Wrinkle-faced male bats lower face masks to copulate

Centurio senex is a wrinkle-faced bat found in Mexico, Central America, and northern South America. Interestingly, this species shows a distinct sexual dimorphism: Adult males have a fold of skin under the chin that can be raised to cover the lower part of the face like a mask, suggesting that it might be used during courtship behavior. But this species has rarely been studied, so little is known about its behavior and natural history. In the new study, the researchers report the first observations of echolocation and mating behavior of C. senex. The authors analyzed synchronized audio and video recordings from an aggregation of males located on 53 perches in Costa Rica over a period of six weeks.

This species appears to use lek courtship, in which females choose mates from clusters of sexually displaying presumably territorial males. Among mammals, lek courtship is known to be used by only 12 species, mainly seals and hoofed mammals. When females approached, the perched males beat their wings and emitted very loud, low-frequency whistling calls. The males lowered their masks immediately before copulation, then sang enthusiastically and raised their masks again after mating.

According to the authors, future encounters with C. senex may close some of the current gaps in knowledge on the behavior of one of the most iconic bats of the Neotropics.

The authors add: "[Centurio senex] 'court with the mask on'...the mating system of the most enigmatic bat species in the Neotropics appears to be lek, a rarely recorded mating system in bats."