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Linear transportation infrastructures (LTIs) are established drivers of habitat fragmentation and barrier effects. Yet, they represent an increasing surface of managed seminatural habitats where increased consideration of biodiversity outputs is needed in an era of global biodiversity decline. A combined effort by both scientists and stakeholders is, therefore, needed to evaluate the promises and limits of these alternatives so that they best achieve their conservation potential. Our study explores the effects of forest powerline clearings on biodiversity, as well as the potential benefits of integrated vegetation management (IVM) as alternatives to clear‐cuts. We recorded the acoustic activity at 35 pairs of forest/clearing stations in two forested regions of France in 2021. Our results suggest that powerline clearings represent increased movement opportunities for bats and, most particularly, edge‐foraging species. They also provide suitable habitats for bush‐cricket species, particularly species requiring thermophilic conditions. We detected no direct benefit from IVM on bat communities. However, bush‐cricket communities appeared richer, more acoustically active, and statistically different from adjacent forests in clearings favoring secondary vegetation compared with clear‐cut ones. This collaborative study provides data on understudied taxa in the context of LTIs and sheds light on conservation promises and limits associated with their management. [ABSTRACT FROM AUTHOR]

Knowledge of species' functional traits is essential for understanding biodiversity patterns, predicting the impacts of global environmental changes, and assessing the efficiency of conservation measures. Bats are major components of mammalian diversity and occupy a variety of ecological niches and geographic distributions. However, an extensive compilation of their functional traits and ecological attributes is still missing. Here we present EuroBaTrait 1.0, the most comprehensive and up-to-date trait dataset covering 47 European bat species. The dataset includes data on 118 traits including genetic composition, physiology, morphology, acoustic signature, climatic associations, foraging habitat, roost type, diet, spatial behaviour, life history, pathogens, phenology, and distribution. We compiled the bat trait data obtained from three main sources: (i) a systematic literature and dataset search, (ii) unpublished data from European bat experts, and (iii) observations from large-scale monitoring programs. EuroBaTrait is designed to provide an important data source for comparative and trait-based analyses at the species or community level. The dataset also exposes knowledge gaps in species, geographic and trait coverage, highlighting priorities for future data collection. [ABSTRACT FROM AUTHOR]

Wind power generation has grown exponentially over the past 20 years to meet international goals of increasing the share of renewables in energy production. Yet, this process has too often been conducted at the cost of airborne biodiversity such as birds and bats. The latter are severely threatened due to deaths by collision at wind turbine. The UNEP/EUROBATS agreement that came into force in 1994 is now ratified by 37 countries; since 2008, it recommends to site wind turbines at least 200 m away from woody edges to decrease bat fatality risks. However, 14 years later we still do not know to what extent this international recommendation has been applied in Europe. We assessed siting distances between woody edges and wind turbines for the largest wind energy producers among the UNEP/EUROBATS parties: the UK, Germany, and France. We show that 61%, 78%, and 56%, respectively, of the installed wind turbines did not comply with UNEP/EUROBATS guidelines, without improvement over time. We identified probable causes of these findings and provided key policy recommendations to achieve compliance to UNEP/EUROBATS guidelines such as better: (i) inclusion in regulatory texts, (ii) notification of the environmental authorities, and (iii) strategic, well‐informed, forward planning of areas suitable for wind turbine development. [ABSTRACT FROM AUTHOR]

Copyright of Methods in Ecology & Evolution is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Roads have a multitude of negative effects on wildlife, including bat casualties. Most bat species rely on life history traits characterised by high adult survival (associated with greater longevity) and low reproduction rates (hence slow population growth rates). Therefore, road kills are expected to negatively affect local abundance and bat population dynamics. Bat overpasses are among the proposed improvements intended to increase bat flight height to reduce collisions, but their effectiveness has rarely been tested. In this study, we performed a before-after analysis to assess the effectiveness of one bat overpass on bat flight height. We used a novel approach, the bat tracking toolbox (BTT), to reconstruct bat flight paths from thermal videos. We obtained 268 bat flight paths and our results showed that the flight height of bats increased significantly after the installation of the bat overpass. Considering that bat overpasses can help in some situations to increase habitat connectivity and reduce the collision risk, this mitigation measure needs to be further investigated in different contexts of road construction and/or road requalification. [ABSTRACT FROM AUTHOR]

Despite the key importance of the landscape matrix for bats, we still not fully understand how the effect of forest composition interacts at combined stand and landscape scales to shape bat communities. In addition, we lack detailed knowledge on the effects of local habitat structure on bat-prey relationships in forested landscapes. We tested the assumptions that (i) forest composition has interacting effects on bats between stand and landscape scales; and (ii) stand structure mediates prey abundance effects on bat activity. Our results indicated that in conifer-dominated landscapes (> 80% of coniferous forests) bat activity was higher in stands with a higher proportion of deciduous trees while bats were less active in stands with a higher proportion of deciduous trees in mixed forest landscapes (~ 50% of deciduous forests). Moth abundance was selected in the best models for six among nine bat species. The positive effect of moth abundance on Barbastella barbastellus was mediated by vegetation clutter, with dense understory cover likely reducing prey accessibility. Altogether, our findings deepen our understanding of the ecological processes affecting bats in forest landscapes and strengthen the need to consider both landscape context and trophic linkage when assessing the effects of stand-scale compositional and structural attributes on bats. [ABSTRACT FROM AUTHOR]

Background: Artificial light at night is recognized as an increasing threat to biodiversity. However, information on the way highly mobile taxa such as bats spatially respond to light is limited. Following the hypothesis of a behavioural adaptation to the perceived risks of predation, we hypothesised that bats should avoid lit areas by shifting their flight route to less exposed conditions. Methods: Using 3D acoustic localization at four experimentally illuminated sites, we studied how the distance to streetlights emitting white and red light affected the Probability of bats Flying Inside the Forest (PFIF) versus along the forest edge. Results: We show that open-, edge-, and narrow-space foraging bats strongly change flight patterns by increasing PFIF when getting closer to white and red streetlights placed in the forest edge. These behavioural changes occurred mainly on the streetlight side where light was directed. Conclusions: The results show that bats cope with light exposure by actively seeking refuge in cluttered environment, potentially due to involved predation risks. This is a clear indication that bats make use of landscape structures when reacting to light, and shows the potential of vegetation and streetlight orientation in mitigating effects of light. The study nevertheless calls for preserving darkness as the most efficient way. [ABSTRACT FROM AUTHOR]

The development of transportation infrastructure has been identified as one of the main pressures on biodiversity. The effects of transport infrastructure are more documented for terrestrial mammals, birds and amphibians than for bats. To assess the impacts of roads on bat activity, we carried out full-night acoustic recordings of bat calls at 306 sampling points at different distances from a major road at three study sites in France. To assess the relationship between bat activity and the distance to the major road, we performed generalized linear mixed model analyses for thirteen different species or groups and additionally explored the non-linear effect with generalized additive mixed models. Our results showed that low-flying species are more affected than high-flying species. Indeed, we found a significant negative effect of major roads on bat activity for the 'clutter-adapted' species, Eptesicus serotinus , Myotis spp., Pipistrellus pipistrellus and Rhinolophus hipposideros. These results demonstrate that the road-effect zone of major roads extends up to five kilometres. Extrapolating those road-effects zones to the major roads in the European Union, we estimated that 35% of the European Union is potentially negatively impacted. Finally, it seems urgent to consider these road effects with the cumulative effects of other roads by improving habitat connectivity and foraging areas in land use policies. Additionally, to implement drastic conservation practices for species of conservation concern in environmental impact assessment studies, efficient mitigation and offset measures implemented should be sized proportionally to the disturbance caused. • Major roads affect activity in five of the thirteen studied taxa. • Low-flying species are more affected than those that fly in the open. • Road impacts may be due to road kills, traffic disturbance and ruptured connectivity. [ABSTRACT FROM AUTHOR]

• We performed a Before-After Control-Impact analysis (BACI) to assess the efficiency of a bat overpass. • An acoustic flight path reconstruction approach was used to quantify bat crossings. • We detected a significant increase of bat crossings between the two periods at the treatment site. • An overpass correctly placed could efficiently restore bat habitat connectivity. Roads have a multitude of negative effects on wildlife, including their prominent role in habitat fragmentation. Habitat fragmentation particularly affects bats during their nightly movements between roosts and foraging areas. Bat overpasses are among the proposed improvements intended to reduce the fragmentation impact of roads, but they have rarely been tested. In this study, we performed a Before-After Control-Impact analysis (BACI) to assess the efficiency of one bat overpass on the number of bat crossings, by using an acoustic flight path reconstruction (AFPR) approach. We obtained 888 bat crossings of five taxa. Our results showed that the number of bat crossings increased significantly after the installation of the bat overpass. Finally, we demonstrated that an overpass correctly placed with respect to a narrow commuting route (a twenty-meter-wide hedgerow) could efficiently restore bat habitat connectivity. [ABSTRACT FROM AUTHOR]

Acoustic detectors have become increasingly used by bat workers to investigate bat ecology and assess the impacts of anthropogenic pressures. Within these studies, the metric used, 'bat activity', is based on the number of bat passes, without considering the bat pass duration (i.e. each event of a bat detected within the range of an ultrasonic detector). We expected that bat pass duration may contain information about site quality in terms of foraging potential. Because bats are expected to have a more sinuous trajectory and slower velocity when they exhibit foraging behaviour, as opposed to commuting behaviour, we hypothesize a longer bat pass duration in favourable habitats; during seasons with important energetic demands; or during night peak activity. We used datasets from a large-scale acoustic bat survey (n = 2890 sites), with a total of 24,597 bat pass measures from 6 taxa, and performed GLMM modelling. We detected a significant effect of habitat type on bat pass duration for five taxa. Shorter bat pass durations were detected at the beginning of the night. We detected longer pass durations during the lactation period or just before hibernating, while weather conditions or ageing and wear of the detector rarely influenced bat pass duration. Bat pass duration appears to be a simple and easy measure for position calls on a gradient between commuting vs. foraging behaviour. We suggest that the traditional measure of bat activity may be weighted by bat pass duration by giving more weight to events with potentially stronger links to foraging behaviour. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Light pollution is a major threat to biodiversity worldwide. There is a crucial need to elaborate artificial lighting recommendations to mitigate its impact on wildlife. In the present study, we investigated how streetlight spatial position and light trespass impacted the use of ecological corridors by transiting bats in anthropogenic landscapes. Through a paired, in situ experiment, we estimated how streetlight distance of impact and vertical and horizontal illuminance influenced the transiting activity of 6 species and 2 genera of bats. We selected 27 pairs composed of 1 lit site and 1 control unlit site in areas practicing either part-night or full-night lighting. We recorded bat activity at 0, 10, 25, 50 and 100 m, and measured vertical and horizontal light illuminance at the 5 distance steps (range = 0.1–30.2 lx). While streetlight attraction effect was mostly limited to a 10 m radius for Pipistrellus sp. and Nyctalus sp., streetlight avoidance was detected at up to 25 and 50 m for Myotis sp. and Eptesicus serotinus , respectively. Streetlight effects on Myotis sp. and Nyctalus sp. remained after lamps were turned-off. Illuminance had a negative effect on Myotis sp. below 1 lx, a mixed effect on E. serotinus , and a positive effect on the other species, although a peak of activity was observed between 1 and 5 lx for P. pipistrellus and N. leisleri. We recommend separating streetlights from ecological corridors by at least 50 m and avoiding vertical light trespass beyond 0.1 lx to ensure their use by light-sensitive bats. [ABSTRACT FROM AUTHOR]

As light pollution is currently considered to be a major threat to biodiversity, different lighting management options are being explored to mitigate the impact of artificial lighting on wildlife. Although part-night lighting schemes have been adopted by many local authorities across Europe to reduce the carbon footprint and save energy, their effects on biodiversity are unknown. Through a paired, in situ experiment, we compared the activity levels of 8 bat species under unlit, part-night, and full-night lighting treatments in a rural area located 60 km south of Paris, France. We selected 36 study locations composed of 1 lit site and a paired unlit control site; 24 of these sites were located in areas subject to part-night lighting schemes, and 12 sites were in areas under standard, full-night lighting. There was significantly more activity on part-night lighting sites compared to full-night lighting sites for the late-emerging, light-sensitive Plecotus spp., and a similar pattern was observable for Myotis spp., although not significant. In contrast, part-night lighting did not influence the activity of early emerging bat species around streetlights, except for Pipistrellus pipistrellus for which there was significantly less activity on part-night lighting sites than on full-night lighting sites. Overall, no significant difference in activity between part- and full-night lighting sites were observed in 5 of the 8 species studied, suggesting that current part-night lighting schemes fail to encompass the range of activity of most bat species. We recommend that such schemes start earlier at night to effectively mitigate the adverse effects of artificial lighting on light-sensitive species, particularly along ecological corridors that are especially important to the persistence of biodiversity in urban landscapes. [ABSTRACT FROM AUTHOR]

• Bat diversity peaked in landscapes with intermediate forest fragmentation levels. • Road density had negative effects on functional and phylogenetic bat diversity. • Road density impacted bat activity differently between forest edges and interiors. • Forest fragmentation mediated road density effects on bats at landscape scale. • Our study advocates for more holistic approaches in fragmentation studies. Road construction is expanding worldwide, exacerbating both direct mortality by road-kills and habitat fragmentation, especially for mobile vertebrates such as bats. Understanding how road density affects bat communities in mosaic landscapes of various compositions and configurations is therefore critical. We acoustically sampled bat communities in 172 landscapes of southern France to: (i) disentangle the relative and interacting effects of road density and forest fragmentation by farmland on the activity of bat communities; (ii) investigate how road density affects different aspects of bat diversity (taxonomic, functional and phylogenetic) and species activity according to their life-history traits; and (iii) assess whether road density effects on bats change with the level of forest fragmentation. Forest amount and patchiness were more important than road density for all components of bat diversity, except for functional evenness. Bat diversity peaked in landscapes with intermediate levels of forest fragmentation, while road density had negative effects on functional and phylogenetic diversity. The effect of road density on the activity of R. ferrumequinum, R. hipposideros , N. leisleri and P. pipistrellus was only negative in landscapes with either a low forest amount or a low number of forest patches. By better understanding interactions between forest fragmentation and road density, our study will contribute to a more adequate landscape planning that will improve the resilience of bat communities to both road expansion and forest fragmentation. Moreover, the complex landscape-level interactions between habitat fragmentation and matrix quality on bats advocate for the use of a more holistic view in future fragmentation studies. [ABSTRACT FROM AUTHOR]

Few reports have been published on detection distances of bat calls because the evaluation of detection distance is complicated. Several of the approaches used to measure detection distances are based on the researcher's experience and judgment. More recently, multiple microphones have been used to model flight path. In this study, the validity of a low-cost and simple detectability metric was tested. We hypothesize that the duration of an echolocating-bat-pass within the area of an ultrasonic bat detector is correlated with the distance of detection. Two independent datasets from a large-scale acoustic bat survey—a total of 25,786 bat-passes from 20 taxa (18 species and two genera)—were measured. We found a strong relationship between these measures of bat-pass duration and published detection distances. The advantages of bat-pass duration measures are that, for each study, experimenters easily produce their own proxy for the distance of detection. This indirect measure of the distance of detection could be mobilized to monitor the loss in microphone sensitivity used to monitor long-term population trends. Finally, the possibility of producing an index for distance of detection provides a weight for each bat species' activity when they are aggregated to produce a bat community metric, such as the widely used "total activity". [ABSTRACT FROM AUTHOR]

Although diel activity time is a major axis of species' niche space, very few conservation measures focus on preserving daily periods free of anthropogenic pressures. While the spatial ecology of bats has received much attention, less is known about their temporal ecology, the knowledge being dispersed in studies of limited taxonomical, spatial and temporal range. We used data from the French bat monitoring program based on citizen science and standardised acoustic recordings (4409 sites monitored and 9807 nights monitored from 2014 to 2020) to characterise the diel activity patterns of 20 bat species so that their consideration in mitigation measures can help conservation. We designed a method to extract times of key descriptors and describe bat activity distribution throughout the night. We found that bat species could be separated in three functional groups characterised by a crepuscular activity, an activity that occurs when it is completely dark or an intermediate activity. We showed variations of diel activity patterns depending on season. We argue that accounting for these complex diel activity patterns would help design efficient mitigation measures, for instance to reduce the exposure of bats to light pollution or wind turbines. Overall, we advocate multi-taxa approaches to design conservation policies adapted to both the temporal and spatial distributions of species. [Display omitted] • Conservation should include species temporal distribution besides their spatial one. • Citizen science programs enable the study of bat diel activity patterns at wide scales. • Similarities in diel activity patterns of bats enable functional groups to be defined. • Seasons can interact with the time of night to determine diel activity patterns. • Diel activity patterns should be considered when designing efficient mitigation measures. [ABSTRACT FROM AUTHOR]

Rural landscapes are undergoing widespread changes, of which homogenization and the installation of wind turbines are important components. To keep track of the impacts of homogenization and the presence of wind turbines on biodiversity, the responses of vulnerable organisms should be assessed considering their combined effects. We have tested the response of bat activity to the interaction between agricultural landscape gradients reflecting the degree of homogenization (parcel size, parcel diversity and density of hedges), and the presence of wind turbines. To do this, we combined acoustic sampling data gathered from 2014 to 2020 throughout continental France with land use and wind turbine siting data. GLMMs showed that each echolocation guild (LRE: long, MRE: mid, and SRE: short-range echolocators) responded to different gradients. Increasing parcel sizes and lower densities of hedges correlated negatively with the activity of MRE and SRE bats. Activity of LRE and SRE bats was lower, and that of MRE bats (mostly Common Pipistrelles Pipistrellus pipistrellus) was higher, when wind turbines were present. In landscapes containing wind turbines, hedge density correlated positively with LRE activity, and parcel diversity fostered SRE activity. Therefore, increasing hedge densities, or dividing large monocultures into more diverse cropland configurations, may compensate for negative effects of wind turbine presence on bat activity. Siting of new wind turbines should still avoid high-quality locations were bat activity and diversity are currently high, as the negative impact is bound to include not only habitat loss, but also enhanced mortality by collision. [ABSTRACT FROM AUTHOR]