Residents stunned after wild weather creates 'insane' sight in Aussie suburbs
Severe winds could have coincided with Australia's annual migration of bogong moths, sending them as far away as New Zealand.
A Sydney jogger was shocked when his pathway was taken over by an “insane" swarm of moths as wild weather pummelled the east coast last weekend. "They were flying frantically everywhere, it felt like I was in a giant swarm. I kept running into them, one went in my eye and one even flew into my mouth", he told Yahoo News.
His encounter in the city’s east is one of several reports of moths being discovered by residents in unusually large numbers in parks and homes around Australia. While many of these are isolated incidents, it’s feared September’s fierce winds may have coincided with one of Australia’s most important natural events — the annual migration of the bogong moth.
“The bogong moths are starting to do their migration now. With that unseasonably warm weather we've had over winter, the bogong moths are likely to be travelling a lot earlier,” conservation biologist Dr Marissa Parrott told Yahoo News.
“We do know from previous times that really strong winds can blow them very much off course," she said. "Even as far as places like New Zealand… and down to Tasmania as well. It was a pretty big event for our beautiful moths to be hit with such an impressive set of winds”.
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Strong winds a 'death sentence' for bogong moths
Bogong moths weigh less than 0.33 grams and are no bigger than the tip of your thumb, but they once migrated across the country in their billions, with their bodies combining to block out the moon. Then in 2021, after a sudden drop in sightings, the species was placed on the IUCN list of threatened species and listed as endangered.
The decline had an immediate impact on the mountain pygmy possum which lies dormant during the winter months. It wakes in spring to feed on bogong moths which fly from feeding grounds in Queensland’s Darling Downs and dry inland regions of NSW and Victoria to Australia’s alpine regions where they lay their eggs.
Parrott leads bogong moth research at Zoos Victoria, which includes monitoring a website called Moth Tracker where ordinary Aussies can log sightings of the species in their suburb and contribute to the protection of the species.
Parrott doubts moths driven severely off course would be able to recover and continue their migration, but it’s too early to say whether the weather has had a significant impact on the species.
“They travel on the warm, high winds, and use the light from the stars, the light on the horizon, and the Earth's magnetic field to migrate,” Parrott said. She added, “Being blown so far off course is likely going to be a death sentence for those poor moths.”
How can Aussies help protect new waves of migrating moths?
With the first wave of migration interrupted it’s more important than ever for Australians to do their bit and help the subsequent attempts by other bogong moths to reach the alps in October, November and even into December.
This can include switching off your outside lights at night and drawing your curtains so moths aren’t drawn from their migration path, and planting native species into your garden for habitat. And if one enters your house, instead of reaching for insect spray, you can carefully take it outside so it can continue on its way.
“If they were blown off course this time, we would hope it would be just a proportion of that population and others will still be starting to travel,” she said.
“It could have had quite an impact on these early cohorts of moths. And it might mean that moths start arriving later in the alps, if they were affected by these winds. But we would hope there will be plenty more moths being able to migrate later this year.”
Is climate change a threat to future of bogong moth?
Unfortunately for bogong moths, weather is becoming more severe and unpredictable because of climate change, which is primarily caused by the burning of fossil fuels like gas and coal — two commodities Australia exports around the globe.
Moth experts are concerned about the impact of bushfire and floods, but extreme drought, like the one which occurred prior to the bogong moth being listed as endangered is the biggest concern.
"[Droughts] are a major problem, because as the ground dries out, there are no broadleaf plants, and the broadleaf plants are what the little caterpillars need to eat and to grow and to turn into bogong moths," Parrott explained.
"And we know they are very susceptible to extreme heat and that's why they spend the warmer months in the alps."
While the moths are internationally listed by the IUCN, Australia is yet to follow suit, and authorities are still weighing up whether to declare it endangered.
"Even if their numbers are creeping back now, who knows when the next major heatwave will hit," Parrott said.
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