Chalinolobus gouldii     CHGO

Characteristic frequency between 25 and 34 kHz. Consecutive pulses often alternate in frequency and sometimes shape when in “typical” search phase. The upper pulses may drop out when “cruising” in open spaces leaving only the lower pulses.
Good quality calls should not be confused with any other species.


CgouM000741, 161128 00:15:53, Megalong Valley, Google Earth

Detail of the above:

Feeding buzz: