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Surveying biodiversity using bioacoustics has become increasingly common worldwide, although it is mostly concentrated in temperate regions. The variety of automatic recorders, the development of free analytical tools, and several acoustic indices have increased the number of studies worldwide. The bioacoustic approach is essential for application in poorly surveyed regions with the pressure of human activities, such as the Brazilian cerrado. We tested the association of four bat diversity metrics (taxonomic, phylogenetic, and two functional diversity metrics, being one based on morphological and the other on acoustical traits, with five commonly used acoustic indices. We used a dataset of 608.4 h obtained from 30 sampling points in three protected areas in Central Brazil. Using Flexible Discriminant Analysis, we identified 21 bat species used in our subsequent analysis. The Entropy index was the best predictor of taxonomic and phylogenetic diversity, whereas the Acoustic Complexity Index was the best predictor of functional morphological diversity. We concluded that acoustic indices are suitable for estimating the diversity of insectivorous bats in the cerrado. However, we registered only part of the bat community, and bats can vary seasonally masking the real diversity of the study area; thus, this method should be used parsimoniously. [ABSTRACT FROM AUTHOR]

Species distribution modelling (SDM) gained importance on biodiversity distribution and conservation studies worldwide, including prioritizing areas for public policies and international treaties. Useful for large-scale approaches and species distribution estimates, it is a plus considering that a minor fraction of the planet is adequately sampled. However, minimizing errors is challenging, but essential, considering the uses and consequences of such models. In situ validation of the SDM outputs should be a key-step—in some cases, urgent. Bioacoustics can be used to validate and refine those outputs, especially if the focal species' vocalizations are conspicuous and species-specific. This is the case of echolocating bats. Here, we used extensive acoustic monitoring (>120 validation points over an area of >758,000 km2, and producing >300,000 sound files) to validate MaxEnt outputs for six neotropical bat species in a poorly-sampled region of Brazil. Based on in situ validation, we evaluated four threshold-dependent theoretical evaluation metrics' ability in predicting models' performance. We also assessed the performance of three widely used thresholds to convert continuous SDMs into presence/absence maps. We demonstrated that MaxEnt produces very different outputs, requiring a careful choice on thresholds and modeling parameters. Although all theoretical evaluation metrics studied were positively correlated with accuracy, we empirically demonstrated that metrics based on specificity-sensitivity and sensitivity-precision are better for testing models, considering that most SDMs are based on unbalanced data. Without independent field validation, we found that using an arbitrary threshold for modelling can be a precarious approach with many possible outcomes, even after getting good evaluation scores. Bioacoustics proved to be important for validating SDMs for the six bat species analyzed, allowing a better refinement of SDMs in large and under-sampled regions, with relatively low sampling effort. Regardless of the species assessing method used, our research highlighted the vital necessity of in situ validation for SDMs. [ABSTRACT FROM AUTHOR]

Aim: Field surveys are necessary to overcome Wallacean shortfalls. The task is even more important when human pressure on tropical—megadiverse—ecosystems is considered. However, due to financial constraints, spatial and temporal prioritization is required. Here, we used the concept of environmental complementarity to identify non‐surveyed regions for bats that are environmentally different from other already surveyed regions. We highlighted regions in Brazil where field inventories could be conducted to locate new occurrences or even new bat species. Location: Brazil. Methods: We based our analysis on environmental characterization aiming to identify dissimilar regions to those already sampled for bats in Brazil. We used 21 environmental variables to characterize 1,531 unique localities where bats occur. Then, we applied the parameters of a generalized linear model (GLM) to extrapolate the expected values of the environmental variables for the entire country. We compared the predicted values of localities with newly described bat species occurrence against the values for other bat species. Results: We found that sites from which recently discovered species were described are environmentally distinct from the sites where previously described species occur. Therefore, new occurrences and even new species could be found in regions that are environmentally dissimilar from those already surveyed. By crossing the model with a human footprint map, we defined temporal priorities for field inventories. Regions such as the Northern Cerrado and Western Caatinga should be surveyed first. Similar approaches could be undertaken for other biological groups or regions, allowing the identification of spatial congruence and the development of a comprehensive national programme for biological field inventories. Main conclusion: Newly described species occurred in environments dissimilar to those previously identified, showing that environmental complementarity analysis is a valid approach to define priority regions for new bat inventories. [ABSTRACT FROM AUTHOR]

Aim: The effective conservation and management of any given species frequently requires basic knowledge on its distribution, which is problematic for highly mobile, species‐ and ecologically‐rich groups, like bats. Moreover, to produce detailed distributions for continental‐sized, bat species‐rich countries, like Brazil, is difficult, especially considering that ~60% of the country has not a single formal bat record. Using Species Distribution Modelling (SDM), we assessed the potential distribution of >100 species of Brazilian bats. Location: Brazil. Methods: We (a) updated data on the distribution of 135 bat species, (b) generated SDMs for each species, (c) constructed species richness maps for Brazil, (d) determined areas of endemism and (e) identified areas harbouring threatened species. Results: Amazonia harbours the highest bat species richness (76% of the species), followed by the Atlantic Forest (66%), Cerrado (65%) and the Caatinga (53%). Richness in 5 × 5 km grid cells varied between 23 and 117 species and 70% of Brazil's territory is predicted to have 50–90 species, and 25% >90 species. Coastal Atlantic forest, mainly in its north‐eastern region, and along its contact zone with the Caatinga biome had the highest potential richness. However, there is a severe regional sampling bias: 48% of the records available were from the Atlantic Forest and 21% were from along the Amazon River. Main conclusions: Pantanal and Pampa are clearly under sampled, with <50% of their expected richness already assessed. Endemic and endangered bat species are in the Atlantic Forest, Cerrado and Caatinga, the most threatened biomes in Brazil. In addition to the seven nationally threatened bat species in Brazil, the situation for other species is worrisome: In a business‐as‐usual scenario, local extinctions in large portions of the country may happen before basic information gaps are filled. [ABSTRACT FROM AUTHOR]

The greatest current threat to terrestrial fauna is continuous and severe landscape modification that destroys and degrades animal habitats. This rapid and severe modification has threatened species, local biological communities, and the ecological services that they provide, such as seed dispersal, insect predation, and pollination. Bats are important pollinators of the Cerrado (woodland savanna) because of their role in the life cycles of many plant species. However, there is little information about how these bat species are being affected by habitat loss and fragmentation. We used radio-tracking to estimate the home ranges of Glossophaga soricina (Pallas, 1776) and Lonchophylla dekeyseriTaddei, Vizotto & Sazima, 1983. The home range of G. soricina varies from 430 to 890 ha. They combine shortrange flights of up to 500 m to nearby areas with longer flights of 2 to 3 km that take them away from their core areas. The maximum flight distance tracked for L. dekeyseri was 3.8 km, and its home range varies from 564 to 640 ha. The average distance travelled by this species was 1.3 km. Our data suggest that G. soricina and L. dekeyseri are able to explore the fragmented landscape of the Central Brazilian Cerrado and that they are likely to survive in the short- to medium-term. The natural dispersal ability of these two species may enable them to compensate for continued human disturbance in the region. [ABSTRACT FROM AUTHOR]

The article examines whether vampire bat population control practices pose a threat to the endemic bat Lonchophylla dekeyseri of the Cerrado, considered the most extensive woodland-savanna in South America. The VORTEX program was used to model different vampire bat management scenarios, which cause mortality to the bat populations. Bats act as pollinators of native plants and as seed dispersers which help restore degraded areas. Findings revealed that management practices have serious impacts on the endemic bat. Decreases in survival probability and genetic diversity were observed, as well as declines resulting from interaction between bat management and inbreeding depression.