Grey-headed Flying-fox

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). 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. 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. 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. …

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. 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. 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. 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.

Around dusk, grey-headed flying foxes leave the roost and travel up to 50 km a night to feed on pollen, nectar and fruit. The species consumes fruit flowers and pollens of around 187 plant species. These include eucalypt, particularly Corymbia gummifera, Eucalyptus muelleriana, E. globoidea and E. botryoides, and fruits from a wide range of rainforest trees, including members of the genus Ficus. These bats are considered sequential specialists, since they feed on a variety of foods. 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. …