Free-Tailed Bats and Mastiff Bats (Molossidae)
Free-tailed bats and mastiff bats
(Molossidae)
Class Mammalia
Order Chiroptera
Suborder Microchiroptera
Family Molossidae
Thumbnail description
Free-tailed and mastiff bats, with a thick tail extending well beyond the tail membrane and long, narrow wings adapted for rapid flight in open airspace; a broad snout, often with wrinkles, which projects well over the lower lip; ears usually somewhat flattened and stiff, lying low over the head, and tilted forward; body covered with short, dense fur
Size
Small- to large-sized with forearms ranging 1.1–3.4 in (2.7–8.5 cm) in length and weighing 0.2–3.8 oz (5–167 g)
Number of genera, species
12 genera; 90 species
Habitat
Tropical, subtropical, and warmer temperate regions; arid as well as moist, forested habitats
Conservation status
Critically Endangered: 3 species; Endangered: 1 species; Vulnerable: 15 species; Lower Risk/Near Threatened: 21 species; Data Deficient: 4 species
Distribution
Throughout the warmer parts of the world, on all continents except Antarctica, on the Malay Archipelago and southern Pacific islands east to Fiji, and throughout much of the Caribbean
Evolution and systematics
Fossils of the family date from the late Eocene in Europe, late Oligocene or early Miocene in South America, Miocene in Africa, and Pleistocene in Asia, Australia, North America, and the East and West Indies. Morphological and molecular data place free-tailed and mastiff bats in the superfamily Vepertilionoidea allied with the vespertilionid bats (Vespertilionidae) and the funnel-eared bats (Natalidae). Other authors place them in the superfamily Molossoidea.
Physical characteristics
Free-tailed and mastiff bats (molossids) are small- to large-sized bats, distinctly characterized by a thick tail that protrudes well beyond the tail membrane. The tail is not so long as in the mouse-tailed bats (Rhinopomatidae). Most species have a broad face, with a wrinkled snout and lips, and the snout projects well over the lower lip. Their eyes are small. Their umbrella-like ears vary in size, but typically the ears lie low over the head, are stiff, rounded, and project forward, often with a lateral orientation. The ears are often connected over the forehead. These bats have long, narrow wings, and the wing and tail membranes are tough and leathery. The hind legs are short and strong and the feet are broad and fringed with long bristles. Some species are well endowed with glands on their chins, throats, and chest regions, and they often have a distinctive odor. Most free-tailed and mastiff bats have short brown fur, but in some, the fur is gray or black. Males of some species of the genus Chaerephon develop head crests of erectile hair during the mating season, while others have tufts of hair associated with chest glands. Members of the genus Cheiromeles (one or two species) are almost completely hairless. These "naked" bats also have wing pouches, or flaps of skin along the sides of the body, into which they place their folded wings. A few crevice-roosting species in the genera Molossops and Mormopterus have distinctly flattened skulls.
Distribution
Except for bats of the family Vespertilionidae, molossids have the widest distribution of any family of bats. They are found throughout the warmer parts of the world, including southern Europe, much of Africa, southern Asia, Malaysia, Australia, the Australasian region east to Fiji, in central and southern North America, Central America, the Caribbean Islands, and all except the southern-most portion of South America.
Habitat
They occur in a wide range of habitats and are common in natural, rural, and urban areas. They reach their greatest abundance in arid and semi-arid habitats. Natural roosting sites include caves, rock crevices, tree cavities, bark, rotting logs, foliage, and holes in the ground (Cheiromeles). These bats also commonly roost in human-made structures, including
buildings, mines, tunnels, culverts, under bridges, and in bat houses. They are commonly found under corrugated steel roofs, roof tiles, or in attics of tropical houses, and they tolerate high temperatures that can exceed 130°F (55°C).
Behavior
Molossids tend to be active throughout the year. Populations of Brazilian free-tailed bats (Tadarida brasiliensis) in
temperate, seasonal habitats are known to engage in long-distance, annual migrations that exceed 800 mi (1,300 km). However, other populations of the same species are known to remain in place or to engage only in short-distance seasonal movements and to utilize torpor to survive cold temperatures during relatively mild winters. Most molossids are colonial, with colony sizes typically reported as a few tens to a few hundreds of individuals. There are some reports of solitary bats, and numerous accounts of colonies into the thousands of bats. Brazilian free-tailed bats in the southwestern United States and northern Mexico form cave colonies of tens of millions of bats, which are the largest known aggregations of mammals. The behavior of this large family of bats is characterized by diversity and plasticity.
Feeding ecology and diet
These strong-flying bats typically pursue insects in open, uncluttered airspace above the canopy and they can fly to high altitudes. Studies in Africa, Australia, and North America document foraging by molossids at altitudes of several hundred feet (meters) above ground level. Radar shows that Brazilian free-tailed bats fly to altitudes of up to 2 mi (3.2 km) over central Texas, and research has confirmed that large numbers of these bats are actively feeding on insects at altitudes of at least 4,000 ft (1,219 m) above the ground. Molossids detect and pursue insects using relatively low-frequency echolocation calls (typically <30kHz, but <10kHz in some species) that travel long distances in open airspace. Recent studies suggest remarkable diversity in their echolocation calls.
Molossids are known to forage in groups and to exploit patches of insects such as emerging swarms of termites, winged ants, and large migratory populations of moths. They also forage around streetlights that attract concentrations of insects. These bats prey on a great variety of insects. Recent studies of Brazilian free-tailed bats document that their insect prey consists of at least 12 orders and 35 families of insects. Moths (Lepidoptera) and beetles (Coleoptera) provide the bulk of their prey, but all evidence indicates that Brazilian free-tails, in particular, and molossids, in general, are highly opportunistic feeders that exploit a diverse diet of insects.
Reproductive biology
Little is known regarding mating behavior of most molossids. Chaerephon pumila is reported to roost and mate in stable harem groups of about 20 females attended by a single male. Evidence suggests that Tadarida brasiliensis mates promiscuously during a brief period in spring when males and females assemble at specific sites. Many reports of the use by molossids of low-frequency vocal communication, the abundance of scent glands, and the existence of obvious structures for social displays such as head crests all suggest that molossids engage in a diversity of social interactions and mating systems that are, as yet, unstudied.
Females of most species appear to give birth to a single young annually. However, some species are reported to be polyestrus, giving birth twice (Molossus ater and M. molossus) or three times (Chaerephon pumila) annually, in parts of their geographic ranges. Cheiromeles is additionally unique among mollosids in giving birth to twins during a single annual reproductive period. Where known, gestation is usually two to three months in length, and the period from birth to weaning typically lasts five to six weeks. Studies on milk composition and reproductive energetics in Brazilian free-tailed bats demonstrate an extremely high-fat content in the milk of females,
allowing for the rapid growth of their young. During the period of peak lactation, it is estimated a lactating female Brazilian free-tailed bat has energy demands of 106 kj/day to meet her needs and those of her growing young, requiring that the female consume approximately 70% of her body weight in insects each night.
During pregnancy and lactation, females typically roost in maternity colonies, separated from adult males. But, even in the largest maternity colonies that contain tens of millions of individuals, females relocate and selectively nurse their own young. The mating system is not known for all species, but most are thought to be polygynous.
Conservation status
Extremely fragmented or limited distributions, coupled with near-term concern for the integrity of critical habitat, are responsible for the listing of Chaerephon gallagheri, Mops niangarae (both African), and Otomops wroughtoni (Asian) as Critically Endangered, and for the listing of Mormopterus phrudus (South American) as Endangered. All 15 species listed as Vulnerable are considered to be at risk because of projected or suspected loss and degradation of habitat, and/or because populations are small and restricted in their area of occupancy. Thus, the loss of habitat, coupled with restricted distributions, contributes the most concerns for the conservation of these bats. Although it still forms the largest aggregations of mammals in existence, Tadarida brasiliensis is the only bat listed on Appendix I (Endangered) of the Bonn Convention of Migratory Animals. This listing results from the extreme vulnerability of these bats to so many individuals being aggregated at only a limited number of sites, and the fact that many formerly huge cave colonies in the United States and Mexico either no longer exist or have suffered severe reductions in the populations. Habitat destruction, disturbance, vandalism, and poisoning from pesticides are the major risks to these bats.
Significance to humans
Where they are abundant, molossid bats can provide important service to humans by consuming huge numbers of insects that are agricultural pests. The 100 million Brazilian free-tailed bats that occupy Texas each summer consume an estimated 1,000 tons of insects each night, with many of these
insects known to be adult cotton bollworms, fall armyworms, and other moths that are major crop pests. The guano of molossid bats that live in large colonies is harvested commercially by local farmers as a rich source of nitrogen for fertilizer.
As with all mammals, bats can contract and transmit rabies virus. The rabies virus associated with Brazilian free-tailed bats has been implicated in the deaths of approximately 12 people in North and South America over the last three decades. Other human health concerns involve Histoplasma capsulatum, a fungus that commonly grows in bat (and bird) guano that can infect humans and cause histoplasmosis, typically of the human respiratory system via inhalation. The habits of molossids of roosting in houses and other buildings may result in human contacts and their risks of exposure to rabies or histoplasmosis.
Species accounts
List of Species
Lesser-crested mastiff batNaked bat
Greater house bat
Giant mastiff bat
White-striped free-tailed bat
Brazilian free-tailed bat
Lesser-crested mastiff bat
Chaerephon pumila
taxonomy
Chaerephon pumila (Cretzschmar, 1830), Massawa, Eritrea.
other common names
English: Crested free-tailed bat.
physical characteristics
Forearms ranging in length 2.5–2.9 in (6.2–7.2 cm); weighing 1.0–1.3 oz (31–39 g). It has long ears and very long narrow wings. Males develop a head crest of hair during the mating season.
distribution
Throughout much of sub-Saharan Africa, from Senegal to Yemen and south to South Africa. Also in Madagascar.
habitat
Present from sea level to over 6,560 ft (2,000 m), from semi-arid to humid montane forest, and in urban habitats.
behavior
Roosts in caves, tree hollows, and buildings. Most known colonies consist of up to a few tens of individuals, but colonies of hundreds have been reported from lava tubes in Kenya. It is reported to mate in year-round harems of three to 21 females attended by a single adult male, with young females recruited into their natal groups.
feeding ecology and diet
Forage high above the canopy with very rapid flight and using low-frequency echolocation calls. Known to eat moths, beetles, and grasshoppers.
reproductive biology
Polygynous. Reproductive schedule may vary geographically; in Kenya, they mate in August with a single young born in December–January.
conservation status
Listed by the IUCN as Vulnerable due to documented and projected population declines and disturbance and destruction of known roost sites.
significance to humans
Guano is mined for fertilizer from formerly large cave roost sites in Kenya. May consume insects that are agricultural pests.
Naked bat
Cheiromeles torquatus
taxonomy
Cheiromeles torquatus Horsfield, 1824, Penang, Malaysia. May be synonymous with the only other species in the genus, C. parvidens.
other common names
English: Hairless bat, naked bulldog bat.
physical characteristics
The largest molossid and the most distinctive with forearms ranging in length 2.8–3.6 in (7–9 cm); weighing 3.2–5.7 oz (96–170 g). Naked bats are almost completely devoid of hair with dark gray to black skin. Deep flaps of skin on the sides of the body from the upper wing bones to lower leg bones form a wing pouch into which the bats push their folded wings using the hind feet. The first toe of each foot is opposable and has a flattened nail rather than a claw.
distribution
Peninsular Malaysia, Borneo, Java, Sumatra, the Philippines, and associated smaller islands.
habitat
Tropical forest.
behavior
Roosts in caves, rock crevices, tree cavities, and holes in the ground. Formerly found in colonies of up to 200,000 in large caves, and up to 1,000 individuals in tree cavities. They are capable of crawling swiftly on the ground.
feeding ecology and diet
A strong, fast-flying bat that forages above the canopy and in open areas on a variety of insects, particularly winged ants and termites.
reproductive biology
Typically produces twins. Mating system is not known, but most likely polygynous.
conservation status
Several large cave populations have declined substantially due to human disturbance, collection for food by local human populations, and persecution because these bats were mistakenly considered a pest of crops. Rated by IUCN as Lower Risk/Near Threatened.
significance to humans
Eaten by local human populations. Have a unique symbiotic association with a distinct suborder of earwigs (Insecta, Dermaptera, Arexiniina) which resulted in Niah Cave in Sarawak being designated as an earwig sanctuary.
Greater house bat
Molossus ater
taxonomy
Molossus ater Geoffroy, 1805, Cayenne, French Guiana.
other common names
English: Velvety free-tailed bat, Guianan mastiff bat.
physical characteristics
Forearms ranging in length 1.9–2.1 in (4.8–5.2 cm); weighing 0.5–1.3 oz (14–40 g). It has short, rounded ears that are connected across the forehead. Range in color from reddish brown to black, often with two color phases.
distribution
Northern Mexico to Peru, northern Argentina, Brazil, and the Guianas, also on Trinidad.
habitat
Moist to dry areas in forested and open habitats, as well as in rural and urban habitats.
behavior
Roosts in tree hollows, foliage, and caves and very commonly in buildings, where it can be found under galvanized roofing or in attics where temperatures can exceed 130°F (55°C). Colonies range in size from a few bats to several hundred individuals.
feeding ecology and diet
Characterized by fast erratic flight in pursuit of insects from near the ground to high in open air. This bat fills its large cheek pouches with insects and returns to the roost to consume its food.
reproductive biology
Produces a single young, however, reported to produce two young per year in different seasons in several parts of its range. Males and females segregate and may roost separately even when roosting at the same site. Mating system is not known, but most likely polygynous.
conservation status
Rated by IUCN as Lower Risk/Least Concern.
significance to humans
Can be a nuisance due to guano accumulations and odor resulting from its habit of roosting in buildings. May consume insects that are agricultural pests.
Giant mastiff bat
Otomops martiensseni
taxonomy
Otomops martiensseni (Matschie, 1897), Magrotto Plantation, Tanga, Tanzania.
other common names
English: Big-eared free-tailed bat.
physical characteristics
Forearms ranging in length 2.5–2.9 in (6.2–7.2 cm); weighing 1.0–1.3 oz (31–39 g). A good-sized bat with long ears and very long narrow wings.
distribution
Widely distributed in eastern Africa, including Central African Republic, Djibouti, Ethiopia, Democratic Republic of the Congo, Kenya, Tanzania, Angola, Zimbabwe, Malawi, and Natal. Also reported from Madagascar, Ghana, and Yemen.
habitat
Present from sea level to over 6,560 ft (2,000 m), from semi-arid to humid montane forest, and in urban habitats.
behavior
Roosts in caves, tree hollows, and buildings. Most known colonies consist of up to a few tens of individuals, but colonies of hundreds have been reported from lava tubes in Kenya. In buildings in South Africa small groups of females and young roost with single adult males suggesting a harem mating system.
feeding ecology and diet
Forage high above the canopy with very rapid flight and using low-frequency echolocation calls. Known to eat moths, beetles, and grasshoppers.
reproductive biology
Reproductive schedule may vary geographically; in Kenya, they mate in August with a single young born in December–January. Thought to be polygynous.
conservation status
Listed by the IUCN as Vulnerable due to documented and projected population declines and disturbance and destruction of known roost sites.
significance to humans
Guano is mined for fertilizer from formerly large cave roost sites in Kenya. May consume insects that are agricultural pests.
White-striped free-tailed bat
Tadarida australis
taxonomy
Tadarida australis (Gray, 1839), New South Wales, Australia.
other common names
None known.
physical characteristics
Forearms ranging in length 2.4–2.5 in (5.9–6.3 cm); weighing 1.1–1.5 oz (33–44 g). This bat has dark fur and two white ventral to lateral stripes.
distribution
Endemic to Australia. Found throughout southern Australia, approximately south of the tropic of Capricorn, but not in Tasmania.
habitat
Found in forest, scrub, grassland, and urban habitats.
behavior
Roost in tree cavities alone or in groups of up to a few tens of individuals. Strong hind legs and retractable tail membrane allow them to scurry on the ground with surprising agility.
feeding ecology and diet
Forages above the canopy mostly on moths, true bugs, and grasshoppers. Many of its prey are agricultural pests.
reproductive biology
Mate in August, with the birth of a single young in December–January, young wean in May. Mating system is not known.
conservation status
Listed by the IUCN as Lower Risk/Near Threatened.
significance to humans
Consumes insects that are agricultural pests.
Brazilian free-tailed bat
Tadarida brasiliensis
taxonomy
Tadarida brasiliensis (Geoffroy, 1824), Parana, Brazil.
other common names
English: Guano bat, Mexican free-tailed bat.
physical characteristics
Forearms ranging in length 1.4–1.8 in (3.6–4.6 cm); weighing 0.3–0.5 oz (10–15 g).
distribution
One of the most widespread bats in the Western Hemisphere, found throughout the southern half of the United States, Mexico, Central America, South America to southern Chile and Argentina, and much of the Lesser and Greater Antilles.
habitat
Brazilian free-tailed bats are most abundant in arid and semi-arid habitats, but are common in urban areas, and present in moist forest and scrub habitats.
behavior
Maternity colonies have been estimated at up to 30 million bats. They form the largest, densest aggregations of mammals known to exist, and provide spectacular nightly emergences and flights to high altitudes in search of insect prey.
feeding ecology and diet
Their diverse diet includes at least 12 orders and 35 families of insects, many of which are agricultural pests.
reproductive biology
Single young born annually in May–July, wean at six weeks of age. Lifespan to 10 years. Mating system thought to be promiscuous.
conservation status
Listed by the IUCN as Lower Risk/Near Threatened. Listed on Appendix 1 of the Bonn Convention for the Conservation of Migratory Animals due to documented loss and decline of numerous colonies and the vulnerability of such large aggregations.
significance to humans
Consumes enormous numbers of agricultural pests. Guano provides valuable fertilizer. These bats are implicated in several human rabies infections.
| Common name / Scientific name / Other common names | Physical characteristics | Habitat and behavior | Distribution | Diet | Conservation status |
| Wrinkle-lipped free-tailed bat Chaerephon plicata | Reddish brown to almost black coloration. Pelage is dense and soft, face covered with black bristles, underparts slightly paler. Head and body length 1.8–4.8 in (4.5–12.1 cm), tail length 0.8–2.4 in (2–6 cm), forearm length 1.1–2.6 in (2.7–6.6 cm), weight 0.6–1.1 oz (17–31 g). | Found in caves in groups of 200,000 or more individuals. Range from sea level to 660 ft (200 m) within forested habitat. Roosts in hollow trees, crevices, caves, or roofs. A single offspring is produced at a time. | India and Sri Lanka to south China and Vietnam, southeast to Philippines, Borneo, and Lesser Sunda Islands; Hainan, China; and Cocas Keeling Islands, Indian Ocean. | Mostly small moths and beetles. | Not threatened |
| Northern mastiff bat Chaerephon jobensis | Medium brown and white upperparts and slightly grayer underparts. Heavily wrinkled upper lip overhangs lower jaw. Head and body length 3.1–3.5 in (8–9 cm), tail length 1.4–1.8 in (3.5–4.5 cm), forearm length 1.8–2 in (4.6–5.2 cm), weight 0.7–1.1 oz (20–30 g). | Found in open forests, savanna, and agricultural areas, sometimes in mountains from sea level to 4,590 ft (1,400 m). Colonies up to 350 individuals. | New Guinea, north and central Australia, Solomon Islands, Vanuatu, Fiji, and perhaps Bismarck Archipelago. | Moths, grasshoppers, termites, and other insects that are caught in fast, direct aerial flight. | Not threatened |
| Lesser naked bat Cheiromeles parvidens | Nearly devoid of hair. Dark brown, thick, elastic skin, great development of conspicuous glandular throat sac, and wing pouches. Head and body length 1.8–4.5 in (4.5–11.5 cm), tail length 2–2.8 in (5–7.1 cm), forearm length 2.8–3.4 in (7–8.6 cm). | Found in agricultural areas from sea level to 660 ft (200 m). Roosts in colonies of about 20,000 individuals in hollow trees, rock crevices, and holes in the earth. Normally two offspring produced per year. | Sulawesi and the Philippines; Mindanao, Misamis Oriental, and South Cotabato, and Negros. | Consists of termites, or other insects caught in open air, such as grasshoppers and moths. | Lower Risk/Near Threatened |
| Western bonneted bat Eumops perotis English: Western mastiff bat | Mostly consistent coloration of dark gray to brownish gray. Very narrow wings. Largest bat found in United States. Head and body length up to 6.9 in (17.5 cm), forearm length 2.8–3.2 in (7.2–8.2 cm), weight 2.3–2.6 oz (64–74 g) | Found in many habitats from rainforest to arid scrub. Roosts in small groups in tree holes, cliffs, and human dwellings. Forages at great heights. Single offspring born in a year. | California and Texas, United States, to Zacatecas and Hidalgo, Mexico; Colombia to northern Argentina and eastern Brazil; and Cuba. | Species feeds extensively on Hymenoptera. Specializes on butterflies and moths. | Not threatened |
| Wagner's bonneted bat Eumops glaucinus | Upperparts are cinnamon brown to black, underparts slightly paler brown. Large ears rounded or angular. Head and body length 1.6–5.1 in (4–13 cm), tail length 1.4–3.1 in (3.5–8 cm), forearm length 1.5–3.3 in (3.7–8.3 cm). | Found in moist habitats and multistratal tropical evergreen forest. Group sizes can range from 10–20 to 70. Adult males and females do not segregate. | Jalisco, Mexico, to Peru, northern Argentina, and Brazil; Jamaica; Cuba; and Florida, United States. | Consists of small insects, mainly members of the order Hymenoptera, caught near ground level to tree top height. | Not threatened |
| Common name / Scientific name / Other common names | Physical characteristics | Habitat and behavior | Distribution | Diet | Conservation status |
| Greenhalli's dog-faced bat Molossops greenhalli | Upperparts are yellowish brown to black, underparts gray. Broad face, widely separated eyes, no development of wrinkles on lips. Head and body length 1.6–3.7 in (4–9.5 cm), tail length 0.6–1.5 in (1.4–3.7 cm), forearm length 1.1–2 in (2.8–5.1 cm). | Found mostly at low elevations. Roosts in hollow branches of large trees in colonies of 50–75 individuals. Males and females remain together throughout year. | Nayarit, Mexico, to Ecuador and northeastern Brazil; and Trinidad. | Consists mainly of insects, mainly moths. | Not threatened |
| Pallas's mastiff bat Molossus molossus | Gray brown to dark brown coloration. Many have two color phases: bi-colored or one, consistent color. Head and body length 2–3.7 in (5–9.5 cm), tail length 0.8–2.8 in (2–7 cm), forearm length 1.4–1.6 in (3.6–4.1 cm), weight 0.4–0.5 oz (12–15 g). | Found in both moist and dry areas within a variety of forested and open habitats. Roosts in buildings, hollow trees, logs, and holes in rocks or trees. Generally two offspring produced per year. | Sinaloa and Coahuila, Mexico, to Peru, northern Argentina, Uruguay, Brazil, and Guianas; Greater and Lesser Antilles; Margarita Island, Venezuala; Curacao and Bonaire, Netherlands Antilles; and Trinidad and Tobago. | Feeds on insects, mainly moths, beetles, and flying ants. | Not threatened |
| Miller's mastiff bat Molossus pretiosus | Dorsal pelage is dark brown, almost black. Largest species of Molossus. Head and body length 1.9–4.5 in (4.8–11.5 cm), tail length 1.5–2.1 in (3.8–5.4 cm), forearm length 1.8–1.9 in (4.6–4.9 cm). | Found in open areas, such as grassland savannas, dry woodlands, and cactus and thorn scrub. Polyestrus. Form small colonies under palm leaves, in hollow trees, and under roofs. | Guerrero, Oaxaca, Mexico; and Nicaragua to Colombia, Venezuela, and Guyana. | Consists of hard items, such as beetles, and other aerial insects, mainly moths. | Not threatened |
| Spurelli's free-tailed bat Mops spurelli | Upperparts vary from reddish brown to almost black, underparts are paler. Head and body length 2–4.8 in (5.2–12.1 cm), tail length 1.3–2.2 in (3.4–5.6 cm), forearm length 1.1–2.6 in (2.9–6.6 cm), weight 0.2–2.3 oz (7–64 g). | Includes forest, woodland, savanna, and dry brushland. | Liberia; Ivory Coast; Ghana; Togo; Benin; Rio Muni and Bioko, Equatorial Guinea; and Democratic Republic of the Congo (Zaire). | Hard-bodied insects, such as beetles. | Not threatened |
| Midas free-tailed bat Mops midas | Upperparts reddish to black, underparts paler. Ears are joined over top of head by band of skin, very wrinkled lips. Head and body length 2–4.8 in (5.2–12.1 cm), tail length 1.3–2.2 in (3.4–5.6 cm), forearm length 1.1–2.6 in (2.9–6.6 cm), weight 0.2–2.3 oz (7–64 g). | Prefers open woodland with scattered, tall trees and open spaces. Emerge after sunset. High, fast flight while foraging. Female may have two offspring in one year. | Senegal to Saudi Arabia, south to Botswana and Transvaal, South Africa; and Madagascar. | Hard-bodied insects, such as beetles. | Not threatened |
| Natal free-tailed bat Mormopterus acetabulosus | Upperparts are dark brown, grayish brown, or charcoal. Underparts are paler. Head and body length 1.7–2.6 in (4.3–6.5 cm), tail length 1.1–1.6 in (2.7–4 cm), forearm length 1.1–1.6 in (2.9–4.1 cm), weight 0.2–0.7 oz (6–19 g). | Found in tropical forests, woodlands, open areas, and cities, roost mainly in roofs and tree hollows. Roost in colonies of fewer than 10 to several hundred individuals. A single offspring is produced each year. | Reunion and Mauritius, Mascarene Islands; Madagascar, South Africa; and Ethiopia. | Mainly insects above tree canopy, water holes, or creeks. Sometimes prey on the ground. | Vulnerable; threatened by fragmented population and declining habitat |
| Beccari's mastiff bat Mormopterus beccarii | Upperparts dark red brown or charcoal, underparts are paler. Wings are long, narrow, and tapered. Head and body length 1.7–2.6 in (4.3–6.5 cm), tail length 1.1–1.6 in (2.7–4 cm), forearm length 1.1–1.6 in (2.9–4.1 cm), weight 0.2–0.7 oz (6–19 g). | Found within habitat range from sea level to 980 ft (300 m). Occurs in sclerophyll woodland within openings of tropical forest. Roosts in colonies of up to 50 individuals. | Molucca Islands, New Guinea, adjacent small islands, and northern Australia. | Consists of moths, beetles, dipterans, orthopterans, and homopterans. Forages mostly aerial insects over water. | Not threatened |
| Bini free-tailed bat Myopterus whitleyi | Upperparts dark brown, underparts light reddish yellow to white. Ears are shorter than head, muzzle projects beyond jaws, end of nose is separate from upper lip. Head and body length 2.2–2.6 in (5.6–6.6 cm), tail length 1–1.3 in (2.5–3.3 cm), forearm length 1–3.3 in (2.5–3.3 cm). | Found only in rainforest zone. Solitary. Flies in forest at night to hunt. | Ghana, Nigeria, Cameroon, Democratic Republic of the Congo (Zaire), and Uganda. | Consists of small, soft-bodied prey. | Not threatened |
| Common name / Scientific name / Other common names | Physical characteristics | Habitat and behavior | Distribution | Diet | Conservation status |
| Pocketed free-tailed bat Nyctinomops femorosaccus | Upperparts brownish to grayish brown, whitish basal area. Thicker, smaller ears close to crown. Head and body length 3.9–4.3 in (10–11 cm), tail length 1.3–1.7 in (3.4–4.4 cm), weight 0.4–0.6 oz (11.5–18 g). | Colonial, roosts mainly in crevices of cliffs, slopes, and rocky outcrops. Squeaky chatter much of the time in day roosts. Females characteristically give birth to one offspring annually. | Guerrero, Mexico, to New Mexico, Arizona, and California, United States, and Baja California, Mexico. | Consists mostly of large moths (only bodies are eaten), and smaller prey species, including flying ants and leafhoppers (entire insect is eaten). | Not threatened |
| Wroughton's free-tailed bat Otomops wroughtoni | Upperparts are reddish brown, pale brown, or dark brown with grayish or whitish area on the back of the neck and upper back. Head and body length 2.4–3.9 in (6–10 cm), tail length 1.2–2 in (3–5 cm), and forearm length 1.9–2.8 in (4.9–7 cm). | Roosts in caves, hollow trees, and human-made structures. Usually solitary or associate in male groups. Breeding season occurs near end of autumn. | Southern India. | Insects, as far as known. | Critically Endangered; single habitat location is declining, being degraded |
| Big-eared mastiff bat Otomops papuensis | Dorsal fur is red brown, paler at base. Pale brown upperparts, light brown underparts. | Endemic to Papua New Guinea, found from sea level to 980 ft (300 m). Usually solitary or associate in small groups. | Southeastern New Guinea, in two localities: Mai-u River and Vailala River. | Aerial insects found above forest canopy. | Vulnerable; very little known distribution |
| Big crested mastiff bat Promops centralis | Upperparts are drab brown to glossy black, underparts slightly paler. Largest of Promops species. Short, broad skull, short and rounded ears, throat sacs present. Head and body length 2.4–3.5 in (6–9 cm), forearm length over 2 in (5 cm). | Colonies of up to six individuals found roosting under palm leaves. Not as gregarious as other molossid bats. | Jalisco and Yucatán, Mexico, to Peru, northern Argentina, and Suriname; and Trinidad. | Insects, as far as known. | Not threatened |
| European free-tailed bat Tadarida teniotis | Coloration from reddish brown to almost black, heavy crest of long straight hairs on back of membrane uniting ears. "Bulldog" face, large ears, and very long, narrow wings. Head and body length 1.8–4.8 in (4.5–12.1 cm), tail length 0.8–2.4 in (2–6 cm), forearm length 1.1–2.6 in (2.7–6.6 cm), weight 0.4–0.5 oz (10–15 g). | Found in mountainous forests or in fissures in the sides of cliffs, natural rock formations, or roofs of caves. Can fly high and travel long distances. | France, Portugal and Morocco to Japan, southern China, and Taiwan; Madeira, Portugal, and Canary Islands, Spain. | Small insects, mainly moths. | Not threatened |
| Egyptian free-tailed bat Tadarida aegyptiaca English: Egyptian tomb bat; German: Faltlippen Fledermäuse; Spanish: Murciélagos guaneros | Coloration varies from reddish brown to almost black. Ears are separated. Head and body length 2.4–3.9 in (6.5–10 cm), tail length 1.2–2.3 in (3–5.9 cm), forearm length 1.8–2.6 in (4.5–6.6 cm), weight 0.5–1.4 oz (14–39 g). | Found in forest or open country, generally roosts in trees and buildings. | South Africa to Nigeria, Algeria, and Egypt to Yemen and Oman, east to India and Sri Lanka. | Small insects, mainly moths. | Not threatened |
Resources
Books
Altringham, John D. Bats: Biology and Behaviour. Oxford: Oxford University Press, 1996.
Barbour, R. W., and W. H. Davis. Bats of America. Lexington: University of Kentucky Press, 1969.
Churchill, Sue. Australian Bats. Sydney: New Holland Publishers, 1998.
Crichton, E. G., and P. H. Krutzsch, eds. Reproductive Biology of Bats. London: Academic Press, 2000.
Hill, J. E., and J. D. Smith. Bats: A Natural History. Austin: University of Texas Press, 1984.
Hutson, A. M., et al. Microchiropteran Bats: Global Status Survey and Action Plan. Cambridge, UK: International Union for the Conservation of Nature and Natural Resources, 2001.
Neuweiler, Gerhard. The Biology of Bats. Oxford: Oxford University Press, 1998.
Nowack, R. M. Walker's Bats of the World. Baltimore: Johns Hopkins University Press, 1991
Wilson, Don E., and DeeAnn M. Reeder, eds. Mammal Species of the World: A Taxonomic and Geographic Reference. 2nd edition. Washington, DC: Smithsonian Institution Press, 1993.
Periodicals
Jones, Kate E., et al. "A Phylogenetic Supertree of Bats (Mammalia: Chiroptera)." Biological Reviews 77 (2002): 223–259.
Organizations
Bat Conservation International. P.O. Box 162603, Austin, TX 78716 USA. Phone: (512) 327-9721. Fax: (512) 327-9724. E-mail: [email protected] Web site: <http://www.batcon.org>
The Bat Conservation Trust. 15 Cloisters House, 8 Battersea Park Rd., London, SW8 4BG UK. Phone: 020 7627 2629. Fax: 020 7627 2628. E-mail: [email protected] Web site: <http://www.bats.org.uk/aboutbct.htm>
IUCN Species Survival Commission, Chiroptera Specialist Group. Web site: <http://www.iucn.org>
Gary F. McCracken, PhD