'île Amsterdam (55 km2), le second à partir de 1992 par éradication des lapins sur trois îles (1,45 à 1,65 km2) à Kerguelen. Sur l'île Amsterdam, les capacités et la vitesse de restauration des communautés dépendent du niveau de la perturbation des milieux engendrée par les bovins. Alors qu'une dizaine d'années a suffi à la restauration des communautés végétales sur certains secteurs dont les sols étaient peu dégradés, l'évolution est lente et les espèces introduites restent dominantes sur de larges secteurs où l'érosion du sol atteint un seuil d'irréversibilité. A Kerguelen, les processus de restauration, plus lents, ont été de plus fortement influencés et limités par les changements climatiques récents (sécheresse estivale de plus en plus fréquente) qui bénéficient aux espèces introduites, originaires de régions plus tempérées, et pénalisent les espèces locales pour lesquelles ces conditions sont entièrement nouvelle

Impact des changements climatiques et de la fréquentation humaine sur la biodiversité des îles subantarctiques françaises

L’invasion des écosystèmes par des espèces exotiques constitue, en conjonction avec les changements climatiques, une des plus grandes menaces pour la biodiversité mondiale, après la destruction des habitats. Même dans les régions antarctiques et subantarctiques, des espèces étrangères à la faune et à la flore locales ont été introduites dès la fin du 18e siècle. La majorité de ces introductions sont associées à la fréquentation humaine et aux visites des navires. Par ailleurs, comme le prédisent la plupart des modèles, les régions de hautes latitudes sont les plus sensibles aux changements climatiques. Les observations faites à Kerguelen confirment cette tendance et attestent de l’impact déjà bien visible des augmentations de température (1,3°C depuis le milieu des années 1960) et des déficits hydriques estivaux récurrents ces dernières années. Avec ces changements climatiques rapides, une augmentation du nombre d’introductions d’espèces et de leur succès d’établissement est attendue, de même que la fragilisation de la faune et la flore locales, d’où de notables conséquences prévisibles quant à la biodiversité de ces régions très particulières.Biological invasions, in connection with climate changes, are amongst the most significant threats to biodiversity worldwide. Even in antarctic and subantarctic regions, alien species arrived since the end of the 18th century. Most of these introductions are obviously associated with human activities and ship landings. Otherwise, as predicted by many global circulation models, rates of warming are expected to be stronger at higher latitudes. Our study on the Kerguelen Islands confirms this trend and demonstrates that the effects of warming (+ 1.3°C since the mid 1960s) and summer droughts on plants and invertebrates are now visible. With climate change occurring rapidly, both the numbers of introductions and the success of colonisation by alien species are likely to increase, with as consequence subsequent impacts on the entire ecosystem

House mouse colonization patterns on the sub-Antarctic Kerguelen Archipelago suggest singular primary invasions and resilience against re-invasion

Starting from Western Europe, the house mouse (Mus musculus domesticus) has spread across the globe in historic times. However, most oceanic islands were colonized by mice only within the past 300 years. This makes them an excellent model for studying the evolutionary processes during early stages of new colonization. We have focused here on the Kerguelen Archipelago, located within the sub-Antarctic area and compare the patterns with samples from other Southern Ocean islands

New challenges in solar architectural innovation

Among the century’s main challenges, climate change and the need for energy sources diversification are of great importance. In this context, renewable energies undoubtedly have an important role to play. Photovoltaic (PV) electricity is especially well suited to face these energy challenges. It is now established that the low thin film photovoltaic panels production costs will allow, even in continental climate, to reach low electricity cost, providing easy installation, public acceptance and high reliability. However, architectural considerations are often neglected in the current integration of PV panels. Taking into consideration specific architectural aspects like the surface appearance and the colour of the PV modules can become the key for the successful development of new, well integrated solar systems. To achieve this goal, our team, within the Archinsolar [1] project framework, works on the development of new generation of photovoltaic elements based on silicon thin films technologies (amorphous and micromoph). These new elements will be ultra-reliable and manufacturable at a very low cost, allowing a good architectural integration, respectful of the environment, landscape and built environment. Genera

Innovative Solution for Building Integrated Photovoltaics

Among the main challenges of our century, the climate change and the need of diversification of the energy sources are of most importance. Renewable energies undoubtedly have an important role to play, photovoltaic (PV) electricity being especially well suited to face these energy challenges. However, the current integration of PV panels often comes without architectural consideration. In this context, the Archinsolar project [1] aims to develop a new generation of photovoltaic elements based on silicon thin films technologies (amorphous and micromorph), ultra-reliable and manufacturable at a very low cost, allowing a unique architectural integration, respectful of the bui lt environment and overall landscape. Here we will present our new developments on innovative PV elements including colored PV panels and a solar tile using a composite back-structure

Seabird Modulations of Isotopic Nitrogen on Islands

The transport of nutrients by migratory animals across ecosystem boundaries can significantly enrich recipient food webs, thereby shaping the ecosystems’ structure and function. To illustrate the potential role of islands in enabling the transfer of matter across ecosystem boundaries to be gauged, we investigated the influence of seabirds on nitrogen input on islands. Basing our study on four widely differing islands in terms of their biogeography and ecological characteristics, sampled at different spatial and temporal intervals, we analyzed the nitrogen isotopic values of the main terrestrial ecosystem compartments (vascular plants, arthropods, lizards and rodents) and their relationship to seabird values. For each island, the isotopic values of the ecosystem were driven by those of seabirds, which ultimately corresponded to changes in their marine prey. First, terrestrial compartments sampled within seabird colonies were the most enriched in δ15N compared with those collected at various distances outside colonies. Second, isotopic values of the whole terrestrial ecosystems changed over time, reflecting the values of seabirds and their prey, showing a fast turnover throughout the ecosystems. Our results demonstrate that seabird-derived nutrients not only spread across the terrestrial ecosystems and trophic webs, but also modulate their isotopic values locally and temporally on these islands. The wealth of experimental possibilities in insular ecosystems justifies greater use of these model systems to further our understanding of the modalities of trans-boundary nutrient transfers

British Red Squirrels Remain the Only Known Wild Rodent Host for Leprosy Bacilli

<p>Eurasian red squirrels (Sciurus vulgaris) in the British Isles are the most recently discovered animal reservoir for the leprosy bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Initial data suggest that prevalence of leprosy infection is variable and often low in different squirrel populations. Nothing is known about the presence of leprosy bacilli in other wild squirrel species despite two others (Siberian chipmunk [Tamias sibiricus], and Thirteen-lined ground squirrel [Ictidomys tridecemlineatus]) having been reported to be susceptible to experimental infection with M. leprae. Rats, a food-source in some countries where human leprosy occurs, have been suggested as potential reservoirs for leprosy bacilli, but no evidence supporting this hypothesis is currently available. We screened 301 squirrel samples covering four species [96 Eurasian red squirrels, 67 Eastern gray squirrels (Sciurus carolinensis), 35 Siberian chipmunks, and 103 Pallas's squirrels (Callosciurus erythraeus)] from Europe and 72 Mexican white-throated woodrats (Neotoma albigula) for the presence of M. leprae and M. lepromatosis using validated PCR protocols. No DNA from leprosy bacilli was detected in any of the samples tested. Given our sample-size, the pathogen should have been detected if the prevalence and/or bacillary load in the populations investigated were similar to those found for British red squirrels.</p

Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues