Disk-Winged Bats: Thyropteridae

Disk-winged bats use only their suction-like disks to grip and stick to the smooth surfaces of the curled-up leaves in which they roost. They do not use their feet or claws to touch the surface of the leaves.

These bats can support their entire weight with the suction of a single disk. Sweat glands keep the disks' undersurfaces moist, which helps provide the vacuum seal for sticking to the surface. Beneath each disk is a muscle that controls the vacuum. This muscle can create the seal and, when the bat wants to come unstuck, the muscle also undoes the seal. These bats will also lick their disks to help with the suction. Studies have found that these bats have lost the ability to roost on rough surfaces, such as trees and rocks.

Generally only one or two disk-winged bats roost in the same leaf, yet observers have found as many as eight individuals in one leaf. Roosting inside curled leaves protects them from the weather and predators. Leaves open within days, and groups must change roosts often.

Like all bats, these bats are nocturnal, meaning that they are active at night. When more than one bat roosts in a leaf, these bats spread out evenly, one above the other. In Costa Rica, a study reported that group sizes ranged from one to nine, and averaged six bats. Generally, the same group moves together from one old leaf to a new roosting site. Bats in this family have been found roosting with bats in another family, the proboscis bat.

Unlike most other bats, individuals in this family typically hang with their head upward. Disk-winged bats use echolocation (eck-oh-loh-KAY-shun) to find prey (animals hunted for food) and detect objects. Echolocation is a process for locating objects by emitting, sending out, sounds, which are reflected back to the bat by objects in the sound's path.

Females roost together in hollow logs to give birth. Males in this family are thought to be polygynous (puh-LIJ-uh-nus), meaning they mate with more than one female during the mating season.