Passive acoustic monitoring and automated detection of the American bullfrog

Biological invasions pose significant threats to biodiversity and ecosystem functioning. Removal of introduced species is most successful when detected early. We evaluate the effectiveness of passive acoustics combined with automated recognition in detecting the invasive American bullfrog (Lithobates catesbeianus). We applied this technique to two real-world monitoring programs aimed at determining the optimal time of day for monitoring the species in Europe, for which we recorded the species in Belgium and Italy; and for evaluating the effectiveness of BirdNET (a free and user-friendly automated recognizer) in analyzing a large dataset collected in Spain. BirdNET was highly effective in automatically detecting the bullfrog presence, with a detection rate (compared to visual inspection of sonograms) of 89.5% using default settings (85 of 95 recordings with known presence), and 95.8% with user-specific settings (91 of 95 recordings detected). The system showed remarkable precision, correctly identifying 99.7% (612 out of 614) of the verified predictions, and with only one mislabelled recording (predicted to be present when it was absent). The species’ vocal activity in Belgium and Italy was higher during the night compared to crepuscular periods. Recording analyses and output verification of the dataset collected in Spain was carried out in 3.8% of the recorded time, and resulted in significantly reduced effort compared to visual inspection. Our study highlights the effectiveness of this technique for remotely surveying the American bullfrog, making it a significantly potential tool for informing management decisions, particularly for the early detection of the species’ arrival in new areas.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This project was partially funded by the Department of Climate Action, Food, and Rural Agenda of Catalan Regional Government. CP-G acknowledges the support of the Ministerio of Educación y Formación Profesional through the Beatriz Galindo Fellowship (Beatriz Galindo – Convocatoria 2020)

Forest expansion in mountain protected areas: trends and consequences for the landscape

Mountain regions in Western Europe have gone through a massive rural–urban migration and the collapse of their traditional socioeconomic system. As a result, forest has occupied many old pastures and croplands. In protected areas – such as National Parks – changes in the landscape can affect biodiversity and other services, including the values that motivated their declaration. Any policy decision in these areas requires quantifying the extent and impact of land-cover changes and their consequences on landscape structure and functioning. In this study we analyze the patterns of change in forest cover during six decades in three mountain National Parks in Spain. Our aim is to quantify those patterns, their effects on the landscape, and discuss the potential consequences for the main natural values and services. We assessed changes in forest cover through reclassification of aerial ortophotographs taken in 1956–57 (past images) and 2016–17 (recent images). The three Parks show a relatively low change in total forest area (+5–10%), and a much larger increase in dense forest (+20–30%), with an important effect of land-use legacies, and similar patterns of landscape homogenization. There were fewer but larger forest patches in 2016 than in 1956, and most of the gain in dense forest occurred in core areas (+20%), while transition areas such as edges, bridges or loops decreased between 30 and 55%. Given their potential consequences on biodiversity and other services, these patterns of land-cover change and landscape configuration should be explicitly considered when designing the sustainable management of abandoned landscapes in protected areas.This work was supported by the Spanish National Parks Autonomous Agency (OAPN) through the research grant GESCLIMFOR (979S/2013), and by the Ministry of Science through the project VULBIMON (CGL2017-90040-R) and a Juan de la Cierva contract to Aitor Ameztegui (IJCI-2016-30049

Data from: Spatial prioritisation of EU’s LIFE-Nature program to strengthen the conservation impact of Natura 2000

1. Despite advances in conservation efforts within Europe during recent decades, assessments highlight a need for adequate financing mechanisms to support the Natura 2000 network; the centrepiece of the EU´s Biodiversity Strategy. Besides the need for greater investment (currently only covering a fifth of the estimated cost of the network), better planning for this investment could help better achieve conservation goals. 2. We demonstrate a method that could be used to identify priority Natura 2000 sites, and species therein, that could guide investment in the future. We first used the lists of key species associated with each Natura 2000 site to map the distribution of all priority species covered by the Birds and Habitats Directives. We then used Marxan software to prioritise allocation of conservation funds among all Natura 2000 sites, while trying to mimic the observed conservation effort implemented under the LIFE Program, the main financial tool of the EU´s Biodiversity Strategy, in the period 1992-2013. 3. Some Natura 2000 sites show exceptional value, holding species that either do not, or only very rarely, occur elsewhere in the network. These priority sites were concentrated mainly on islands and in the south western, eastern and northern extremes of Europe´s mainland thus reflecting patterns in species richness and endemism. 4. We found a poor relationship between the priorities identified here and the way funds had been distributed in previous LIFE-Nature Programs. 5. Policy implications. We propose that prioritisation exercises like the one shown here could be used to inform a top-down EU regulation mechanism by providing lists of site and species priorities that better reflect European conservation needs. These recommendations, performed at continental scale, could then help guide LIFE project proposals from the Member States and fill the current gap in the coverage of priority species. This top-down control mechanism could be integrated in the current system of budget distribution, rather than replacing it completely, to enhance the efficiency of conservation investment in the EU and achievement of continental goals.18-Jan-201

Hermoso et al

Distribution of key species in Natura 2000, used in this stud

Contrasting impacts of precipitation on Mediterranean birds and butterflies

The climatic preferences of the species determine to a large extent their response to climate change. Temperature preferences have been shown to play a key role in driving trends in animal populations. However, the relative importance of temperature and precipitation preferences is still poorly understood, particularly in systems where ecological processes are strongly constrained by the amount and timing of rainfall. In this study, we estimated the role played by temperature and precipitation preferences in determining population trends for birds and butterflies in a Mediterranean area. Trends were derived from long-term biodiversity monitoring data and temperature and precipitation preferences were estimated from species distribution data at three different geographical scales. We show that population trends were first and foremost related to precipitation preferences both in birds and in butterflies. Temperature preferences had a weaker effect on population trends, and were significant only in birds. The effect of precipitation on population trends operated in opposite directions in the two groups of species: butterfly species from arid environments and bird species from humid habitats are decreasing most. Our results indicate that, although commonly neglected, water availability is likely an important driver of animal population change in the Mediterranean region, with highly contrasting impacts among taxonomical groups

Designing an optimal large-scale reintroduction plan for a critically endangered species

1. Optimization methods are routinely used for landscape-level conservation planning, but still underused in supporting species recovery programs. A possible barrier is the difficulty in representing and optimizing complex multidimensional problems: for example, many species recovery programs require management at the population level, but also allocation of effort and resources across populations and over time. Optimization methods can help, but they must strike a balance: too much realism can be computationally unfeasible, but too much simplification can limit relevance for complex programs, exactly where decision support might be most needed. 2. We show how integer linear programming can be used to solve such a complex problem, combining multiple site-level demographic models with realistic management constraints under different sources of stochasticity and uncertainty. We apply this protocol to reintroduction planning for the critically endangered Montseny brook newt Calotriton arnoldi, optimizing site restoration efforts, captive releases from limited and variable stocks, and short-and long-term monitoring, all across 17 sites over 10 years. 3. For C. arnoldi, the optimal solution was generally to open as many sites as possible, as soon as allowed by budget, and to reinforce sites with additional releases. The number of new populations that could be established was limited not only by the high initial costs of restoring and preparing sites for releases, but also because opening new sites would require subsequent monitoring, eventually adding up to unsustainable costs. 4. Synthesis and applications. Our results suggest releases of Calotriton arnoldi should be dictated first by habitat restoration capacity, then by long-term sustainability. More generally, our study shows how quantitative decision-support methods can improve the value of science for conservation, and help managers find solutions to complex problems. However, deploying those methods requires close collaboration between managers and scientists, to ensure models are realistic, results are relevant, and the whole process is informative

Global Warming and Long-Distance Spread of Invasive <i>Discoglossus pictus</i> (Amphibia, Alytidae): Conservation Implications for Protected Amphibians in the Iberian Peninsula

Discoglossus pictus is a North African amphibian that was introduced in southern France early the 20th century and has spread south and north along the Mediterranean coastal plains up to 170 km. In order to disentangle the conservation implications of the spread of D. pictus for sensitive native species, we examined the impact of long-term climate warming on the basis of niche overlap analysis, taking into account abiotic factors. The study area covered the distribution ranges of all genus Discoglossus species in northwestern Africa (659,784 km2), Sicily (27,711 km2), the Iberian Peninsula, and southern France (699,546 km2). Niche overlap was measured from species environmental spaces extracted via PCA, including climate and relief environmental variables. Current and future climatic suitability for each species was assessed in an ensemble-forecasting framework of species distribution models, built using contemporary species data and climate predictors and projected to 2070′s climatic conditions. Our results show a strong climatic niche overlap between D. pictus and native and endemic species in the Iberian Peninsula. In this context, all species will experience an increase in climatic suitability over the next decades, with the only exception being Pelodytes punctatus, which could be negatively affected by synergies between global warming and cohabitation with D. pictus.</i

PRECIPITATION DEFICIT OR INCREASED WARMING? WHICH ONE IS DRIVING THE IMPACT OF CLIMATE CHANGE ON MEDITERRANEAN BIRD POPULATIONS?

Climate change is often equated to climate warming because it’s more prominent global effect is the increase of temperature. In Europe as a whole, as well as in their temperate and boreal regions, there are already strong evidences that temperature rise is shifting bird populations and communities. However, this general pattern has not been clearly found in the Mediterranean region, where the majority of ecosystems are more shaped by water availability than by temperature constraints, and where climate change is also associated with decreased rainfall. In this study we compared the part played by temperature and precipitation preferences in driving bird population trends in Catalonia (north-west Mediterranean basin). Trends were estimated with long-term monitoring data and the temperature and precipitation preferences were calculated using atlas data