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 superfamily Pteropodoidea, which is one of two superfamilies in the suborder Yinpterochiroptera. Internal divisions of Pteropodidae have varied since subfamilies were first proposed in 1917. From three subfamilies in the 1917 classification, six are now recognized, along with various tribes. As of 2018, 197 species of megabat had been described.
They reach sexual maturity slowly and have a low reproductive output. Most species have one offspring at a time after a pregnancy of four to six months. This low reproductive output means that after a population loss their numbers are slow to rebound. A quarter of all species are listed as threatened, mainly due to habitat destruction and overhunting. Megabats are a popular food source in some areas, leading to population declines and extinction. They are also of interest to those involved in public health as they are natural reservoirs of several viruses that can affect humans.
List of genera
Main article: List of fruit bats
- subfamily Cynopterinae
- genus Aethalops – pygmy fruit bats
- genus Alionycteris
- genus Balionycteris
- genus Chironax
- genus Cynopterus – dog-faced fruit bats or short-nosed fruit bats
- genus Dyacopterus – Dayak fruit bats
- genus Haplonycteris
- genus Latidens
- genus Megaerops
- genus Otopteropus
- genus Penthetor
- genus Ptenochirus – musky fruit bats
- genus Sphaerias
- genus Thoopterus
- subfamily Eidolinae
- genus Eidolon – straw-coloured fruit bats
- subfamily Harpiyonycterinae
- subfamily Nyctimeninae
- subfamily Pteropodinae
- genus Melonycteris
- subfamily Rousettinae
- tribe Eonycterini
- genus Eonycteris – dawn fruit bats
- tribe Epomophorini
- tribe Myonycterini
- tribe Plerotini
- genus Plerotes
- tribe Rousettini
- genus Rousettus – rousette fruit bats
- tribe Scotonycterini
- tribe Stenonycterini
- genus Stenonycteris
- tribe Eonycterini
- Incertae sedis
As of 2014, the International Union for Conservation of Nature (IUCN) evaluated a quarter of all megabat species as threatened, which includes species listed as critically endangered, endangered, and vulnerable. Megabats are substantially threatened by humans, as they are hunted for food and medicinal uses. Additionally, they are culled for actual or perceived damage to agriculture, especially to fruit production. As of 2019, the IUCN had evaluations for 187 megabat species. The status breakdown is as follows:
- Extinct: 4 species (2.1%)
- Critically endangered: 8 species (4.3%)
- Endangered: 16 species (8.6%)
- Vulnerable: 37 species (19.8%)
- Near-threatened: 13 species (7.0%)
- Least-concern: 89 species (47.6%)
- Data deficient: 20 species (10.7%)
Megabats are threatened by habitat destruction by humans. Deforestation of their habitats has resulted in the loss of critical roosting habitat. Deforestation also results in the loss of food resource, as native fruit-bearing trees are felled. Habitat loss and resulting urbanization leads to construction of new roadways, making megabat colonies easier to access for overharvesting. Additionally, habitat loss via deforestation compounds natural threats, as fragmented forests are more susceptible to damage from typhoon-force winds. Cave-roosting megabats are threatened by human disturbance at their roost sites. Guano mining is a livelihood in some countries within their range, bringing people to caves. Caves are also disturbed by mineral mining and cave tourism.
Megabats are also killed by humans, intentionally and unintentionally.
Half of all megabat species are hunted for food, in comparison to only eight percent of insectivorous species, while human persecution stemming from perceived damage to crops is also a large source of mortality. Some megabats have been documented to have a preference for native fruit trees over fruit crops, but deforestation can reduce their food supply, causing them to rely on fruit crops.
They are shot, beaten to death, or poisoned to reduce their populations.
Mortality also occurs via accidental entanglement in netting used to prevent the bats from eating fruit. Culling campaigns can dramatically reduce megabat populations. In Mauritius, over 40,000 Mauritian flying foxes were culled between 2014 and 2016, reducing the species’ population by an estimated 45%. Megabats are also killed by electrocution. In one Australian orchard, it is estimated that over 21,000 bats were electrocuted to death in an eight-week period. Farmers construct electrified grids over their fruit trees to kill megabats before they can consume their crop. The grids are questionably effective at preventing crop loss, with one farmer who operated such a grid estimating they still lost 100–120 tonnes (220,000–260,000 lb) of fruit to flying foxes in a year. Some electrocution deaths are also accidental, such as when bats fly into overhead power lines.
Climate change causes flying fox mortality and is a source of concern for species persistence. Extreme heat waves in Australia have been responsible for the deaths of more than 30,000 flying foxes from 1994 to 2008. Females and young bats are most susceptible to extreme heat, which affects a population’s ability to recover. Megabats are threatened by sea level rise associated with climate change, as several species are endemic to low-lying atolls.
Read more here at Wikipedia
World Population 1960-2018