Note, we never published this paper because Mac was uncertain that call type 2 could be attributed to Bufo and that it might have been an artifact. It is very low amplitude and the sound level has to be increased greatly for it to be audible. However, at the time when I was in the field listening (with an amplified signal and amplified headphones), the type 2 call was very conspicuous against the very quiet background noise levels. I never got a chance to do any more recordings with Bufo marinus. Should be easy to do in areas where they occur. To clarify, even if Bufo was the sound source we never assert that the type 2 call was actually a vocalization, it may well have been associated with some type of movement or physiological process (egg extrusion? amplexus?, or even from the tadpoles).

Data First record of underwater sounds of the cane toad (Bufo marinus)