Names for P. hypomelanus include the island fox, Condoro Island flying fox, variable flying fox, lesser flying fox, kluang kechil, kalong kecil, memboi, and udawed, depending on geographic location. The word Pteropus comes from the Greek word pteron, meaning ‘foot’. In addition, the Greek words hypo, meaning ‘below’ or ‘underneath’, and melan, meaning ‘black’ or ‘dark’, help derive the more specific name hypomelanus.
It has been recently discovered that a Pasteurella-like organism has been causing cases of pneumonia in P. hypomelanus.
Variable flying foxes have keen eyesight, hearing, and sense of smell. They communicate with vocalizations, touch, visual displays, and chemical cues. They use their sense of smell and vision to navigate and locate food.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
The most serious threat to variable flying foxes is deforestation and over hunting. Pteropus hypomelanus was placed on the Convention of International Trade in Endangered Species of Wild Fauna and Flora (CITES) list in 1989. It is not on the 2004 IUCN Red List of Threatened Species or the U.S. Federal list.
US Federal List: no special status
CITES: appendix ii
IUCN Red List of Threatened Species: least concern
Variable flying foxes are considered destructive agricultural pests by orchard growers.
Negative Impacts: crop pest
Natives of the Philippines and Malaysia export these bats as food. Variable flying foxes are considered a delicacy in some parts of its range. A typical dish includes the animal in its entirety, fur, wings and innards, which is boiled in coconut milk and eaten as is. However, P. hypomelanus is protected in many areas.
Positive Impacts: food ; produces fertilizer; pollinates crops
Variable flying foxes act as pollinators and seed dispersers, as do many other members of the genus Pteropus. About half of bat-dependent plants are used for nourishment, materials, and medicine by humans.
Ecosystem Impact: disperses seeds; pollinates
Mutualist Species:
Variable flying foxes feed primarily on fruit and nectar from wild and cultivated plants. Known food sources include pawpaw fruits, mangos, jambu, bananas or plantains, figs, banyan flowers, berries of the damba tree, fruits of cultivated crops, flowers of the kapok tree, chico, coconut flowers, and fruits of the babolo tree. Food is found through a highly specialized sense of sight and smell. Variable flying foxes eat about half of their own body weight daily.
Plant Foods: seeds, grains, and nuts; fruit; nectar; pollen; flowers
Primary Diet: herbivore (Frugivore , Nectarivore )
Pteropus hypomelanus is found in the Indo-Australian region, including the Philippines, Solomon Islands, Papua New Guinea, Trobiand, and the Woodlork Islands and west to Thailand and the Mergui Archipelago, but excluding Java and the lesser Sunda shelf islands. Variable flying foxes are also found in the Maldives and on islands along the eastern and western coastal regions of the Malay Peninsula. They are not found on the mainland Malay peninsula or on mainland India or Sri Lanka.
Biogeographic Regions: oriental (Native ); australian (Native )
Other Geographic Terms: island endemic
Variable flying foxes are found at elevations ranging from sea level to greater than 900 meters in the Philippines, but it is uncommon to find them in montane upland forest and submontane rainforest. However, variable flying foxes are found no higher than 100 meters above sea level in the Conflict Islands. Forested areas of small to medium sized islands and lowland and disturbed forests are the main habitat of P. hypomelanus. They can be found in broadleaf forests, coconut groves, and orchards.
Range elevation: 0 to >900 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest
Other Habitat Features: agricultural
Little is known about lifespan in variable flying foxes. Wild caught, captive variable flying foxes have been known to live 9 years.
Range lifespan
Status: captivity: 9 (high) years.
Average lifespan
Status: captivity: 20.3 years.
A naked dorsal tibia distinguishes P. hypomelanus from other Pteropus species. Length of forearm, overall body size, and locality generally are also useful for differentiating between members of the genus Pteropus. Variable flying foxes have a nearly four foot wingspan (1.21 m). Overall body length is 183 to 240 mm. Variable flying foxes are sexually dimorphic with males weighing 567 to 576 g and females weighing 467.5 to 472.5 g. They are distinguished from Pteropus faunulus by their larger body size, larger teeth, and shorter fur. The species P. hypomelanus has a forearm length of 121 to 150 mm and a skull length of 62.1 to 69.0 mm. The specis Pteropus dasymallus is different in its longer and denser pelage and fur on the upper surface of its dorsal tibia. The species P. hypomelanus is smaller than Pteropus alecto, Pteropus conspicillatus, Pteropus macrotis, Pteropus neohibernicus and Pteropus vampyrus. Also, a pale patch of fur on the chest of P. hypomelanus distinguishes it from P. vampyrus. Variable flying foxes differ from Pteropus pumilus in their larger size and dark brown hairs on the throat instead of pale gray. Variable flying foxes are distinguished from Dobsonia chapmani by the presence of a claw on the second digit and by having four upper and two lower incisors.
The body of P. hypomelanus is fully furred and fur color is highly variable. The fur on the head is most commonly dark brown, but can range from light to yellowish brown. This head and mantle pelage color varies geographically, being darker in the western portions of the range and lighter in eastern portions of the range. Dorsum fur is brown to reddish brown while some subspecies have gray or silver hairs. Stomach color ranges from a golden buff to a cream buff. The hair around the eyes is generally grayish in color. The ears are covered in long, sparse hair on the front, but are nearly naked towards the back. The hair is short and dense on the forehead but becomes longer gradually from the neck to the mantle. The dorsal fur of P. hypomelanus is quite short while the ventral fur is an average length. The midline of the back attaches to the wing membranes as well as the base of the first phalanx of the second toe.
The cranium of P. hypomelanus is large, elongate, and robust, with well-developed postorbital processes and a bony spur on anterior surface of the zygomatic arch. There is often a well-developed sagittal crest, formed by the fusion of the temporal ridges.
Males have basal metabolic rates that are higher than expected, given their body size (0.627 ± 0.0216 cm3O2/g•h). Females have basal metabolic rates lower than expected, 83% of the expected value, given their body size (0.487 ± 0.0167 cm3O2/g•h)
Range mass: 467.5 to 576 g.
Range length: 183 to 240 mm.
Average wingspan: 1.21 m.
Range basal metabolic rate: 0.487 ± 0.0167 to 0.627 ± 0.0216 cm3.O2/g/hr.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Variable flying foxes are hunted by humans for food. Their noisy roosting habits allow hunters to easily find them. Variable flying foxes are also often exported as a food source.
Known Predators:
Anti-predator Adaptations: cryptic
During the summer, P. hypomelanus will organize into camps, or harems. Males become very territorial over both harems of females and entire roosts. They mark their area with a scent gland on their throat. During the mating season, P. hypomelanus, which is polygynous, will mate more than once per day for several days. Over the gestation period, males and females separate, with pregnant females forming a separate colony. In those colonies, females participate in mutual caretaking and grooming. During birth, which occurs during the day, females will hang upside-down using the claws on their wings and their feet and lick their genitals until the pup’s head begins to emerge, a process that may last many hours. After birth, the pups, which can weigh up to 10% of the mother’s weight, will assume a comfortable suckling position while attaching to a nipple.
Mating System: polygynous
In the Philippines, a P. hypomelanus pregnancy occurred in April and births recorded in April and May. The mating season of Pteropus species is usually from February to April. Lactating females were found in August, and lactation generally lasts about six weeks. Reproductive maturity is obtained at the age of one year for both males and females. In a captive setting, females were able to give birth each month of the year with a peak in the birth period occurring in May and June. Gestation lasts for 180 to 210 days.
Breeding interval: Variable flying foxes breed once yearly.
Breeding season: The breeding season generally extends from February to April for species in the genus Pteropus.
Range number of offspring: 1 (low) .
Range gestation period: 180 to 210 days.
Average weaning age: 6 weeks.
Average time to independence: 4 to 6 months.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous
After birth, P. hypomelanus mothers will fly with young pups for two to three weeks, until they become too heavy. At that point the pup is left behind with other young. In a month, the young learn enough coordination to explore and, by January and February, they form small groups around their mothers. When the young are able to take care of themselves, the mother will breed again. Young P. hypomelanus remain dependent on their mothers for about 4 to 6 months.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
The small flying fox, island flying fox or variable flying fox (Pteropus hypomelanus) is a species of flying fox in the family Pteropodidae.[2] It is found in Australia, Cambodia, Indonesia, Malaysia, the Maldives, Myanmar, Papua New Guinea, the Philippines, the Solomon Islands, Thailand, and Vietnam.[1]
The small flying fox is quite variable in its colouring. The head is usually dark brown but can be yellowish-brown and is paler in the eastern part of the animal's range. The back is tawny-brown and the underparts some shade of buff. The ears are partially furred and the wing membranes are black. The fur is short on the back and medium-length on the underparts. This bat can be distinguished from the rather similar Ryukyu flying fox (Pteropus dasymallus) by the fact that its tibia are bare rather than covered with fur.[3]
The small flying fox is native to islands in the Indo-Pacific region. Its range includes the Maldives, the Andaman Islands, the Nicobar Islands, Melanesia, the Philippines, Tioman Island, Indonesia, Papua New Guinea and the Solomon Islands. It is found at altitudes of up to about 900 metres (3,000 ft). In many parts of its range it roosts in small outlying islands and flies to larger bodies of land to forage at night.[1]
Small flying foxes feed mostly on the fruit of native and introduced trees but also consume flowers and nectar. The diet includes pawpaws, mangos, jambul, bananas, figs, flowers of the kapok tree (Ceiba pentandra) and the banyan, tree and flowers and fruits of cultivated crops. They consume about half their body weight each day.[3]
These bats become sexually mature at about one year of age. The breeding season varies according to location and the gestation period is about 200 days. A single pup is born which is weaned at about six weeks but remains dependent on its mother for a further four months or so.[3] In two instances, twins have been documented—once in 2009 and once in 2017. Both sets of twins were born at Lubee Bat Conservancy in Gainesville, Florida.[4]
The small flying fox is known to be preyed upon by the white-bellied sea eagle, which has been recorded to hunt the bats by dropping them into the sea repeatedly.[5]
The small flying fox is rated as being near-threatened by the IUCN. It has a wide range and is generally abundant and faces no major threats as a whole. In some areas it is threatened by deforestation and tourism-related activities and in the Philippines and elsewhere it is hunted for food. It is also regarded as a pest by farmers whose crops are raided.
The small flying fox, island flying fox or variable flying fox (Pteropus hypomelanus) is a species of flying fox in the family Pteropodidae. It is found in Australia, Cambodia, Indonesia, Malaysia, the Maldives, Myanmar, Papua New Guinea, the Philippines, the Solomon Islands, Thailand, and Vietnam.
