Butterfly Bat
Encyclopedia
The variegated butterfly bat (Glauconycteris variegata) is a species of vesper bat
. It is sometimes also called the leaf-winged bat, or simply the butterfly bat. It is not currently endangered, but may be threatened by habitat loss.
The body is covered in long, silky fur of highly variable colour, although usually yellowish or light grey, and lacking the prominent patterns found on some closely related species. The fur on the undersides is white or very pale grey, and that on the face and ears is brown. The wing membranes also have a sparse covering of hair, and have a distinctive reticulated pattern of dark veins, from which the bat takes the first part of its name.
The bat has a domed head and a short snout with a deep groove running between the nostrils. The lower lip is large and padded, but the upper lip has a simpler appearance, without any of the folds seen in some other bat species. The ears are relatively short, with a small tragus
.
The wings are long and narrow in shape, suggesting that the bat is agile in the air, but is not efficient at high speed flight. Its flight speed during foraging has been measured as 4 m/s.
, and bushveldt habitats south of the Sahara desert, at elevations of up to 1000 metres (3,280.8 ft). It is found in a narrow band of territory running from Senegal
in the west as far as southern Ethiopia
and Somalia
in the east, and in much of southern and eastern Africa outside the tropical rainforest, as far as northern Namibia
, Zimbabwe
, and South Africa
.
Two subspecies are currently recognised, although the exact classification has varied considerably over the years:
s, in open terrain, close to the ground or above open water. Their ultrasonic
calls are frequency modulated, sweeping from 70 to 30 Hz.
There is a single breeding season each year, which occurs during the winter. The exact timing of the breeding season varies widely across the range, based primarily on latitude, ranging from December in the north to August in the south. A single young is born after a gestation
period of about three months, and is weaned
before the age of two months.
Vesper bat
Vesper bats , also known as Evening bats or Common bats, are the largest and best-known family of bats. They belong to the suborder Microchiroptera . There are over three hundred species distributed all over the world, on every continent except Antarctica...
. It is sometimes also called the leaf-winged bat, or simply the butterfly bat. It is not currently endangered, but may be threatened by habitat loss.
Description
Variegated butterfly bats are relatively small bats, averaging 10 centimetres (3.9 in) in total length, with a 4.7 centimetres (1.9 in) tail, and weighing around 11 gram (0.388013583156232 oz). Females are slightly larger than males, with an average wingspan of 32 centimetres (12.6 in), compared with a typical male wingspan of 31 centimetres (12.2 in).The body is covered in long, silky fur of highly variable colour, although usually yellowish or light grey, and lacking the prominent patterns found on some closely related species. The fur on the undersides is white or very pale grey, and that on the face and ears is brown. The wing membranes also have a sparse covering of hair, and have a distinctive reticulated pattern of dark veins, from which the bat takes the first part of its name.
The bat has a domed head and a short snout with a deep groove running between the nostrils. The lower lip is large and padded, but the upper lip has a simpler appearance, without any of the folds seen in some other bat species. The ears are relatively short, with a small tragus
Tragus
The tragus is a small pointed eminence of the external ear, situated in front of the concha, and projecting backward over the meatus. Its name comes from the Greek: tragos, goat, and is descriptive of its general covering on its under surface with a tuft of hair, resembling a goat's beard...
.
The wings are long and narrow in shape, suggesting that the bat is agile in the air, but is not efficient at high speed flight. Its flight speed during foraging has been measured as 4 m/s.
Distribution
The variegated butterfly bat is found in many forested, savannaSavanna
A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.Some...
, and bushveldt habitats south of the Sahara desert, at elevations of up to 1000 metres (3,280.8 ft). It is found in a narrow band of territory running from Senegal
Senegal
Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...
in the west as far as southern Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
and Somalia
Somalia
Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...
in the east, and in much of southern and eastern Africa outside the tropical rainforest, as far as northern Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...
, Zimbabwe
Zimbabwe
Zimbabwe is a landlocked country located in the southern part of the African continent, between the Zambezi and Limpopo rivers. It is bordered by South Africa to the south, Botswana to the southwest, Zambia and a tip of Namibia to the northwest and Mozambique to the east. Zimbabwe has three...
, and South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.
Two subspecies are currently recognised, although the exact classification has varied considerably over the years:
- Glauconycteris variegata variegata - southern parts of the range
- Glauconycteris variegata phalaena - northern parts of the range
Behaviour
Variegated butterfly bats are nocturnal, spending the day roosting in trees in small groups of up to ten individuals. Unlike many other bats, they do not wrap themselves in their wings while roosting. During the night they forage for flying insects, especially mothMoth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
s, in open terrain, close to the ground or above open water. Their ultrasonic
Animal echolocation
Echolocation, also called biosonar, is the biological sonar used by several kinds of animals.Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects...
calls are frequency modulated, sweeping from 70 to 30 Hz.
There is a single breeding season each year, which occurs during the winter. The exact timing of the breeding season varies widely across the range, based primarily on latitude, ranging from December in the north to August in the south. A single young is born after a gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
period of about three months, and is weaned
Weaning
Weaning is the process of gradually introducing a mammal infant, either human or animal, to what will be its adult diet and withdrawing the supply of its mother's milk.The process takes place only in mammals, as only mammals produce milk...
before the age of two months.