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Lifespan, longevity, and ageing

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Maximum longevity: 23.6 years (captivity) Observations: One specimen about 23.6 years old is still alive in captivity (Richard Weigl 2005).
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Associations

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Other Pteropus species are known to be preyed upon by snakes, such as brown tree snakes (Boiga irregularis). However, beyond reports of humans killing these animals, information pertaining to specific predators of P. poliocephalus was not found.

Known Predators:

  • humans
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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Link Olson, University of Alaska Fairbanks
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Morphology

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Pteropus poliocephalus is the largest bat in Australia. As with all members of Pteropodidae, P. poliocephalus does not have a tail, and claws are present on the first and second digits. They do not echolocate, and therefore, the distinctive enlarged tragus or leaf-ornamentation found in most species of Microchiroptera is not present. Since they do not echolocate, they must rely on their large eyes for navigation and finding food.

As the species' common name implies, grey-headed flying-foxes have faces which are fox-like. The body is dark grey, with the fur on the head being of a lighter color grey. There is also a reddish-brown collar of fur that encircles the neck. Fur on the legs extends all the way to the ankle, which is one distinguishing characteristic from other members of the genus Pteropus. The patagium is black, and it is possible for the wingspan of some individuals to be up to one meter. The head and body length is between 230 and 289 mm, with an average of 253 mm. The forearm length is between 138 and 180 mm, with an average of 161 mm. Weight generally varies between 600 and 1000 g, with an average of 677 g. However, some individuals have been recorded as weighing more than 1 kg. These figures are somewhat different according to different sources, but they are generally within a few units of each other. These bats have a basal metabolic rate of approximately 3.162 cm^3 oxygen/h.

Range mass: 600 to 1000 g.

Average mass: 677 g.

Range length: 230 to 289 mm.

Average length: 253 mm.

Average wingspan: 1 m.

Average basal metabolic rate: 316.2 cm3.O2/g/hr.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger

Average basal metabolic rate: 1.768 W.

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Life Expectancy

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Grey-headed flying-foxes generally live for a long period of time, with the average reproductively active adult being between 6 and 10 years old. Two individuals are reported to have been 15 years old. However, the expected lifespan of wild individuals ranges from 21.6 to 59.2 months. Lifespan is affected mostly by food availability and negative human interactions, such as deforestation and culling. In captivity, where food availability is not an issue for survival, these bats have a much longer lifespan.

Range lifespan
Status: wild:
21.6 to 180 months.

Average lifespan
Status: wild:
40.4 months.

Typical lifespan
Status: wild:
21.6 to 59.2 months.

Average lifespan
Status: wild:
40.4 months.

Average lifespan
Status: captivity:
23.6 years.

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Habitat

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Pteropus poliocephalus is found in a variety of habitats including rainforests, woodlands, and swamps located in Eastern Australia. They are typically found at elevations less than 200 m, but have been found at elevations as great as 700 m. These bats prefer to roost in the branches of large trees. They are usually not found more than 150 km inland and are even present on some secluded islands. Because of encroachment of human activity into their habitats, they are sometimes found in suburban areas, using the agricultural lands of their human neighbors as a food source. Pteropus poliocephalus is a semi-migratory species. The migrations of these animals have been attributed to different reasons. They often go where the food supply is abundant, although it has been hypothesized that they also undertake these long-distance flights to enhance their mating opportunities, or to gather more information about other parts of their range.

Range elevation: 700 (high) m.

Habitat Regions: temperate ; tropical ; terrestrial

Terrestrial Biomes: forest ; rainforest

Wetlands: swamp

Other Habitat Features: suburban ; agricultural ; riparian

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Distribution

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Pteropus poliocephalus is endemic to the eastern coast of Australia. These bats can be found from Bundaberg and Mayborough in Queensland to Melbourne in Victoria. The previous range has shifted southward by approximately 750 km, possibly due to a change in climate.

Biogeographic Regions: australian (Native )

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Untitled

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Measures taken of flight speed for P. poliocephalus in a wind tunnel showed values between (21 to 24 km/h); however, higher values (49, 52, and 63 km/h) indicate that at times the bats can obtain faster speeds with assistance from wind currents.

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Link Olson, University of Alaska Fairbanks
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Behavior

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What P. poliocephalus lacks in echolocation, it has made up for with a sophisticated array of vocalizations, which are comprised of a series of complicated squeaks and squeals. There are more than 20 different calls which these bats use in communicating with each other, and because they form large groups, roosting sites can be quite noisy.

Because they do not echolocate, they rely heavily on vision and olfaction in perceiving their environment. Their large eyes help them in navigating through their habitat. Males are known to use a strongly scented secretion in marking territory, and females are able to find their young by scent. Olfaction is also used in locating food items. Although not specifically reported, it is likely that there is important tactile communication between mothers and their young as well as between mates.

Communication Channels: visual ; tactile ; acoustic ; chemical

Other Communication Modes: scent marks

Perception Channels: visual ; tactile ; acoustic ; chemical

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Link Olson, University of Alaska Fairbanks
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Conservation Status

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At one time P. poliocephalus had a much larger range; however, that range is now shrinking due to habitat destruction. Many areas of their habitat are becoming increasingly urbanized, such as in S.E. Queensland and northern New South Wales (NSW). Also, conservation reserves are limited, and in NSW < 15% of suitable habitat is within these reserves.

The main threat to P. poliocephalus is the destruction of habitat through deforestation. Females are particularly subject to spontaneous abortions due to loss of habitat and food sources, or when they are disturbed at the nesting site during the last few weeks of pregnancy. There are no regulations pertaining to the shooting of these animals, and farmers whose crops are perceived as being threatened often kill them. These bats also suffer from the tendency to fly into power lines, thus dying from electrocution. Black flying-foxes (Pteropus alecto) also pose a threat because they are competitors over food and habitat, and P. poliocephalus has been known to mate and thus hybridize with them.

Currently this species is listed as vulnerable under the NSW Threatened Species Conservation Act 1995, schedule 2, and under the Environment Protection and Biodiversity Conservation Act 1999. It was at one point estimated that the population numbered somewhere in the millions. Recently, however, figures indicate that the population has had an approximately 30% decline over the last 10 years. However, not all organizations view this species as being threatened. It is listed on CITES as being of least concern, and not even present in a number of other threatened and/or endangered databases.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: vulnerable

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Link Olson, University of Alaska Fairbanks
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Nancy Shefferly, Animal Diversity Web
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Benefits

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Pteropus poliocephalus is often believed to be detrimental to cultivated fruit crops, and thus farmers sometimes view the species as a pest. However, these bats only resort to eating fruit crops when other food sources become sparse. They are also thought to be a potential carrier of viral pathogens.

Negative Impacts: crop pest; causes or carries domestic animal disease

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Link Olson, University of Alaska Fairbanks
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Benefits

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Since P. poliocephalus eats many different fruits and nectars, it is an important pollinator, especially for certain Eucalyptus species. They are also important in transporting and distributing the seeds long distances. Therefore, there is a great possibility that a population reduction of this bat would have some negative long-term impacts on the regeneration of Australia’s forests. As a result of habitat destruction decreasing their range, they have thus had a reduction in migratory patterns, which, too, may lead to negative consequences for the ecosystem and for humans.

Positive Impacts: pollinates crops

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Associations

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Many different fruits and pollens are consumed by P. poliocephalus, making this species highly important in seed dispersal and pollination of plants. Certain plants enjoy a wider range due to the long-distance seed dispersal that these bats offer. Without this, certain plant species could be negatively affected.

Ecosystem Impact: disperses seeds; pollinates

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Link Olson, University of Alaska Fairbanks
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Trophic Strategy

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Foraging occurs at night, and it is not unusual for individuals to fly up to 50 km away from their campsites, although most tend to stay within 15 km. These bats tend to forage in forest canopies, open forests, rainforests, and even swamps; however, they sometimes visit cultivated gardens and fruit crops in search of food. When eating, the bats bite pieces off of their food, and then chew it vigorously, spitting out portions that are not swallowed. Different foods are eaten at different times of the year, depending on availability.

The diet of P. poliocephalus includes fruits, pollen, nectar, and bark. Their preferred food source is eucalyptus blossom, of which Eucalyptus gummifera, Eucalyptus muellerana, Eucalyptus globoidea and Eucalyptus botryoides are most often consumed. The main sources utilized for pollen consumption belong in the families Myrtaceae and Proteaceae, although pollens from other families are consumed when present. One of their favorite fruits is fig (Ficus); however, these bats have been known to consume stone fruits (e.g. peach, plum, nectarine). Occasionally they also consume the leaves of poplar (g. Populus) and grey mangrove (Avicennia marina). Other food items that have been found in fecal matter include fruits from Phoenix canariensis, Ligustrum and Solanum mauritianum, among many others.

Plant Foods: leaves; wood, bark, or stems; fruit; nectar; pollen; flowers

Primary Diet: herbivore (Frugivore )

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Link Olson, University of Alaska Fairbanks
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Reproduction

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During the nursing period, males and females form monogamous mating-pairs. Males utilize strong-smelling secretions from their scapular glands (located on the shoulder) and loud calls in order to establish territories and ward off unwanted males.

Mating System: monogamous

Grey-headed flying foxes mate annually between April and May, with males reaching reproductive maturity at approximately 30 months of age. Mating has been observed throughout the year; however, males are only fertile during the mating period. Females that are close to giving birth segregate from the males. Mothers give birth to a single young between October and November, after a 6-month gestation period. Twins are extremely rare and do not usually survive in the wild. Weaning occurs between 5 and 6 months of age, and offspring are independent after about 6 months.

Breeding interval: Grey-headed flying-foxes breed once yearly.

Breeding season: Breeding occurs from April to May

Range number of offspring: 1 to 2 (rare).

Average number of offspring: 1.

Average gestation period: 6 months.

Range weaning age: 5 (low) months.

Average weaning age: 6 months.

Average time to independence: 6 months.

Average age at sexual or reproductive maturity (male): 30 months.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous

Average birth mass: 80 g.

Average number of offspring: 1.

Average age at sexual or reproductive maturity (male)
Sex: male:
540 days.

Average age at sexual or reproductive maturity (female)
Sex: female:
540 days.

When born, the young weigh between 46 and 92 grams and are somewhat altricial, as they cannot fly and have no fur on the underside. Female P. poliocephalus carry their young, which cling to the fur on the mother's belly, for the first 4 to 5 weeks after birth. Females carry their young even while foraging. For the next 12 weeks or so, the young are left at the nesting site at night while the mother forages. At about 3 months of age the young are independent enough to forage on their own; however, they are not completely weaned until about 6 months of age. This extended period of nursing is due to the fact that bats provide their young with milk until they have at least 90% of their adult wingspan and at least 70% of their adult body mass, because the young cannot achieve sustained flight until they have reached these dimensions. Females have been known to abandon their young in times of food shortages.

Although males do not directly care for the young, they do mark and defend territories for their families during the period of nursing. Thus, they play some role in protecting the young.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female); pre-independence (Provisioning: Female, Protecting: Male, Female)

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DeHaven, C. 2005. "Pteropus poliocephalus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteropus_poliocephalus.html
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Christina DeHaven, University of Alaska Fairbanks
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Link Olson, University of Alaska Fairbanks
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Biology

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Grey-headed flying foxes roost in large colonies, or 'camps', of up to tens of thousands of individuals among exposed branches during the day (7) (8). At dusk these bats emerge from the colony in search of food (9) (10), travelling up to 50 kilometres to their feeding areas (11) (12) (13). Their diet consists of fruit from a range of native and introduced species, as well as pollen and nectar, particularly of Eucalypt trees (11) (14) (15) (16) (17). Breeding is seasonal, and from January onwards males defend mating territories, which they demarcate by scent-marking, loud calls and aggression (18). Mating generally occurs between March and May (18) (19), with a single young born six months later between September and November (15). Females then carry their pup during foraging flights for the first three weeks, after which they are left behind in the camp (4) (15). Young are capable of flight and follow their mother to forage after three months, but are not weaned until five to six months (15) (19) (18).
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Conservation

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In response to these growing threats, roost sites have been legally protected since 1986 in New South Wales and 1994 in Queensland (22). The grey-headed flying fox was also listed as vulnerable under the Environment Protection and Biodiversity Conservation Act in 1999, and the New South Wales Threatened Species Conservation Act Schedule 2 in 1995, which required that a Recovery Plan be prepared by 2006 (27) (29) (30). Conservation reserves are limited, and future efforts to protect more key foraging areas would be extremely beneficial, by helping to ensure that food supplies are available throughout the year (2). Research into alternative, non-lethal crop protection mechanisms, and encouragement of horticulturists to use them, is also crucial in the fight to protect this species (2). As important pollinators and seed dispersal agents, these bats are integral in maintaining healthy forest ecosystems (16). Thus, unless swift action is taken to halt further population reductions, the decline of the grey-headed flying fox is likely to have a serious negative, long-term impact on the regeneration of Australia's forests, and the host of unique fauna they harbour.
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Description

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The grey-headed flying fox is one of the largest bats in Australia, with the maximum recorded wingspan exceeding an impressive 1.5 metres (4). This bat has a dark grey body, a paler grey head, and a conspicuous collar of rich russet-coloured fur encircling the neck (4). As with all members of the Pteropodidae family, this bat lacks a tail and has claws on the first and second digits. Uniquely, however, the body fur of this species extends all the way down to the ankle, distinguishing it from other flying foxes (Pteropus species), which only bear fur down to their knees (4).
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Habitat

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Found in a variety of habitats, including rainforests, woodlands, mangroves, swamps, but also in suburban and cultivated areas (4) (5). Typically found no more than 100 kilometres inland, and amongst trees at around 200 metres above sea level, although individuals have been recorded at elevations as great as 700 metres (4).
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Range

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Endemic to the east coast of Australia, from Bundaberg in Queensland to Melbourne in Victoria (4) (5) (6).
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Status

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Classified as Vulnerable (VU) on the IUCN Red List (1), and listed on Appendix II of CITES (3). Listed as Vulnerable on the New South Wales Threatened Species Conservation Act 1995 and the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 in Australia (2).
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Threats

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Although once thought to number in their millions, in 2002 there were estimated to be around 400,000 grey-headed flying foxes remaining (20). The most significant threat facing the bat is the destruction of foraging and roosting habitat due to expanding urbanisation and agriculture (7) (15). Climate change may also pose a threat to the grey-headed flying-fox as climate models are predicting significant increases in the occurrence of temperature extremes and recent research has shown that since 1994, more than 24,500 grey-headed flying foxes have died in their roosts when temperatures exceeded 42 degrees Celsius (21). Another serious threat is direct killing of animals in orchards and destruction of roosts. Many farmers perceive the bats to be pests due to the destruction they cause to crops and often kill them (22). Further more, negative public perception and consequent persecution of the species has intensified in the last decade with the discovery that it carries three new diseases that are potentially fatal to humans, Hendravirus, Menanglevirus and Australian Bat Lyssavirus (23) (24) (25). The exact numbers of bats killed is unknown, but estimates have been made as high as 100,000 annually, with the death of pregnant or lactating females obviously having an additional knock-on impact on the survival of their young (26). There is also a tendency for these bats to fly into power lines and die from electrocution. Black flying foxes (Pteropus alecto) pose a further threat through competition for food and habitat, and hybridisation between the grey-headed flying fox and the black flying fox has been observed (7) (27) (28).
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Grey-headed flying fox

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The grey-headed flying fox (Pteropus poliocephalus) is a megabat native to Australia.[3] The species shares mainland Australia with three other members of the genus Pteropus: the little red P. scapulatus, spectacled P. conspicillatus, and the black P. alecto. The grey-headed flying fox is the largest bat in Australia.

The grey-headed flying fox is endemic to the south-eastern forested areas of Australia, principally east of the Great Dividing Range. Its range extends approximately from Bundaberg in Queensland to Geelong in Victoria, with outlying colonies in Ingham and Finch Hatton in the north, and in Adelaide in the south. In the southern parts of its range it occupies more extreme latitudes than any other Pteropus species.

As of 2021 the species is listed as "Vulnerable" on the IUCN Red List of Threatened Species.[1]

Taxonomy

A description of the species was published by Coenraad Temminck in his 1825 monograph of mammals. Hybridisation with the species Pteropus alecto has been noted where their ranges intersect.[3]

The common names for Pteropus poliocephalus include grey-headed kalong.[4] The entry in Gould's Mammals of Australia (1863) gave the bat the title grey-headed vampire.[5]

Description

Wingspan is visible as this flying fox skims water to drink.

The grey-headed flying fox is the largest bat in Australia, with the adult wingspan reaching up to 1 m (3 ft 3 in) in length and weighing up to 1 kg (2.2 lb).[6] Weight generally varies between 600 and 1,000 g (21 and 35 oz), with an average of 700 g (25 oz). The combined length of the head and body is from 230 to 290 mm. The forearm length is a range from 138 to 180 mm. The length of the ear from the tip to base is 30 to 37 mm.[7]

The overall colour of the pelage is a dark-grey body with a light-grey head, separated by a reddish-brown collar. The fur on the body is long and streaked with grey, the broad and well defined collar completely encircles the neck with hair that is golden orange in tone. A unique characteristic among bats of the genus Pteropus is fur on the legs that extends all the way to the ankle.[7]

Like many megachiropterans, the species lacks a tail. All of these bats possess claws on its first and second digits. The head is simple in form, with the characteristic 'dog-like' appearance of the genus. Since it does not echolocate, it lacks the tragus or leaf ornamentation found in many species of Microchiroptera. It relies on smell and, predominately, sight to locate its food (nectar, pollen and native fruits) and thus has relatively large eyes for a bat.

The voice of P. poliocephalus consists of a complex series of squeals and screechings.[7] They will flap their wings in hot weather, using blood pumped through the patagium to cool the body temperature.[8]

The grey-headed flying fox is long-lived for a mammal of its size. Individuals reportedly survived in captivity for up to 23 years, and a maximum age of up to 15 years seems possible in the wild.

Ecology

Distribution

The distribution range is at the eastern regions of the Australian continent, mostly within 200 kilometres of the coast, from Gladstone in Queensland through to the southern Gippsland region and populations around the city of Melbourne. The breeding range has been recorded as progressing southward, the temperate climate of Melbourne and Geelong and no further north than Maryborough, Queensland.[7]

Urbanisation may displace the species, or provide habitat that accommodates their feeding or roosting preferences. The city of Brisbane has many roosts occupied by the species; a famous colony at the Indooroopilly Island is noted for the evening departure of the bats across the local river. Within the central business district of Sydney, they can be seen travelling along city streets to feed at Moreton Bay fig trees at Hyde Park.[9] The species was recorded as an occasional visitor to the national capital Canberra, although the flowering eucalypts at Commonwealth Park have seen more permanent camps established close to the city.[10]

The species was surveyed during the 1920s by Francis Ratcliffe, who recorded the populations in estimates of quarter, half, or one million in camps, generally located around 40 kilometres apart. These numbers have greatly declined since this first survey.[11]

Habitat and movements

Grey-headed flying fox colony

Grey-headed flying foxes live in a variety of habitats, including rainforests, woodlands, and swamps.[12] These camps are variable in size and are seasonally relocated; the warmer parts of the year find them occupying cool and wet gullies in large groups.[7] During the day, individuals reside in large roosts (colonies or 'camps') consisting of hundreds to tens of thousands of individuals. Colonies are formed in seemingly arbitrary locations. Roost vegetation includes rainforest patches, stands of melaleuca, mangroves, and riparian vegetation, but roosts also occupy highly modified vegetation in urban areas. A prominent example existed for many years at the Royal Botanic Gardens in Sydney. However, the botanic gardens instituted a controversial policy to remove them from the garden grounds. The camp is now dispersed across Queensland.[13][14]

Movements of grey-headed flying foxes are influenced by the availability of food. Their population is very fluid, as they move in response to the irregular blossoming of certain plant species. They are keystone pollinators and seed dispersers of over 100 species of native trees and plants.[15] The grey-headed flying fox is a partial migrant that uses winds to facilitate long-distance movement. It does not migrate in a constant direction, but rather in the direction that will be the most beneficial at the time.[16]

Although recorded in small numbers sporadically throughout the 20th century, it was not until the 1980s that grey-headed flying foxes routinely visited Melbourne,[17] with a permanent camp since the 1990s. Their residence at the Melbourne Botanic Garden was the subject of controversy, and the bats were eventually discouraged and moved to Yarra Bend at the city's river. The camp at this site was decimated during a heat wave, requiring its rehabilitation to sustain the relocated population. The forced relocations are also said to have led to the discovery of the orchards of the Goulburn Valley.[18] Similarly, the first recorded permanent camp in Adelaide was established in 2010. The spread is likely due to global warming, habitat loss and drought; while the location of the new camps appears to be in response to urbanisation: a reliable food supply[19] (such as native eucalypt plantings and backyard fruit trees) and warmer temperatures due to climate change and urban heat islands.[17][20]

Diet and foraging

Feeding on plant nectar.

Around dusk, grey-headed flying foxes leave the roost and travel up to 50 km a night to feed on pollen, nectar and fruit.[16] The species consumes fruit flowers and pollens of around 187 plant species.[21] These include eucalypt, particularly Corymbia gummifera, Eucalyptus muelleriana, E. globoidea and E. botryoides,[12][22] and fruits from a wide range of rainforest trees, including members of the genus Ficus.[12][22] These bats are considered sequential specialists, since they feed on a variety of foods.[22] Grey-headed flying foxes, along with the three other Australian flying fox species, fulfill a very important ecological role by dispersing the pollen and seeds of a wide range of native Australian plants. The grey-headed flying fox is the only mammalian nectarivore and frugivore to occupy substantial areas of subtropical rainforests, so is of key importance to those forests.

The teeth, tongue and palate of the pteropodid bats are able to extract plant juices from food, only swallowing smaller seeds of the meal. Incisors hold items such as fruit, and the fibrous material is ejected from the mouth after it is masticated and the juice is swallowed; larger seeds may be held in the mouth and dispersed several kilometres from the tree. The need for the elaborate intestinal tract of most herbivores is consequently removed. Some fruiting plants produce food for flying-foxes, and P. poliocephalus is attracted to the scent of their flowers and fruit and is able to locate the pale colour that indicates the source; the fruit and blooms of species that attract birds in the daylight are usually contrasting reds and purples. The food source is also presented away from the foliage that may obstruct the bat's access.[23]

Most of the trees on which this species forages produce nectar and pollen seasonally and are abundant unpredictably, so the flying fox's migration traits cope with this. The time when flying foxes leave their roosts to feed depends on foraging light and predation risk. Flying foxes have more time and light when foraging if they leave their roosts early in the day. The entire colony may leave later if a predatory bird is present, while lactating females leave earlier. With males, the bachelors leave earlier than harem-holding males, which guard and wait until all their females have left. The flying foxes that leave the roost earlier are more vulnerable to predation, and some flying foxes will wait for others to leave, a phenomenon labelled the "after you" effect.[24]

Social organisation

Groupings and territories

Grey-headed flying foxes form two different roosting camps, summer camps and winter camps.[25] Summer camps are used from September to April or June. In these camps, they establish territories, mate, and reproduce.[25] Winter camps are used from April to September. The sexes are separated in winter camps and most behaviour is characterised by mutual grooming.[25] Summer camps are considered "main camps", while winter camps are referred to as "transit camps".[25]

In their summer camps, starting in January, male grey-headed flying foxes set up mating territories. Mating territories are generally 3.5 body lengths along branches.[26] These flying foxes' neck glands enlarge in males in the mating season, and are used to mark the territories.[26] The males fight to maintain their territories, and this is associated with a steep drop in the males' body condition during this time.[27][28] Around the beginning of the mating season, adult females move from the periphery towards the central male territories where they become part of short-term 'harems' that consist of a male and an unstable group of up to five females.[26] Centrally located males are polygamous, while males on the periphery are monogamous or single.[25][26] The mating system of the grey-headed flying fox is best described as a lek because males do not provide any essential resources to females and are chosen on the basis of their physical location within the roost, which correlates with male quality.[26]

Reproduction

Mother with near-mature pup

Matings are generally observed between March and May, but the most likely time of conception is April.[29] Most mating takes place in the territories and during the day. Females have control over the copulation process, and males may have to keep mating with the same females.[30] Females usually give birth to one young each year.[31] Gestation lasts around 27 weeks,[32] and pregnant females give birth between late September and November. Late births into January are sometimes observed. The altricial newborns rely on their mothers for warmth.[33] For their first three weeks, young cling to their mothers when they go foraging. After this, the young remain in the roosts. By January, young are capable of sustained flight, and by February, March or April are fully weaned.

Predation

Flying foxes are preyed on by eagles, goannas and snakes.[25]

The camps of P. poliocephalus attract a number of larger predators. including both terrestrial and aerial hunters. The sea eagle Haliaeetus leucogaster will capture these bats in flight as they leave their roosts. The snake species Morelia spilota is frequently found as a resident at these camps, lazily selecting an individual from the apparently unconcerned group at a branch. The bat is seized in the jaws and encircled by the python's body, then swallowed head first to be digested over the next week.[34] The species was reported by John Gould as being eaten by the indigenous Australians.[5]

Conservation

A grey-headed flying fox electrocuted between electricity transmission lines in suburban Sydney

The grey-headed flying fox is now a prominent federal conservation problem in Australia. Early in the last century, the species was considered abundant, with numbers estimated in the many millions. In recent years, though, evidence has been accumulating that the species is in serious decline. An estimate for the species in 2019 put the number at 586,000[35] and the national population may have declined by over 30% between 1989 and 1999 alone.[36]

Threats

A male grey-headed flying fox, suffering from heat stress during a heatwave in New South Wales

Grey-headed flying foxes are exposed to several threats, including loss of foraging and roosting habitat,[37] competition with the black flying fox, and mass die-offs caused by extreme temperature events.[26] When present in urban environments, grey-headed flying foxes are sometimes perceived as a nuisance. Cultivated orchard fruits are also taken, but apparently only at times when other food items are scarce. Because their roosting and foraging habits bring the species into conflict with humans, they suffer from direct killing of animals in orchards and harassment and destruction of roosts. Negative public perception of the species has intensified with the discovery of three recently emerged zoonotic viruses that are potentially fatal to humans: Hendra virus, Australian bat lyssavirus and Menangle virus.[38] However, only Australian bat lyssavirus is known from two isolated cases to be directly transmissible from bats to humans. No person has ever died from ABLV (Lyssavirus) after having had the ABLV post-exposure vaccine.[39]

The urbanised camps of cities were noted as succumbing to poisoning during the 1970s to 1980s, identified as the lead in petrol that would accumulate on the fur and enter the body when grooming. The mortality rate from toxic levels of lead in the environment dropped with the introduction of unleaded fuel in 1985. An introduced plant, the cocos palm Syagrus romanzoffiana, now banned by some local councils, bears fruit that is toxic to this species and has resulted in their death; the Chinese elm Ulmus parvifolia and privet present this same hazard. The species is vulnerable to diseases that may kill large numbers within a camp, and the sudden incidence of premature births in colonies is likely to significantly impact the re-population of the group; the cause of these disorders or diseases in unknown.[40]

Recent research has shown, since 1994, more than 24,500 grey-headed flying foxes have died from extreme heat events alone.[41] Unsuitable backyard fruit tree netting also kills many animals and may bring them into close contact with humans, but can be avoided by using wildlife-safe netting. Barbed wire accounts for many casualties; this can be ameliorated by removing old or unnecessary barbed wire or marking it with bright paint.[39][11]

The early twentieth century saw the incursion of Pteropus poliocephalus to the opportunities they discovered at orchards, and the government placed a bounty on the declared pest.[40] Their reputation for destroying fruit crops was noted by John Gould in 1863,[5] though the extent of actual damage was often greatly exaggerated. When Ratcliffe submitted his report, he noted the number of paid bounties was 300,000, and this would not have included the mortally wounded escapees or those left suspended at roosts by the grip that is held by their weight. This species continued to be killed or wounded by shotguns, many remaining disabled where they fell after the bounty was stopped, despite the advice of Ratcliffe and later researchers on an ineffective and uneconomical practice and the needless extermination of the population. Orchardists have begun shifting to the use of netting that also discourages the daytime visits of birds. The impact of indiscriminate shooting of bats has resulted in the species being declared vulnerable to extinction, to the tree species that relied on them for regeneration, the subsequent alteration to the forest ecology of the eastern states[40]

Status and protection

To answer some of the growing threats, roost sites have been legally protected since 1986 in New South Wales and since 1994 in Queensland. In 1999, the species was classified as "Vulnerable to extinction" in The Action Plan for Australian Bats,[42] and has since been protected across its range under Australian federal law, listed as Vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). A species recovery plan was created by the federal Department of Agriculture, Water and the Environment and the South Australian Department for Environment and Water and published in 2021.[43][44]

As of 2021 the species is listed as "Vulnerable" on the IUCN Red List of Threatened Species under criteria A2ace and A4ac. Justification for the assessment says that "although the population is relatively large (exceeding 10,000 mature individuals) and it has a large extent of occurrence (> 20,000 km²), a continuing population decline is inferred to be more than 30–35% over the last three generations", and that further decline is expected.[1]

Wildlife rescue

Crib full of abandoned babies rescued by Wildcare Australia in care at The Bat Hospital

Baby flying foxes usually come into care after having been separated from their mothers. Babies are often orphaned during four to six weeks of age, when they inadvertently fall off their mothers during flight, often due to disease or tick paralysis (their own and/or that of the mother).[45]

Bat caregivers are not only specially trained in techniques to rescue and rehabilitate bats, but they are also vaccinated against rabies. Although the chance of contracting the rabies-like Australian bat lyssavirus is extremely small, bat caregivers are inoculated for their own protection.

Gallery

References

  • Richards, G.C.; Hall, L.S.; Parish, S. (photography) (2012). A natural history of Australian bats: working the night shift. CSIRO Publishing. ISBN 9780643103740.
  1. ^ a b c Eby, P.; Roberts, B.; Pennay, M.; Welbergen, J.A. (2021). "Pteropus poliocephalus". IUCN Red List of Threatened Species. 2021: e.T18751A22085511. doi:10.2305/IUCN.UK.2021-3.RLTS.T18751A22085511.en. Retrieved 12 December 2021.
  2. ^ Temminck, C.J. (1824). Monographie de mammalogie (in French). Paris.
  3. ^ a b Simmons, N.B. (2005). "Order Chiroptera". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 342. ISBN 978-0-8018-8221-0. OCLC 62265494.
  4. ^ England, Royal College of Surgeons of (1859). Descriptive catalogue of the specimens of natural history in spirit contained in the museum. Vertebrata: Pisces, Reptilia, Aves, Mammalia. Richard Taylor. p. 124.
  5. ^ a b c Gould, J. (1863). The mammals of Australia. Vol. 3. Printed by Taylor and Francis, pub. by the author. pp. pl. 28 et seq.
  6. ^ "Grey-headed Flying-fox - profile". NSW Environment, Energy and Science. 2 June 2014. Retrieved 30 December 2021.
  7. ^ a b c d e Menkhorst, P.W.; Knight, F. (2011). A field guide to the mammals of Australia (3rd ed.). Melbourne: Oxford University Press. p. 146. ISBN 9780195573954.
  8. ^ Richards 2012, p. 50.
  9. ^ Richards 2012, pp. 28–30.
  10. ^ Richards 2012, p. 33.
  11. ^ a b Richards 2012, p. 107.
  12. ^ a b c Menkhorst, P. 1995. "Grey-headed Flying-fox". pp. 156–158 in P. Menkhorst, ed. Mammals of Victoria. Melbourne: Oxford University Press.
  13. ^ "Sydney's flying foxes now Bundy's problem". North Queensland Register. 2 August 2012. Archived from the original on 30 December 2012. Retrieved 22 February 2014.
  14. ^ "Say goodbye to Sydney's colony of bats". Australian Geographic. 17 February 2011. Archived from the original on 5 October 2013. Retrieved 22 February 2014.
  15. ^ "L Pope 2014" / Some Touch of Pity, pub=sid harta
  16. ^ a b Tidemann, C. R.; Nelson, J. E. (2004). "Long-distance movements of the grey-headed flying fox (Pteropus poliocephalus)". Journal of Zoology. 263 (2): 141. doi:10.1017/S0952836904004960.
  17. ^ a b David Lindenmayer; Mark A. Burgman (2005). Practical Conservation Biology. CSIRO Publishing. p. 247. ISBN 9780643090897.
  18. ^ Richards 2012, pp. 34–35.
  19. ^ Grey-headed Flying-foxes in South Australia, South Australian Department of Natural Resources, (accessed 11-May-2018)
  20. ^ Richards 2012, pp. 118.
  21. ^ Williams, N. S. G.; McDonnell, M.J.; Phelan, G.K.; Keim, L.D.; der Ree, R. (2006). "Range expansion due to urbanisation, increased food resources attract Grey-headed Flying-foxes (Pteropus poliocephalus) to Melbourne". Austral Ecology. 31 (2): 190–198. doi:10.1111/j.1442-9993.2006.01590.x.
  22. ^ a b c Parry-Jones, K. A.; Augee, M. L. (2001). "Factors affecting the occupation of a colony site in Sydney, New South Wales by the Grey-headed Flying-fox Pteropus poliocephalus (Pteropodidae)". Austral Ecology. 26: 47–55. doi:10.1111/j.1442-9993.2001.01072.pp.x.
  23. ^ Richards 2012, p. 70.
  24. ^ Welbergen, J. A. (2006). "Timing of the evening emergence from day roosts of the grey-headed flying fox, Pteropus poliocephalus: the effects of predation risk, foraging needs, and social context". Behavioral Ecology and Sociobiology. 60 (3): 311–322. doi:10.1007/s00265-006-0167-3. S2CID 45452998.
  25. ^ a b c d e f Nelson, J. E. (1965). "Behaviour of Australian Pteropodidae (Megachiroptera)". Animal Behaviour. 13 (4): 544–557. doi:10.1016/0003-3472(65)90118-1. PMID 5882814.
  26. ^ a b c d e f Welbergen, J.A. (2005) "The social organisation of the grey-headed flying-fox". PhD thesis, University of Cambridge, Cambridge.
  27. ^ Welbergen, J. A. (2011). "Fit females and fat polygynous males: Seasonal body mass changes in the grey-headed flying fox". Oecologia. 165 (3): 629–637. Bibcode:2011Oecol.165..629W. doi:10.1007/s00442-010-1856-1. PMID 21153744. S2CID 13532917.
  28. ^ Welbergen, J.A. (2010). "Growth, bimaturation, and sexual size dimorphism in wild gray-headed flying foxes (Pteropus poliocephalus)". Journal of Mammalogy. 91 (1): 38–47. doi:10.1644/09-mamm-a-157r.1.
  29. ^ Martin, L., Kennedy, J.H., Little, L., & Luckhoff, H.C. (1993) "The reproductive biology of Australian flying-foxes (genus Pteropus)". In Ecology, evolution and behaviour of bats (ed S.M. Swift), pp. 167–186. Oxford, London.
  30. ^ Welbergen, J.A. (2002). "Second year report: The social organisation of the Grey-Headed Flying-Fox, Pteropus poliocephalus: causes, consequences, and conservation." The Department of Zoology, The University of Cambridge, Cambridge.
  31. ^ Hall, L. S.; Richards, G. C. (2000). Flying-foxes: fruit and blossom bats of Australia. Sydney: University of New South Wales Press. ISBN 0-86840-561-2.
  32. ^ O'Brien, G.M. (1993). "Seasonal reproduction in flying-foxes, reviewed in the context of other tropical mammals". Reproduction, Fertility and Development. 5 (5): 499–521. doi:10.1071/rd9930499. PMID 8190905.
  33. ^ Bartholomew, G.A.; Leitner, P.; Nelson, J.E. (1964). "Body temperature oxygen consumption and heart rate in three species of Australian flying-foxes". Physiological Zoology. 37 (2): 179–198. doi:10.1086/physzool.37.2.30152330. JSTOR 30152330. S2CID 86940598.
  34. ^ Richards 2012, p. 104–105.
  35. ^ Westcott, David (May 2019). "The National Flying-Fox Monitoring Program" (PDF). Department of the Environment and Energy. Retrieved 24 December 2019.
  36. ^ Richards, G. (2000). In Proceedings of a workshop to assess the status of the Grey-headed Flying-Fox (eds G. Richards & L. Hall). Australasian Bat Society, Canberra.
  37. ^ Eby, P. (1995). "The biology and management of flying-foxes" in NSW. Rep. No. 18. N.S.W. National Parks and Wildlife Service, Hurstville.
  38. ^ Allworth, A.; Murray, K.; Morgan, J.A. (1996). "Human case of encephalitis due to a lyssavirus recently identified in fruit bats" (PDF). Communicable Diseases Intelligence. 20: 504.
  39. ^ a b Pope, L. (2014). Some Touch of Pity. Sid Harta Publishers.
  40. ^ a b c Richards 2012, pp. 107–109.
  41. ^ Welbergen, J.; Klose, S.; Markus, N.; Eby, P. (2008). "Climate change and the effects of temperature extremes on Australian flying-foxes". Proceedings of the Royal Society B: Biological Sciences. 275 (1633): 419–425. doi:10.1098/rspb.2007.1385. PMC 2596826. PMID 18048286.
  42. ^ "The Action Plan for Australian Bats - Recovery outlines: Grey-headed Flying-fox". Environment.gov.au. Retrieved 22 February 2014.
  43. ^ "Pteropus poliocephalus — Grey-headed Flying-fox". Species Profile and Threats Database. SPRAT Profile. Department of Agriculture, Water and the Environment (Australia). Retrieved 30 December 2021. CC BY icon.svg Attribution 4.0 International (CC BY 4.0) licence.
  44. ^ "National Recovery Plan for the Grey-headed Flying-fox Pteropus poliocephalus". Department of Agriculture, Water and the Environment (Australia), and the Government of South Australia, Department for Environment and Water. 2021. PDF
  45. ^ Dovas. "There's A Bat Hospital in Australia That Takes in Abandoned Baby Bats". Bored Panda. Retrieved 12 December 2017.
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Grey-headed flying fox: Brief Summary

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The grey-headed flying fox (Pteropus poliocephalus) is a megabat native to Australia. The species shares mainland Australia with three other members of the genus Pteropus: the little red P. scapulatus, spectacled P. conspicillatus, and the black P. alecto. The grey-headed flying fox is the largest bat in Australia.

The grey-headed flying fox is endemic to the south-eastern forested areas of Australia, principally east of the Great Dividing Range. Its range extends approximately from Bundaberg in Queensland to Geelong in Victoria, with outlying colonies in Ingham and Finch Hatton in the north, and in Adelaide in the south. In the southern parts of its range it occupies more extreme latitudes than any other Pteropus species.

As of 2021 the species is listed as "Vulnerable" on the IUCN Red List of Threatened Species.

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