GREY-HEADED Flying foxes

A Grey-headed Flying-fox (GHFF) camp of National Importance is located in the Wolli Creek Valley in bushland close to the creek, and not far west of Turrella Reserve. Although it’s possible that the GHFF roosted in the Valley in earlier times, the current camp dates from mid-2007. At that time there were a few hundred GHFF. The camp has since grown to thousands, with fluctuations in the population occurring throughout the year/s.

In November 2016 around 24,000 Flying-foxes were counted, which is the highest number yet recorded. Ongoing population information is obtained by monthly ‘fly-out’ counts; ie counting the number of GHFF as they exit their camp to feed for the night. WCPS volunteers have been conducting these fly-out counts since April 2008 (see monthly fly-out counts for more on this WCPS volunteer activity), when a research project sought to obtain data about the population dynamics and movements of the GHFF across their range. This research involved monthly, synchronised counts of as many GHFF camps as possible up and down their range along the east coast of Australia.

Since then volunteers have continued monthly monitoring of the the population of GHFF at Turrella/Wolli creek. We also contribute data to the  the National Flying Fox Monitoring Program (NFFMP) via quarterly counts.  The NFFMP is a collaborative project between Federal and State Governments, which aims to establish a reliable benchmark for the size of flying-fox populations, and to monitor population trends in later years. GHFF are listed as a ‘vulnerable’ species under both NSW and Federal legislation. It is also on the International Union for The Conservation of Nature’s (IUCN’s) red list of threatened species. Habitat destruction is one the leading causes of their decline in numbers.

The Wolli Valley camp is generally occupied continuously throughout the year, so it is called a permanent, as opposed to a seasonal camp. However, in some years when there is good flowering of particular Eucalyptus tree species – which are significant food sources for the GHFF – they may leave their Wolli (and other Sydney) camps for other areas of NSW, or south-east Qld. This can lead to high concentrations of GHFF in those areas for the duration of the flowering period.

In common with many GHFF camps, the Wolli camp is located close to water, a section of Wolli Creek, which provides an important source of water for the GHFF. On hot evenings, they can be seen dipping into the creek to cool off, and obtain water, before going out to feed for the night. After belly-dipping into the water (which takes skill to master) they land in nearby trees, then lick the water off their belly fur. See a great video of this activity.