Despite Facing Possible Extinction, Koala Numbers Are Booming In One City

Experts say the country's koala populations are falling due to habitat loss and global warming, but a fertility program for the marsupial has kicked off in South Australia.

While it's believed koalas might be extinct on the east coast in 30 years, their ballooning numbers in Adelaide are wreaking havoc on native vegetation.

New research has calculated around 150,000 koalas in the Mount Lofty Ranges and Adelaide Hills, with 50,000 on Kangaroo Island alone.

A birth control program for SA's koalas has now been implemented to prevent over-browsing, where herbivore animals feed on leaves, plants and shrubs.

READ MORE: 'Australia's Orangutan': Urgent Calls To Protect The Vulnerable Koala

READ MORE: Koalas Could Go Extinct Without Urgent Help, World Wildlife Fund Warns

"Over-browsing deteriorates the health of the trees, which are their food trees, and those trees eventually die," Natural Resources Adelaide and Mt Lofty Ranges regional director Brenton Grear said.

"The outcome is eventually the death of the trees but also potentially some pretty catastrophic deaths of koalas through no food source."

The fertility program reportedly involves trained staff hoisting koalas down from their trees, giving them the hormone implant and then letting them go.

The process takes less than 10 minutes and "has been developed to minimise disturbance" to the koalas, Grear told the ABC.

He cited evidence the implants can be effective throughout the remainder of the koala's life, even if they are removed.

A resident gives a drink to a wild, heat-stressed koala in her backyard on December 19, 2015 in Adelaide during an extreme heatwave. Image: Morne de Klerk/Getty.

Despite the numbers listed above, the Australian Koala Foundation (AKF) has estimated there are no more than 80,000 koalas left in the country.

The AKF has monitored the 128 federal electorates of Australia since 2010 and found 41 of them have no koalas, according to a recent press release.

“The AKF thinks there are no more than 80,000 koalas in Australia. This is approximately one percent of the eight million koalas shot for fur and sent to London between 1890 and 1927,” said Deborah Tabart OAM, AKF Chairman.

While estimates differ on just how many koalas remain in the wild, experts agree koala populations are falling due to habitat loss and global warming.

For example, koala populations in parts of Queensland and New South Wales have declined by as much as 80 percent due to climate extremes like severe droughts and heat waves, according to biologist Christine Adams-Hosking from the University of Queensland.

Other threats to the species include disease and deforestation.

With AAP and CBS.