|Townsend's Big-eared Bat, Corynorhinus townsendii|
The microbats constitute the suborder Microchiroptera within the order Chiroptera (bats). They are most often referred to by their scientific name. Other English names are "insectivorous bats", "echolocating bats", "small bats" or "true bats". All these names are somewhat inaccurate, because not all microbats feed on insects, and some of them are larger than small megabats.
The distinctions between microbats and megabats are:
- Microbats use echolocation, whereas megabats do not typically (The Egyptian fruit bat Rousettus egyptiacus is an exception).
- Microbats lack the claw at the second toe of the forelimb.
- The ears of microbats do not close to form a ring: the edges are separated from each other at the base of the ear.
- Microbats lack underfur; they have only guard hairs, or are naked.
Most microbats feed on insects. Some of the larger species hunt birds, lizards, frogs or even fish. Microbats that feed on the blood of large mammals (vampire bats) exist in the Americas south of the United States. Microbats are 4 to 16 cm long. Leaf-Nosed Microbats are also known to be fruit and nectar-eating. Three species of Leaf-Nosed Bats follow the bloom of columnar cacti in Northwest Mexico and Southwest United States northward in the spring and then the blooming agaves southward in the fall.
Microbats generate ultrasound via the larynx and emit the sound through the nose or the open mouth. Microbat calls (help·info) range in frequency from 14,000 to over 100,000 hertz, well beyond the range of the human ear (typical human hearing range is considered to be from 20 Hz to 20,000 Hz). The emitted vocalizations form a broad beam of sound that is used to probe the environment. See the main article on animal echolocation for details.
Some moths have developed a protection against bats. They are able to hear the bat's ultrasounds and flee as soon as they notice these sounds, or stop beating their wings for a period of time to deprive the bat of the characteristic echo signature of moving wings which it may home in on. To counteract this, the bat may cease producing the ultrasound bursts as it nears its prey, and thus avoid detection.
This is the classification according to Simmons and Geisler (1998):
- Family Rhinopomatidae (mouse-tailed bats)
- Family Craseonycteridae (Bumblebee Bat or Kitti's Hog-nosed Bat)
- Family Rhinolophidae (horseshoe bats)
- Family Nycteridae (hollow-faced bats or slit-faced bats)
- Family Megadermatidae (false vampires)
- Family Natalidae (funnel-eared bats)
- Family Myzopodidae (sucker-footed bats)
- Family Thyropteridae (disk-winged bats)
- Family Furipteridae (smoky bats)
- Family Noctilionidae (bulldog bats or fisherman bats)
- Family Mystacinidae (New Zealand short-tailed bats)
- Family Mormoopidae (ghost-faced bats or moustached bats)
- Family Phyllostomidae (leaf-nosed bats)
- Whitaker, J.O. Jr, Dannelly, H.K. & Prentice, D.A. (2004) Chitinase in insectivorous bats. Journal of. Mammalogy, 85, 15–18.
- A Natural History of the Sonoran Desert, Edited by Steven Phillips and Patricia Comus, University of California Press, Berkeley p. 464
- Bat World Sanctuary
- Illustrated Identification key to the bats of Europe (see "Recent publications")
- Bat Conservation International
- Bat flight realtime simulation