How to prioritize areas for new ant surveys? Integrating historical data on species occurrence records and habitat loss

Habitat loss is a leading cause of extinctions, which may occur even before species are recorded or formally described. On the other hand, limitations in species distribution data and sampling biases can hamper inferences about patterns of species richness that form the basis of conservation strategies. Insects, despite their crucial roles in terrestrial ecosystems, are still largely neglected when dealing with biological inventories. Among insects, ants are of unique importance because of their species richness, widespread distribution, and due to their key ecosystem functions such as seed dispersal, soil nutrient cycling, predation, and biological control. In this study, we prioritize different Brazilian biomes and ecoregions for new ant surveys based on information on the distribution of occurrence records and two estimates of habitat loss for the period between 2000 and 2016. We compiled nearly 8000 ant occurrence records, including a total of 1170 species. The Caatinga was the biome showing the greatest urgency for new inventories, whereas the Atlantic Forest had the lowest urgency. However, there were considerable differences of priority between ecoregions belonging to each biome, thus underscoring the need to pay special attention to these geographical units and their characteristic associated with ant species. The prioritization of poorly studied sites with an imminent risk of habitat loss can be a valuable starting point for filling knowledge gaps and can help in formulating new strategies of conservation. The dataset provided here may also be useful in studies on the distribution of ant diversity in Brazil.