Inventory, Features, and Protection of Underground Roosts Used by Bats in Mexico

The disturbance and loss of diurnal roosts is one of the major causes of decline in cave-dwelling bat populations, thus the identification and protection of these sites is essential to the implementation of effective conservation plans. We conducted a search for information on caves, mines, tunnels, and culverts used as roosts by bats in Mexico, in order to create an inventory and a database, as well as a list of priority sites for their protection. In total, 970 underground roosts have been reported: 73.7% are caves, 16.6% are mines, 5.2% are culverts, and 4.5% are tunnels. The roost sites are more commonly located in tropical deciduous forests (24%) and secondary vegetation modified by farming (18.5%). In 92% of underground roosts, the surrounding vegetation has been altered for several causes. Regarding internal disturbance, 46.6% of the 176 roost sites analyzed present little to no disturbance, 43.7% have moderate levels of disturbance, and 9.7% are highly disturbed. The use of underground roosts was documented for 88 bat species included in 44 genera and seven families. Of these, six species are endemic to Mexico and according to the IUCN Red List, three are listed as Near Threatened, three as Vulnerable and two as Endangered. Based on species richness and bat abundance, we considered 53 sites as having the highest priority for conservation of cave-dwelling bats in Mexico, and based on a Complementarity Analysis we identified 167 roosts that must be protected to maintain a greater diversity of bats in the country. It is urgent to implement actions to regulate visits to roosts in order to prevent structural and microenvironmental deterioration, in addition to preserving the foraging areas around roosts, so that conservation of cave-dwelling bats will be more effective at both a local and regional level.