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Future dynamics of biological invasions are highly uncertain because they depend on multiple social–ecological drivers. We used a scenario-based approach to explore potential management options for invasive species in Europe. During two workshops involving a multidisciplinary team of experts, we developed a management strategy arranged into 19 goals relating to policy, research, public awareness, and biosecurity. We conceived solutions for achieving these goals under different plausible future scenarios, and identified four interrelated recommendations around which any long-term strategy for managing invasive species can be structured: (1) a European biosecurity regime, (2) a dedicated communication strategy, (3) data standardization and management tools, and (4) a monitoring and assessment system. Finally, we assessed the feasibility of the management strategy and found substantial differences among scenarios. Collectively, our results indicate that it is time for a new strategy for managing biological invasions in Europe, one that is based on a more integrative approach across socioeconomic sectors and countries.

1. Invasive alien species are one of the major threats to global biodiversity, ecosystem integrity, nature's contributions to people and human health. While scenarios about potential future developments have been available for other global change drivers for quite some time, we largely lack an understanding of how biological invasions might unfold in the future across spatial scales. 2. Based on previous work on global invasion scenarios, we developed a workflow to downscale global scenarios to a regional and policy-relevant context. We applied this workflow at the European scale to create four European scenarios of biological invasions until 2050 that consider different environmental, socio-economic and socio-cultural trajectories, namely the European Alien Species Narratives (Eur-ASNs). 3. We compared the Eur-ASNs with their previously published global counterparts (Global-ASNs), assessing changes in 26 scenario variables. This assessment showed a high consistency between global and European scenarios in the logic and assumptions of the scenario variables. However, several discrepancies in scenario variable trends were detected that could be attributed to scale differences. This suggests that the workflow is able to capture scale-dependent differences across scenarios. 4. We also compared the Global- and Eur-ASNs with the widely used Global and European Shared Socioeconomic Pathways (SSPs), a set of scenarios developed in the context of climate change to capture different future socio-economic trends. Our comparison showed considerable divergences in the scenario space occupied by the different scenarios, with overall larger differences between the ASNs and SSPs than across scales (global vs. European) within the scenario initiatives. 5. Given the differences between the ASNs and SSPs, it seems that the SSPs do not adequately capture the scenario space relevant to understanding the complex future of biological invasions. This underlines the importance of developin

Future dynamics of biological invasions are highly uncertain because they depend on multiple social–ecological drivers. We useda scenario-based approach to explore potential management options for invasive species in Europe. During two workshops involv-ing a multidisciplinary team of experts, we developed a management strategy arranged into 19 goals relating to policy, research,public awareness, and biosecurity. We conceived solutions for achieving these goals under different plausible future scenarios, andidentified four interrelated recommendations around which any long-term strategy for managing invasive species can be struc-tured: a European biosecurity regime, a dedicated communication strategy, data standardization and managementtools, and a monitoring and assessment system. Finally, we assessed the feasibility of the management strategy and found sub-stantial differences among scenarios. Collectively, our results indicate that it is time for a new strategy for managing biologicalinvasions in Europe, one that is based on a more integrative approach across socioeconomic sectors and countries

The co-occurrence of morphologically similar species may be enabled by differences in resource use that limit the effects of interspecific competition, allowing coexistence. This study aimed to evaluate differences in nest structure and to characterise nesting microhabitats to test for nesting niche segregation among sympatric steppe passerines. From 2016 to 2019, we monitored and characterised the nest structure and nesting habitat of 71 nests from five sympatric passerines in shrub steppes in Central Spain: the Eurasian Skylark Alauda arvensis, the Greater Short-toed Lark Calandrella brachydactyla, Dupont's Lark Chersophilus duponti, the Tawny Pipit Anthus campestris and the Western Black-eared Wheatear Oenanthe hispanica. Nest structure was characterised by eight morphometric variables, while principal component analyses (PCA), MANOVA and univariate ANOVA were performed to characterise and evaluate differences in nesting microhabitat between species in both horizontal and vertical dimensions. All species built their nests under short vegetation (< 20cm) and with a similar nest depth. However, there were significant differences among species for some of the considered variables. For example, the three monitored lark species built their nests in areas with lower plant cover compared to the two non-lark species. GLM on PCA axes showed that some species differed in some aspect of nesting niche. In general, the Eurasian Skylark built its nests in areas with higher grassland cover, while the Greater Short-toed Lark selected more open areas, with a higher bare ground cover. Dupont's Lark, the Tawny Pipit and the Western Black-eared Wheatear nested mainly in shrubby areas dominated by chamaephytes. Overall, our results suggest the existence of nesting microhabitat segregation, mainly of the Eurasian Skylark with the rest of the species, which may contribute to explaining the coexistence between species that could potentially compete for nesting sites. This work contribut, La coexistencia de especies morfológicamente similares puede estar motivada por diferencias en el uso de los recursos que limitan los efectos de la competencia interespecífica, permitiendo la coexistencia. Este estudio tiene como objetivo evaluar las diferencias en la estructura de los nidos y caracterizar los microhábitats de nidificación para probar la segregación del nicho de nidificación entre paseriformes esteparios simpátricos. Entre 2016 y 2019 se monitorizó y caracterizó la estructura del nido y el hábitat de nidificación de 71 nidos de cinco paseriformes simpátricos en estepas arbustivas del centro de España: alondra común Alauda arvensis, terrera común Calandrella brachydactyla, alondra ricotí Chersophilus duponti, bisbita campestre Anthus campestris y collalba rubia Oenanthe hispanica. La estructura de los nidos se caracterizó mediante ocho variables morfométricas mientras que se realizaron análisis de componentes principales (PCA), MANOVA y ANOVA univariante para caracterizar y evaluar las diferencias en el microhábitat de nidificación entre parejas de especies tanto a escala horizontal como vertical. Todas las especies construyeron sus nidos bajo vegetación corta (< 20 cm) y con una profundidad de nido similar; sin embargo, mostraron diferencias entre las especies para algunas de las variables consideradas. Por ejemplo, las tres especies de aláudido construyeron sus nidos en zonas con menor cobertura vegetal en comparación con las otras dos especies. Los GLM sobre los ejes del PCA mostraron que algunas de las especies diferían en algún aspecto del sitio de nidificación. En general, la alondra común construyó sus nidos en zonas con mayor cobertura de pastizales, mientras que la terrera común seleccionó zonas más abiertas, con mayor cobertura de suelo desnudo. La alondra ricotí, el bisbita campestre y la collalba rubia anidaron principalmente en zonas arbustivas dominadas por caméfitos. En general, nuestros resultados sugieren la existencia de una segrega

Open semi-natural ecosystems have been historically shaped by anthropogenic land-use, and the abandonment or intensification of these activities implied a detrimental alteration of their landscapes. Extensive sheep grazing has gradually decreased during the 20th century in Mediterranean steppes, triggering changes across all taxa. Here, we address the effect of sheep grazing on both arthropod biomass and space use by insectivorous steppe birds, using an endangered passerine as a model species. We found that biomass of different arthropod groups peaked at intermediate levels of grazing, and that both short-term grazing (affecting arthropod biomass) and long-term grazing (affecting vegetation structure) explain space use by insectivorous birds, whereas only long-term processes are decisive for bird territory establishment. Our results emphasise the role of sustained moderate grazing intensity in the conservation of steppe biodiversity. In the current decline context of extensive sheep grazing, agricultural policies should prioritise these practices to ensure the persistence of open semi-natural ecosystems.

Bird vocalisations, like any other acoustic signals, attenuate over distance, and therefore their structure degrades progressively. Such degradation may have an impact on the ability of automated signal recognition software, to detect and correctly identify bird vocalisations. BirdNET is a recently launched automated bird song recogniser commonly employed by researchers and the public. However, few studies have assessed its performance and our current knowledge about how BirdNET performance may vary over distance or with species is very limited. I aimed to evaluate whether BirdNET's ability to correctly identify bird vocalisations of three bird species varied over distance or according to recorder type and target species using a playback broadcast from 10 to 150m away. BirdNET's ability to correctly identify bird songs varied among species and generally decreased over distance but did not vary among recorder types. Overall BirdNET recall rate, defined as the percentage of vocalisations detected, and correctly identified, by the software, was 59.9% (499 vocalisations correctly identified of 840 vocalisations broadcast). A significantly higher number of vocalisations were correctly identified when broadcast at 50m or closer (mean recall rate of 92.2%), when compared to vocalisations broadcast farther than that distance (mean recall rate of 34.9%). Recall rate was also significantly higher for the Grasshopper Sparrow and the Hooded Warbler, when compared to the Gray Vireo. The number of misclassifications varied over distances and did not follow a linear pattern. This study provides valuable information that may contribute to improved surveys and for expanding the use of BirdNET for surveying bird communities using passive acoustic monitoring., Las vocalizaciones de las aves, como cualquier otra señal acústica, se atenúan con la distancia y, por lo tanto, la estructura de las vocalizaciones de las aves se degrada progresivamente. Tal degradación puede tener un impacto en la capacidad de programas automatizados de reconocimiento de señales a la hora detectar e identificar correctamente las vocalizaciones de las aves. BirdNET es un reconocedor automatizado de cantos de pájaros de reciente creación y comúnmente empleado por investigadores y el público. Sin embargo, pocos estudios han evaluado su rendimiento y nuestro conocimiento actual sobre cómo el rendimiento de BirdNET puede variar en función de la distancia o entre especies es muy limitado. Aquí, mi objetivo era evaluar si la habilidad de BirdNET para identificar correctamente las vocalizaciones de tres especies de aves variaba según la distancia, el tipo de grabadora empleada y entre especies, utilizando una grabación reproducida de 10 a 150 m. La habilidad de BirdNET para identificar correctamente los cantos de las aves varió entre las especies y, en general, disminuyó con la distancia, pero no varió entre los dos tipos de grabadores testados. La tasa de detección de BirdNET, definida como el porcentaje de vocalizaciones detectadas e identificadas correctamente por el software, fue del 59,9% (499 vocalizaciones identificadas correctamente de las 840 vocalizaciones reproducidas). Se identificó de manera correcta y significativa un mayor número de vocalizaciones cuando se emitieron a 50 m o más cerca (tasa media de detección del 92,2%), en comparación con las vocalizaciones emitidas a más de esa distancia (tasa media de detección del 34,9%). La tasa de detección también fue significativamente más alta para el chingolo saltamontes y la reinita encapuchada, en comparación con el vireo gris. El número de clasificaciones erróneas varió con las distancias y no siguió un patrón lineal. Ese estudio proporciona información valiosa que puede contribuir a mejorar

Parental food provisioning is crucial for the growth and survival of offspring. Growth rate depends on food quality and food supplied to offspring may differ from what adults use for their own. In the case of steppe passerine birds, detailed characterization on nestling dietary composition, as well as prey choice and resource partitioning among species, is a pending subject. Dietary differences between nestlings and adults remain also largely unexplored. By using faecal DNA metabarcoding, we described the diet of nestlings and adults of five shrub-steppe passerine species over the 2017–2019 breeding seasons in central Spain. We also monitored arthropod availability in the field to assess dietary selection. We expected interspecific dietary differences to limit competition for food resources among sympatric species, as well as parental selection of high quality prey for nestlings. We also predicted age-related differences, with nestlings being fed nutrient-rich prey more frequently than adults. The main arthropod orders provisioned to nestlings were Orthoptera, Julida, Araneae and Lepidoptera. Nestlings of the different species showed high interspecific diet overlap, indicating both a coincidence in growth needs among bird species and no or little limitation of the most profitable resources during the breeding season. Adults of all species showed higher diet richness than nestlings, and age-related differences in prey composition were mainly driven by the selection of the most easily digestible, larger protein- and calcium-rich prey for nestlings, which may favour their rapid growth, and avoiding highly sclerotized and less nutritional prey such as ants. Our study sheds light on the basic ecology and conservation of these declining steppe birds, indicating that interspecific competition may not be a major factor during the breeding season. Given the current global decline of arthropods, further long-term research would be necessary, along with the implementation of e

1. Invasive alien species are one of the major threats to global biodiversity, ecosystem integrity, nature's contributions to people and human health. While scenarios about potential future developments have been available for other global change drivers for quite some time, we largely lack an understanding of how biological invasions might unfold in the future across spatial scales. 2. Based on previous work on global invasion scenarios, we developed a workflow to downscale global scenarios to a regional and policy-relevant context. We applied this workflow at the European scale to create four European scenarios of biological invasions until 2050 that consider different environmental, socio-economic and socio-cultural trajectories, namely the European Alien Species Narratives (Eur-ASNs). 3. We compared the Eur-ASNs with their previously published global counterparts (Global-ASNs), assessing changes in 26 scenario variables. This assessment showed a high consistency between global and European scenarios in the logic and assumptions of the scenario variables. However, several discrepancies in scenario variable trends were detected that could be attributed to scale differences. This suggests that the workflow is able to capture scale-dependent differences across scenarios. 4. We also compared the Global- and Eur-ASNs with the widely used Global and European Shared Socioeconomic Pathways (SSPs), a set of scenarios developed in the context of climate change to capture different future socio-economic trends. Our comparison showed considerable divergences in the scenario space occupied by the different scenarios, with overall larger differences between the ASNs and SSPs than across scales (global vs. European) within the scenario initiatives. 5. Given the differences between the ASNs and SSPs, it seems that the SSPs do not adequately capture the scenario space relevant to understanding the complex future of biological invasions. This underlines the importance of developin

Food availability plays a key role affecting almost every aspect of bird ecology, including bird population, distribution, reproduction, and behavior. Understanding the functional relationship between prey availability and insectivorous birds’ diet is important in the current scenario of habitat loss and declining of insect and bird populations. We used a fecal metabarcoding approach coupled with prey availability sampling (arthropod abundance and biomass) to test for evidence of selective foraging in a shrub-steppe passerine assemblage over the 2017–2019 breeding seasons in semi-natural steppes of central Spain. The results showed that the six bird species selected specific arthropod taxa. Heteroptera, Orthoptera, Araneae, Lepidoptera and some Coleoptera families were the main selected prey taxa, while Formicidae appeared to be avoided, suggesting that shrub-steppe passerines tend to select prey items providing essential nutrients and energy during the breeding season, while poor quality ones are neglected. Our findings highlight the utility of metabarcoding dietary data to assess prey selection patterns in insectivorous passerines and provide valuable information for the development of conservation and management programs to ensure the long-term availability of crucial food resources for shrub-steppe birds and other insectivores.

The Asian hornet (Vespa velutina) has rapidly become a source of stress for the beekeeping sector. Several methods have been developed to control its impact and spread, though some of these impose a high risk for native insects. Among these methods are electric harps, which are physical barriers that electrocute hornets pass through two wires powered by a current generator. Here we evaluated the selectiveness and risk of damage for local entomofauna of the electric harps in a study carried out over three years and four locations in Girona province (NE Catalonia, Spain). The electric harps showed a high selectiveness, with 90.5% of all insects trapped (3331 individuals) catalogued as Asian hornets, although this greatly varied over years and locations with values ranging from 29.9 to 94.3%. The risk of damage to electric harps for local entomofauna was very low in all surveyed areas and years. Native insects, excluding domestic honey bees, accounted for, as a mean, 1.2% of all insects trapped over the study period (range 0–2.4%). Our results suggest that electric harps might be a useful environmentally-friendly method aiming to reduce predation pressure of the Asian hornet at beehives.

The Dupont’s lark (Chersophilus duponti) is an endangered passerine typical of Mediterranean shrub-steppes, whose European distribution is restricted to Spain. Here, we update the population size and distribution range of the species at a European scale and evaluate (i) the current status; (ii) the change in population size and distribution range of the species from 2004 to 2009 to the current period (2017–2022); and (iii) the effectiveness of the current network of special protection areas (SPAs) for protecting the Dupont’s lark. The European Dupont’s lark population showed a decrease of 29.9%, declining from ca. 3267 to 2289 territorial males from 2004 to 2009 to the current period. Moreover, the species has suffered a contraction in its distribution range of 35.9%, with only 39.3% of the species’ territories located within the current network of SPAs. Our findings agree with the previously described decline of the Dupont’s lark in Europe. The population decline was even larger in peripheral regions, which suggests that the species is suffering a centripetal process of contraction and extinction. These results indicate that if there is no change in present-day declining forces, several peripheral populations will reach extinction in a few decades and the overall population size of the species will continue decreasing. Our study should be considered as a last call for action and used for implementing urgent conservation measures to protect the species and its habitat. Future studies should focus on analyzing and managing the factors driving the species’ extinction and future actions for the conservation of the species should focus on increasing the percentage of the Dupont’s lark territories within protected areas, since the data are alarmingly low for a species that is facing clear risk of extinction.

The efficient analyses of sound recordings obtained through passive acoustic monitoring (PAM) might be challenging owing to the vast amount of data collected using such technique. The development of species-specific acoustic recognizers (e.g., through deep learning) may alleviate the time required for sound recordings but are often difficult to create. Here, we evaluate the effectiveness of BirdNET, a new machine learning tool freely available for automated recognition and acoustic data processing, for correctly identifying and detecting two cryptic forest bird species. BirdNET precision was high for both the Coal Tit (Peripatus ater) and the Short-toed Treecreeper (Certhia brachydactyla), with mean values of 92.6% and 87.8%, respectively. Using the default values, BirdNET successfully detected the Coal Tit and the Short-toed Treecreeper in 90.5% and 98.4% of the annotated recordings, respectively. We also tested the impact of variable confidence scores on BirdNET performance and estimated the optimal confidence score for each species. Vocal activity patterns of both species, obtained using PAM and BirdNET, reached their peak during the first two hours after sunrise. We hope that our study may encourage researchers and managers to utilize this user-friendly and ready-to-use software, thus contributing to advancements in acoustic sensing and environmental monitoring.

Invasive alien species are one of the major threats to global biodiversity, ecosystem integrity, nature's contributions to people and human health. While scenarios about potential future developments have been available for other global change drivers for quite some time, we largely lack an understanding of how biological invasions might unfold in the future across spatial scales. Based on previous work on global invasion scenarios, we developed a workflow to downscale global scenarios to a regional and policy-relevant context. We applied this workflow at the European scale to create four European scenarios of biological invasions until 2050 that consider different environmental, socio-economic and socio-cultural trajectories, namely the European Alien Species Narratives (Eur-ASNs). We compared the Eur-ASNs with their previously published global counterparts (Global-ASNs), assessing changes in 26 scenario variables. This assessment showed a high consistency between global and European scenarios in the logic and assumptions of the scenario variables. However, several discrepancies in scenario variable trends were detected that could be attributed to scale differences. This suggests that the workflow is able to capture scale-dependent differences across scenarios. We also compared the Global- and Eur-ASNs with the widely used Global and European Shared Socioeconomic Pathways (SSPs), a set of scenarios developed in the context of climate change to capture different future socio-economic trends. Our comparison showed considerable divergences in the scenario space occupied by the different scenarios, with overall larger differences between the ASNs and SSPs than across scales (global vs. European) within the scenario initiatives. Given the differences between the ASNs and SSPs, it seems that the SSPs do not adequately capture the scenario space relevant to understanding the complex future of biological invasions. This underlines the importance of developing independent b

The Dupont’s lark (Chersophilus duponti) is an endangered passerine typical of Mediterranean shrub-steppes, whose European distribution is restricted to Spain. Here, we update the population size and distribution range of the species at a European scale and evaluate (i) the current status; (ii) the change in population size and distribution range of the species from 2004 to 2009 to the current period (2017–2022); and (iii) the effectiveness of the current network of special protection areas (SPAs) for protecting the Dupont’s lark. The European Dupont’s lark population showed a decrease of 29.9%, declining from ca. 3267 to 2289 territorial males from 2004 to 2009 to the current period. Moreover, the species has suffered a contraction in its distribution range of 35.9%, with only 39.3% of the species’ territories located within the current network of SPAs. Our findings agree with the previously described decline of the Dupont’s lark in Europe. The population decline was even larger in peripheral regions, which suggests that the species is suffering a centripetal process of contraction and extinction. These results indicate that if there is no change in present-day declining forces, several peripheral populations will reach extinction in a few decades and the overall population size of the species will continue decreasing. Our study should be considered as a last call for action and used for implementing urgent conservation measures to protect the species and its habitat. Future studies should focus on analyzing and managing the factors driving the species’ extinction and future actions for the conservation of the species should focus on increasing the percentage of the Dupont’s lark territories within protected areas, since the data are alarmingly low for a species that is facing clear risk of extinction.

The frequency and intensity of extreme weather events represent a threat for biological diversity and are expected to increase in many regions over the following decades due to climate change. Our current knowledge about the impact of extreme weather events on the population dynamics of bird species is very limited. Here, we evaluated the impact of an extreme winter snowstorm on the abundance of 14 populations of the threatened Dupont’s Lark Chersophilus duponti, a resident bird whose European population is restricted to Spain. We found a drastic and significant population decline in the next reproductive season following the extreme weather event. During the control period (2017–2020) the species suffered an overall annual decline of 19.4% (±5.0, SE). However, the overall annual decline after the storm was 67.6% (±9.4, period 2019–2021), with a mean decline of 66.5% (±15.9) for seven populations monitored both the year before and the year after the snowstorm (period 2020–2021). The snow covered the ground for over 10 days in central and eastern Spain, which together with a subsequent extreme cold wave could have reduced the species ability to find food resources and properly thermoregulate, forcing the species to move to unknown areas. Indeed a few days after the storm, several individuals were reported in areas typically avoided. Such displacements may increase the mortality risk for dispersing individuals, besides the direct effects of the extreme cold event, such as thermal challenges to energy balance or a reduced immune function. We discuss the potential role that extreme weather events may have on the population dynamics and conservation of the species.

Automated recognition software is paramount for effective passive acoustic monitoring. BirdNET is a free and recently developed bird sound recognizer. I performed a literature review to evaluate the current applications and performance of BirdNET, which is growing in popularity but has been subject to few assessments, and to provide recommendations for future studies using BirdNET. Prior research has employed BirdNET for a wide range of purposes but few studies have linked BirdNET detections to ecological processes or real-world monitoring schemes. Among evaluated studies, average precision (% detections correctly identified) usually ranged around 72–85%, and recall rate (% target species vocalizations detected) ranged around 33–84%. Some studies did not assess BirdNET performance, which hampers the interpretation of the ecological results and may provide poorly informed decisions. Recommendations on how to evaluate BirdNET efficiency are provided. The impact of the confidence score threshold, a user-selected parameter as the minimum score for detections reported, on BirdNET output although variable among species is consistent. The use of high confidence score thresholds increases the percentage of detections correctly classified but lowers the proportion of calls and bird species detected. The selection of an optimal score may depend on the priorities of the user and research goals. BirdNET is a great tool for automated bird monitoring but it should be used with caution due to inherent challenges for automated bird identification. The continued refinement of BirdNET suggests further improvements in the coming years.

Passive acoustic monitoring coupled with automated signal recognition software has been widely used in recent years as an effective and affordable tool for wildlife monitoring and to combat illegal activities within protected areas. Here, we evaluate this technique to monitor the patterns of illegal cattle occurrence in the Brazilian Pantanal over a complete annual cycle. We aim to provide one of the first assessments of the performance of automated signal recognition software to detect ungulates. Cattle occurrences reached their maximum during the end of the dry season when lowland areas provide excellent pastures for cattle. In contrast, cattle occurrences were very low during the rainy season when the study area was seasonally inundated. Automated software was an efficient tool that was able to detect approximately three-quarters of cow calls within the recordings. Passive acoustic monitoring can be used to direct patrols to areas where illegal activities, such as cattle and poaching or logging, have been confirmed, which could be a method that would be especially well suited for remote areas, such as tropical forests. Future studies should evaluate whether there is a relationship between cattle grazing intensity and its associated impacts on wildlife and flora. Rapid advances in automated recognition and the recent development of low-cost recorders foresee a new era of acoustic ecology for improved conservation in the short term.

A comprehensive review of the natural history of the Woodlark Lullula arborea in Spain.