Grey-headed fruit bat
The grey-headed flying-fox is the largest bat in Australia. They have a dark-grey body with a light-grey head, separated by a reddish-brown collar that circles the entire neck. The fur on the body is long and streaked with grey.They also have fur on the legs all the way down to the ankle, something unique to the genus Pteropus. Adults may have a wingspan reaching one metre in length and be up to one kilogram in weight.
Like many megabats, the Grey-headed flying-fox doesn’t have a tail. All of these bats possess claws on its first and second finger. Since they don’t use echolocation, they don’t have the huge and complex ears of the insect-eating microbats. Instead, they rely on smell and sight to locate its food, and so they have relatively large eyes for a bat. Their pointed snout and small, pointy ears gives them a distinctly dog-like appearance, hence the name ‘flying-fox’. However, these megabats are not closely related to canines. In actual fact, they are far more closely related to primates – like monkeys, apes, and us!
Pollen, nectar and fruit makes up the bulk of the diet of this species. 187 plant species have been recorded as being used for food by Grey-headed flying-foxes. The bats will chew up their food, swallowing down the juices before spitting out all the unwanted fibrous material. Due to their food trees blossoming seasonally and unpredictably, Grey-headed flying-foxes have been recording up to 50km in a single night just to reach flowering or fruiting trees.
Grey-headed flying-foxes live in a variety of habitats, including rainforests, woodlands, and swamps.Their ‘camps’ are variable in size and move seasonally; in the warmer parts of the year they will roost in cool and wet gullies in large groups. Roost vegetation includes rainforest patches, stands of melaleuca, mangroves, and waterside vegetation, but roosts also occupy highly modified vegetation in urban areas.
They are found throughout the eastern regions of Australia, mostly within 200 kilometres of the coast, from Gladstone in Queensland through to the southern Gippsland region and populations around Melbourne. The breeding range seems to be moving south towards the temperate climate of Melbourne and Geelong and no further north than Maryborough, Queensland.
Grey-headed flying-foxes are very vocal, able to make a complex series of squeals and screeches. They will flap their wings in hot weather, using blood pumped through the patagium to cool the body temperature.
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.
During the day, individuals reside in large roosts (colonies or ‘camps’) consisting of hundreds to tens of thousands of individuals. Camps will form in a range of locations and the population of each camp can vary greatly depending on season and food availability.
The Grey-headed flying-fox is now considered vulnerable. 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. The National Grey-headed Flying-fox population was estimated to be 680,000 (±164,500) in 2015 and the national population may have declined by over 30% between 1989 and 1999 alone