Austronomus australis     AUAU

Former Tadarida australis

Distribution map based on Atlas of Living Australia

Powerful, audible just above 10 kHz.

This is the only bat in NSW that emits calls below 15 kHz. But sometimes Saccolaimus flaviventris can produce a “low harmonic” between 9 and 13 kHz.

In the open, flat and sloped around 10 kHz. In search mode there is often some frequency variability a bit above 15 kHz. When in active hunt mode, harmonics are produced to help reaching frequencies as high as 50-60 kHz.

Here is a typical recording of the searching phase.

AausM000624, ZC, 161108 22:46:47, Megalong Valley, Google Earth

Two bats cruising:

AausM000267, 161212 23:04:34, Megalong Valley, Google Earth

Here is one in active hunt/attack together with another bat, probably Vespadelus darlingtoni.
Note the harmonics! They effectivly creates FM-components up around 70 kHz. Good for focusing and navigating in clutter! Note that there are some calls overloading the recorder.

AausM000212, 161104 22:03:40, Megalong Valley, Google Earth

And this is an example showing a feeding buzz:

AausM000402,161119 21:03:19, Megalong Valley, Google Earth