Recent advances in machine learning have accelerated automated species detection across diverse ecological domains, enabling large-scale, non-invasive monitoring of biodiversity. In ornithological research, the combination of passive acoustic monitoring (PAM) and rapidly-developing novel identification tools such as BirdNET—a deep learning–based sound recognition algorithm—offers new opportunities for surveying vocally active bird communities. Here, we present the first worldwide evaluation of BirdNET using 4224 one-minute recordings from 67 sites across all continents annotated by local experts. More specifically, we assessed the capacity of BirdNET to accurately identify individual vocalizations and characterize bird communities based on the automated analysis of passively collected soundscapes. We further analyzed how its performance varies across continents, biomes, species, and minimum confidence thresholds. The proportion of correct BirdNET predictions (precision) was generally high and consistent across continents (range: 0.57–0.71) and biomes (range: 0.55–0.76). In contrast, the proportion of vocalizations successfully detected (recall) was generally lower and more heterogeneous across continents (range: 0.24–0.52) and biomes (range: 0.34–0.72), reflecting differences in species coverage and local ecological context. BirdNET predictive power, as measured by the Precision-Recall Area Under the Curve (PR AUC; higher values indicating better performance), was highest in North America, Oceania, and Europe (range: 0.16–0.23), moderate in Central/South America (0.13), and lowest in Africa and Asia (range: 0.03–0.04). Species-specific analyses revealed substantial heterogeneity in detection accuracy, with optimal confidence thresholds varying widely by species and analytical goal. Our results establish a global reference point for BirdNET reliability and highlight where algorithmic refinement and expanded acoustic sampling are most needed.

Under the current global biodiversity crisis, there is a need for automated and noninvasive monitoring techniques that can gather large amounts of data cost-effectively at various ecological scales, from local to large spatial scales. These data can then be analyzed to inform stakeholders and decision-makers. One such technique is passive acoustic monitoring, which is commonly coupled with automatic identification of animal species based on their sound. Automated sound analyses usually require the training of sound detection and identification algorithms. These algorithms are based on annotated acoustic datasets which mark the occurrence of sounds of species inside sound recordings. However, compiling large annotated acoustic datasets is time-consuming and requires experts, and therefore, they normally cover reduced spatial, temporal, and taxonomic scales. This data paper presents WABAD, the World Annotated Bird Acoustic Dataset for passive acoustic monitoring. WABAD is designed to provide the public, the research community, and conservation managers with a novel and globally representative annotated acoustic dataset. This database includes 5047 min of audio files annotated to species-level by local experts with the start and end time and the upper and lower frequencies of each identified bird vocalization in the recordings. The database has a wide taxonomic and spatial coverage, including information on 91,931 vocalizations from 1192 bird species recorded at 72 recording sites in 29 recording locations (mainly countries) and distributed across 13 biomes. WABAD can be used, for example, for developing and/or validating automatic species detection algorithms, answering ecological questions, such as assessing geographical variations on bird vocalizations, or comparing acoustic diversity indices with species-based diversity indices. The dataset is published under a Creative Commons Attribution 4.0 International license that permits redistribution and reuse on the condition that the original work is properly credited.

The extensive transformation of natural habitats into monoculture tree plantations implies the loss of suitable habitats for native species, negatively impacting biodiversity maintenance. Among the main landscape factors influencing the ecological potential of forestry landscapes to support native species, forest corridors are of central importance; however, assessments of their effectiveness across multiple taxa—especially among species with varied movement capacities—remain limited. To evaluate the role of corridors, in a heterogeneous forestry landscape in the Atlantic Forest of Argentina, we assessed species richness and composition of three taxonomic groups (anurans, birds and mammals) in tree plantations (pine and eucalypt) and forest (corridors and continuous), using technology-based biodiversity monitoring. Data from passive acoustic monitoring and camera trapping revealed a consistent pattern of species richness across taxa, with the highest richness in forest corridors, followed by continuous forests, pine plantations, and eucalypt plantations. For birds and mammals, a similar number of forest-dependent species were found in both continuous forests and forest corridors. In anurans and mammals, species composition changes between forest corridors and continuous forests were primarily driven by species replacement; while in birds, these changes were driven by differences in species richness. Across all taxa, forest corridors most closely resembled the community integrity of continuous forests. The species richness and composition patterns found for taxonomic groups with varying habitat requirements underscore the potential of forest corridors as a powerful and profitable conservation tool in forestry landscapes.

Under the current global biodiversity crisis, there is a need for automated and non-invasive monitoring techniques that are able to gather large amounts of information cost-effectively at large scales. One such technique is passive acoustic monitoring, which is commonly coupled with automatic identification of animal species based on their sound. Automated sound analyses usually require the training of sound detection and identification algorithms. These algorithms are based on annotated acoustic datasets which mark the occurrence of sounds of particular species. However, compiling large annotated acoustic datasets is time consuming and requires experts, and therefore they normally cover a reduced spatial and taxonomic scale. This data paper presents WABAD, the World Annotated Bird Acoustic Dataset for passive acoustic monitoring. WABAD is designed to provide the public, the research community, and conservation managers with a novel and globally representative annotated acoustic dataset. This database includes 5,044 minutes of audio files annotated to species-level by local experts with the start and end time, and the upper and lower frequencies of each identified bird vocalisation in the recordings. The database has a wide taxonomic and spatial coverage, including information on 90,662 vocalisations from 1,147 bird species recorded at 70 recording sites in 27 countries and distributed across 13 biomes. WABAD can be used, for example, for developing and/or validating automatic species detection algorithms, answering ecological questions, such as assessing geographical variations on bird vocalisations, or comparing acoustic diversity indices with species-based diversity indices. The dataset is published under a Creative Commons Attribution Non Commercial 4.0 International copyright.

BirdNET is a popular machine learning tool for automated recognition of bird sounds. However, evidence on how to optimize its settings for accurate bird monitoring remains limited. Here, we evaluate how BirdNET settings influence model performance in identifying bird vocalizations and characterizing bird communities, using 4224 1-min recordings from 67 recording locations worldwide. Giving equal importance to recall and precision, a low confidence score threshold (0.1-0.3) appears optimal for detecting bird vocalizations, whereas higher thresholds (around 0.5) are more suitable for characterizing bird communities. Based on our findings, we recommend increasing the Overlap parameter from its default value of 0 to 2 s, as this consistently improves BirdNET performance in detecting both bird vocalizations and species presence. The effect of the Sensitivity parameter varied across regions. However, a value of 0.5 maximizes global performance for community-level analyses across all confidence thresholds, and a value of 1.5 generally yields better results for vocalization-level studies, particularly at low confidence thresholds. Our findings offer practical guidance for selecting BirdNET settings in passive acoustic bird surveys, enhancing both the identification of bird vocalizations and the characterization of bird communities.

Species loss by habitat replacement operating as an ecological filter is a well-known consequence of modern human activities. In contrast, the ecological and evolutionary response of species overcoming those filters in converted habitats has not been thoroughly explored. Species that persist are subject to novel and potentially stressful conditions that may induce certain morphological changes. We evaluated changes in the functional morphology of three anuran species persisting after the conversion of areas of the Atlantic Forest into pine plantations. We specifically evaluated differences in body size and body condition indices, head width, and hind legs' length between adult individuals from both habitats and sexes. Habitat conversion and sexual dimorphism affected the morphology of the three anurans, with varying effects upon species and traits. Regarding the effect of habitat conversion, Elachistocleis bicolor increased body condition in plantations with no changes in the other traits, Physalaemus cuvieri showed only a marginal increment in residual body mass in plantations, and Odontophrynus americanus exhibited a substantial increment in body size while maintaining its body condition in plantations. Remarkably, none of the results suggested these persistent anurans were stressed by forest conversion. This study shows that habitat conversion may induce intraspecific morphological changes in ecologically relevant traits of persistent species, and that disturbed areas do not necessarily imply stressful, low quality habitats affecting all persistent native species negatively.

The replacement of native forests by high-density tree plantations affects the richness and composition of animal communities through the modification of the resource availability, hydrological regimes, nutrient cycles and soil structure. Previous studies have been conducted mainly on birds and mammals, whereas few have explored the response of anurans, a taxon considered at risk and in steep decline. With this study we aimed to evaluate changes in anuran diversity associated with native forest replacement by pine plantations (Pinus taeda) in the southern Atlantic forest of Argentina, a highly diverse and threatened ecosystem. Additionally, we intended to explore the role of the micro-habitat (terrestrial, aquatic) in the response. We characterized vegetation and habitat structure and sampled anurans in terrestrial and aquatic micro-habitats in the native forest and pine plantations monthly over two consecutive years (2012-2014), using three complementary techniques (pitfall traps, audio strip transects and larval sampling). A total of 964 individuals of 21 species were captured: Physalaemus cuvleri, Odontophrynus americanus and Elachistocleis bicolor were the most abundant species. Replacement of the structurally complex native forest by extremely simplified monoculture tree plantations influenced the patterns of anuran alpha and beta diversity. However, these changes were micro-habitat-dependent: changes in anuran diversity in the terrestrial habitat were explained by species loss, while those in the aquatic habitat were explained by both species loss and turnover. The arboreal species of the family Hylidae (eight) were found absent from tree plantations. Both the hydroperiod instability of the water bodies and the simplified vegetation structure of the tree plantations are probably limiting the suitability for both reproduction and larval development of some specialist species. The native vegetation surrounding the water bodies in the tree plantations constitutes a central element to maintain anuran diversity, through increasing the hydroperiod and providing a habitat for species reproduction in the southern Atlantic forest and to facilitate the movement of individuals among native forest remnants.

In this study we analysed the body size, age structure, age at maturity, longevity and growth pattern of Argenteohyla siemersi pederseni in north-eastern Argentina using skeletochronological methods. Body size was sexually dimorphic; females were significantly larger and heavier than males, regardless of age. As A. s. pederseni is an explosive breeder with only one reproductive episode per year, we assumed that each Line of Arrested Growth (LAG) observed was equivalent to one period of decreasing growth, LAGs reflecting a direct estimation of individual age. The minimum number of LAGs counted was two for males and three for females, but there was no sexual difference in longevity. The von Bertalanffy's growth coefficients (K) were higher in males than in females for both size and body mass. Females had a lower growth rate than males, took longer to reach the minimum maturation size, and were older and larger at reproduction.

El Parque Nacional El Palmar (PNEP) es una importante área protegida de la zona este de la provincia de Entre Ríos, Argentina, creado para conservar uno de los últimos fragmentos de palmera yatay (Butia yatay). En este estudio se examina la biodiversidad de la comunidad de anfibios anuros que habitan tres tipos de ambientes del Parque; el pajonal, el pastizal y la selva en galería. Los muestreos se llevaron a cabo entre los meses de primavera-verano de 2008 y 2009. En total se registraron 16 especies de anfibios para el PNEP, distribuidas en 6 familias y 9 géneros. Entre los tipos de ambientes, el pajonal exhibió la mayor diversidad y riqueza de especies. Las abundancias relativas de las especies fueron equitativas dentro de los tres ambientes y existieron diferencias significativas en la composición de especies entre los mismos, siendo el pajonal y el pastizal los más similares. Este trabajo es un aporte significativo al conocimiento de la herpetofauna del PNEP y una base para estudios futuros sobre historia natural de los anfibios. Así también brinda una herramienta para el manejo y conservación del área protegida. El Palmar National Park (NPEP) is an important protected area in the eastern of Entre Rios Province, Argentina. It was created for preserving one of the last fragments of yatay palm (Butia yatay). This study examines the biodiversity of the community of anurans that inhabit three types of environments of the Park, the grassland, the straw zone and the gallery forest. Sampling was conducted between the spring-summer 2008 and 2009. There were found 16 species of amphibians for NPEP, belonging to 6 families and 9 genera. Among the types of environments, the straw zone showed the highest diversity and species richness. The relative abundances of the species were equitative in all three environments and there were significant differences in species composition among them being the grassland and pasture the most similar. This work is a significant contribution to the knowledge of the NPEP herpetofauna and a basis for future studies of natural history of amphibians. This also provides a tool for this protected area management and conservation.