Because spotting is slow and expensive, estimates of koala populations vary wildly.
Photo: 123RF
As a result, it's difficult for scientists and conservationists to know just how many koalas are out there.
In New South Wales the population could be around 36,000, but last year's NSW parliamentary inquiry heard those figures are "outdated and unreliable" and the real number could be half that.
The same inquiry recommended exploring the use of drones to gain a more accurate head-count.
Happily, researchers from the University of Newcastle were already testing drones in collaboration with the NSW Department of Planning, Industry and Environment.
Their study, published in the journal