Flying Fox Supporters Australia founder Jillian Snell is concerned about the time it has taken to modify the plan. “I don’t want thousands of bats to die this summer because of bureaucratic red tape,” she said. “The sprinklers sit on the surface of the trees. It’s improbable they’ll have any effect on the landscape.”
It is estimated about 100,000 Australian bats perished in the last bushfire season due to the extreme heat, fire and depleted food supply. There are just 300,000 grey-headed flying foxes left nationwide and they are endangered.
In December 2019, 5000 of Victoria’s Yarra Bend Park’s 30,000 flying foxes perished in a single heatwave. Within three months, the park responded by erecting canopy sprayers so the bats could keep cool.
Scientists estimate up to 30 per cent of the flying-fox habitat was destroyed in last year’s east-coast bushfires.
The grey-headed flying fox plays a pivotal role in Australia’s biodiversity by pollinating the land and regenerating our forests. Unlike smaller pollinators such as birds and bees, flying foxes can spread large seeds and transport pollen over vast distances.
The University of Sydney’s school of biological sciences associate Kerryn Parry-Jones said “water sprinklers placed up trees is an extremely efficient method of spraying flying-foxes during a heat stress intervention”, and “considerable” death happens when intervention does not occur.
Although Parramatta’s flying foxes roost in trees on either side of the river, in extreme heat they are not able to successfully cool themselves by skimming the body of water without getting heatstroke.
Despite their similar make-ups, Yarra Bend and Parramatta Park have different flying-fox protection mechanisms. Yarra Bend’s sprinklers cover 20-30 per cent of the park. It has ground sprayers to dampen vegetation and lower the ambient temperature, mid-level canopy sprayers to cool the non-juvenile flying-foxes, and over-canopy sprayers that allow the bats to fly through and cool off during the day.
Ms Snell cannot reconcile why Parramatta has not been similarly proactive but acknowledges there are various stakeholders affected by the sprinkler plan.
“It’s not that Parramatta Park doesn’t want the sprinklers but they’re not the only body who has land where the colony roosts; there’s Parramatta Council, there’s the Park Trust, there’s Cumberland Hospital, there’s Infrastructure NSW. I understand they must all be consulted, but we need to act fast,” she said.
A spokesperson for Parramatta Park’s Trust said it is looking closely at a range of sprinkler systems, including the Yarra Bend system, and intends to “mimic” the way it works upon completion of their investigation.
Amelia McGuire is a junior producer at The Sydney Morning Herald.