Where do the flying foxes go?

Grey-headed flying-foxes generally make their home in the Eurobodalla during the warmer months and head north for winter when the weather gets cold. However, as Batemans Bay residents know all too well, 2016 was an exceptional year due to the widespread flowering of spotted gums and the flying-foxes stayed throughout winter as well.

The flying-foxes took advantage of the abundant food on offer, as the spotted gums produced a profusion of pollen and nectar. This sporadic winter flowering event, which occurs every four to seven years depending on seasonal variations, attracted more than 200,000 flying-foxes to Batemans Bay.

2017 has been a more typical year as far as flying-fox comings and goings are concerned. The flying-foxes left the Eurobodalla at the end of autumn, as did all the flying-foxes in the nearby Bega and East Gippsland shires.

As camps on the south coast of NSW were emptying, camps up north were filling up. From June through to August most of the population were in camps in south-eastern Queensland, north-eastern NSW and in the Sydney and Hunter regions.

Just as the flying-foxes left our shire in May, about 100,000 animals arrived in a small town west of Muswellbrook to take advantage of a white box (gum tree) flowering event. A little later, 100,000 visited Tamworth to continue their feast on the white box flowers.

Data gained over the last few years has shown that during the cooler months - May to November - about 60 per cent of Australia’s grey-headed flying-fox population is found in Queensland.

When the weather starts warming up, flying-foxes start arriving back in the Eurobodalla, depending on food availability. In the warmer months - November to May - approximately 80 per cent of the population are found in NSW, with only 15 per cent in Queensland and five per cent in Victoria. Between five and 20 per cent of the population reside in Victoria all year around.

Monitoring the flying-fox population is useful for a variety of reasons but is especially important because they are so often in conflict with humans, while at the same time being of conservation concern.

The large size of flying-fox camps and their very mobile nature means that estimating flying-fox numbers is not straightforward. The national flying-fox monitoring program, a joint project between the federal and state governments and the CSIRO, undertakes quarterly counts at all known daytime roost sites of Grey-headed Flying-foxes across the species' range.