Pteropodidae
191 species
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.
The understanding of the evolution of megabats has been determined primarily by genetic data, as the fossil record for this family is the most fragmented of all bats. They likely evolved in Australasia, with the common ancestor of all living pteropodids existing approximately 31 million years ago. Many of their lineages probably originated in Melanesia, then dispersed over time to mainland Asia, the Mediterranean, and Africa. Today, they are found in tropical and subtropical areas of Eurasia, Africa, and Oceania.
The megabat family contains the largest bat species, with individuals of some species weighing up to 1.45 kg (3.2 lb) and having wingspans up to 1.7 m (5.6 ft). Not all megabats are large-bodied; nearly a third of all species weigh less than 50 g (1.8 oz). They can be differentiated from other bats due to their dog-like faces, clawed second digits, and reduced uropatagium. Only members of one genus, Notopteris, have tails. Megabats have several adaptations for flight, including rapid oxygen consumption, the ability to sustain heart rates of more than 700 beats per minute, and large lung volumes.
Most megabats are nocturnal or crepuscular, although a few species are active during the daytime. During the period of inactivity, they roost in trees or caves. Members of some species roost alone, while others form colonies of up to a million individuals. During the period of activity, they use flight to travel to food resources. With few exceptions, they are unable to echolocate, relying instead on keen senses of sight and smell to navigate and locate food. Most species are primarily frugivorous and several are nectarivorous. Other less common food resources include leaves, pollen, twigs, and bark.
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.
Megabats are widely distributed in the tropics of the Old World, occurring throughout Africa, Asia, Australia, and throughout the islands of the Indian Ocean and Oceania. As of 2013, fourteen genera of megabat are present in Africa, representing twenty-eight species. Of those twenty-eight species, twenty-four are only found in tropical or subtropical climates. The remaining four species are mostly found in the tropics, but their ranges also encompass temperate climates. In respect to habitat types, eight are exclusively or mostly found in forested habitat; nine are found in both forests and savannas; nine are found exclusively or mostly in savannas; and two are found on islands. Only one African species, the long-haired rousette (Rousettus lanosus), is found mostly in montane ecosystems, but an additional thirteen species' ranges extend into montane habitat.: 226
Outside of Southeast Asia, megabats have relatively low species richness in Asia. The Egyptian fruit bat is the only megabat whose range is mostly in the Palearctic realm; it and the straw-colored fruit bat are the only species found in the Middle East. The northernmost extent of the Egyptian fruit bat's range is the northeastern Mediterranean. In East Asia, megabats are found only in China and Japan. In China, only six species of megabat are considered resident, while another seven are present marginally (at the edge of their ranges), questionably (due to possible misidentification), or as accidental migrants. Four megabat species, all Pteropus, are found on Japan, but none on its five main islands. In South Asia, megabat species richness ranges from two species in the Maldives to thirteen species in India. Megabat species richness in Southeast Asia is as few as five species in the small country of Singapore and seventy-six species in Indonesia. Of the ninety-eight species of megabat found in Asia, forest is a habitat for ninety-five of them. Other habitat types include human-modified land (66 species), caves (23 species), savanna (7 species), shrubland (4 species), rocky areas (3 species), grassland (2 species), and desert (1 species).
In Australia, five genera and eight species of megabat are present. These genera are Pteropus, Syconycteris, Dobsonia, Nyctimene, and Macroglossus.: 3 Pteropus species of Australia are found in a variety of habitats, including mangrove-dominated forests, rainforests, and the wet sclerophyll forests of the Australian bush.: 7 Australian Pteropus are often found in association with humans, as they situate their large colonies in urban areas, particularly in May and June when the greatest proportions of Pteropus species populations are found in these urban colonies.
In Oceania, the countries of Palau and Tonga have the fewest megabat species, with one each. Papua New Guinea has the greatest number of species with thirty-six. Of the sixty-five species of Oceania, forest is a habitat for fifty-eight. Other habitat types include human-modified land (42 species), caves (9 species), savanna (5 species), shrubland (3 species), and rocky areas (3 species). An estimated nineteen percent of all megabat species are endemic to a single island; of all bat families, only Myzopodidae—containing two species, both single-island endemics—has a higher rate of single-island endemism.
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.
The understanding of the evolution of megabats has been determined primarily by genetic data, as the fossil record for this family is the most fragmented of all bats. They likely evolved in Australasia, with the common ancestor of all living pteropodids existing approximately 31 million years ago. Many of their lineages probably originated in Melanesia, then dispersed over time to mainland Asia, the Mediterranean, and Africa. Today, they are found in tropical and subtropical areas of Eurasia, Africa, and Oceania.
The megabat family contains the largest bat species, with individuals of some species weighing up to 1.45 kg (3.2 lb) and having wingspans up to 1.7 m (5.6 ft). Not all megabats are large-bodied; nearly a third of all species weigh less than 50 g (1.8 oz). They can be differentiated from other bats due to their dog-like faces, clawed second digits, and reduced uropatagium. Only members of one genus, Notopteris, have tails. Megabats have several adaptations for flight, including rapid oxygen consumption, the ability to sustain heart rates of more than 700 beats per minute, and large lung volumes.
Most megabats are nocturnal or crepuscular, although a few species are active during the daytime. During the period of inactivity, they roost in trees or caves. Members of some species roost alone, while others form colonies of up to a million individuals. During the period of activity, they use flight to travel to food resources. With few exceptions, they are unable to echolocate, relying instead on keen senses of sight and smell to navigate and locate food. Most species are primarily frugivorous and several are nectarivorous. Other less common food resources include leaves, pollen, twigs, and bark.
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.
Megabats are widely distributed in the tropics of the Old World, occurring throughout Africa, Asia, Australia, and throughout the islands of the Indian Ocean and Oceania. As of 2013, fourteen genera of megabat are present in Africa, representing twenty-eight species. Of those twenty-eight species, twenty-four are only found in tropical or subtropical climates. The remaining four species are mostly found in the tropics, but their ranges also encompass temperate climates. In respect to habitat types, eight are exclusively or mostly found in forested habitat; nine are found in both forests and savannas; nine are found exclusively or mostly in savannas; and two are found on islands. Only one African species, the long-haired rousette (Rousettus lanosus), is found mostly in montane ecosystems, but an additional thirteen species' ranges extend into montane habitat.: 226
Outside of Southeast Asia, megabats have relatively low species richness in Asia. The Egyptian fruit bat is the only megabat whose range is mostly in the Palearctic realm; it and the straw-colored fruit bat are the only species found in the Middle East. The northernmost extent of the Egyptian fruit bat's range is the northeastern Mediterranean. In East Asia, megabats are found only in China and Japan. In China, only six species of megabat are considered resident, while another seven are present marginally (at the edge of their ranges), questionably (due to possible misidentification), or as accidental migrants. Four megabat species, all Pteropus, are found on Japan, but none on its five main islands. In South Asia, megabat species richness ranges from two species in the Maldives to thirteen species in India. Megabat species richness in Southeast Asia is as few as five species in the small country of Singapore and seventy-six species in Indonesia. Of the ninety-eight species of megabat found in Asia, forest is a habitat for ninety-five of them. Other habitat types include human-modified land (66 species), caves (23 species), savanna (7 species), shrubland (4 species), rocky areas (3 species), grassland (2 species), and desert (1 species).
In Australia, five genera and eight species of megabat are present. These genera are Pteropus, Syconycteris, Dobsonia, Nyctimene, and Macroglossus.: 3 Pteropus species of Australia are found in a variety of habitats, including mangrove-dominated forests, rainforests, and the wet sclerophyll forests of the Australian bush.: 7 Australian Pteropus are often found in association with humans, as they situate their large colonies in urban areas, particularly in May and June when the greatest proportions of Pteropus species populations are found in these urban colonies.
In Oceania, the countries of Palau and Tonga have the fewest megabat species, with one each. Papua New Guinea has the greatest number of species with thirty-six. Of the sixty-five species of Oceania, forest is a habitat for fifty-eight. Other habitat types include human-modified land (42 species), caves (9 species), savanna (5 species), shrubland (3 species), and rocky areas (3 species). An estimated nineteen percent of all megabat species are endemic to a single island; of all bat families, only Myzopodidae—containing two species, both single-island endemics—has a higher rate of single-island endemism.
