University of Sydney researchers using GPS collars fitted to koalas found the vulnerable mammals were most at risk from living in small patches of forests near roads and train tracks, a university release said Monday.
In 2006, prompted by concerns koalas were in serious decline in New South Wales, the state government commissioned a population survey.
The study identified one area -- near the town of Gunnedah -- where the koala numbers were high and increasing rapidly.
"We knew a massive tree planting effort had taken place in the 1990s, so we wanted to know if that campaign had led to an increase in koalas and whether we could use this information to guide areas of koala decline," Mathew Crowther of Sydney's school of biological sciences said.
Results showed that koalas were actively using the newly planted trees in Gunnedah.
"It is encouraging to see that koalas can use a variety of trees, including newly planted eucalyptus, and are not restricted to old-growth forests," Crowther said.
"The fact that the koalas in Gunnedah are using trees planted in the 1990s means that simply planting the right trees could expand their habitat and mitigate some of the current problems we are seeing with koalas living in such fragmented patches of forest," he said.