Project Description

Grey-headed flying foxes (Pteropus poliocephalus)

This is the only mainland flying fox species endemic to Australia, meaning the other flying fox species also occur outside of Australia. Grey-headed flying foxes are the only species to have fur to the ankle, the other mainland species have fur that stops at the knee. Unfortunately this may help them in the cold weather but may not help in the heat stress events exacerbated by climate change. Like all flying fox species, their main ecological services are pollination and seed dispersal, especially during climate change.

They often share camps with Black flying foxes where their range overlaps. Their most northern camp is Ingham in far north Queensland. Here they commonly share the camp with the other three mainland species of flying fox, the only flying fox camp in Australia with all four species. However the local Council dispersed this camp in 2020 and intends to keep them out of the town park – it is unknown if the four species will come together again to roost elsewhere in the area. During starvation events in NSW, Greys become more nomadic than the Blacks in search their search for food. (Pers.Comm Peggy Eby). They extended their range to Canberra and Adelaide in 2003 during a starvation event on the Australian east coast.

Grey-headed flying fox records from Atlas of Living Australia
grey-headed flying foxes area nectar feeders and important pollinators

All species of flying foxes love nectar and are essential pollinators in various ecosystems..

all flying foxes carry their young until they are too heavy to carry

All flying foxes carry their young for the first month or so. When born, the pups are initially unable to control their own body temperature, or hang independently.

The main threats Grey-headed flying foxes face include:

“Understanding the feeding behaviour and food resources is important for effective conservation of these highly mobile threatened species when their habitat is declining in quantity and quality.” This statement is from an interesting article Flying Foxes and Cicadas  that reports observing Greys catching cicadas on the wing when light levels are good and the insects are flying, or from among foliage when the insects are at rest. They conclude “seasonal congregations of larger insects such as cicadas may be an important way for flying foxes to supplement the nitrogen in there otherwise protein restricted diets”. While this behaviour has not been observed in the other Australian flying fox species it is probable that they also do this.

Photo below: This Grey-headed flying fox was flying in the day time to get a drink. It was a day where the temperatures in Melbourne got to 48 degrees and many people died in bushfires. Bats skim the water to get their bellies wet, then lick the water off their fur.

Grey-headed flying fox drinking, photo taken in Melbourne at Yarra Bend.

PTEROPUS POLIOCEPHALUS

DESCRIPTION

As the name suggests the head of this beautiful flying fox is covered in grey fur, varying from light grey to dark grey. It is the only Australian flying fox with a mantle of rusty brown/orange fur encircling the neck. The belly fur is similarly colouredoften with flecks

DISTRIBUTION & HABITAT

Until recently Grey-headed flying foxes were only found in the coastal belt from Rockhampton in Queensland to Melbourne in Victoria. Their distribution has changed since 2000, north to Ingham, west to Adelaide and Canberra, and many places around Victoria. Single individuals have also been seen at Tolga Scrub. They are extremely mobile flying 2268–2564 kms a year and have a  very high estimated daily colony turnover rate of 17.5 ± 1.3%.

DIET

Fruit and nectar mainly, but flowers, pollen, leaves of particular plants, salt from sea water and mangrove leaves, and occasionally insects. They are particularly dependent on Myrtacae family, especially eucalypts and so are at the mercy of seasonal and unseasonal rainfall. Dr Peggy Eby has done a lot of research on this and how it feeds into starvation events and even Hendra spillover events.

MATING SEASON

Mating occurs in the early part of the year with conception peaking March to April. At this time of year the males put on a lot of weight and defend their territory.  They try to leave their branch/es only for short periods to feed. Males mark their territory with secretions from their scapular glands.

BIRTHING SEASON

Soon after mating, the colonies break into smaller groups close to food resources for winter, but come back into larger colonies in spring ready for birthing. The pregnancy is 27 weeks long and so most pups are born between October and December. They are usually born with the head facing the mother. The mother can spend up to an hour once the head is out before pushing the pup out completely. By then she has cleaned up the face of the pup and it is usually fully alert to help get itself onto the breast.

LIFE HISTORY OF THE PUP UP TO JUVENILE AGE

When the pup is born it cannot maintain its own body temperature and must remain on mum all the time, hanging on as she flies out at night to feed. The claws bed into her fur and the mouth is firmly on the nipple. By about 6 weeks of age the pup is too heavy to fly with and it is left in a creche in the roost with other pups. Here they become very active at night doing a lot of flapping and eventually short flights by 12 weeks of age. We have had mothers caught on barbed wire fences with pups up to 250 gms so it’s not that they can’t fly with the bigger pups, but it is hard work. Until now they have been completely dependent on their mother’s milk. As they gain strength for longer flights they learn to feed on suit and nectar, until they are fully weaned at 5-6 months age. They tend to hang with their own age group before fully joining the adult like of the camp in their third year.

POPULATION

CSIRO counts can be found at The National Flying-fox Monitoring Program.

CONSERVATION

Listed at the federal and state levels as vulnerable, but is likely to be up-listed since tens of thousands perished in the 2019-2020 drought and bushfire season. Refer to Conservation of Australian Flying Foxes

MORE INFORMATION

Little Aussie Battlers
Churchill, Sue (2008) Australian Bats. Out of print, soon to be superseded by an expanded digital version
Hall, Les & Richards, Greg (2000) Flying Foxes, Fruit and Blossom Bats of Australia
Eby, Peggy. Search for some of the 35 publications in her name.
Westcott, DA, Heersink, DK, McKeown, A, Caley P (2015)The status and trends of Australiaâs EPBC-Listed flying-foxes. CSIRO, Australia, found online here
Smith, Helen at al (2019) Flying Foxes and Cicadas 
Major, Fiona (2020) ACTWildlife_PostHailReport_2020. Injuries and Deaths of GHFFs in Commonwealth Park, ACT.
IUCN Red List
C Extreme mobility of the world’s largest flying mammals creates key challenges for management and conservation Wellbergen et al 2020