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Order Chiroptera


Bats are unmistakable. No mammals other than bats have true wings and flight. Bat wings are modified forelimbs, much as are bird wings, except in the case of bats the flight surface is covered with skin and supported by four fingers, while in birds the flight surface is provided mostly by feathers and is supported by the wrist and two digits. The flight membrane usually extends down the sides of the body and attaches to the hind legs. Bats also often have a membrane called a uropatagium that runs between their hind legs and includes their tail (if they have one).

Bats are the second-most speciose group of mammals, after rodents. The approximately 925 species of living bats make up around 20% of all known living mammal species. In some tropical areas, there are more species of bats than of all other kinds of mammals combined.

Bats are found throughout the world in tropical and temperate habitats. They are missing only from polar regions and from some isolated islands.

There are two major groups of bats, usually given the rank of suborders, Megachiroptera and Microchiroptera The Megachiroptera includes one family (Pteropodidae) and about 166 species. All feed primarily on plant material, either fruit, nectar or pollen. The remaining 16 families (around 759 species) belong to the Microchiroptera. The majority of species are insectivorous, and insectivory is widely distributed through all microchiropteran families. But many microchiropterans have become specialized for other kinds of diets. Some are carnivorous (feeding on rodents, other bats, reptiles, birds, amphibians, even fish), many consume fruit, some are specialized for extracting nectar from flowers, and one group of three species feeds on nothing but the blood of other vertebrates. Megachiropterans and microchiropterans differ in many other ways. The "megabats" are found only in the Old World tropics, while "microbats" are much more broadly distributed. Microbats use highly sophisticated echolocation for orientation; megabats orient primarily using their eyes (members of one genus are capable of a primitive form of echolocation). Megabats control their body temperature with a tight range of temperatures and none hibernates; many microbats have labile body temperatures, and some hibernate. Megabats have claws on the second digits supporting their wings (with one exception); this is never the case in microbats. Megabats have relatively simple external ears; microbats often have large and relatively complex pinnae, including an enlarged tragus or antitragus. Microbats often have dilambdodont dentition or cheek teeth whose morphology can easily be related to dilambdodont teeth; megabats have simplified cheek teeth that are difficult to interpret. A controversy has arisen recently concerning whether the two major groups of bats are monophyletic. While this issue is not settled, at present most evidence seems to favor the hypothesis that they are monophyletic; that is, the most recent common ancestor shared by the two groups would also be classified as a bat.

An important cranial characteristic for recognizing bat families is the nature of the premaxilla.

The earliest fossil bat is a remarkably well preserved animal from early Eocene rocks in the Green River formation of Wyoming. Given thename Icaronycteris, it comes from a species that is clearly microchiropteran. This implies that the split between the two groups occurred substantially earlier, and the fossil sheds no light on the question of whether bats are monophyletic.

Literature and references cited

Koopman, K.F. 1984. Bats. Pp. 145-186 in Anderson, S. and J. K. Jones, Jr. (eds). Orders and Families of Recent Mammals of the World. John Wiley and Sons, N.Y. xii+686 pp.

Savage, R. J. G. and M. R. Long. 1986. Mammal Evolution, an Illustrated Guide. Facts of File Publications, New York. 259 pp.

Vaughan, T. A. 1986. Mammalogy. Third Edition. Saunders College Publishing, Fort Worth. vii+576 pp.

Wilson, D. E., and D. M. Reeder. 1993. Mammal Species of the World, A Taxonomic and Geographic Reference. 2nd edition. Smithsonian Institution Press, Washington. xviii+1206 pp.

Click on a name below to learn more about that family.

Suborder Megachiroptera

*	Family Pteropodidae (Old World fruit-eating bats)

Suborder Microchiroptera

*	Family Rhinopomatidae (long-tailed or mouse-tailed bats)
*	Family Craseonycteridae (bumblebee bat)
*	Family Emballonuridae (sac-winged or sheath-tailed bats)
*	Family Nycteridae (slit-faced or hollow-faced bats)
*	Family Megadermatidae (false vampire bats)
*	Family Rhinolophidae (horseshoe bats or Old-World leaf-nosed bats)
*	Family Noctilionidae (bull-dog or mastiff bats)
*	Family Mormoopidae (naked-backed bats)
*	Family Phyllostomidae (New World leaf-nosed bats)
*	Family Natalidae (funnel-eared or long legged bats)
*	Family Furipteridae (smoky or thumbless bats)
*	Family Thyropteridae (disc-winged bats)
*	Family Myzopodidae (old world sucker-footed bats)
*	Family Vespertilionidae (evening bats)
*	Family Mystacinidae (New Zealand short-tailed bats)
*	Family Molossidae (free-tailed bats)


Suborder Megachiroptera

*	Family Pteropodidae (Old World fruit-eating bats)


Members of this family are the "flying foxes" and other fruit-eating bats of the Old World. Pteropodids are the only family of the Suborder Megachiroptera. They include around 166 living species placed in approximately 42 genera. Species of pteropodids can be found in tropical and subtropical regions of Africa, through southern and central Asia to Australia, including the Philippines and a number of Pacific islands. They are especially diverse in southeastern Asia and Indo-Australia. 
Species included in the Animal Diversity Web:

  Subfamily Macroglossinae 
  Subfamily Pteropodinae 


Suborder Microchiroptera

*	Family Rhinopomatidae (long-tailed or mouse-tailed bats)
*	Family Craseonycteridae (bumblebee bat)
*	Family Emballonuridae (sac-winged or sheath-tailed bats)
*	Family Nycteridae (slit-faced or hollow-faced bats)
*	Family Megadermatidae (false vampire bats)
*	Family Rhinolophidae (horseshoe bats or Old-World leaf-nosed bats)
*	Family Noctilionidae (bull-dog or mastiff bats)
*	Family Mormoopidae (naked-backed bats)
*	Family Phyllostomidae (New World leaf-nosed bats)
*	Family Natalidae (funnel-eared or long legged bats)
*	Family Furipteridae (smoky or thumbless bats)
*	Family Thyropteridae (disc-winged bats)
*	Family Myzopodidae (old world sucker-footed bats)
*	Family Vespertilionidae (evening bats)
*	Family Mystacinidae (New Zealand short-tailed bats)
*	Family Molossidae (free-tailed bats)



The rhinopomatids are called mouse-tailed or long-tailed bats after their long free tail. They are the only microchiropteran bats with tails nearly as long as their head and body. The tail membrane is reduced and does not enclose the tail. These bats are small to medium-sized (head and body length of 5.0 to 9.0 cm). They are typically grey-brown to dark brown on their backs, but they may be paler on their bellies.

Long-tailed bats have large, simple, cup-shaped ears joined at the base by a fleshy band across the forehead. There is a small tragus (fleshy ear outgrowth). There is also a fleshy ridge over the slit-like nostrils, but no noseleaf. The slit nostrils can be closed to exclude sand and dust. The sides of the muzzle are swollen, and this can be seen on the skull as well as in live specimens. The palatal branch of the premaxillary is reduced and fused in the midline below the nasal opening. The skull lacks postorbital processes, and the auditory bullae are large. The dental formula is 1/2, 1/1, 1/2, 3/3 = 28 and the molars are dilambdodont.

These bats are primarily insectivorous. They may survive the winter, when fewer insects are available, by becoming torpid.

The family contains only 1 genus (Rhinopoma) with 3 species. This family of bats is known from North and West Africa, the Middle East, Pakistan-Afghanistan, and Thailand.

Rhinopomatids live in treeless arid regions and roost in caves, rock clefts, wells, houses, and pyramids. They are gregarious and colonial. One species (R. microphyllum) has inhabited the Egyptian pyramids for at least 3000 years.

Rhinopomatids have no fossil record. They are sometimes considered to be the most primitive living microchiropterans, because of their free premaxillae, and the structure of their wings and thorax.


Kitti's hog-nosed bat or bumblebee bat

This family contains only one species, Craseonycteris thonglongyai. This species was first discovered and described in 1974. With its discovery, C. thonglongyai became the smallest known mammal, weighing only two grams at maturity. It is extremely rare, only having been observed in the Kwai river drainage in Thailand. Craseonycterids are thought to be most closely related to rhinopomatids and emballonurids but are distinct enough from both groups to warrant familial status.

Craseonycterids lack tails and calcars. Their wings are long and broad to aid in hovering. Their nose, which appears to be mounted on a raised platform and has slit-like, vertical nostrils, resembles that of a hog. These bats have large ears and traguses that appear swollen. Their uropatagium is long.

The skulls of craseonycterids lack postorbital processes. Their premaxillae are not fused to the surrounding bones, but they form a complete ring around the narial opening. The palate ends at the level of the last molars. The teeth are dilambdadont and the dental formula is 1/2, 1/1, 1/2, 3/3 = 28.

Craseonycteris thonglongyai roosts deep in limestone caves in loose groups of fewer than 20 individuals. It is known to eat insects and spiders. It is believed to catch insects on the wing and may also glean arthropods from tree-top foliage. These bats are capable of hovering, an activity that may have led to selection for the small size of this species.

Not much is known about the reproduction and ecology of these rare animals, and no fossils have been discovered.


sac-winged or sheath-tailed bats

Emballonurids are known as sac-winged or sheath-tailed bats. The first of these names describes the glandular sac usually found on the propatagium (leading edge of the wing) in many species. This gland produces a scent used in social displays and to mark territories. Males of some species have a pouch at the base of the throat that may serve a similar function. Emballonurids are also known as sheath-tailed bats because their tail appears to be sheathed in a membrane (uropatagium or interfemoral membrane). The tip of the tail protrudes from the top of this membrane and does not extend for the full length of the membrane.

This family includes 13 genera and 47 species. Their range is tropical and subtropical in both the Old and the New World. 


hispid bats, slit-faced bats

This family is composed of a single genus containing 12 species. Their distribution includes both tropical forests and arid tropical regions in Africa and Southeast Asia.

Nycterids are small to medium in size. All have a peculiar deep longitudinal slit running along the top of the rostrum posterior to the nose. Its borders are fleshy and complex and partially conceal the opening. The function of this pouch is not known, but it has been suggested that it might somehow be involved in echolocation (like the noseleaf of phyllostomids, a structure that is absent in nycterids). Most slit-faced bats are orange, brown, or gray. They have large, oval ears with a small but well-developed tragus.

The skulls are distinctive due to a deep depression between the orbits, which probably contains the pouch described above. Postorbital processes are present but hard to distinguish because of the unusually broad supraorbital ridges extending over the orbits. The premaxillae are made up of palatal branches only. These are well developed and completely fill the space between the maxillae. These bats have a characteristic that is otherwise unknown among mammals: the posterior tip of the last caudal vertebra (at the tip of the tail) is `T' shaped.

The molars of nyterids are dilambdodont. The dental formula is 2/3, 1/1, 1/2, 3/3 = 32. Upper incisors are 2- or 3-lobed.

Nycterids have been found roosting alone, in pairs or in small family groups. This group has a great diversity of roosting habits, including caves, hollow logs, tree branches, tunnels, and human houses. They also sometimes roost in the burrows of other mammals such as hedgehogs, porcupines, and aardvarks.

The diet of slit-faced bats is diverse. Most species specialize on arthropods, and one species, Nycteris grandis, regularly catches and eats vertebrates. They forage close to surfaces including rock faces and bushes.

The supposed sister groups to the Nycteridae are the Megadermatidae and Rhinolophidae. No fossils are known.


false vampires

Megadermatids are medium-sized to large bats with a head and body length of 6.5 to 14.0 cm. These "false vampires" or yellow-winged bats look comical with their long erect noseleaf (fleshy protrusion from the nose) and huge ears. Echolocation calls are made through the nose, and the large noseleaf focuses the sound, acting like a megaphone. Megadermatid ears also have a fleshy protrusion called a tragus. The tragus is divided in this family, and the ears are joined at the base by a band of skin across the forehead. There is an extensive tail membrane (uropatagium), but the tail itself is short or absent.

The megadermatid family includes 4 genera and 5 species. These bats are found in the Old World tropics and subtropics: Central Africa, South Asia, the Malay region, Philippines and Australia. 


(horseshoe bats or Old-World leaf-nosed bats)

The Rhinolophidae is a large family of bats, including approximately 130 species grouped in 10 genera. It is sometimes divided into two families, the Rhinolophidae (horse-shoe bats) and Hipposideridae (Old World leaf-nosed bats). There is little question that these two groups of bats are closely related, but current practise is to classify them as subfamilies (Hipposiderinae and Rhinolophinae) in a single family. Many species are extremely difficult to distinguish.

All rhinolophids have leaf-like protuberances on their noses. In hipposiderine species, these take the shape of a horseshoe; in rhinolophines, they are leaf- or spear-like. Echolocation calls are emitted through these structures, which may serve to focus the sound. The ears of these bats vary in size and lack a tragus. Most rhinolophids are dull brown or reddish brown in color. They vary in size from small to moderately large.

Rhinolophids have distinctive premaxillae, with palatal branches only. The premaxillae on opposite sides of the skull are neither fused with each other nor are they fused with the maxillary bones. Rhinolophid skulls often have distinct sagittal and lambdoidal crests. The palate is unusually short due to deep indentations at both ends. The molars are dilambdodont, and the dental formula is 1/2, 1/1, 1-2/2-3, 3/3 = 28-32.

Rhinolophids inhabit temperate and tropical regions of southern Europe, Africa, and Asia south to northern and eastern Australia, including many Pacific islands. All species are insectivorous, hawking insects in flight. Their roost habits are diverse; some species are found in large colonies in caves, some prefer hollow trees, and others sleep in the open, among the branches of trees. Members of northern populations may hibernate during the winter; at least one species is migratory. Like many vespertilionid bats, females of some rhinolophid species mate during the fall and store the sperm over the winter, conceiving and gestating young beginning in the spring.

The earliest rhinolophids in the fossil record are known from the Middle Eocene.



bulldog bats

Two species (placed in a single genus) make up this family, the members of which are called bull-dog or mastiff bats. Noctilionids are medium-sized bats, often brightly colored (varying from bright rufous in males to drab gray-brown in females). The region around the mouth is distinctive. The lips are full and form cheek pouches, in which the bats store food as they feed while flying. A uropatagium extends somewhat beyond the knees. The tail of bulldog bats runs through the uropatagium for about half the length of the membrane, then exits dorsally, and the terminal part of the tail is free. The feet and claws range from relatively large (Noctilio albiventris) to relatively enormous (Noctilio leporinus) in size, and the legs are proportionately longer than in most other bats. The ears are moderately large and a tragus is present.

Bulldog bats have a pungent odor, described by some investigators as "fishy:"

In the skull, the premaxillae are fused with each other and with the maxillae, and both nasal and palatal branches of the premaxillae are present (the latter very small and indistinct in adults). The auditory bullae are small. Postorbital processes, found in many other kinds of bats, are completely lacking. The dental formula of noctilionids is 2/2, 1/1, 1/2, 3/3 = 34; and the molars are dilambdodont.

Both species of noctilios feed on insects, and N. leporinus takes fish, frogs, and crustaceans as well. To capture fish, these bats use their echolocation to locate exposed fins or ripples made by fish swimming near the surface. They then drag their claws through these ripples. Their hind claws are unusually large and sharp and serve as efficient gaffs. Once out of the water, the fish is carried to a perch, where it is eaten by the bat. Noctilio leporinus may also capture insects and crustaceans on the surface of the water.

These bats usually roost near water, often in hollow trees or in deep cracks in rocks.

Bulldog bats are a Neotropical group, found from northern Mexico, through Central America, south to Paraguay and northern Argentina. Few fossils are available, and those that are known are from the Pleistocene. Bulldog bats may be related to two other New World families, Phyllostomidae and Mormoopidae.



moustached bats, ghost-faced bats, and naked-backed bats

This neotropical family is composed of two genera containing eight species, distributed from Brazil to the southern United States. Based on evidence from morphology, chromosome structure, and biochemical features, mormoopids are thought to be closely related to the Phyllostomidae, and until recently it was included in that family as the subfamily Chilonycterinae. The Mormoopidae also appears to be close to the Noctilionidae, and it has been suggested that those three New World families may have shared a common ancestor in the Paleocene.

These small to medium-sized bats lack a well-developed noseleaf, but they do have a small bump on their noses roughly in the position of that structure. Their lips are large, and their lower lips are complexly folded and ornately decorated with plates and flaps of skin. The mouth is distinctively shaped like a funnel when open. Mormoopids also have a fringe of stiff hairs on their muzzles; hence the name "moustache bat." Their eyes are small compared to the eyes of phyllostomids of similar body size. The ears vary in size and shape but always have a tragus (which always has a secondary fold). In some species, the wings attach to the body high along the midline of the back, so that the surface of the back appears naked. Beneath the wings, however, is a normal coating of fur. The fur of most species is brown or reddish brown, but within species some individuals vary considerably in color.

The skulls of mormoopids lack postorbital processes. The premaxillae are complete and fused to each other and to the adjacent maxillae. The palatal branches are well developed and define two palatal formina. The dental formula of members of this family is 2/2, 1/1, 2/3, 3/3 = 34. The molars are dilambdodont.

These bats are strictly insectivorous and generally live near water. They roost gregariously, sometimes in very large colonies, and some species are thought to roost exclusively in caves. They can be found in a wide range of habitat types, from rainforest to arid deserts.

The fossil record of mormoopids is poor, extending only to the Pleistocene.



New World leaf-nosed bats are a common and diverse group that includes around 143 species, placed in 49 genera. The relationships of these genera are not fully understood. Currently, living phyllostomids are arranged in 7 or 8 subfamilies. The Phyllostominae includes carnivorous, insectivorous, and fruit-eating species. Members of this subfamily tend to have a number of primitive characteristics. The Glossophaginae is made up of nectar feeders, bats with remarkable adaptations of tongue and rostrum for extracting nectar and pollen. They are also capable of hovering flight. The monophyly of this group is open to question; some nectar feeders are sometimes placed in the separate subfamily, Lonchophyllinae. The Carolliinae includes a small group of frugivores, possibly related to glossophagines. The subfamily Stenodermatinae is the largest of the family. Stenodermatines are primarily fruit-eaters, and many show strong specializations for frugivory. The Brachyphyllinae is a group of fruit and nectar eating species restricted to the West Indies. They may be related to stenodermatines or glossophagines. Finally, the Desmodontinae comprises the vampires, a group of 3 species that rely entirely on blood for food.

The most conspicuous characteristic of phyllostomids is a "noseleaf," a fleshy protuberance from the nose that ranges from in size from nearly as long as the head to, in a few species, complete absence. Many species also have bumps, warts, and other protuberances on the head near the noseleaf or on the chin. In most species, the noseleaf is a relatively simple spear-shaped structure, not nearly as complex as that of rhinolophids.

Phyllostomids lack postorbital processes, and their premaxillae are complete and fused to each other and to the maxillae. The palatal branches of the premaxillae isolate two lateral palatal foramina. The bony tails of phyllostomids vary from apparently absent to long, even extending slightly beyond the edge of the uropatagium. A tragus is present.

Species in the Animal Diversity Web:

  Subfamily Brachyphyllinae 
  Subfamily Carolliinae 
  Subfamily Desmodontinae 
  Subfamily Glossophaginae 
  Subfamily Lonchophyllinae 
  Subfamily Phyllostominae 
  Subfamily Stenodermatinae 



funnel-eared bats

The family Natalidae is composed of a single genus with five species. These bats are found in tropical lowlands of the New world, from northern Mexico south to Brazil. They also occur in the West Indies.

Natalids are small bats with relatively long legs. Their skulls are high-crowned, with the braincase rising abruptly from the long muzzle. Each ear is large and funnel-shaped and includes a short tragus. The outer edge of the ear joins the skull near the margin of the mouth. Adult males have a structure on the face or muzzle called the natalid organ, which is composed of cells that may be sensory or secretory, although the exact function is unknown. Natalids lack a noseleaf. The fur of these bats is distinctively long and silky, and it varies in color from grey to yellowish to chestnut. They have a well-developed uropatagium, which encloses the tail.

The skulls of natalids include complete premaxillae; the palatal and nasal branches are fused with the maxillae, and the palatal branches are fused at the midline, isolating two palatal foramina. The molars are dilambdodont, and the dental formula is 2/3, 1/1, 3/3, 3/3 = 38.

Natalids are quite common in some areas, often roosting in caves and mines. Social groups range in number from very large to fewer than ten. The flight of these bats is fluttery and moth-like.

Natalids feed exclusively on small insects.

These bats are probably closely related to the Thyropteridae and Furipteridae.



Smoky bats

This family consists of two genera with one species in each genus. Like the natalids, furipterids are small, neotropically distributed members of the superfamily Vespertilionoidea, the largest of the four superfamilies of microbats.

Smoky bats are very small bats with much reduced thumbs that are mostly enclosed in the wing membrane. The crown of their head is inflated, and they have large, well-separated ears with a small tragus. Curiously, the ears appear to cover their small eyes so that from the front, these bats look strangely eyeless. Furipterids have a small noseleaf, and one species, Amorphochilus, has three triangular fleshy projections from its lower jaw. Their tail is enclosed in the uropatagium; a short portion may project beyond. The fur of furipterids is gray or gray-brown in color and appears coarse.

The premaxilla of furipterids has palatal branches that are reduced to filaments. These bats lack postorbital processes. Their dental formula is 2/3, 1/1, 2/3, 3/3 = 36, and their molars are dilambdadont. The upper canines are relatively small, about the height of the upper premolars.

These bats are strictly insectivorous and may be further limited in diet to moths and butterflies.

Furipterids live in diverse habitats from lowland rainforest to the super-dry western deserts of South America. Colonies range from 100 to 300 individuals and are known primarily from caves and man-made structures.

Furipterids appear to be closely related to the family Natalidae and Thyropteridae. They have no fossil record.



disk-winged bats; New World sucker-footed bats

This family of neotropical bats contains one genus with two species. Their common name is derived from the suction cups found on the wrists and ankles of these animals. These bats roost, head-up, inside the smooth tubes formed as young banana or heliconia leaves unfurl. The suction cups allow these bats to stick to the walls of these leaves, protected from rain and hidden from predators. Since the leaves open in a matter of a few days, groups are forced to change roosts often. Generally, the whole group moves together from the old leaf to a new one.

Thyropterids are small bats with a long and slender snout. They have no noseleaf, but they do have small warts on their noses above their nostrils. They have an abrupt "forehead," that is, the crown of their head rises abruptly above their muzzle. Their ears are moderately large and funnel-shaped, and the other edge is attached near the angle of the mouth. A tragus is present. The wing membranes of members of this family extend unusually far down their legs, arising on their feet near the base of the claws. Most individuals are reddish brown or pale brown in color on the back, and whitish or brownish on the undersurface.

The premaxillae of thyropterids are complete, and their palatal branches isolate two palatal foramina. Thyropterids lack a postorbital process. The dental formula is 2/3, 1/1, 3/3, 3/3 = 38 and the molars appear dilambdodont. There is a gap between the incisors and canines, and between the right and left incisors.

Perhaps the strangest feature of these bats is their relationship to the family Myzopodidae (the old world sucker-footed bats). Myzopodids are bats found only in the rainforests of far-off Madagascar. The myzopodids also have suction cups and roost in young, rolled leaves, but their suction cups are thought to be the result of an evolutionary convergence with the suction cups of thyropterids. Unfortunately, there is no fossil record for the thyropterids.

These bats feed exclusively on insects.



(old world sucker-footed bats)

The single species in this family, Myzopoda aurita, is found only in Madagascar, although there are fossil myzopodids known from Pleistocene beds in Africa. Like the neotropical Thyropteridae, myzopodid bats have suction-cups on their wrists and ankles that allow them to roost inside rolled leaves. The suction cups appear to have been evolved independently of those found on thyropterid bats. Myzopodids are placed in the superfamily Vespertilionoidea.

Myzopodids are medium-sized bats with large ears. Their toes have only two phalanges, and they are united for most of their length. The thumb is small and has a vestigial claw, similar to the New World furipterids. The premaxillae are fused and their palatal branches define two palatal foramina. The dental formula of myzopodids is 2/3, 1/1, 3/3, 3/3 = 38, and the molars are dilambdodont.

Little is known about the natural history of this rare species. Its members are believed to be insectivorous.

Technical characters



This is the largest family of bats: it includes 35 genera and 318 species! With this many species there are exceptions to almost every generalization about this family.

To make the family more manageable to taxonomists, some authors split it into subfamilies. Unfortunately, there seems to be little agreement about the composition of these taxa. One scheme (Wilson and Reeder, 1993) employs the following subfamilies: Kerivoulinae (genus Kerivoula), Murininae (Murina and Harpiocephalus, both with tube-like nostrils), Miniopterinae (genus Miniopterus, these have very long 3rd fingers), Tomopeatinae (Tomopeas, with thick, leathery ears like the molossids), Vespertilioninae (all the other genera).

Species included in database:
  Subfamily Kerivoulinae 
  Subfamily Miniopterinae 
  Subfamily Murininae 
  Subfamily Vespertilioninae 

Accounts marked with a p contain pictures, t contain narrative text (student authored), a contain anatomical still/QTVR images, and s contain digitized sound clips. 
Vespertilionids, or evening bats, have small eyes, no noseleaf (rudimentary in Nyctophilus and Pharotis), and ears with both a tragus (fleshy ear outgrowth) and an anterior basal lobe (except Tomopeas). Their tails are relatively long and extend to the edge of the tail membrane or beyond. This large family includes a wide range of sizes. Some vesper bats weigh only 4 grams as adults, whereas others weigh up to 50 grams. Most of these bats are black or brown colored, but some are orangish or have other markings.

Morphologists identify vespertilionid bat skulls by the unfused premaxilla, the trend towards short jaws, and the absence of any postorbitalprocess. The number of teeth in this family varies from 28 to 38 depending on the species. The dental formula is 1-2/2-3, 1/1, 1-3/2-3, 3/3. The incisors are small and separated right from left, and the premolars and molars are dilambdadont. These bats are primarily insectivorous, and most hawk insects in flight, often using their wings like tennis rackets and swatting the insects into the tail membrane. Some species eat fish (Pizonyx, Myotis spp.), and most species defend a feeding territory.

Many vespertilionids live in caves, but these bats can also be found in mine shafts, tunnels, old wells, rock crevices, buildings, etc. Some species contaminate man's habitations with feces and noise, but this annoyance is more than offset by the bats' consumption of huge quantities of insects. Some species roost in large colonies, but others are solitary or live in small groups or pairs. Males and females tend to roost apart most of the year, and some species have maternity colonies.

The mating system varies widely within the vespertilionids. Many species show resource defense polygyny, the most common mating system in bats. Other vespertilionid mating systems include promiscuity in Myotis lucifugus and lekking in some Miniopterus species.

This group of bats has a worldwide distribution. Vesper bats live in tropical forests, deserts, and temperate zones -- only polar regions and some remote isles are vespertilionid-free. The vespertilionid genus Myotis has the widest distribution of all bat genera. Temperate zone bats are faced with a dilemma when cold weather drives insects away. Some species (Lasiurus, Lasionycteris, Nyctalus, some Pipistrellus) migrate to areas where there is more food, while many other species of vespertilionids hibernate.

Hibernating bats lower their body temperatures and remain inactive for several days or even months at a time. They often hibernate in caves where the ambient temperature does not fall below freezing. These bats then drop their body temperature to as low as 2 C. Since maintaining a high body temperature requires using up many calories, these bats save a lot of energy by lowering their body temperature in hibernation. These bats survive the winter by living off fat stores and making occasional foraging trips during warmer weather. Hibernation is known in at least some species of the following genera: Antrozous, Eptesicus, Miniopterus, Myotis, Nyctalus, Pipistrellus, and Plecotus.

Many hibernating species and a few non-hibernators delay giving birth until spring or summer, when food is plentiful. Vespertilionid bats typically mate in the fall. They then postpone birthing by three different methods. Females from many species of vespertilionids store sperm in the uterus from fall matings throughout the winter. The females ovulate in the spring and give birth in late spring or early summer. Miniopterus females do not store sperm; instead, they delay implantation of the blastocyst, which remains free in the female reproductive tract until environmental conditions improve. Finally, in some Eptesicus, Miniopterus and Myotis females, the blastocyst implants in the uterus, but further development is delayed until spring.

The reproductive and physiological adaptations described above allow vespertilionid bats to succeed in temperate as well as tropical zones. This family shows extraordinary variability in mating, reproductive, and seasonal strategies. Vespertilionids also show a wide range of wing shapes, roosting behavior, and foraging strategies. These bats have been successful world wide.

Michigan is home to eight species of bats, shown here in dorsal, ventral, and lateral views. An additional species (the evening bat, Nycticeius humeralis) has been captured in the state, but it is at the limit of its northern distribution in the Great Lakes region and may not reside here regularly.



(New Zealand short-tailed bats)

This family is composed of a single genus containing two species (one of which may be extinct). Mystacinids are found only on the islands of New Zealand.

These bats are unique in their ability to hide their wings beneath a leathery membrane when not in use. Partially as a result of this adaptation, mystacinids are unusually well adapted to foraging on the ground, and spend a large percentage of their waking time hunting prey on the forest floor. They are also known to burrow. They also have very tough wing membranes and relatively broad wings, which allow them to take off from a flat surface.

Mystacinids are medium-sized bats with a long snout. The nose projects well over the lips, and the slit-like nostrils are located in a pad covered with stiff, short bristles. The ears are moderately large and contain a long, narrow and pointed tragus. Their tails project above the surface of the uropatagium for a short distance. The legs are short but strongly built, and the feet are broad and end in sharp, strong claws (the claw on their thumb is also unusually well developed). The fibulae are unusually well developed, which probably contributes to the strength and manueverability of the hind legs. Short-tailed bats are gray-brown or black-brown in color. Individual hairs are tipped grayish, giving the bat a "frosted" appearance. The fur is somewhat velvety in texture.

The skulls of mystacinids have well developed premaxillae, the palatal branches of which isolate two lateral foramina. Their teeth are dilambdadont; the dental formula is 1/1, 1/1, 2/2, 3/3 = 28.

Unlike some other bats found in New Zealand, mystacinids do not experience prolonged hibernation and are sometimes observed actively foraging on warm winter nights. Their diet includes resting and flying arthropods, and lesser amounts of fruit, nectar and pollen. They sometimes also forage on carrion. Roosting mystacinids are typically found in large trees and colony size ranges greatly.

The known extant species is at risk from rats and from the clearing of forests.

Recent molecular analysis has moved these bats from the superfamily Vespertilionoidea to the superfamily Phyllostomatoidea, but the phylogenetic affinities of the mystacinids are not well understood. No fossils have been discovered.



free-tailed bats

3 species of molossids. Notice the range in size.

Molossids are known as free-tailed bats, because their bony tail extends to the end of a well-developed tail membrane (uropatagium) and considerably beyond. They often crawl backwards when on the ground, using their tail as a sort of "feeler." Molossids are small to moderately large bats, with forearms ranging from around 27 mm to approximately 86 mm in length. Their muzzles are usually short and broad, and they often have wide, fleshy lips that may have folds or creases. Many have a distinctive pad over their noses; this pad is often endowed with odd bristles with spatulate tips. Most free-tailed bats have relatively short but broad ears. The tragus is tiny, but opposite it, an antitragus is unusually well developed. All species have long, narrow wings, apparently adapted for fast but relatively unmanueverable flight in open places. Their wing and tail membranes are unusually tough and leathery. Molossids also have short, strong legs and broad feet. Like their nose pads, molossids' feet are well endowed with sensory bristles (also with spatulate tips). They are excellent climbers, perhaps because they launch themselves for flight from a considerable height above the ground. Because of their long, narrow wings, they must attain considerable speed before they can develop enough lift to fly. They accomplish this by falling some distance from their roost or take-off point.

Molossids generally have short, even velvety fur. Most are black or brown, and many species have distinctive reddish and brownish or blackish color phases.

Roosting area for Tadarida
Molossids are found in the New World from the central United States south to southern Argentina. In the Old World, they occur in southern Europe and Africa, eastward through tropical and subtropical Asia to Australia. All members of the family are insectivorous, catching their prey on the wing. Their roosting habits range from solitary to living in immense colonies of millions of bats, usually in caves. In the neighborhood of these large colonies, molossids may consume enormous numbers of insects. Approximately 85 species of molossids are placed in around 12 genera.

Technically, molossids can be recognized by a combination of the following characters:

*	long tail, tip of tail free of uropatagium
*	tragus tiny, antitragus conspicuous
*	no noseleaf
*	3rd phalanx of the 3rd finger is cartilaginous for most of its length
*	no postorbital processes
*	premaxillae with or without palatal branches
*	dilambdodont teeth
*	dental formula 1/1-3, 1/1, 1-2/2, 2-3/3