- Koala colony rebounded three years after the experimental research began.
- The population was at "immediate risk of local extinction".
- Federal government to consider research and whether to fund its wider rollout.
A Brisbane koala colony that was near collapse has not only recovered but more than doubled through a new way of dealing with the disease that threatens the endangered animals: chlamydia.
In 2019, 60% of the Belmont Hill Reserve colony was infected and there was just one healthy breeding female.
"The population was crashing," University of Queensland Head Researcher Sean FitzGibbon said.
"Now, we've got numerous females that are reproducing ... and there's now the likelihood that the colony will exist long into the future."
Dr FitzGibbon led a team of three, including two ecologists and a wildlife vet, to develop the new management approach.
They hope to roll it out to at least a dozen colonies in steep decline, but the approach is costly and time consuming.
A huge amount of time, money, and effort goes into treating sick koalas around Australia, but efforts are largely ‘fingers crossed’, opportunistic, and ‘ad hoc’ in nature.
The researchers took what they believed to be the first ‘systematic’ approach to wiping out the sexually transmitted infection and reviving the population.
Sick koalas are treated in the field by a vet, who assesses whether they're infected.
Some of them needed to be euthanised straight away. The aim was to rid the colony of infected animals.
Despite the colony plummeting to just seven since the program's start, with successful breeding in the wild and the injection of four healthy koalas rescued from other areas, the population has doubled to 15 in just two years.
“Over one to two generations of breeding, you start to get an acceleration, as you don't have those infertile animals impeding the population growth,” vet Amber Gillett said.
"We don't want to claim we've wiped chlamydia out entirely, but we may have.
"There's always the possibility that there is another koala out there that we haven't found."
The Belmont Hill Reserve is almost a closed colony, hemmed in by suburbia, a motorway, and a busy thoroughfare.
Researchers say the project could work in other populations that were similarly closed off and therefore almost negating the risk that chlamydia would be re-introduced.
The program would not be as successful in a sprawling national park.
The researchers also examined if there are areas in the reserve that the koalas gravitate to, if and when they cross roads, and what each koala's travelling range is (to determine how much bushland would be needed to sustain one).
The researchers are now calling on the Queensland government and local councils to work together to get koala survey teams to take a more strategic approach to treating sick koalas and conserving them.
A key to the program’s success has been having a vet accompany the survey team and do on-site assessments and detecting the disease even at low levels.