The findings of a parliamentary inquiry into koalas has led to renewed calls for a special national park in south-western Sydney and protective measures along Heathcote Road.
The NSW upper house inquiry found koalas could become extinct in NSW by 2050 without urgent government intervention to protect their habitat.
The report recommended an urgent survey of koala numbers following last summer's bushfires and for the government to "urgently prioritise the protection of koala habitat and corridors in the planning and implementation stages of urban growth areas".
Sutherland Shire Environmental Centre said there were "kill zones" along Heathcote Road, which should be looked into by Sutherland Shire Council and state MPs.
The centre also called for the disused Cawley's Bridge over the M6 motorway to be turned into a safe wildlife crossing.
State Labor MLC Mark Buttigieg, who was a member of the committee, said it was vital a Georges River Koala National Park be established.
In 2018, wildlife advocates in St George and Sutherland Shire said six koalas had been killed on Heathcote Road in the last year, including two within a week.
They called for measures to be taken to protect the colony who move between the upper Georges River and the western fringe of the shire.
Secretary of Georges River Environmental Alliance Sharyn Cullis said the colony, which was the only one in NSW free from disease, was believed to number about 400, with hundreds more in the Holsworthy military reserve
The Leader reported responses from the various authorities on what they were doing on the issue.