NSW Primary Industries uses heat-seeking drones to conduct Port Stephens koala survey

Elusive: Drones successfully completed a koala survey.
Elusive: Drones successfully completed a koala survey.

Drone technology designed to find lost bushwalkers has been adapted to help locate shy koalas hiding in the treetops of Port Stephens.

NSW Primary Industries and University of Newcastle researchers recently completed a survey of the region's koalas using the heat-seeking unmanned aircraft.

Department of Planning, Industry and Environment Senior research scientist Adam Roff said the drones had proven to be more accurate and efficient than traditional ground-based methods.

"Using drones, what we have found consistently is that we find twice as many koalas as spotlighting teams working alongside us on the ground," he said. "Our small teams use a third of the people and find double the number of koalas."

The drones, equipped with thermal cameras, are flown at night when ambient temperatures are coolest.

They survey in parallel lines to search the entire forest canopy.

If a detection is made, the drone stops to determine the size of the signal. A smaller infrared detection usually indicates small creatures like possums and bats.

The drones also monitor the kind of movement detected.

If the infrared blob moves quickly, then it is less likely to be a koala.

The location of each detection is marked by the drone with GPS so that the drone, or a ground team, can head back at daybreak to verify if it is a koala.

Flying 70 metres above the ground at 30 km/h, each drone can survey 100 to 200 hectares per night.

"People can only walk at 5 km/h; the drone is an expert koala spotter," Dr Roff said.

The drone survey program is part of a $193.3 million state government package which aims to double the number of koalas in NSW by 2050.

New Australian Koala Foundation data shows koalas are in rapid decline around Australia, with 30 per cent of the iconic species lost in just three years.

The latest figures reveal a three-year decline as high as 41 per cent in NSW and the ACT, 37 per cent in Queensland, 31 per cent in SA and 16 per cent in Victoria.

Australia's koala populations are now estimated to be between 32,065 to 57,920 - down from 45,745 to 82,170 in 2018. "Land clearing is lethal to koala populations," AKF chair Deborah Tabart said.

"Over the past few years, we have seen huge land clearance particularly across NSW and south east Queensland, for farming, housing development and mining."

The AKF tracks populations with the Koala Habitat Atlas and estimates koala numbers in each of the 128 federal electorates that have, or did have, koalas since white settlement.

The numbers show the koala is now extinct in 47 electorates and only one, in the South Australian electorate of Mayo, has more than 5000 koalas.

Some regions have remaining populations estimated to be as small as just five to 10 koalas.

Ms Tabart says every federal politician in these electorates is on notice to protect not only the koalas in their electorate but the habitat needed for their survival.

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