A recent study by the Department of Environment and Climate Change found the koala, the grey-headed flying-fox and the green and golden bell frog are under threat in Wollondilly.

The study identified 53 out of 550 native fauna species as threatened in the Sydney metropolitan catchment area.

Landcare Australia CEO Brian Scarsbrick said he was ``staggered'' that one in 10 of our wildlife species were under threat in the Sydney area.

``This alarming study is a call to arms for anyone interested in preserving our wildlife to help protect and restore the natural habitat of our threatened indigenous wildlife,'' he said.

The study listed bushfires, public visits, trail bikes, horse riding, weed infestation and water quality as some of the main threats to wildlife in the Wollondilly area.

The catchment authority said the Dharawal conservation area near Appin was ranked the third most important wildlife site in Sydney because it supported priority habitats grassy woodland, heathland and freshwater wetland.

Visit www.landcareonline.com/directory to find your nearest group.