Prioritizing bat roosts for conservation with a global multicriteria bat roost priority index based on community science

Prioritization in conservation is crucial for the development of efficient and effective decision-making policies. For many decades, the importance of some species and their habitats has been assessed and applied in conservation legislation, but bats and their diurnal roosts have ofbeen overlooked. Several approaches have been used to categorize bat roosts based on their conservation importance. However, such assessments are often limited to expert-level assessments, are developed for specific regions, or do not consider long-term monitoring data from community science. We devised an index, the bat roost priority index (BRP), for prioritization of bat roosts for conservation in which community science and roost seasonality, uniqueness, and vulnerability are integrated. Using community data from 568 bat roosts, we applied the BRP to the 50 most well-sampled and compared the results with 3 other indices. We then examined the strengths and limitations of the different indices. We also used the BRP to define important bat conservation areas in specific regions in terms of underground and aboveground roosts, an important need and common request from policy makers. The BRP improved on previous prioritizations in that it classifies roosts based on biotic and vulnerability variables, provides a linear classification of all assessed roosts according to conservation action priority, and offers objective quantification of the threats affecting a roost. To illustrate the potential of the BRP, we defined important areas for bat conservation in Catalonia (Spain) based on the index. The BRP is available on the Bat Monitoring Programme online platform, where index values are calculated and shown for every registered bat roost. The BRP can be easily adapted and thus, has strong scalability potential for use with regional to continental datasets.