Bats that are part of the Emballonuridae family are more commonly called sac-winged bats, a name that’s been bestowed upon them because they have glandular sac that’s located on the edge of their wings. There are also people who refer to this family as sheath-tailed bats because the bat’s tails are encased in a tail membrane that makes it appear sheathed, especially while the bat is in flight. The very tip of the tail extends past the membrane. When the bat isn’t flying, the way the tip protrudes around the folded membrane bears a strong resemblance to a retractable ball point pen.
Emballonuridae bats rely on their wing sac to help them mark territories and researchers have also noticed that the scent the gland produces also aides in communication. No one knows exactly why some bats developed (or perhaps lost) the glandular sac as they evolved.
Additional features that help identify a bat as a member of the Emballonuridae family include a brown or grey coat, smooth faces, plain noses, medium sized (by microbat standards,) smallish cup-shaped ears that have a tragus at the opening. Although fast, the narrow wing design means that Emballonuridae bats don’t enjoy the easy, graceful maneuverability of other types of bats. A closer look at their wings reveals that the second fingers is without phalanges and that there are only 2 phalanges in the third finger.
The Emballonuridae family includes 47 different bat species that represent 13 different bat generas. You’ll find members of this family in both Old and New World tropical and subtropical climates. Most members of the Emballonuridae family live in small, harem style colonies that include up to 8 females, though there are some exceptions.
Examples of Emballonuridae family members include:
- Chestnut Sac Winged Bat
- Greater Dog-Like Bat
- Naked-Rumped Pouch Winged Bat
- Northern Ghost Bat
- Thomas’s Shaggy Bat