Fig S6 Multiple humpback whale singers chorusing

Fig S6 A spectrographic view of songs from different humpback whales overlapping intensely. Different song units are easily identifiable from this spectrogram, also, a trained observer can recognize different phrases occurring in this recording. However, it is not clear where an individual whale starts and ends a phrase nor when that same whale starts singing a new phrase or repeating the previous one. That is due to either similar phrases sung at the same time resulting in a cluster of similar song units where it is impossible to identify what singers sang which phrase and units, or where louder units mask weaker song units, thus, making it unclear where the weaker phrase starts and/or ends.