Rocky River Frog (Litoria lesueuri)
The Rocky River Frog is found locally only in the Lerderderg Gorge (not quite in Melton). They have also been heard in the Brisbane Rangers. It can be distinguished by its large head.
Details of these frogs can be seen on: http://frogs.org.au/frogs/species/Litoria/lesueuri & http://frogs.melbournewater.com.au