RED CROWNED TOADLET Pseudophryne australis (Gray, 1835)
This distinctive small frog is found only in the sandstone hill country to the north, south and west of Sydney, within a radius of about 150 kms.
Averaging 3 cm in length it is usually found around seepage’s on hillsides, associated wet rock crevices and under nearby rocks.
In these situations this species often occurs in colonies numbering up to 50 individuals, where they can often be heard calling to one another. The eggs laid are firm, and deposited in moist crevices or next to small ponds, often in a crude nest, where the young tadpoles live after hatching. It is assumed that from egg to young frog takes about three months, although young toadlets are rarely seen.
The call of this frog is a harsh 'squelch' sound. However as this and most other species of Pseudophryne have lost the outer and part of the inner ear, it is a mystery as to how they actually hear airborne sounds.

The above was from the book Australian Reptiles and Frogs by Raymond Hoser and now available on a fantastic CD-Rom along with a vast amount of other information, papers and the like on reptiles, frogs and other wildlife.