During their migration past Barrow, Alaska each spring, bowhead whales, Balaena mysticetus, are remarkably vocal, producing
- patterned sequences of complex sounds referred to as "songs"
- exchange calls with other whales in a form of vocal interaction referred to as counter-calling
- and repeated calls for an extended period of time or during counter-calling exchanges with other whales.
The illustration below shows a sound spectrogram of 13 calls, part of a bowhead whale "song," recorded during the spring 2000 bowhead census. To hear the recording, click on the spectrogram. The lower-frequency calls (highlighted in pink) were made by a different bowhead whale and are not part of the "song." The faint distant siren-like sounds (highlighted in green) were made by bearded seals, Erignathus barbatus. (To hear more bearded seals, click here.)