Flying Foxes (Grey-headed Fruit Bats) (Pteropus poliocephalus) seem to move out of their traditional areas in high summer. As a former resident of Canberra, I know that they would occasionally appear there - which is certainly not regular Flying Fox country.
I lived on Anzac Parade, in Reid, (in front of the War Memorial). The ceremonial avenue in front of the War Memorial is flanked on each side by 6 rows of Tasmanian Blue Gums. They flower in high summer. The scent of sweet Eucalyptus was overwhelming. Once a year, at the full moon in either late January, or early February, Flying Foxes would swarm around the tops of those Eucalypt trees, which for those few days were redolent with sweet-smelling nectar. It always seemed to me as if the plants planned their flowering to coincide with this warm summer evening invasion. However, as they were Tasmanian Eucalypts, that is unlikely, for that area (where those trees evolved) is outside of their natural range. So the explanation is probably more to do with pollination of their flowers by large moths.
My experience of the partiality of Flying Foxes for Eucalyptus blossom is confirmed in the following extract from a website on Flying Fox biology: The preferred food of flying-foxes is the blossom of eucalypts and some other native trees, and various bush fruits, like Moreton Bay Fig. The bats are beneficial to the trees because they act as pollinators and dispersers of their seeds. The great distances they can fly means they carry pollen and seeds far from the parent tree.
"Flying Foxes in Australia"
*****Here in Robertson, I have noticed, in the last few days, that suddenly there are Flying Foxes around. They do not reside here all the time, but apparently they come in, on warm summer evenings. Significantly, the moon is waxing - towards a full moon. I do not know if this suits the Flying Foxes, or whether it simply makes them more apparent, when the night sky is quite bright. I figure both statements are likley to be true.
Last night, after the "No Borefield in the Southern Highlands" meeting, I was packing gear into my car, when suddenly there was a loud, shrill squabbling noise coming from the trees next door. I assumed it was Possums. I knew it was not the large Brush-tailed Possums, for I am familiar with their noises (both amorous and combative). So, I figured it was a noise made by the much smaller Ring-tailed Possums. Suddenly, the next moment, I heard a flapping sound as a large Flying Fox flew out from the dense cover of the neighbouring tree - then it flew silently away. Normally their wing flap is silent, but when they flap against branches as they drop out of the trees, they hit small branches, and make a noise.
So, according to the Melbourne Planetarium, we are one night short of the Full Moon. Tomorrow night, look out for those ghostly shapes flying around, especially if you have any fruit trees near your house, or other trees which might be in flower just now. If, like tonight, it is slightly misty, even better, as the moon light will illuminate the cloud or mist, and make it easier to see the Flying Foxes against the light grey sky.
Flying Foxes seem to love a high summer full moon, and it means they can explore new and fertile hunting grounds - such as Robertson.
Love your local Flying Fox - they will only be here for a few days, most probably.