Understanding species' evolutionary history is essential for comprehending trait diversity. Evolutionary relationships among many species, however, have conflicted phylogenetic inferences due to evolutionary discordances and need additional sources of information. Phylogenetic relationships of symbionts can inform about the evolution of their hosts. In this study, we reconstructed the evolutionary relationships among Sardinian salamander ectoparasitic leeches to resolve evolutionary discordances among their hosts, the Sardinian Speleomantes salamander species, and proposed novel evolutionary hypotheses that account for host-parasite evolutionary processes. We inferred the most up-to-date phylogeny for Batracobdella leeches and uncovered high levels of genetic diversity in B. algira, a species commonly known as the amphibian leech, revealing three divergent lineages. Leech phylogeny complemented previous information about Sardinian Speleomantes evolutionary history. Our comparison of this parasite phylogeny with the most recent inferred salamander tree revealed potential processes of host-parasite co-evolution and a host-switching event in the studied system. In both trees, a clade comprising species with the most northeastern distributions in Sardinia (S. flavus, S. imperialis, and S. supramontis and their respective leeches) was recovered. The phylogenetic position of the S. genei ectoparasitic leech was incongruent with that of its host in previous studies, which recovered S. genei as sister to the other Sardinian Speleomantes. Disentangling the evolutionary processes underlying these host-parasite interactions is important for understanding not only the evolution of these parasitic leeches but also that of their amphibian hosts.

Emerging infectious diseases are one of the biggest challenges in a globalized world. To date, resources have been allocated to prevent and control the spread of zoonotic and livestock pathogens. We argue that, in line with the One Health approach, equitable efforts, financial resources, attention, and coordination are required for wildlife-only pathogens to halt biodiversity loss. Deploying the amphibian fungus Batrachochytrium salamandrivorans as a model, we demonstrate the unbalanced efforts among countries in Europe regarding surveillance, disease response, prevention, public outreach, and research. We compare investments with B. salamandrivorans l-free countries such as the United States, concluding that structural resources are urgently needed to curb the effects of this fungus within Europe and beyond. We encourage dialogue among authorities, researchers, and stakeholders and propose a coordinated European Union-level program of €6-10 million over 5-7 years to implement B. salamandrivorans action plans and define structural funding requirements for future wildlife disease mitigation.

Aims Island ecosystems represent a paramount opportunity to investigate interspecific interactions and ecological niche dynamics under constrained conditions. This study investigates how insularity and species coexistence influence the spatial distribution, ecological niche differentiation, and morphological adaptations of long-eared bats (Plecotus spp.) in a central area of the Mediterranean.Location Italy.Taxon Plecotus auritus, Plecotus austriacus and Plecotus sardus.Methods We used an integrated approach combining species distribution models, ecological niche analyses, and morphometric comparisons to investigate P. auritus and P. austriacus across the Italian Peninsula and the endemic P. sardus restricted to Sardinia island.Results A significant niche differentiation among the three species in Sardinia occurred, with P. auritus mostly occurring at high elevations and P. austriacus and P. sardus exhibiting spatial overlap. Insular populations exhibited reduced niche widths. Comparison between insular and mainland populations revealed significant size differences, with insular bats showing large body sizes, particularly P. sardus, which is the largest among the three species.Conclusions Conservation efforts should prioritise habitat protection and management strategies that account for the unique ecological dynamics of island bat populations. This study highlights the complexity of interspecific interactions and morphological adaptations in insular environments and provides insights into the ecological and evolutionary processes shaping bat communities on Mediterranean islands.Time Period Current.

BackgroundConspicuous color patterns are traditionally believed to advertise the toxicity of prey to potential predators. However, many aposematic species show drastic variation in coloration, indicating the possibility of other functions of coloration such as intraspecific communication. To study these other functions, we can investigate the influence of intrinsic (e.g., sex) and external factors (e.g., climate) on color variation. We used the aposematic European fire salamander (Salamandra salamandra) to study drivers of variation in the yellow-to-black ratio of the dorsal coloration based on citizen science data available in a new online database.ResultsOur results suggest a widespread sexual dichromatism in fire salamanders in Germany with males displaying a larger yellow-to-black ratio, i.e. are more yellow, than females. This dichromatism persisted even after correcting for a sex-difference in body shape that accounts for some of the variation in the yellow-to-black ratio. Among six investigated putative drivers of this color variation, the proportion of the aposematic yellow coloration increased with latitude but showed no association with other environmental variables such as temperature or the productivity of the habitat.ConclusionsIntegrating citizen science data in this study enabled a comparison of fire salamander populations across large parts of their distribution and highlights widespread sexual dichromatism. Future studies should further investigate potential mechanisms of mate choice in fire salamanders and other selective forces on coloration such as differential predation pressure between both sexes or the role in crypsis. Lastly, multi-national studies supported by citizen science data could fully unravel the extent of color variation in this species.

Harlequin frogs, genus Atelopus, are a species-rich group of bufonid anurans from the Neotropics with more than 100 species. For nearly four decades now, this group has suffered from massive population declines. Almost all species are threatened with extinction, and many populations and several species are considered extinct or possibly extinct. This results in a limited sampling available for studies on harlequin frog systematics, especially in terms of molecular genetic information. However, efficient conservation of harlequin frogs requires an improved taxonomy. This is further complicated through the circumstance that many Atelopus species are relatively poor in external morphological characters combined with a high level of intra-specific character variation (e.g. coloration and body size). At the same time, cryptic diversity exists with well differentiated species (supported by osteology and molecular genetics) almost indistinguishable by external morphology. We compiled the largest dataset to date for mitochondrial (12S, 16S, cyt b) and nuclear (POMC, RAG1) markers and present a phylogeny (likelihood and Bayesian inference methods) including 152 samples from 104 populations scattered over the entire geographic range of the genus. Four allo- or parapatric main clades are distinguished: I. Sierra Nevada; II. Venezuelan-Andean; III. Andean-Chocó-Central American (with the ignescens and the varius-longirostris clades); and IV Amazonian (containing the tricolor and the flavescens-spumarius clades). The phylogenetic relationships within these clades remain to be resolved. Taxonomic implications included both splitting and lumping, but taxonomic action is here only taken for populations related to A. spumarius from western Amazonia. Besides redescriptions of A. spumarius sensu stricto and A. colomai, we describe two new species based on morphology, skull osteology and bioacoustics. Additional yet understudied populations from Amazonia may be allocated to these species or may represent additional undescribed taxa.

Human-induced pressures such as climate and land-use changes in the Anthropocene disproportionately threaten island ecosystems and the endemic species they host. Shedding light on the ecological needs of island species is key to the conservation of these fragile ecosystems and their unique species. Here we present the ecological needs of a bat species endemic to Sardinia, the long-eared bat Plecotus sardus, and analyse the relationship between this Critically Endangered species and the insular environment at different spatial scales to inform action for its conservation. We show that besides displaying a unique phenology and roost use, the species is closely associated with the dry broadleaf forests of native oaks Quercus ilex and Quercus suber at all scales and, in contrast, is negatively affected by coniferous stands, open pastures and urban environments. Our results not only provide key information for the conservation of P. sardus but also provide insights into the unique adaptations of insular endemic species to the fragile island ecosystems, highlighting the importance of ecological studies to informing conservation in biodiversity hotspots. We also demonstrate that protection and restoration of key habitats, particularly within 2 km of roosts, are key to protecting the few known reproductive colonies.

The role of evolutionary and ecological processes with regard to the bauplan of anuran larvae remains little understood. We studied tadpoles of 144 lentic or lotic taxa in 22 families from seven zoogeographic regions. Using stacked high-resolution images, standardized examination of 30 morphological characters of preserved tadpoles (of body, tail, oral disc) were scored and compared to the impact of phylogenetic signal (multiple nuclear and mitochondrial markers) and macro-climate. Additionally, larvae were characterized as living in a lentic versus lotic environment and if nutrition specialist or not. Categorical Principal Component Analysis, distance matrices and pairwise correlation analyses were performed. Our results suggest that phylogeny has a higher impact on the morphology than habitat (i.e. lentic, lotic), while no effect of macro-climate or food specialization was found. We emphasize the value of highly standardized morphological data when investigating the influence of different factors of phenotypic variation.

Crop rotation is an important strategy for pest reduction. For mono-, or oligophagous pests that overwinter at a previously infested site, crop rotation means that the pests must find new host crop sites in the following year, and it is more efficient if a pest-specific distance is applied. Here, we report the development of a GIS-based tool for efficient cultivation planning using the example of the pest complex pea moth (Cydia nigricana) and grain and green peas (Pisum sativum). Monitoring data for four consecutive years (2016–2019) from 513 sites were used. Infestation of pea seeds and the distance to the previous year’s pea sites were recorded. An adjustable Python script was developed by means of infestation–distance–correlation as a pest and crop-specific minimum migration distance (MD). The output of the tool is a risk map as decision support for cultivation planning. It shows different risk buffers with distances from 1261 m to 1825 m, depending on the cultivation type. The web tool is easily adjustable to other pests and crops anywhere in the world. The tool helps to prevent damages caused by agricultural, mono-, or oligophagous insect pests and consequently reduces pesticide applications for the benefit of the environment and biodiversity.

Bats are the second largest mammalian order and are an endangered species group with a strong need for contamination monitoring. To facilitate non-invasive monitoring of the ecological burden in bat populations, a multiresidue method for the simultaneous quantification of 119 analytes including pesticides, persistent organic pollutants (POPs), active pharmaceutical ingredients (APIs), polycyclic aromatic hydrocarbons (PAHs), UV blockers, plasticizers, and other emerging pollutants in bat guano with gas chromatography tandem mass spectrometry (GC-MS/MS) was developed. Sample preparation and clean-up were performed with a modified QuEChERS approach based on DIN EN 15662. The method uses 1.00 g bat guano as sample with acetonitrile and water for liquid-liquid extraction. Phase separation is assisted by citrate-buffered salting out agent. For clean-up of the extract, primary secondary amine (PSA) was combined with graphitized carbon black (GCB). The lower limits of quantification (LLOQ) ranged between 2.5 and 250 µg kg−1. Linearity was shown in a concentration range from the respective LLOQs to 1250 µg kg−1. The median of the mean recovery was 102.4

Many pests damage pea crops, which potentially leads to reduced quality and yield losses. Since pests occur at different phenological growth stages of pea crops, the prediction of growth stages, for example as BBCH stages, is beneficial. In this study, three models have been developed to simulate growth stages of grain and green pea crops, for the latter with early and late sowing dates. All data, such as BBCH stages and air temperature, were collected in Germany in a three-year study under practical farming conditions at 415 sample sites. For the development of each model, a Gompertz regression model based on the observed data was performed. The model validation suggests that each model precisely and reliably predicts pea crop growth stages for spring-sown peas. Amongst others, the RMSEIndex for grain peas was 3.4; for green peas, early and late sowing dates, respectively, they were 3.4 and 4.5. SIMONTO-Pea (SIMulation of ONTOgenesis) is the first model that predicts detailed pea crop growth stages based on the BBCH scale. This innovation is especially beneficial for users such as advisors and farmers dealing with spring-sown pea crops as a decision support system in monitoring and pest management according to pea crop growth stages.

For many species, population sizes are unknown despite their importance for conservation. For population size estimation, capture-mark-recapture (CMR) studies are often used, which include the necessity to identify each individual, mostly through individual markings or genetic characters. Invasive marking techniques, however, can negatively affect the individual fitness. Alternatives are low-impact techniques such as the use of photos for individual identification, for species with stable distinctive phenotypic traits. For the individual identification of photos, a variety of different software, with different requirements, is available. The European fire salamander (Salamandra salamandra) is a species in which individuals, both at the larval stage and as adults, have individual specific patterns that allow for individual identification. In this study, we compared the performance of five different software for the use of photographic identification for the European fire salamander: Amphibian & Reptile Wildbook (ARW), AmphIdent, I3S pattern+, ManderMatcher and Wild-ID. While adults can be identified by all five software, European fire salamander larvae can currently only be identified by two of the five (ARW and Wild-ID). We used one dataset of European fire salamander larval pictures taken in the laboratory and tested this dataset in two of the five software (ARW and Wild-ID). We used another dataset of European fire salamander adult pictures taken in the field and tested this using all five software. We compared the requirements of all software on the pictures used and calculated the False Rejection Rate (FRR) and the Recognition Rate (RR). For the larval dataset (421 pictures) we found that the ARW and Wild-ID performed equally well for individual identification (99.6% and 100% Recognition Rate, respectively). For the adult dataset (377 pictures), we found the best False Rejection Rate in ManderMatcher and the highest Recognition Rate in the ARW. Additionally, the ARW is the only program that requires no image pre-processing. In times of amphibian declines, non-invasive photo identification software allowing capture-mark-recapture studies help to gain knowledge on population sizes, distribution, movement and demography of a population and can thus help to support species conservation.

Amphibians globally suffer from emerging infectious diseases like chytridiomycosis caused by the continuously spreading chytrid fungi. One is Batrachochytrium salamandrivorans (Bsal) and its disease ‒ the ‘salamander plague’ ‒ which is lethal to several caudate taxa. Recently introduced into Western Europe, long distance dispersal of Bsal, likely through human mediation, has been reported. Herein we study if Alpine salamanders (Salamandra atra and S. lanzai) are yet affected by the salamander plague in the wild. Members of the genus Salamandra are highly susceptible to Bsal leading to the lethal disease. Moreover, ecological modelling has shown that the Alps and Dinarides, where Alpine salamanders occur, are generally suitable for Bsal. We analysed skin swabs of 818 individuals of Alpine salamanders and syntopic amphibians at 40 sites between 2017 to 2022. Further, we compiled those with published data from 319 individuals from 13 sites concluding that Bsal infections were not detected. Our results suggest that the salamander plague so far is absent from the geographic ranges of Alpine salamanders. That means that there is still a chance to timely implement surveillance strategies. Among others, we recommend prevention measures, citizen science approaches, and ex situ conservation breeding of endemic salamandrid lineages.

Recognizing the influence of pathogen diversity on infection dynamics is crucial for mitigating emerging infectious diseases. Characterising such diversity is often complex, for instance when multiple pathogen variants exist that interact differently with the environment and host. Here, we explore genotypic and phenotypic variation of Batrachochytrium salamandrivorans (Bsal), an emerging fungal pathogen that is driving declines among an increasing number of European amphibian species. For thirteen isolates, spanning most of the known temporal and geographical Bsal range in Europe, we mapped phenotypic diversity through numerous measurements that describe varying reproductive rates in vitro across a range of temperatures. Bsal isolates are revealed to have different thermal optima and tolerances, with phenotypic variation correlating with genomic diversity. Using a mechanistic niche model of the fire salamander (Salamandra salamandra) as an example, we illustrate how host steady-state body temperature and Bsal thermal range variation may influence pathogen growth through space and time across Europe. Our combined findings show how the identity of emergent pathogen variants may strongly influence when and which host populations are most at risk.

Zusammenfassung Der Ausbau der Windenergie findet zunehmend im Wald statt, da hier häufig windhöffige und damit ökonomisch attraktive Standorte zu finden sind. Allerdings ist hier der Konflikt mit dem Artenschutz im Allgemeinen und dem Fledermausschutz im Speziellen besonders hoch. In diesem Beitrag beleuchten wir vor dem Hintergrund des gesetzlich vorgegebenen normativen Rahmens den artenschutzrechtlichen Teil der Windkraftplanung im Wald mit Bezug auf Fledermäuse – von der Untersuchungsplanung über die eingesetzten Methoden bis zur Bewertung. Bezogen auf Fledermäuse stehen hier insbesondere die Vermeidung der direkten Tötung sowie die Verminderung der Beeinträchtigung ihres Lebensraums im Fokus der Betrachtung. Bundesland-spezifische Arbeitshilfen stecken den Untersuchungsumfang, die einzusetzenden Erfassungsmethoden und den räumlichen und zeitlichen Untersuchungsrahmen ab. Sie empfehlen zudem Maßnahmen zur Kompensation potenziell negativer Auswirkungen eines Eingriffs. Ihr Effekt auf die methodische Qualität der Fachbeiträge zu Fledermäusen ist jedoch gering. Meist kommen im Rahmen der speziellen artenschutzrechtlichen Prüfung zu Fledermäusen die Quartierbaumsuche, Netzfang, unterschiedliche Varianten des akustischen Monitorings (aktiv und passiv) sowie die Radiotelemetrie zum Einsatz. Insbesondere bei der bevorzugt empfohlenen akustischen Erfassung mindern zahlreiche methodische Probleme auf der technischen und der analytischen Ebene die Aussagekraft. Auch der Erfolg des Fangs von Fledermäusen mit Netzen hängt von zahlreichen Parametern ab. Die Quartierbaumerfassung lässt sich in ihrem Erfolg deutlich durch die Radiotelemetrie verbessern. Zur sinnvollen Quantifizierung des Lebensraumanspruchs einer Fledermauspopulation jedoch werden mittels Radiotelemetrie in der Regel zu wenige Tiere zu kurz untersucht. Die Bewertung der erhobenen Daten, hier gezeigt anhand akustisch ermittelter Aktivitätsdichten, erfolgt subjektiv, da Bewertungskriterien fehlen. Die am häufigsten empfohlenen und somit umgesetzten Methoden der Konfliktvermeidung und -minimierung sind CEF- (= Continued Ecological Function) und FCS-Maßnahmen (= Favourable Conservation Status) sowie das Gondelmonitoring und die selektive Abschaltung der WEA. Auch diese Maßnahmen entfalten z. T. Schwächen; die Bewahrung und Entwicklung von Waldstandorten als/zu ökologisch wertvollen Lebensräumen sowie die Verminderung der Schlagopferzahl durch spezielle Algorithmen (ProBat-Tool) sehen wir jedoch als sinnvoll an. Abschließend formulieren wir Anregungen zur Verbesserung und Objektivierung der Eingriffsplanung von WEA im Wald. Summary The development of wind energy is concentrating in forests, as windy and thus economically favourable sites can often be found here. However, the conflict with species conservation in general and bat conservation in particular is especially high in forests. We here examine the impact assessment on bats in the context of the legally prescribed normative framework in wind farm planning in the forest – from the study design to the methods used and the assessment itself. With regard to bats, the focus here is on avoiding direct killing and reducing the impairment of their habitat. Guidance documents for the German federal states define the extent of the surveys, the survey methods, and the spatial and temporal scope of a survey. They also recommend measures to compensate for potential negative impacts of wind energy plants (WEP). However, their effect on the quality of the expert reports on bats is low. In most cases, the search for roost trees, mist netting, different types of acoustic monitoring (active and passive) and radio tracking are used. In particular, numerous methodological problems at the technical and analytical levels reduce the validity of acoustic surveys. The success of mist netting bats also depends on numerous parameters. The success of roost tree surveys can be significantly improved by radio tracking. However, for a meaningful quantification of the habitat requirements of a bat population, radio tracking is usually used on too few animals for too short a time. The evaluation of the collected data, shown here on the basis of acoustically determined activity densities, is subjective because evaluation criteria are lacking. The most frequently recommended and thus implemented methods of conflict mitigation are CEF (= Continued Ecological Function and FCS (= Favourable Conservation Status) measures as well as nacelle monitoring and selective shut-down of wind turbines. These measures also show some weaknesses, but we consider the maintenance and development of forest sites as or into ecologically valuable habitats, as well as the reduction of the number of bat fatalities by means of specific algorithms (ProBat tool), to be sensible. Finally, we make suggestions for improving and objectifying the impact assessment of wind-energy facilities in forests.

Molecular gut content analysis is a popular tool to study food web interactions and has recently been suggested as an alternative source for DNA-based biomonitoring. However, the overabundant consumer's DNA often outcompetes that of its diet during PCR. Lineage-specific primers are an efficient means to reduce consumer amplification while retaining broad specificity for dietary taxa. Here, we designed an amplicon sequencing assay to monitor the eukaryotic diet of mussels and other metazoan filter feeders and explore the utility of mussels as natural eDNA samplers to monitor planktonic communities. We designed several lineage-specific rDNA primers with broad taxonomic suitability for eukaryotes. The primers were tested using DNA extracts of different limnic and marine mussel species and the results compared to eDNA water samples collected next to the mussel colonies. In addition, we analysed several 25-year time series samples of mussels from German rivers. Our primer sets efficiently prevent the amplification of mussels and other metazoans. The recovered DNA reflects a broad dietary preference across the eukaryotic tree of life and considerable taxonomic overlap with filtered water samples. We also show the utility of a reversed version of our primers, which prevents amplification of nonmetazoan taxa from complex eukaryote community samples, by enriching fauna associated with the marine brown algae Fucus vesiculosus. Our protocol will enable large-scale dietary analysis in metazoan filter feeders, facilitate aquatic food web analysis and allow surveying of aquacultures for pathogens. Moreover, we show that mussels and other aquatic filter feeders can serve as complementary DNA source for biomonitoring.

We introduce a novel ultra-low power system for tracking animal movements over long periods with an unprecedented high-temporal-resolution. The localization principle is based on the detection of cellular base stations using a miniaturized software-defined radio, weighing 2.0 g, including the battery, and having a size equivalent to two stacked 1-euro cent coins. Therefore, the system is small and lightweight enough to be deployed on small, wide-ranging, or migrating animals, such as European bats, for movement analysis with an unprecedented spatiotemporal resolution. The position estimation relies on a post-processing probabilistic RF pattern-matching method based on the acquired base stations and power levels. In several field tests, the system has been successfully verified, and a run-time of close to one year has been demonstrated.

Anuran amphibians have intensively been studied to understand Amazonian biodiversity. Improved methods and sampling has revealed that many widespread nominal species in fact are complexes of species with smaller allopatric ranges. Pan-Amazonian anuran species are rather an exception. In a case study using the three-striped poison frog (Anura: Dendrobatidae: Ameerega trivittata), we ask how the pan-Amazonian distribution of this taxon can be explained and hypothesize that dispersal has played a major role. Species delimitation and intraspecific relationships of the study species were examined from novel and existing (GenBank) sequences of the mitochondrial 16S rRNA gene from 108 specimens of 38 localities using maximum likelihood and Bayesian methods. We performed BioGeoBEARS models using a time-calibrated population tree to reconstruct the biogeographic history. Our results support that A. trivittata is a pan-Amazonian species scattered over its geographic range. Being of Late Miocene origin, the species rapidly spread into newly available space and repeatedly dispersed for-and backward, while vicariance played a major role only in the Early Pliocene. We suggest that intrinsic morphological and life history characteristics (adult size, relative reproductive success) make A. trivittata a more successful disperser than other species, so that riverine barriers are more permeable and hamper allopatric speciation. We conclude that there is no universal causality explaining Amazonia biodiversity, because species-specific biological characteristics are key determents of biogeographical histories. Comparatively better dispersal advantages foster larger geographic ranges and can explain pan-Amazonian distributions.

In the European Union (EU), all bat species are legally protected by the Habitats Directive (HD). Especially the goal of keeping or restoring a favourable conservation status for protected species and habitats is an outstanding innovation in the law of nature conservation. The Directive does not only focus on rare species close to extinction, but has the goal of viable populations for all species included in the pertinent annexes. However, most bat populations are still far away from reaching this goal, which leads to the question why the Habitats Directive may have failed to achieve its objective. We argue that the pluralism of definitions of the concept of 'population' is a major problem in the application of the Directive. Concerning bats, several population definitions are possible that fit biological aims as well as aims of legal protection. But without clear assignment which definition should be used in the application of nature conservation law, the pluralism of the population definition offers the possibility of arbitrary use, and with it the failure of bat conservation. In consequence, we describe different population definitions and give suggestions to avoid arbitrary delimitation. When applying species protection law, the population must be specified through ecological parameters rather than merely through statistical approaches. In case of migrating bats, we found that the objectives of the HD can only be achieved with individual-based approaches. Population-based protection is doomed to failure because of the lack of knowledge about meaningful population delimitation. Thus, strong EU-wide effort is necessary to completely implement legal bat protection.

AbstractAnthropogenic biodiversity loss is extreme in amphibians. Despite ongoing conservation action, it is difficult to determine where we stand in overcoming their extinction crisis 1,2. Extinction risk is not equally distributed across amphibians 3-5. Among the most threatened amphibians are the 131 Neotropical harlequin toads (Atelopus), many of which dramatically declined since the late 1980s with several considered possibly extinct 5,6. Recently, more than 30 species have been rediscovered7, raising hope for a reversing trend in the amphibian extinction crisis. We use harlequin toads, for which comprehensive past and present population status, threat and conservation action data are available, as a model for examining whether the amphibian extinction crisis is still in a state of emergency. We show that since 2004 no species has improved its population status, suggesting that the conservation community has not yet bent the curve. Threats such as pathogen spread and habitat change persist unabated; additionally, climate change is expected to be a future threat. More on-the-ground mitigation strategies need implementation, especially habitat protection and disease management, combined with captive conservation breeding. With harlequin toads serving as a model for amphibians with high extinction risk, it is clear that the amphibian extinction crisis is still underway.

Hibernation is one of the most important behaviours of bats of the temperate zone. During winter, when little food or liquid water is available, hibernation in torpor lowers metabolic costs. However, the timing of emergence from hibernation is crucial for the resumption of the reproductive process in spring. Here, we investigate the spring emergence of six bat species or pairs of bat species of the genera Myotis and Plecotus at five hibernation sites in Central Europe over 5 years. Using generalized additive Poisson models (GAPMs), we analyze the influence of weather conditions (air and soil temperature, atmospheric pressure, atmospheric pressure trend, rain, wind, and cloud cover) as predictors of bat activity and separate these extrinsic triggers from residual motivation to emerge from hibernation (extrinsic factors not studied; intrinsic motivation). Although bats in a subterranean hibernaculum are more or less cut off from the outside world, all species showed weather dependence, albeit to varying degrees, with air temperature outside the hibernaculum having a significant positive effect in all species. The residual, potentially intrinsic motivation of species to emerge from their hibernacula corresponds to their general ecological adaptation, such as trophic specialization and roosting preferences. It allows the definition of three functional groups (high, medium and low residual activity groups) according to the degree of weather dependence of spring activity. A better knowledge of the interplay of extrinsic triggers and residual motivation (e.g., internal zeitgebers) for spring emergence will help to understand the flexibility of a species to adapt to a changing world.