Thousands of rainbow lorikeets and hundreds of flying foxes have been hospitalised in Queensland in the past year with a mysterious paralysis that can affect the animals’ ability to fly, swallow and even breathe.
Lorikeet paralysis syndrome has struck birds in Queensland and New South Wales since at least 2012, and a similar syndrome was identified in flying foxes five years ago.
Scientists don’t yet know whether the two syndromes have the same cause, but they overlap geographically and cases occur seasonally, spiking each December and January.
In 2024, the RSPCA admitted 1,079 flying foxes to its wildlife hospital in Wacol, Brisbane, and nearly 8,000 lorikeets across two facilities, said a wildlife veterinary director at the hospital, Dr Tim Portas.
“Historically, we would see 2,600 lorikeets and 200 flying foxes in any given year,” Portas said.
Not all the admissions last year were due to the syndromes but Portas said “the most common reason that we have lorikeets admitted to us, and certainly that increase with the flying fox [numbers], was predominantly due to paralysis syndrome”.
The wildlife hospital saw an unusually late peak last February, with 195 lorikeets admitted in a single day, and another spike in December. “We’ve seen well over 100 animals a day in December,” Portas said.
Across the border, the NSW Wildlife Information Rescue and Education Service (Wires) said it had not yet seen an increase in animals affected by the condition, but it was bracing for a spike in the coming weeks.
In both lorikeets and flying foxes, the conditions cause hind leg and flight paralysis. “They might initially appear weak and unable to fly,” said Dr Alison Peel of the University of Sydney. “The lorikeets might keep hopping around on the ground, or the flying foxes end up falling low in the branches … they can’t climb back up again like they normally would.”
Peel called the syndromes a “really significant welfare issue”, because severely affected animals can lose their ability to blink, swallow [or] breathe, resulting in suffocation or dehydration.
“The animals that don’t die need total nursing care,” Storm Stanford, a flying fox carer at Wires, said. “You start off having to use injectable fluids to keep them going long enough before they’re able to use their tongue … to actually be able to drink [by] themselves.”
Peel said most animals, if not too severely affected, would survive, requiring several weeks of supportive care to recover and regain flying fitness.
“The thought at the moment is that there’s some common cause,” said Peel, who co-leads the paralysis syndromes working group, which is seeking to identify the culprit. “There’s no indication that it’s anything spreading from animal to animal.”
“We seem to find it happens in summertime; some years are worse than others, there’s loose association with heavy rain.
“It could be some naturally occurring fungal toxin or bacterial toxin like [botulinum toxin],” she said, suggesting that changing environmental conditions may have increased the toxin to levels not previously present.
She encouraged anyone who spotted an unwell animal to call their local wildlife rehabilitation group or veterinarian instead of picking it up themselves.
Pallas said the syndromes presented in a similar way to water fowl affected by botulism, which occurs when the birds inadvertently ingest botulinum toxin. The potent nerve toxin, commonly known as botox, is produced by Clostridium botulinum bacteria.
Article by:Source Donna Lu Science writer
