A keystone speciesAustralian flying-foxes (also known as fruit bats) are our largest flying mammals, and their energy for flight is reliant upon the sugar-rich nectar of native hardwoods, native seed-heavy fruits and berries, and more recently, introduced species found in urban backyards and orchards.
Their mobility (some can disperse 500 km in 2 days!) makes them keystone pollinators and seed dispersers. However, their effectiveness is reliant on large populations. |
|
Justin Welbergen
|
Grey-headed flying-foxesThe grey-headed flying-fox (GHFF, Pteropus poliocephalus) is listed as Vulnerable under the EPBC Act 1999. This national legislation affords this species protections and safeguards to prevent population declines.
|
Flying-foxes in the Australian Capital Territory
Grey-headed flying-fox
Wild Photos by Justin Welbergen |
GHFFs are predominantly distributed along the eastern coast of Australia, with a few camps (often non-permanent locations) extending to inland regions. Historical records show that before 2003 GHFFs had been an occasional visitor to the Australian Capital Territory (ACT). A search of museum records and historical databases between 1965 and 2002 revealed 12 records of GHFF in Canberra.
Commonwealth Park
The Commonwealth Park camp (or roost) has been occupied seasonally since 2003, and the Australasian Bat Society has regularly surveyed the camp ever since. |
|
Lake Ginninderra
In recent years, Lake Ginninderra has also become a camp for flying-foxes, especially when the colony at Commonwealth Park becomes large (>5000 FFs). In 2021, this included a small group of little red flying-foxes (LRFFs, Pteropus scapulatus). While GHFFs have grey faces, silver–black fur (to the knees), and an orange collar, LRFFs are <half their size, with red-brown fur and more translucent wings. By monitoring the number, species, and density of flying-foxes at Commonwealth Park and Lake Ginninderra, we could find that they become of high conservation importance in the future! |
|
Surveys
|
Why do we do it?
Since 2013, the Australasian Bat Society has conducted (a) flying-fox surveys at Commonwealth Park as part of a contract with National Capital Authority, and (b) quarterly censuses for the ACT and Commonwealth Governments as part of the National Flying-fox Monitoring Program, using the CSIRO flying-fox census method. By monitoring the number, species, and density of flying-foxes at Commonwealth Park and Lake Ginninderra, we could find that they become of high conservation importance in the future! When do we do it? During the warmer months of the year when the flying-foxes come south from Queensland (Oct–May), we conduct a count each week on either a Saturday or Sunday morning. How do we do it? We walk beneath the colony, and count the number of bats in each tree, then sum the number bats in each tree 'type' (see the shapes on the map). Since the bats are often chatting and moving around during the day, they are relatively easy to see. If you're lucky, you can often find mothers with pups! Counting bats isn't difficult, but it can take a while - depending on how many there are it can take between 5 mins and 3 hrs. Normally the surveys can be done by one person, but in Feb–Mar the numbers can get high (5000-9000), so in those cases counting with several people lightens the load. Do I need any special skills? Nope - just a free weekend morning and a phone! You'll need to wear closed shoes, avoid light clothing and keep your mouth closed while counting (in case of droppings), and avoid looking directly upwards for extended periods by taking breaks. Snacks and water are a good idea, you can listen to music or a podcast while counting if that isn't too distracting. How can I get involved? Contact us at [email protected]! |
Justin Welbergen
Map of tree types (shapes) and paths at the location of the flying-fox camp at Commonwealth Park
|
But aren't bats dangerous?
|
Despite being incredibly important for the health of our forest and woodland ecosystems, flying-foxes often get a bad rap. They have an immune system so advanced that they are able to withstand a much greater load of pathogens, which can make them reservoirs for diseases including the Australian bat lyssavirus and hendra virus.
However, the likelihood of contracting these diseases from a bat are exactly zero if you do not touch them (no touch, no risk). If you ever find a sick, injured, or orphaned bat, contact your local wildlife rescue organisation. In Canberra, this is ACT Wildlife (0432 300 033). |
|
What can I do to help bats?Despite megabats (like flying-foxes) being important pollinators, and microbats being important for insectivores, many species are threatened by habitat destruction, diseases, and human persecution. There are heaps of ways you can help protect your local bats:
1. Keep cats indoors: Domestic cats can attack microbats while hunting at night, so it is best to keep these species apart. 2. Install a bat box: Microbat boxes provide habitat while encouraging your local microbats to control insects! 3. Reduce the use of pesticides: Pesticides can harm microbats that feed on insects, and megabats that feed in trees. 4. Use safe fruit nets: Wildlife can get injured and die in large-mesh garden netting, so swap it for safe meshing that you can't poke your finger through. 5. Keep old and dead trees (when they aren't a hazard): Old and dead trees often have hollows, which provide excellent roosting habitat for microbats. 6. Turn off unnecessary lights outside: Light pollution can disrupt how bats navigate at night. As an added bonus, this saves electricity! 7. Be an ambassador: Learn about bats, and spread awareness of how amazing and important bats are to the people you know. 8. Volunteer: Join your local wildlife rescue organisation or bat research project - like ours! |
|
Project partners
|
|
|
I acknowledge the Ngunnawal and Ngambri peoples as the Traditional Custodians of the land and waters I live and work in, and pay my respects to the Elders past and present. I recognise their continuing connection to Country, and also thank them for protecting its ecosystems since time immemorial.
