A growing colony of grey-headed flying foxes, with wingspans reaching up to 1.5 metres in length, have been wreaking havoc on Adelaide’s power networks, causing around 40 power cuts since January alone.
The 25,000-strong colony declined in numbers due to heatwaves in recent years, but have since rebounded. Grey-headed flying foxes are from the megabat family and are the largest bat in Australia.
According to a spokesperson for SA Power Networks, the power outages caused by the bats becoming entangled in power lines can last between two to 25 hours.
Although the colony often reaches 25,000, a lack of heatwaves during this summer in Adelaide have led to a much larger number of pups surviving than usual. The juvenile bats, unsteady on their wings, appear to be causing most of the problems, said an expert.
Jason van Weenan, an ecologist with the South Australian government’s Green Adelaide programme, told the Guardian that as the young bats head on their first “foraging runs”, they are “getting into strife on the power line infrastructure”.
He said the frequency of power cuts is “particularly noticeable” this year due to the large colony size and an unusually high number of young surviving.
SA Power Networks tweeted on Wednesday: “Adelaide’s bat colony has grown to over 25,000 leading to more power outages as they search for food overnight.
“We know this is frustrating and seek to minimise the impact on the network, and the colony, and are looking for your fresh and cost-effective ideas to do this.”
Bat-sourced power outages are a regular occurrence in Adelaide and according to the firm, are difficult to take targeted defensive action against due to their irregular flight paths and widespread impact across the network.
The animal’s wide wingspan can collide with power lines and pole top equipment, including insulators, transformers and switches. They can also trigger an outage when they come into contact with lightning arrestors.
As of February, SA Power Network said animals are involved in 6 to 7 per cent of power outages, and the increase in cuts can be attributed to the rapid growth of the bat colony.
Paul Roberts, a spokesperson for the network, told the Australian Broadcasting Corporation there are no known schemes to fix the issue and engineers will be “trying to [plug] gaps for a while. The network has been in discussions with researchers from Adelaide University in hopes of finding a more permanent solution to the problem.
