Wahlberg's epauletted fruit bat (''Epomophorus wahlbergi'') is a species of

megabat Megabats constitute the family Pteropodidae of the order Chiroptera (bats). They are also called fruit bats, Old World fruit bats, or—especially the genera ''Acerodon'' and ''Pteropus''—flying foxes. They are the only member of the su ...

in the family Pteropodidae. It is commonly found across southern Africa.

Description

Wahlberg's epauletted fruit bat is brown to tawny colored with white hair patches at the base of the ears. Males are typically darker in coloration than females.Hayman, R.W. and J.E. Hill. 1971. Order Chiroptera. In Meester, J. and H.W. Setzer (eds.) ''The mammals of Africa: an identification manual''. Smithsonian Institution Press, Washington, D.C. This species is named for erectable

epaulette Epaulette (; also spelled epaulet) is a type of ornamental shoulder piece or decoration used as insignia of military rank, rank by armed forces and other organizations. Flexible metal epaulettes (usually made from brass) are referred to as ''sh ...

s of hair that form around large

scent gland Scent gland are exocrine glands found in most mammals. They produce semi-viscous secretions which contain pheromones and other semiochemical compounds. These odor-messengers indicate information such as status, territorial marking, mood, and sexu ...

s in males only. Males are also distinguished from females by air sacs on the neck that may increase the volume of courtship calls. Scent glands are located near the white ear patches in both sexes. Wings are broad as compared to other bat species. Adult wingspan is and for males and females, respectively. Adults weight . The eyes of ''E. wahlbergi'' are large. Ears are simple, oval-shaped, and lack a tragus. The nose is also simple, but the lips are highly folded and expansible. Skulls are and long for males and females, respectively. Species of the genus ''

Epomophorus ''Epomophorus'' (epauletted bat) is a genus of bat in the family Pteropodidae. They have a distribution throughout Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3& ...

'' can be distinguished from other megabats (Family Pteropodidae) by their

eponym An eponym is a person, a place, or a thing after whom or which someone or something is, or is believed to be, named. The adjectives which are derived from the word eponym include ''eponymous'' and ''eponymic''. Usage of the word The term ''epon ...

ous white epaulettes. A single post-dental palatal ridge in ''E. wahlbergi'' distinguishes this species from other members of the genus.

Ecology

Range and Habitat

Wahlberg's epauletted fruit bat is found across

southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of ...

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It m ...

, and

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

habitats at altitudes from sea level up to .Mickleburgh, S., A.M. Hutson, and W. Bergmans. 2008. ''Epomophorus wahlbergi''. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2.. Downloaded on 12 April 2012. Populations have also been found in wooded urban areas and roosting in man-made structures.

Diet

Wahlberg's epauletted fruit bat is frugivorous, its diet mainly consisting of

fig The fig is the edible fruit of ''Ficus carica'', a species of small tree in the flowering plant family Moraceae. Native to the Mediterranean and western Asia, it has been cultivated since ancient times and is now widely grown throughout the world ...

guava Guava () is a common tropical fruit cultivated in many tropical and subtropical regions. The common guava ''Psidium guajava'' (lemon guava, apple guava) is a small tree in the myrtle family ( Myrtaceae), native to Mexico, Central America, the ...

, and various fruits of ''

Diospyros ''Diospyros'' is a genus of over 700 species of deciduous and evergreen trees and shrubs. The majority are native to the tropics, with only a few species extending into temperate regions. Individual species valued for their hard, heavy, dark tim ...

'' species. Collected fruit is typically carried away from the source tree to another tree. The soft tissue and fruit are consumed while the seeds and skins are discarded. Leaves from ''

Balanites ''Balanites'' is an Afrotropical, Palearctic and Indomalayan genus of flowering plants in the caltrop family, Zygophyllaceae. The name ''Balanites'' derives from the Greek word for an acorn and refers to the fruit, it was coined by Alire Del ...

'' species and several

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s may also be eaten.

Behavior

Roosting

''E. wahlbergi'' is

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

. It roosts in well-lit open trees, under palm fronds, in dense forests near rivers, under thatched roofs of sheds, and, rarely, in caves. Roosting groups may be 3–100 individuals. Bats typically change roost locations daily or every few days and may fly as far as 4 km (2.5 mi) to feeding areas. Roost locations may follow the ripening of fruit trees. Alternatively, frequently changing roost sites may be a strategy to decrease

predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

. Females travel greater distances to feeding areas early in the night while males travel farther closer to dawn. Roost trees may be shared with other ''Epomophorus'' species, though roosting groups are formed by single species. While roosting, ''E. wahlbergi'' is camouflaged by

cryptic Cryptic may refer to: In science: * Cryptic species complex, a group of species that are very difficult to distinguish from one another * Crypsis, the ability of animals to blend in to avoid observation * Cryptic era, earliest period of the Earth ...

fur patterns. White ear spots are present in all members of the genus ''Epomophorus'' and may function to break up the outline of the head when viewed from below.

Flight

Flight Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be a ...

in Wahlberg's epauletted fruit bat is relatively slow and somewhat clumsy, often bumping into other individuals and obstacles. An extensive grooming period, lasting up to 30 minutes, usually precedes departure from the roost tree. Most flight occurs in the first three hours of the night.

Mating and reproduction

Outside of

breeding Breeding is sexual reproduction that produces offspring, usually animals or plants. It can only occur between a male and a female animal or plant. Breeding may refer to: * Animal husbandry, through selected specimens such as dogs, horses, and rab ...

activities and parental care, social interaction typically only occurs while roosting. During the mating season, males leave the roost tree, fly to another tree, and make frog-like courtship calls while displaying their erected epaulettes for up to an hour before moving to another tree. Calling males position themselves approximately 50 m (175 ft) from other males and make 75–120 calls per minute. Two

birth Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...

periods occur per year, the first from February to March and the second from October to December The first birth period coincides with peak fruit availability in the

rainy season The rainy season is the time of year when most of a region's average annual rainfall occurs. Rainy Season may also refer to: * ''Rainy Season'' (short story), a 1989 short horror story by Stephen King * "Rainy Season", a 2018 song by Monni * ''T ...

Gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregna ...

is 5–6 months. Litter size is usually one, but, occasionally, two pups may be born. Bats are typically full-grown at 15 months. Females are able to reproduce at 12 months old, while males reach sexual maturity after this but before 18 months of age.

Physiology

Though it does not enter

torpor Torpor is a state of decreased physiological activity in an animal, usually marked by a reduced body temperature and metabolic rate. Torpor enables animals to survive periods of reduced food availability. The term "torpor" can refer to the time ...

, ''E. wahlbergi'' is

heterothermic Heterothermy or heterothermia (from Greek ἕτερος ''heteros'' "other" and θέρμη ''thermē'' "heat") is a physiological term for animals that vary between self-regulating their body temperature, and allowing the surrounding environment to ...

, lowering its

core body temperature Normal human body-temperature (normothermia, euthermia) is the typical temperature range found in humans. The normal human body temperature range is typically stated as . Human body temperature varies. It depends on sex, age, time of day, exert ...

while roosting. In winter, this heterothermy is more pronounced. Portions of the geographic range of ''E. wahlbergi'' incur the largest seasonal temperature variations of the entire

Afrotropical The Afrotropical realm is one of Earth's eight biogeographic realms. It includes Africa south of the Sahara Desert, the majority of the Arabian Peninsula, the island of Madagascar, southern Iran and extreme southwestern Pakistan, and the island ...

region.

Metabolic rate Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...

s increase up to 30% during the winter as compared to summer, allowing individuals to overcome heat loss in lower ambient temperatures. Body mass also increases in winter. An individual's

thermoneutral zone Endothermic organisms known as homeotherms maintain internal temperatures with minimal metabolic regulation within a range of ambient temperatures called the thermal neutral zone (TNZ). Within the TNZ the basal rate of heat production is equal to t ...

may also be broader in the winter than in the summer, allowing a greater temperature tolerance and thus decreasing energy expenditure typically used to compensate for minor changes in core body temperature. In times of heat stress, excessive

saliva Saliva (commonly referred to as spit) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be ...

tion, wing fanning, body licking, and panting help to lower body temperature. Some individuals are intolerant of extreme heat and die at temperatures greater than 40 °C (104 °F).

References

* Acharya, L. 1992. ''Epomophorus wahlbergi''. ''Mammalian Species'' 394: 1–4. {{Taxonbar, from=Q1464571 Epomophorus Mammals described in 1846 Taxa named by Carl Jakob Sundevall Taxonomy articles created by Polbot