Mexican free-tailed bats need caves, rock crevices, or bridges to roost in colonies that can run into the millions, and the limestone canyons of the Hill Country, Balcones Canyonlands, and Devils River supply exactly that kind of terrain. The Texas population belongs to the subspecies Tadarida brasiliensis mexicana, the form famous for its huge maternity colonies.
Records show two spring peaks, February and April, which tracks with bats returning from Mexican wintering grounds and settling into maternity roosts before pups are born in early summer. Counts fall off sharply by winter, when most of the population has migrated south.
NatureServe lists the species S5, secure, in Texas, and it ranks among the more commonly recorded bats in the state’s data, at the 88th percentile, though a single well-watched cave can generate a disproportionate share of any bat species’ records.
Full species profile
