The buzz of robotic helicopters is joining the cacophony of animal calls in Australia's rainforests as biosecurity officers step up the war against harmful weeds.
Two Project ResQu unmanned helicopters developed by the CSIRO have completed trial flights in the Daintree near Cairns, locating weeds like the dreaded "purple plague", Miconia calvescens.
The helicopters, used by Biosecurity Queensland, find the weeds using sophisticated imaging technology in the difficult terrain.
CSIRO Biosecurity Flagship Science Director Gary Fitt says access to dense rainforest is difficult for people, but easy for weeds, which get carried in by animals or blown in from gardens or farms.
"Miconia is among the worst of a number of weeds that pose a significant threat to Australia's precious rainforest remnants," Dr Fitt said.
"Unless detected and eradicated early, they can cause irreversible damage to our native plant and animal populations.
"In the biosecurity space effective surveillance is critical - we need to be able to detect incursions quickly and accurately.
"Technologies like the autonomous helicopter or other autonomous platforms provide us with another tool in the fight against these biological invasions."
The helicopters are small enough to fit in the back of a van, are easy to operate and have built in failsafe mechanisms.