Livingstone's fruit bat
|Livingstone's fruit bat|
|Livingstone's fruit bat range|
Livingstone's fruit bat (Pteropus livingstonii), also called the Comoro flying fox, is a megabat in the genus Pteropus. It is an Old World fruit bat found only in the Comoros islands of the western Indian Ocean.
It is the largest and rarest bat of all Comorian species. Its preferred habitat is montane forest, the destruction of which is a major threat to the bat population. As of 2003, the total population was estimated at 1,200 individuals. Other threats to the bats' survival include storms, hunting and their struggles to readapt to new habitats.
The black-bearded flying fox is believed to be one of the closest relatives of Livingstone's fruit bats, but experts differ as to whether or not these species belong to the same species group. There are no recognised subspecies.
Livingstone's fruit bats are mostly black in colour, with a scattering of golden or tawny hairs over the rump, belly, and flanks. The amount of golden hair varies between individuals, with some also having a narrow band of golden fur down the back, or golden patches on the shoulders, and others being pure black without any paler hair at all. The wings are black and hairless, as are the legs, nose, and large, rounded ears.
Distinguishing characteristics include their rounded ears, the colour of their fur, and their large, orange or red eyes. Livingstone's fruit bats weigh 530 to 620 g (19 to 22 oz). They have a body length of about 30 cm (12 in) and a wingspan of up to 1.4 m (4 ft 7 in). They probably do not exhibit sexual dimorphism, although insufficient female specimens have been captured for this to be certain.
The bats have a relatively slow, flapping flight, and often circle in an attempt to gain height, but are also, unlike nocturnal bats, capable of soaring on air thermals. Their wings have an aspect ratio of 6.52, and a wing loading of 25.8 N/m2, and have been estimated to have a turning circle of 11.3 m (37 ft).
Distribution and habitat
Livingstone's fruit bat is found only on the islands of Anjouan and Mohéli, within the Comoros group between Africa and northern Madagascar. It inhabits primary montane forest between 300 and 960 metres (980 and 3,150 ft), and roosts in tall trees on steep slopes, generally close to water, and where the natural contours of the land help to shield the against the worst of the weather.
Behaviour and biology
The diet of Livingstone's fruit bats consists of fruit, pollen, nectar, seeds, and leaves. They have also been observed to hunt and eat moths in captivity. They forage for food primarily in the upper canopy of the forest, whereas the two other fruit bats native to the Comoros, the Seychelles fruit bat, and the Comoro rousette, forage in the middle and lower canopy, respectively.
They are possibly an important keystone species because of their role as seed dispersers and pollinators.
Livingstone's fruit bats roost in trees, in groups of six to 160 individuals, with up to eight trees per site. These large colonies, referred to as “camps”, can have a dominant male with up to eight breeding females. The males mark their territories by using scent glands located on their neck and shoulders, which produce a strong, musky scent they then rub on the branches of trees.
They are active both day and night, but conduct most of their foraging and flying between around 10 pm and 2 am. They typically fly to a feeding site a few hours before dusk, taking advantage of hot, daytime thermals, and hang from the trees before beginning to feed after nightfall. They drive off intruders on their feeding territory with chattering sounds, clapping their wings, and chasing, sometimes culminating in clawing and biting. When alarmed, they make squeaking sounds or a deep series of "clucks".
After mating, the pregnant females relocate to maternity roost sites to give birth and raise their young until they reach maturity. They give birth to a single pup, typically in early September. The young pups are born fully furred and with their eyes open; their big feet are used to grip onto their mothers directly after birth. They begin to forage at 2.5 to 5.0 mo of age, and males begin to establish territories at 6 mo.
Pteropus livingstonii is listed under Appendix I of the Convention on International Trade in Endangered Species of fauna and flora) In 1995, the IUCN developed an action plan for the species which included research, community education programs, and training of bat monitoring. A nongovernmental organization called Action Comoros initiated this action plan. Action Comoros developed an environmental education program (EEP). The main goals of this EEP were to raise awareness, develop resources, train educators, promote knowledge, foster pride, and involve locals. These EEPs are important in the short-term benefits of conservation and improve a strong foundation of conservation programs for the long term.
A captive-breeding program was initiated by the Durrell Wildlife Conservation Trust in 1992. Having a captive-breeding program could save P. livingstonii from going completely extinct. Many efforts are being made to aid in the survival of P. livingstonii, but as the populations of the natives increase on these Comoros islands, deforestation will continue to rise, as well. As stated by the Durrell Wildlife Conservation Trust, “If the bats’ natural habitat is not protected, this amazing species could be extinct within 10 years.”.
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