Four male koalas have been removed from Victorian plantation forests in Gippsland and transported to Adelaide as part of a breeding program to shore up the future of the species.
Researchers hope the genetically diverse species of Strzelecki koalas will mate with inbred koalas from Kangaroo Island, potentially creating a new generation of disease-resistant koalas.
Professor Chris Daniels from Koala Life, the organisation leading the study, said it was not just South Australia's koala population that could benefit.
"Koalas in Queensland, New South Wales, Victoria, and South Australia all catch a number of different diseases," he said.
"By mixing around different koalas, we wind up with a population that is free of all these diseases … which is really important. That's the aim here."
Thermal technology, drones, portable chlamydia testing kits, and experienced tree climbers were crucial in successfully transporting the koalas to their new home at Cleland Wildlife Park.
"We used drones to identify the animals and we tested the koalas on-site to ensure they were chlamydia free," Professor Daniels said.
"We had very strict ethical considerations to minimise the stress on these animals.
Professor Daniels said taking four smaller males would have a negligible impact on the local population, even though the koalas would never be re-released into the wild.
"Taking [smaller] sub-adult males has minimal effect on the breeding process because often only the bigger alpha males breed with the females [in the bush]."
"Our permit allows us to keep the four males for the rest of their lives. They should be capable of breeding with disease-free females in Adelaide for the next 12 to 13 years."
Program opposed by koala ecologist
The program has been criticised by some leading researchers in the field including specialist koala ecologist Steve Phillips who said the program was unethical with too many unknowns.
"Young male koalas are not tested, they're full of testosterone, they have little regard for the females they're potentially going to be mating with," Dr Phillips said.
"We also know that the recruitment of genes into koala populations is through the females rather than males, so using males in this program means there's a high probability the project will fail.
"Taking just 2–3 per cent of a species could trigger a population decline, and we don't know officially how many Strzelecki koalas are left in that region."
Susie Zent lives in Budgeree and has been advocating for the local koala population for 28 years.
"Before augmenting other koala populations interstate, we'd prefer to get the security of the wild population by protecting its habitat," she said.
The 2018/19 bushfires killed many local koalas in the forest around Ms Zent's home in the Strzelecki Ranges.
"I think the koala numbers in Victoria have been skewed to koalas in Western Victoria where there is an over-abundance, but that's not the case here in [Gippsland]," she said.
The Victorian government said the program had been carefully planned and the impact on the koalas' welfare had been well researched.
"[We have] considered the likely impact on the welfare of the translocated animals, as well as the broader population of these animals at both the source and recipient sites," a spokesperson said.
"Translocation programs must be carefully planned, implemented, monitored and documented to ensure they have the highest chance of success."
Professor Daniels admitted it was an audacious program, but the results were already proving highly successful.
"So far they're settling in really well … we've fed them 'poo smoothies' from animals here, which gives them the bacteria they need effectively avoiding the koala equivalent of 'Bali belly'," he said.
"Yes, this is an audacious project, but so far it's exceeding our expectations. We hope to find out some answers within a year."
