Discovering the Brazilian bat fauna: a task for two centuries?

Brazil is the second most bat species-rich country in the world, but the available information on the occurrence and distribution of bat species in Brazil is still heterogeneous and fragmented. We review the occurrence and distribution of bat species in Brazil, analyse the spatial performance of inventories conducted to date and identify knowledge gaps. We also identify the main factors contributing to the recent increase in the knowledge of the Brazilian bat fauna, and make suggestions for maintaining this momentum into the near future. We plotted record coordinates on a map, grouped them in 0.5 degrees of latitude x 0.5 degrees of longitude grid cells, and analysed records for each of the five terrestrial biomes in Brazil, and for the 1439 priority polygons for the conservation of Brazilian biodiversity. We identified 5502 formal bat records in Brazil, indicating that less than 10% of the country is minimally surveyed, and that for nearly 60% of Brazil there is not a single record of bat species. Record coverage varies from 79% in the Atlantic Forest to 24% in Amazonia, but none of the Brazilian biomes is well surveyed for bats. Bat species have been recorded in only 15% of the priority areas for Brazilian biodiversity conservation. If the current rate of recording bats in empty grid cells (10% every 4 years) was maintained, it would take 33 years for all cells to have a single record. If the current rate of recording >= 20 species in a grid cell (0.8% per year) was maintained, it would take 200 years for the bat fauna of Brazil to be minimally surveyed. Alarmingly, most of the data-poor areas are at the expansion frontiers of the agro-business, near the surrounding deforestation fronts. We make recommendations for scientific research on bats in Brazil, to ensure the conservation of this ecologically important taxon.