CHARACTERISTICS, COMPOSITION, & BEHAVIOR
The humpback whale song is a series of sounds that typically lasts 10-15 minutes and is repeated over time.
The song consists of several different themes (often four to six) sung in a continuous loop. Each theme is composed of sound units distinctly arranged as a phrase, which is repeated for several minutes. The singer progresses through each of the themes (all with different combinations of units/phrases) until he has worked through the entire song. If the song has four themes, the singer will sing themes 1, 2, 3, 4, usually surface to breathe, then dive and start all over again. A song session (continuous singing) can last hours.
In the graphic above, the song themes are given different colors. All singers in the population follow the same pattern of theme composition and progression. Even the amount of time spent on one theme is similar. During this period (January, 2005) about 70 percent of the Hawaii song consisted of theme 3 (yellow).
Whale Song Spectrographs
This whale would sing each of these themes in orders shown, surface to breathe (after blue theme) then dive and begin again with the pink theme. Click on the audio-files below to hear the sound of the phrases in each theme.
UNIQUE CHARACTERISTICS OF HUMPBACK WHALE SONG
The humpback song is unique in that it gradually changes in composition as it is being sung. That is, small changes in song units will change phrase composition and, in turn, entire themes (phrase ‘aaab, aaab’ in Theme 1 may change over time to ‘ab, ab’ and then eventually drop out of the song altogether). Yet all the singers in a population sing the same version of the ever-changing song at any one time. It is not known how this is achieved.
VARYING RATES OF HUMPBACK WHALE SONG CHANGE
The rate of song change varies – the reason is unknown. Humpback songs studied in Bermuda and Hawaii changed gradually, with the entire song composition turning over in four or five years. However, song studies in the South Pacific observed more rapid changes, with the potential for whales to adopt an entirely new song from one year to the next.
SINGING BEHAVIOR
Here is what we know about singing humpback whales:
- Singing is a male behavior pattern. While female humpbacks may produce other sounds, they are not known to sing songs (the biological definition of a song is repeated sounds over time).
- Singers are most often lone adult males. In a minority of encounters, a singer may have an adult companion that may be either male or female.
- It is not known at what age males begin singing, but it is presumed to relate to sexual maturity.
- Singers are often stationary while singing in Hawaii. However, some singers may also sing while moving around the breeding grounds, as well as during migrations.
- Singing seems to peak during the winter breeding season, but singers are known to begin singing during the fall in higher-latitude summer feeding areas and along the migration.
- A typical singing posture is a male singing in a tail up and head down posture, at an angle of about 45 degrees. The tail is generally about 20-40 feet beneath the surface. See the slideshow below.
- Singing typically continues until:
- The singer is joined by another adult whale or a pair of whales;
- The singer stops to join a passing group that includes a female – either a competitive group composed of a female and several males, a male-female pair, or a mother and calf with or without a male escort.
