The Brazilian Free-tailed bat is part of the family Molossidae and is the most common bat in the Americas.

Strangely it is rare in our province of Corrientes but is found in almost all of the other provinces. We only captured this species in October 2019 at the reserve, probably in migration. We believe it is the first captured example in Corrientes.

Its distinguishing feature is the wrinkled lips which is uses to make loud echolocation calls.  The ears are large and almost joined over the top of the head, fur is greyish with a lighter venter and it has a longish free tail.  They have long narrow wings which make them one of the fastest flying bats.