ECOLOGISTS are concerned about the late arrival of flying-foxes to the Ku-ring-gai Flying-Fox Reserve, with experts describing their November absence as “very unusual”.

Grey-headed flying-foxes – Sydney’s most common bat species – are migratory animals. They typically venture to northern NSW and south-eastern Queensland during winter, returning south once the weather warms.  

“Usually the only time the [Ku-ring-gai Flying-Fox Reserve] is abandoned is in the middle of winter,” says Tim Pearson, wildlife ecologist and chairman of the Ku-ring-gai Bat Conservation Society. “But for some reason, they haven’t come back yet.”

Pearson believes that resource shortages, created by the drought and Black Summer bushfires, have caused the bats to deviate from their normal movement patterns. However, fieldwork and research into the long-term impacts of the Black Summer bushfires have been limited by COVID lockdowns and travel restrictions. There is still much we don’t know. 

“The long drought meant that a lot of the eucalypts they feed on didn’t flower well,” he says. “There wasn’t a lot of food to around, so we had pups abandoned and multiple deaths from starvation. After the fires, a lot of their foraging and feed areas were burnt out.” 

Now the bats are turning up in unusual locations, while their traditional camps (such as the Ku-ring-gai Flying-Fox Reserve) are empty.

Although flying-foxes concentrate in different camps across Sydney, ecologists regard them as a single population. They depart at sunset, travelling 20-50km a night to forage for food. 

The sheer distance covered by flying-foxes makes them one of the most important pollinators and seed dispersers on the east coast of Australia. 

“When they’re climbing around in gum trees and licking up nectar, their face and fur get covered in pollen,” says Pearson. “[Because] they fly twenty to fifty kilometres a night looking for food, they will pollinate trees many kilometres away. A lot of the hardwood eucalyptus on the east coast have evolved to depend on the flying foxes for pollination.” 

Flying-foxes are also critical for seed dispersal. According to Pearson, bats chew pieces of fruit while flying, spreading the seeds of native fruit trees across many kilometres. 

“Whatever people think about bats – whether you love them or hate them – they’re a critically important part of our environment,” he says. “Grey-headed flying-foxes are classed as vulnerable in the threatened species category. They’re in trouble primarily because of human causes, such as climate change and habitat destruction. If we don’t actively do something about it, their numbers will continue declining.”

The Ku-ring-gai Bat Conservation Society (KBCS) has protected the Ku-ring-gai Flying-Fox Reserve since 1985. The group has worked alongside Ku-ring-gai Council to monitor bat populations, host community educational programs, and preserve the site through habitat restoration and bush regeneration. 

Pearson is passionate about his work with flying-foxes, describing the animals as gentle, curious and intelligent. However, he warns the public against touching wild animals. 

“If you find a flying-fox in a situation where you can handle it, it’s going to be sick or injured. Like any sick or injured wildlife, it will try to defend itself,” he says. “If you do get scratched or bitten by a flying-fox, seek medical attention immediately.” 

Although the chances of catching a disease from a flying-fox are slim, it could potentially be life-threatening if left untreated. Instead, Pearson calls for a “no touch, no risk” approach. If you find a flying-fox in distress, contact WIRES or Sydney Wildlife.

For more information on the Ku-ring-gai Bat Conservation Society – including bush regeneration volunteering opportunities - go to www.sydneybats.org.au.