A koala colony in the New South Wales Blue Mountains will become one of the most important in the country due to climate change, according to researchers.
The marsupial's population size in Wollemi and Kanangra-Boyd National Park is not known but is believed to have risen in the past decade, despite the species struggling nationally.
Last year, the Commonwealth government listed koalas as endangered, while a NSW parliamentary report found they could be extinct across the state by 2050.
Climate change is a major threat to the species' existence, contributing to an increase in bushfires and heatwaves.
Science for Wildlife conservation ecologist Lachlan Pettit is investigating the suitability of the Blue Mountains area for avoiding the worst of the rise in temperatures.
"During a heatwave, koalas become heat stressed and that can be really bad for the animals' health. We can see high mortality rates," Dr Pettit said.
"The habitats in the Greater Blue Mountains World Heritage Area are critical for koalas to use because there are deep gullies [and] old growth trees which provide a lot of shade and cooling."
Other koala colonies in coastal regions are more likely to feel the effects of climate change compared to those in the Blue Mountains populations, he said.
"Those that are down in low-lying areas that may not have access to the same resources in the landscape to cool them down may feel the impacts of heat more often," Dr Pettit said.
"It might be that populations in areas like the Blue Mountains are the ones that persist into the future."
Hope yet for koalas
According to the World Wildlife Fund, the population of koalas in NSW has fallen by 62 per cent since 2001.
The decline is being driven by bushfires, disease and, in particular, increased habitat loss through development, according to Science for Wildlife executive director Kellie Leigh.
"Development has really been a key threatening process behind the decline of koalas right across the species range," Dr Leigh said.
"All those predictions of extinction that you see in the news are modelled on habitat loss."
However, the Blue Mountains area is listed as a World Heritage site, providing greater protection for the species.
"We have found a real story of hope because there is a million hectares of World Heritage Area that is protected," Dr Leigh said.
"We are finding good numbers of koalas and still have plenty of places to look.
"Together with the diverse habitats, a lot of different trees that they can choose to eat, this has got the potential to be a stronghold for koalas into the future."
