The chestnut sac-winged bat, or Wagner's sac-winged bat (''Cormura brevirostris'') is a species of

sac-winged bat Emballonuridae is a family of microbats, many of which are referred to as sac-winged or sheath-tailed bats. They are widely distributed in tropical and subtropical regions around the world. The earliest fossil records are from the Eocene. Desc ...

native to South and Central America. It is the only species within its genus.

Description

The chestnut sac-winged bat is a relatively small member of its family, with adults usually measuring in length, and weighing . Soft, dense fur covers the body, and the inner parts of the wings, reaching as far as the mid-

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

and mid-

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates wit ...

on both the upper and lower surfaces. The fur is brown-black or red-brown in colour, being darker above, and paler on the underside of the animal. The wings are black, with the membranes extending as far as the ankles. The tail projects from the middle of the membrane between the legs, but does not extend beyond it, so is not visible in silhouette. The tail measures about in length, although only of the tip is visible above the membrane. Males of the species have sacs in the centre of the membranes on the forward surfaces of the wings, which reach from the edge of the membrane almost to the elbow. This distinguishes it from all other sac-winged bats, in which the sac is usually much closer to the body.

Distribution and habitat

In the south, chestnut sac-winged bats are found from eastern

Ecuador Ecuador ( ; ; Quechuan languages, Quechua: ''Ikwayur''; Shuar language, Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechuan ...

and

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

, through northern

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

as far east as central

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. Further north, they are found throughout Colombia,

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in ...

, and

the Guyanas The Guianas, sometimes called by the Spanish loan-word ''Guayanas'' (''Las Guayanas''), is a region in north-eastern South America which includes the following three territories: * French Guiana, an overseas department and region of France * ...

, and through Central America as far as eastern

Nicaragua Nicaragua (; ), officially the Republic of Nicaragua (), is the largest Sovereign state, country in Central America, bordered by Honduras to the north, the Caribbean Sea, Caribbean to the east, Costa Rica to the south, and the Pacific Ocean to ...

. No subspecies have been identified. Their natural habitat is subtropical or tropical moist lowland forests.

Biology and behaviour

Chestnut sac-winged bats forage for insects in openings and gaps just below and around the forest canopy. They are active primarily just after dusk and just before dawn, spending the day resting in cavities in trees or fallen logs. They live in small groups of up to five individuals, each with no more than a single female. The bats' echolocation calls consist of three short pulses, each higher in pitch than the last, and rising from 25 to 32 kHz. This frequency optimises the detection of flying insects at long range. Breeding has been reported to take place between April and May in

Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Co ...

, but may occur at different times of the year elsewhere.

References

{{Taxonbar, from=Q135150 Mammals described in 1843 Emballonuridae Mammals of Colombia Bats of Central America Bats of South America Taxonomy articles created by Polbot