The straw-coloured fruit bat (''Eidolon helvum'') is a large fruit bat that is the most widely distributed of all the African
megabat
Megabats constitute the Family (biology), family Pteropodidae of the Order (biology), order Chiroptera. They are also called fruit bats, Old World fruit bats, or—especially the genus, genera ''Acerodon'' and ''Pteropus''—Pteropus, flyin ...
s. It is quite common throughout its area ranging from the southwestern
Arabian Peninsula
The Arabian Peninsula (, , or , , ) or Arabia, is a peninsula in West Asia, situated north-east of Africa on the Arabian plate. At , comparable in size to India, the Arabian Peninsula is the largest peninsula in the world.
Geographically, the ...
, across forest and
savanna
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...
zones of
sub-Saharan Africa
Sub-Saharan Africa is the area and regions of the continent of Africa that lie south of the Sahara. These include Central Africa, East Africa, Southern Africa, and West Africa. Geopolitically, in addition to the list of sovereign states and ...
. It is listed as
Near Threatened
A near-threatened species is a species which has been Conservation status, categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to Endangered species, endangerment in the ne ...
on the
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...
due to a decreasing population trend. Straw-coloured fruit bats travel in massive colonies of at least 100,000 bats and sometimes massing up to 1 million. From October to end of December every year, in the largest migration of mammals on the planet, up to 10 million straw-coloured fruit bats congregate in
Kasanka National Park,
Zambia
Zambia, officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa. It is typically referred to being in South-Central Africa or Southern Africa. It is bor ...
, roosting in a area of Mushitu forest each day. This migration was only discovered in 1980. Their necks and backs are a yellowish-brown colour, while their undersides are tawny olive or brownish.
Description
The straw-coloured fruit bat is named for the silky yellowish or straw colour of its fur. The wings are black, and the back hair is pale and tawny. Males are generally bright orange and females are usually yellowish. The bats have large cheeks, eyes, and ears. The average weight of these bats ranges from and the animals grow to in length, with wings spanning up to . Males are generally larger than females. The bat's heart is very large, and its wings are long and tapered at the tip. The cheeks of the bat are also large and pouch-like.
Behaviour and ecology
The straw-coloured fruit bat is a highly social species. The bats tend to live in groups of over 100,000 and at times that number may increase to almost one million. At night the bats leave the roost in smaller groups to find food by sight and smell. They have also been seen chewing on soft wood for moisture. These bats can also
pollinate flowers and
disperse seeds through the forests. They are the main agents of seed dispersal for the increasingly rare and economically significant African
teak tree ''
Milicia excelsa''.
Although they feed at night, straw-coloured fruit bats are not necessarily
nocturnal
Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite.
Nocturnal creatur ...
. During the day, they will be found resting and moving among the colony. Year to year, season to season, the bats will return to the same place where they found food the previous year or season.
The mating season of straw-coloured fruit bats is from April to June and is not synchronized among the bats.
Implantation is delayed until October and is synchronized with all females implanting during this time.
The delay corresponds one of two dry periods in the home range of the bats. Birth occurs in February and March.
Diet
The diets of straw-coloured fruit bats vary depending on whether or not they are living in captivity. Wild bats usually eat bark, flowers, leaves,
nectar
Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...
, and fruits. In captivity, they are fed various mixes, including apples, oranges, bananas, grapes, and cantaloupe. In some zoos, they are also fed a
marmoset diet.
Distribution and habitat
The straw-coloured fruit bat is the most widely distributed fruit bat in Africa, and perhaps the world. It appears mainly in Africa, mostly among the
sub-Saharan climates, in many forest and savanna zones, and around the southwestern Arabian peninsula. It can also be found in urban areas and at altitudes up to . It prefers tall trees for roosting.
Threats
The straw-coloured fruit bat is hunted as
bushmeat
Bushmeat is meat from wildlife species that are Hunting, hunted for human consumption. Bushmeat represents a primary source of animal protein and a cash-earning commodity in poor and rural communities of humid tropical forest regions of the worl ...
in West and Central Africa.
In 2011, it was estimated that about 128,400 straw-coloured fruit bats are traded as bushmeat every year in four cities in southern Ghana.
References
External links
{{DEFAULTSORT:Straw-coloured fruit bat
Eidolon (genus)
Bats of Africa
Mammals described in 1792
Bats as food
Taxonomy articles created by Polbot