Regional towns are bracing for the arrival of flying foxes in plague proportions as one species begins its annual migration through Queensland.
The seasonal change comes at a time when some towns are celebrating the successful relocation of major colonies, and others are living alongside roosts in the thousands.
CSIRO experimental scientist Adam McKeown said little red flying foxes were currently tracking south through Queensland after spending winter in Cape York.
"You can expect to see them turning up in north Queensland towns like Charters Towers around this time," Mr McKeown said.
While the bats were crucial long-range pollinators, the little red species was highly disruptive in residential communities.
"The little reds come in vast numbers," Mr McKeown said.
"They fly out at dusk, sometimes up to 70 kilometres, to nearby bushland to forage.
"They sleep or socialise or mate and come back to the roost in town around 4am.
"It's a bit like having your 18-year-old cousin turn up at your house with all his mates, have a huge party, and then leave a week later."
What attracts bats?
Ingham, Charters Towers, and Townsville have had long-standing issues with little red flying foxes near parklands and botanical gardens.
The noise, stench, and defecation from large roosts are the main complaints from nearby residents.
Mr McKeown said while the mammals were disruptive they were simply in search of food such as fruit trees.
"It's very difficult to move them on until that source diminishes," he said.
North Queensland councils have spent years, and in some cases decades, trying to relocate colonies from urban areas.
The current migration of little red flying foxes has councils increasing their efforts to move bats on.
For the Hinchinbrook Shire Council, the migration comes after a successful relocation of 300,000 flying foxes from botanical gardens in Ingham.
The colony had caused major issues at its worst in 2020, even preventing an emergency helicopter from landing in the town.
"It was a tragic situation," Mayor Ramon Jayo said.
"This was not a nice place to be."
The council has found success using audio, visual, and sensory deterrents and now patrols the town early in the morning to move flying foxes on.
But in Charters Towers authorities are struggling to control a roost of thousands in the middle of the town.
Fireworks, green ants, eagles, and helicopters are among the techniques that have been used in the past.
Mayor Frank Beveridge hoped an oasis designed for flying foxes near the town would be a successful alternative roosting site.
"It was an old mining site, now mango trees grow there, it's fenced off, there is a small dam and solar lights, so it looks like a small town," he said.
"I'd like to think the bats may settle there once they are moved on.
"We're looking to use shotgun noise and water in the afternoons and early in the morning."
How can bats be relocated?
Biodiversity Australia consultant Carl Robinson claimed the business had a high success rate with clients looking to relocate a flying fox roost.
But Mr Robinson said the key was in proactive relocation methods.
"Weighing up what are the different attributes that flying foxes really like in this roost, then trying to find a place nearby where they are going to want to be," he said.
"Then we start to train the flying foxes, the same way you would train your dog at home, with positive and negative reinforcements."
Mr Robinson said in one case at Miriam Vale it took two years to relocate a colony of flying foxes that had been roosting over a preschool.
"We'd been through all of the traditional tools — we've used the smoke, we've used the gas cannons, we've used speakers," he said.
"What we rely on fairly heavily is simple audio, visual and sensory queues, we use them in a range of different scenarios to herd the flying foxes from an undesirable location."
When it came to roosting in backyards, Mr Robinson said residents had to act in a lawful manner.
"If a resident were to get flying foxes in their backyard, they first have to determine if that is a roost — a quick search online gives you that information," he said.
"The best thing then to do is contact the local council to see what work can happen.
"It may not even be a relocation, it may be trimming a tree, it may be creating a buffer, it can mean covers for cars and diverters for the runoff on water tanks."
