Thermal drones locating elusive northern NSW koalas in area scorched by bushfires

Heat sensing drones are helping to locate koalas on NSW’s far north coast.(Supplied: University of Sunshine Coast)

By Bronwyn Herbert

Posted , updated 

Thermal drones are being hailed as “game changers” by ecologists searching for koala populations after a surprise discovery in north-east New South Wales.

Drones used in a survey on the Ngunya Jargoon Indigenous Protected Area (IPA) near Wardell over the past six months revealed a population of 32 koalas.

Threatened species ecologist Maria Matthes said the surrounding area was scorched by bushfires in 2019 and inundated by floodwaters earlier this year.

“We didn’t know exactly how well the koalas were doing after the fires and whether they had found sufficient food or not,” she said.

The high-detail drone imagery clearly shows koala movements in the forest trees and picks up the heat signature of their droppings, known as scats.

a koala holding onto a branch surrounded by gum leaves
More than 30 koalas were located at Wardell during the survey.(Supplied: International Fund for Animal Welfare)

Veterinarian Romane Cristescu, who has been leading the research team of ecologists and rangers, describes the technology as a “game changer” with a lot of potential.

She said the traditional method of walking through the bush looking in trees and for scats on the ground was “hard work”, with studies showing up to three quarters of koalas could be missed.

“If you miss three out of four koalas, the data is really barely usable,” Dr Cristescu said.

woman inspecting the paws of her detectiond dog in bushfire affected area
Romane Cristescu is leading thermal drone and detection dog surveys in bushfire-affected areas.(Supplied: International Fund for Animal Welfare)

Covering a bigger area

Dr Cristescu said the drones allowed researchers to cover a much bigger area as they “fly quicker than we can walk”.

“They don’t care about the terrain, but also they are much more accurate than the human sight,” she said.

“Although koalas are really good at hiding, they’re very hot mammals like us and in a eucalypt tree that is much cooler, the koala really stands out.”

people leaning in to look at a collection of koala scat with the sniffer dog close by
Rangers, aided by sniffer dogs, help locate koala scats for further genetic testing.(Supplied: International Fund for Animal Welfare)

After the drones revealed koala activity, detection dogs were released into the IPA to help locate fresh scats.

“We take the scats back to the laboratory and we do molecular analysis and we get all sorts of information that is important for management,” Dr Cristescu said.

Researchers hope the results will help provide a more detailed understanding of the health of the koalas living in the coastal pocket.

Koalas needing treatment

Despite the relatively healthy numbers, some of the koalas required treatment and were diagnosed with chlamydia.

woman wearing a high vis shirt looking up into the tree searching for a koala
Maria Matthes says the area near Wardell was chosen because it was damaged in a 2019 bushfire.(Supplied: International Fund for Animal Welfare)

Ms Matthes said the sick koalas were taken to the nearby Friends of the Koala hospital at Lismore.

“We know that when koalas get stressed, they can get diseased,” she said.

“So having the health checks was one of the important aspects of this survey work.”

The work has been a collaborative project involving the Jali Local Aboriginal Land Council, NSW Department of Planning and Environment, Ballina Shire Council, University of the Sunshine Coast Detection Dogs for Conservation, International Fund for Animal Welfare, and Friends of the Koala.

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