db1022.html, respectively. Yearly d 13 C values for individual stations and global annual averages are presented in tables S3 and S4.

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Aim Species are responding to climate change by changing their distributions, creating debate about the effectiveness of existing networks of protected areas. As a contribution to this debate, we assess whether regional winter abundances and distribution of the Smew Mergellus albellus, a migratory waterbird species listed on Annex I (EU Birds Directive) that overwinters exclusively in European wetlands, changed during 1990–2011, the role of global warming in driving distributional changes and the effectiveness of the network of Special Protection Areas (SPAs, EU Birds Directive) in the context of climate change. Location Europe. Methods We used site‐specific counts (6,883 sites) from 16 countries covering the entire flyway to estimate annual abundance indices and trends at country, region (north‐eastern, central and south‐western) and flyway scales, inside and outside SPAs. We fitted autoregressive models to assess the effect of winter temperature on the annual abundance indices whilst accounting for autocorrelation. Results The Smew wintering distribution shifted north‐eastwards in Europe in accordance with the predictions of global warming, with increasing numbers in the north‐eastern region and declines in the central region. Trends in wintering numbers were more positive in SPAs on the north‐eastern and south‐western part of the flyway. However, a large proportion of the wintering population remains unprotected in north‐eastern areas outside of the existing SPA network. Main conclusions SPAs accommodated climate‐driven abundance changes in the north‐eastern region of the wintering distribution by supporting increasing numbers of Smew in traditional and newly colonized areas. However, we highlight gaps in the current network, suggesting that urgent policy responses are needed. Given rapid changes in species distributions, we urge regular national and international assessments of the adequacy of the EU Natura 2000 network to ensure coherence in site‐safeguard networks for this and other species.

Maximizing the area under biodiversity-related conservation measures is a main target of the European Union (EU) Biodiversity Strategy to 2020. We analyzed whether agrienvironmental schemes (AES) within EU common agricultural policy, special protected areas for birds (SPAs), and Annex I designation within EU Birds Directive had an effect on bird population changes using monitoring data from 39 farmland bird species from 1981 to 2012 at EU scale. Populations of resident and short-distance migrants were larger with increasing SPAs and AES coverage, while Annex I species had higher population growth rates with increasing SPAs, indicating that SPAs may contribute to the protection of mainly target species and species spending most of their life cycle in the EU. Because farmland birds are in decline and the negative relationship of agricultural intensification with their population growth rates was evident during the implementation of AES and SPAs, EU policies seem to generally attenuate the declines of farmland bird populations, but not to reverse them.

Abstract1. Effective prevention and control of invasive species generally relies on a comprehensive, coherent and representative list of species that enables resources to be used optimally. European Union (EU) Regulation 1143/2014 on invasive alien species (IAS) aims to control or eradicate priority species, and to manage pathways to prevent the introduction and establishment of new IAS; it applies to species considered of Union concern and subject to formal risk assessment. So far, 49 species have been listed but the criteria for selecting species for risk assessment have not been disclosed and were probably unsystematic.2. We developed a simple method to systematically rank IAS according to their maximum potential threat to biodiversity in the EU. We identified 1,323 species as potential candidates for listing, and evaluated them against their invasion stages and reported impacts, using information from databases and scientific literature. 4. Policy implications. We propose a systematic, proactive approach to selecting and prioritising IAS for risk assessment to assist European Union policy implementation.We assess an unprecedented number of species with potential to harm EU This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Aim Many species are showing distribution shifts in response to environmental change. We explored (a) the effects of inter‐annual variation in winter weather conditions on non‐breeding distributional abundance of waterbirds exploiting different habitats (deep‐water, shallow water, farmland) and (b) the long‐term shift in the population centroid of these species and investigate its link to changes in weather conditions. Location Europe. Methods We fitted generalized additive mixed Models to a large‐scale, 24‐year dataset (1990–2013) describing the winter distributional abundance of 25 waterbird species. We calculated the annual and long‐term (3‐year periods) population centroid of each species and used the winter North Atlantic Oscillation (NAO) index to explain the inter‐annual and long‐term shifts in their location. Results (a) Year‐to‐year southwestwards shifts in the population centroids of deep‐ and shallow‐water species were linked to negative NAO values. Shallow‐water species shifted northeastwards associated with positive NAO values and the distance shifted increased with increasing NAO. Deep‐water species shifted northeastwards up to zero NAO indices, but showed no further increase at higher NAO values. (b) Deep‐water species showed long‐term northeastwards shifts in distributional abundance throughout the 1990s and the 2000s. Shallow‐water species, on the other hand, shifted northeastwards during the 1990s and early 2000s, but southwestwards thereafter. There were no significant links between the NAO and year‐to‐year movements or long‐term shifts in farmland species’ population centroid. Main Conclusions We provide evidence for a link between both year‐to‐year and long‐term changes in waterbird winter distributional abundances at large geographical scales to short‐ and long‐term changes in winter weather conditions. We also show that species using shallow water, deep‐water and farmland habitats responded differently, especially at high NAO values. As well as important ecological implications, these findings contribute to the development of future conservation measures for these species under current and future climate change.

Omp2a and Omp2b are highly homologous porins present in the outer membrane of the bacteria from the genus Brucella, a facultative intracellular pathogen. The genes coding for these proteins are closely linked in the Brucella genome and oriented in opposite directions. In this work, we present the cloning, purification, and characterization of four Omp2b size variants found in various Brucella species, and we compare their antigenic and functional properties to the Omp2a and Omp2b porins of Brucella melitensis reference strain 16M. The variation of the Omp2a and Omp2b porin sequences among the various strains of the genus Brucella seems to result mostly from multiple gene conversions between the two highly homologous genes. As shown in this study, this phenomenon has led to the creation of natural Omp2a and Omp2b chimeric proteins in Omp2b porin size variants. The comparison by liposome swelling assay of the porins sugar permeability suggested a possible functional differences between Omp2a and Omp2b, with Omp2a showing a more efficient pore in sugar diffusion. The sequence variability in the Omp2b size variants was located in the predicted external loops of the porin. Several epitopes recognized by anti-Omp2b monoclonal antibodies were mapped by comparison of the Omp2b size variants antigenicity, and two of them were located in the most exposed surface loops. However, since variations are mostly driven by simple exchanges of conserved motifs between the two genes (except for an Omp2b version from an atypical strain of Brucella suis biovar 3), the porin variability does not result in major antigenic variability of the Brucella surface that could help the bacteria during the reinfection of a host. Porin variation in Brucella seems to result mainly in porin conductivity modifications.Porins are abundant proteins in the outer membrane of gram-negative bacteria. They create a controlled permeability of the outer membrane toward small hydrophilic solutes such as sugars that are otherwise not allowed to diffuse through the outer membrane (for a review, see references 21, 22, and 24). In a sense, porins are the Achilles' heel of this protective barrier, since they can act as receptors for bacteriophage and colicins (13), surface-exposed antigens (37), complement-binding sites (29), and the gate of entry for some antibiotics (27,28). In some pathogenic bacteria, such as Neisseria gonorrhoeae, porin sequence variations between serotypes are well described and probably allow successive infection by different serotypes presenting different surface-exposed epitopes (20). Neisseria porin genes are subject to frequent horizontal transfer movements of genetic material, allowing for numerous changes in sequence that can hamper vaccine development (18).Brucellae are gram-negative pathogens infecting numerous mammalian species and causing economic losses in domestic cattle, sheep, and goats, as well as human health problems in zones where they are endemic. The mechanisms of pathogenicity of Brucella spp. are still poorly understoo...