Challenging hibernation limits of hoary bats: the southernmost record of Lasiurus cinereus hibernating in North America

It has been suggested that Lasiurus cinereus cinereus migrates from summer roosts at higher latitudes to the coastal regions and southern latitudes in the United States and Mexico to overwinter, where little is known about its winter ecology. We found a hoary bat in a shrub in a conifer forest at high elevation in central Mexico in November 2019. We installed a camera trap and recorded it was hibernating for at least 12.7 days. Our record is by far the most southern hibernation location of tree bats in North America and it shows L. cinereus is capable of hibernating in a non-typical roost. We also open the possibility that camera traps may provide an additional, practical, and easy-to-use tool to study bat hibernation. Our finding expands the ultimate questions of why and where hoary bats decide to hibernate, migrate or both.