A major portion of our 2009 field work focuses on recording singers
Humpback whale song was first described by Roger Payne and Scott McVay (1971) and by Howard Winn, Paul Perkins and T.C. Poulter (1970). Payne and McVay descrbied the hierarchical structure of song, as illustrated in the figure below. Each individual distinguishable part of sound is called a unit (analogous to a note in human music). THe units make up subphrases, which are repeated in phrases, which are repeated in themes. multiple themes make up a song, which itself can be repeated multiple times in a song session.
The hierarchical sructure of song. (redrawn from Payne and McVay (1971))
In addition to this complex structure, we have learned that all of the animals in a population sing fundamentally the same song, although there can be small difference between individual animals. To make the situation even more confusing, the structure of humpback whale song is continuously evolving. To illustrate the first phrase in the figure above has six frequency upsweeps (these units look like a “J”). Over the course of the season, animals might add more “J”s, or their frequency contour (shape) could become more or less steep over time. Thus withing a period of about five years, all of the themes of this year’s song will be replaced with new ones.
It has been established that all singers are male, although females produce other calls on the feeding grounds, such as in cooperative feeding groups.
Examples of Song Structure
Theme 2 (click on spectrogram to play)
Theme 3 (click on spectrogram to play)
Theme 4 (click on spectrogram to play)
Hypotheses of song function
Over the more than 30 years since song was first described, many hypotheses for its function have been advanced. Today, most researchers accept that song functions as an acoustic display. The predominant question concerns the intended audience: other males, females, or both?
PAYNE, R. S. and S. MCVAY. 1971. Songs of humpback whales. Science 173: 585-597.
WINN, H. E., P. J. PERKINS and T. C. POULTER. 1970. Sounds of the Humpback Whale. Pages 39-52 7th Annual Conference on Biological Sonar and Diving Mammals. Menlo Park, Ca.