Both Microbats and Megabats are found in the Parklands. Microbats are the small, commonly insectivorous bats that use echolocation – a sonar hearing system – to detect and capture their prey. Megabats, including the grey-headed flying-fox (Pteropus poliocephalus), use their eyesight and keen sense of smell to locate their food.
Microbats are nocturnal, emerging after sunset from tree hollows or discrete hiding places to feed on insects. These bats are tiny, with a wingspan up to the size of your hand, a body measurement between 35 - 50 mm and weighing as little as 9 grams. Microbat species detected within the Parklands include: Gould’s wattled bat (Chalinolobus gouldii), southern myotis (Myotis macropus), common bent-wing bat (Miniopterus schreibersii) and the east coast free-tailed bat (Mormopterus norfolkensis).
Large numbers of grey-headed flying-foxes (5,000 to ~45,000) – also known as fruit bats – have been roosting within Lachlan swamp since early 2010. A small number of black flying-foxes (P. alecto, up to ~1,000), a more tropical species, also roost within Lachlan Swamp.
Around sunset each night they fly out of the swamp to feed on nectar, blossom and fruit (e.g. figs, paperbark and gum tree flowers). The number of flying-foxes roosting within Lachlan swamp, and the broader Sydney region, is seasonally and annually variable. For example, in November 2014 there were ~20,000, however in November 2015 there were ~10,000 flying-foxes. The number of flying-foxes depends upon the amount of food available in the Sydney region compared to surrounding areas (e.g. south coast NSW, Hunter region, northern NSW, or southeast Queensland). Flying-foxes fitted with satellite transmitters have been recorded moving from the Sydney region to Melbourne (Vic), Dubbo (NSW) and Bundaberg (Qld), and everywhere in between.
Ecologically, flying-foxes are important pollinators at a landscape scale (10’s to 100’s km) and seed dispersers at a local scale (up to ~10 km). Other pollinators, such as birds, bees (including native stingless bees), moths, butterflies, wasps, flies, beetles, small mammals such as gliders, operate over much smaller distances. The wind can also carry pollin long distances; of course, the potential that pollin travels and reaches a flower of the same species a long distance away is relatively low.
Bats and visitors
Visitors are often apprehensive about flying-foxes or fruit bats because of their large numbers and shrieking calls. Human contact with bats has been linked with the transmission of lyssavirus to humans. This disease can only be transmitted through being scratched or bitten by a sick bat (flying-fox or microbat). For this reason it is advised that visitors to the Parklands should never handle bats but call the Centennial Parklands Rangers 0412 718 611 for assistance 24 hours.
Here is the NSW Government advice if you ever come into contact with a bat.
If left alone, fruit bats are harmless animals as they perform essential ecological roles of pollination and dispersal of tree seeds along the eastern Australian coastline. However, despite their fundamental ecological role, fruit bats are often the focus or misdirected and ignorant perceptions. Many believe the Hollywood-esque idea that all bats are vision-impaired, blood-sucking predators from the wildest depths of the earth.
Ironically, a close-up encounter with these supposedly fearful beasts, often reveals quite the opposite. Many people find their dog or fox-like faces quite endearing, showing cute wiggly ears and a wide-eyed expression. Contrary to popular belief, fruit bats have very good eyesight.
So next time you hear the flap of a batwing in the trees, take a moment to consider these night-time natives from a different angle, or for an even closer look, join a guided tour with one of Centennial Parkland's Education Rangers.