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. K E Y W O R D S Chiroptera, Maxent, priority areas, species distribution models | 633 DELGADO-JARAMILLO Et AL.
The big crested mastiff bat, Promops centralis, occurs in Central and South America, but knowledge of its ecology is limited due to its open space hunting strategy, making captures extremely challenging. Notwithstanding, members of the species produce echolocation calls that are easy to identify. After recording calls of P. centralis 1,500 km away from its known range in Brazil, we hypothesized that the distribution range of this species was probably greatly underestimated. To improve the accuracy of P. centralis’ real distribution, we employed acoustic surveys throughout parts of Brazil, conducted after a bibliographic review to gather additional records, and used MaxEnt to model the species’ potential distribution. We have found that P. centralis has a much wider distribution in South America than previously thought, adding more than 3.8 million km2 to its former known area. We also describe an unusual vocalization pattern of P. centralis, with individuals emitting at least three very distinct but highly variable calls. This study shows that bioacoustic surveys and species distribution models can complement traditional methodologies in studying species that are difficult to capture, such as P. centralis, potentially contributing to more effective conservation and management plans.
Species with specific roosting, foraging or breeding requirements are particularly vulnerable to habitat loss and degradation. For bats, the availability and environmental condition of caves can be a limiting factor. The cave specialist Natalus macrourus (formerly Natalus espiritosantensis) is categorized as Near Threatened on the IUCN Red List but as Vulnerable in Brazil, based on a projected population reduction and a decline in its area of occupancy, extent of occurrence and/or quality of habitat. There is a lack of knowledge about the species’ distribution, natural history and ecology, information that is required for conservation. Using new occurrence data and potential distribution modelling we evaluated the distribution of N. macrourus in Brazil, analysed pressures on and threats to the species, and assessed the species’ conservation needs. Natalus macrourus is positively associated with areas with higher probability of cave occurrence and negatively associated with areas of high variation in mean daily temperature and mean annual rainfall. Areas with high environmental suitability for N. macrourus correspond to only 3% of the potential distribution modelled. We estimate that the species has already lost 54% of its natural habitat and that there is < 35% of habitat remaining in areas with high environmental suitability. We calculated that approximately half of the caves in areas with high environmental suitability are < 5 km from mining operations and only 4% of the species’ potential distribution lies within protected areas. Given the strong association of N. macrourus with caves, it is important to protect these habitats, and we recommend that caves where the species is present should receive immediate protection.
Myotis lavali was described from the M. nigricans complex based on museum specimens from the Caatinga of northeastern Brazil. Current records of the species from about 10 localities suggest that M. lavali seems to occur throughout the South American dry corridor, with peripheral records in the Atlantic Forest. Based on new distribution records, we assess if M. lavali is endemic to the South American dry diagonal corridor through species distribution modeling using an ensemble approach. We obtained 35 occurrences for the species and built a consensus scenario based on 12 algorithms to model its distribution. Even using different thresholds to assign presence and absence of M. lavali, 95–99% of its predicted distribution is within the dry corridor, with few areas in the boundary of the Atlantic Forest, especially in deciduous forests. Therefore, our results support that M. lavali is indeed very likely restricted to the dry diagonal and, although it occupies forested areas, the core of its distribution lies in the Caatinga and in the Cerrado regions of Brazil.
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