Some puzzling recordings!
A mix of 30 different FM calls. Download here: FM-2016
Some recordings with many harmonics:
Download all 7 files: What? (Right click; Save source as…)
These are definitely coming from some animal moving around.
You can download the wav-file by right-clicking the link below the spectrogram.
4 seconds expanded to 40:
There is a buzz around 1700 ms.
Another recording with traces of buzz in two positions. In the end there is probably a Chalinolobus gouldii