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.
Two bats cruising:
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.
And this is an example showing a feeding buzz: