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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]

Mitigation hierarchy is applied in many countries to avoid, reduce and compensate for impacts on the environment due to development projects. The design and sizing of measures thus depend directly on the assessment of impacts. However, this assessment is rarely framed by precise methods and is based on ad hoc evaluation that are carried out by environmental consultants by relying on own and more or less sophisticated methods. This article thus proposes to start from the ground up to analyse how impacts on biodiversity are assessed in practice, according to what method, and for what results. A statistical analysis was performed on 29 environmental assessments. We hypothesize that project size and number of species impacted are positively correlated with large impacts; and that measures and their costs are positively correlated with high impact reduction and low compensation. No correlation could be found for any of the factors studied. This result shows that there is considerable flexibility in the assessment of impacts, leading to inconsistent treatment of impacts. In the absence of a standardized method, this should encourage the adoption of sizing rules that compensate for uncertainties. • Avoidance, reduction and compensation measures that compose the mitigation hierarchy are based on the assessment of impacts. • In most countries applying the mitigation hierarchy, impact assessment methods are not scientifically and legally regulated. • The estimation of impacts is not correlated to the number of species impacted, nor to the efforts invested in the measures. • the arbitrary nature of the impact assessments and the dimensioning of the measures reveal a hidden flexibility. [ABSTRACT FROM AUTHOR]

Here are proposed two automatic detectors of Barau's petrel ( Pterodroma baraui ) and tropical shearwater ( Puffinus bailloni ) vocalisations in noisy audio recordings (1) trained with a low number of positive training instances, and (2) whose performances would be the highest possible. To do so, acoustic recordings were performed in one Barau's petrel colony between February and May 2014 (85 h) and in two tropical shearwater colonies in March and April (21 h). Manual and automatic methods of segmentation were combined. Manual segmentation allowed (1) to miss a very few number of positive segments and (2) to avoid introducing false positive instances. Automatic segmentation provided quickly a diversified set of negative instances. Manual labelling must be regarded as an investment, for current and future works. A random forest classifier and classical methods of acoustic signal characterisation (cepstral coefficients, spectral moments, etc.) were tested. Best models were able to discriminate each target species calls from other sounds of its colony with F1 scores of 88% (Barau's petrel, 1015 samples) and 85% (tropical shearwater, 1217 samples). The acoustic monitoring of nocturnal burrow-nesting seabirds based on (1) data collected by autonomous recording units in harsh, windy and wet environments and (2) automatic analysis tools is feasible. The size of our database was limited. Consequently further works will be necessary to study robustness of models on long time-series data. [ABSTRACT FROM AUTHOR]

Insects are the most diverse group of animals on Earth, but their small size and high diversity have always made them challenging to study. Recent technological advances have the potential to revolutionise insect ecology and monitoring. We describe the state of the art of four technologies (computer vision, acoustic monitoring, radar, and molecular methods), and assess their advantages, current limitations, and future potential. We discuss how these technologies can adhere to modern standards of data curation and transparency, their implications for citizen science, and their potential for integration among different monitoring programmes and technologies. We argue that they provide unprecedented possibilities for insect ecology and monitoring, but it will be important to foster international standards via collaboration. Technological developments are opening new possibilities for biodiversity monitoring, but – especially for insects – they come with their own unique set of limitations. Due to the vast diversity of insects, of which at least 80% remain undescribed, traditional monitoring is unable to provide even basic knowledge of the state of most insect species in most places. We appraise four emerging tools and technologies (computer vision, acoustic monitoring, radar, and molecular methods) that provide unprecedented opportunities for insect ecology. These technologies can enhance spatial, temporal, and taxonomic coverage of monitoring, but none can monitor all insects at all scales, and each comes with a set of limitations. Technological integration, open data, and international standards are needed to harness the full potential of novel technologies for insect monitoring. [ABSTRACT FROM AUTHOR]

Abstract Wind energy is rapidly growing as a renewable source of energy but is not neutral for wildlife, especially bats. Whereas most studies have focused on bat mortality through collision, very few have quantified the loss of habitat use resulting from the potential negative impact of wind turbines, and none of them for hub heights higher than 55 m. Such impacts could durably affect populations, creating a need for improvement of knowledge to integrate this concern in implementation strategies. We quantified the impact of wind turbines at different distances on the activity of 11 bat taxa and 2 guilds. We compared bat activity at hedgerows (207 sites) located at a distance of 0–1000 m from wind turbines (n = 151) of 29 wind farms in an agricultural region in the autumn (overall 193,980 bat passes) using GLMMs. We found a significant negative effect of proximity to turbines on activity for 3 species (Barbastella barbastellus , Nyctalus leisleiri , Pipistrellus pipistrellus), 2 species-groups (Myotis spp., Plecotus spp.) and 2 guilds (fast-flying and gleaner). Bat activity within 1000 m of wind turbines by gleaners and fast-flying bats is reduced by 53.8% and 19.6%, respectively. Our study highlighted that European recommendations (at least 200 m from any wooded edge) to limit mortality events likely strongly underestimate the loss of bat activity. The current situation is particularly worrying, with 89% of 909 turbines established in a region that does not comply with recommendations, which themselves are far from sufficient to limit the loss of habitat use. Highlights • High negative effect on bat activity of proximity to wind turbines for some species • Some of these species were so far unknown to be impacted by wind turbines. • Activity of gleaners and fast-flying bats close to turbines is reduced by 53.8% and 19.6%. • The impact occurs over 1000 m around wind turbines. • European recommendations are unapplied and far from sufficient for this impact. [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]

Abstract: In order to face the large and worrying biodiversity decline in agricultural landscapes, important policy instruments like agri-environmental schemes (AES) have been implemented. Studies that have examined the ecological effects of AES are now numerous and generally use indicators of biodiversity such as species richness and diversity as well as species abundance. Yet, it has been shown that simple metrics such as species richness or abundance may give misleading messages about biodiversity status and fate. Moreover, those indicators cannot detect another important source of biodiversity loss, biotic homogenisation. In this context, taking into account to a wider extent ecological difference among species would be more relevant, as well as focusing on the species specialisation which is known to be linked to higher species vulnerability. A bibliographic review investigating the criteria generally used to assess the success of AES showed that 55% of studies used species richness and/or abundance exclusively without any consideration of specialisation or other ecological traits in their evaluation of AES effectiveness. Based on data from the French breeding bird survey and studies at regional scale in France on farmland birds, we show that: (i) species richness and specialisation are generally negatively correlated in agricultural areas, (ii) habitat heterogeneity does not benefit specialist species, and (iii) monitoring of species diversity should be coupled with the monitoring of specialist species to improve conservation strategies in farming systems. Overall, this study emphasizes the need to account for both community richness and composition when assessing AES or similar conservation planning. [Copyright &y& Elsevier]

Abstract: Increases in farming practice intensity and landscape simplification are two well-known threats for many farmland bird species. Nevertheless, the effects of these two factors may differ strongly among species. Here, we propose to use the specialist–generalist concept to assess which bird species are most affected by these two factors. Bird density and intensity of farming practices were assessed within a sample of 58 farms across the Seine-et-Marne region in France, using point counts and a standardised farmer survey. The local abundance of 41 farmland and non-farmland species was related to farming intensity (pesticide applications) and landscape simplification (proportion of arable land), which was quantified using generalised least square models to account for spatial autocorrelation. The more specialised the farmland and non-farmland birds were, the more negatively affected they were by the intensity of farming practices, relative to the generalist bird species. Local habitat simplification had a more positive effect on abundance of the most specialist farmland bird species. This latter relationship was not significant when tested at a landscape scale, which strongly suggests that the sensitivity of farmland specialists to landscape simplification is scale-dependent. Some non-farmland species’ abundance was also reduced by farming intensity and local landscape simplification suggesting that low-input agri-environmental measures could benefit both farmland and non-farmland specialists, regardless of local and landscape habitat context. However, if diversity-enhancing measures should benefit non-farmland populations, it is likely that they do not favour farmland specialist species which are more at risk. We suggest designing of priority areas for farmland specialist birds, and landscape managing accordingly. [Copyright &y& Elsevier]

Although positive effects on biodiversity of woody features in agricultural landscapes are widely recognized, questions remain as to which landscape context to prioritize their implementation and in what proportion. To investigate the response of farmland biodiversity to small woody features (SWF) density in different landscape compositions (cropland, grassland, mixed), we analyzed fine-resolution data from standardized monitoring schemes on 111 birds, 22 bats, and 25 bush cricket's species, at national scale (relying on 3772, 834 and 727 monitoring points) over the period 2015–2019, in metropolitan France. We used Generalized Additive Mixed Models to analyze population and community responses, through different metrics (abundance, species diversity, and functional composition). We found a positive response exhibited by the three taxa to SWF, more especially in cropland where the SWF density is the lowest relative to grassland and mixed landscapes. Also, our results suggested a non-linear response common to the three taxa, with an increased benefit up to at least 6 % of SWF density in cropland, and beyond for most of the metrics but to a lesser extent (e.g., maximum abundance reached at 7–12 % SWF). We note, however, that some species among farmland bird specialists are negatively impacted by SWF. Overall, we emphasize the benefits to promote woody features in agricultural landscapes, notably in cropland, to support biodiversity and its associated ecosystem functions. Our study provides crucial empirical evidence to the recommendations from previous studies and the relevance of the EU Biodiversity Strategy for 2030 to dedicate at least 10 % of farmland to high-diversity landscape features. [ABSTRACT FROM AUTHOR]