Saccopteryx – Sac-winged bats

Named for the pouch-like sacs located on their wings, near their elbows. While small in size, Saccopteryx bats are packed with unique behaviors and adaptations that make them stand out in the world of nocturnal mammals.

One of the most well-known species in this genus is the greater sac-winged bat (Saccopteryx bilineata). These bats are small—roughly the size of a mouse—and have sleek, dark brown or gray fur with striking white lines running down their backs, giving them a distinctive, almost racing-stripe appearance. But their most curious feature is the wing sac, which is more than just a name. In males, this sac is used in scent-marking and mating displays. During the breeding season, males will fill these sacs with a special blend of scents produced by glands, and use them to attract females—essentially creating their own natural cologne!

Saccopteryx bats are also unusual among bats for their social behavior. They often roost in small groups, sometimes in open areas like under tree branches, the sides of buildings, or cave entrances. What’s especially cool is their use of vocal communication. The greater sac-winged bat is one of the few bat species known to have “songs”—complex vocal sequences used by males to defend territory and impress potential mates. These songs can include trills, chirps, and buzzes, and are thought to play a key role in social bonding.

Like many bats, Saccopteryx species are insectivorous, meaning they feed mostly on flying insects such as moths, mosquitoes, and beetles. They use echolocation to navigate and hunt, emitting high-frequency calls and listening for the echoes to detect nearby prey. Their small size, quick reflexes, and keen hearing make them expert hunters in the dark. Because they often forage near forest edges or clearings, they also help keep insect populations in check, playing an important role in natural pest control.