The Grey-headed Flying- foxes (GHFFs) first set up camp in the Wolli valley in mid-2007, and numbered a few hundred. There are no historical records of their previous presence in the valley, although it is possible that they have roosted in the valley in earlier times.
During the day, the Flying-foxes roost by hanging in the canopy of the Eucalyptus and Casuarina trees that can be found in the camp area. These trees were planted in the early 1980’s as part of a revegetation project. As the camp expanded in the summer of 2010, many flying foxes moved over the creek to roost in other tree species as well.
The GHFF camp is close to the creek, and on hot evenings the Flying Foxes can be seen belly dipping in the creek before going out to feed for the night. They do this in order to drink, and to cool off. After skimming the water (which takes skill to master) they can be seen licking the water off their fur, after landing in nearby trees. Click on the YouTube link to see a great video of this activity. www.youtube.com/profile?user=possm1#p/u/0/d_j5aDaykGk
The Wolli Valley camp has been a seasonal camp since it was established, with the flying foxes heading north for the winter. However during 2010, the camp continued to be occupied during the winter months, with reduced numbers of GHFF’s present.
Fly-out counting by WCPS volunteers commenced in April 2008 as part of regular synchronised counts occurring up and down their range along the east coast of Australia. These synchronised counts contribute to research work about the population dynamics and movements of this now vulnerable mammal species. WCPS continues to monitor the presence and numbers of GHFF.
The Royal Botanic Gardens has a controversial proposal to displace the colony of Grey-headed Flying-foxes from the gardens in Sydney. This will cause problems in a number of ways for this vulnerable species. The Society has submitted its objections to the proposal to the public consultation process under Commonwealth legislation that the Gardens have to run. Download the submission here.
See “bat counting” page if you are interested in being involved.
Some Grey-headed flying Fox facts
- The scientific name of the Grey-headed Flying-fox is Pteropus poliocephalus
- They are warm-blooded, nomadic, social mammals.
- They have a wing span of roughly a metre, and weigh up to a kilogram
- They are often called fruit bats, but they feed mainly on the blossoms (nectar and pollen) of Eucalyptus, Banksia and Melaleuca trees, as well as rainforest fruits. They will feed on cultivated fruit when there is a shortage of their native food.
- They feed at night and travel within a radius of up to 40 km from their camp, visiting a number of trees along the way.
- They play an important role in maintaining forests along the east coast of Australia, as they spread seeds and pollinate blossoms during their travels in search of food.
- Only one baby is born each year, usually in October. In urban areas at this time, and for the next few months, female GHFF are particularly in danger of coming into contact with and dying on electric power lines as they carry the (increasing) weight of their young pups while out feeding. Their pups however can often survive this tragedy. For information on what to do if you see a GHFF hanging from power lines download the info sheet (PDF) ‘Flying Foxes on Power lines’ .
- They have many different calls. These calls become louder in the mating season, (March to May) when the males ‘shout’ in the face of females as part of their breeding ritual, and there are squabbles over territory. They also can be heard while out and about feeding in trees at night, as they defend their feeding territory.
- Despite the numbers now seen in urban areas around Sydney, overall GHFF numbers have dramatically declined. In 2001 The Commonwealth, NSW and Victorian governments listed the GHFF as a threatened species. It has been classified as ‘vulnerable’.
- It’s estimated that the area of habitat available for GHFF’s has been reduced by 50% since European occupation. Human activities such as land clearing for agriculture and urban expansion have lead to this reduction.
If you encounter an injured Grey-headed Flying-fox, do not handle the animal but contact WIRES on 8977 3333 or Sydney Wildlife on 9413 4300.
For further background information on GHFF download article prepared by Andrew Smith (2007).
Useful Links for more information:
www.sydneybats.org.au – Flying Foxes in Sydney. Contains lots of useful information and links to other relevant websites
www.abs.ausbats.org.au – Australasian Bat Society
www.environment.nsw.gov.au – The website of the NSW Department of Environment Climate Change and Water (DECCW)
www.bellingen.com/flyingfoxes/ – Information about the Bellingen camp in northern NSW. Some superb photographs can be found on this site.
http://australianmuseum.net.au/Australian-bats – Information from The Australian Museum website.
Wildlife Habitats – For information about native plants of the Wolli valley that can provide food for GHFF’s see our Wildlife Habitat Plants page