Humpback Whale Songs

Humpback whales produce the longest and most varied songs in the animal world. These intricate vocalisations range from high squeaks to low guttural growls. These songs are produced by moving air back and forth through body passages.

Analysis has shown that the sounds produced are organised into long sequences. Each sequence normally lasts 10 - 15 minutes and can be repeated without pause, for hours. The sequences are always arranged into cycles characteristic of each population, so that all humpbacks in one area sing only the local song. These songs evolve with time and each year the song is a little different, but every change is picked up and incorporated into the current sequence.

Humpback whales typically sing at sound frequencies of between 20-3000 Hz and occasionally produce frequencies as high as 8000 Hz and lower than 20 Hz. The average human ear can sense between 150-16 000 Hz, so many of the very low frequencies are out of our range and evidence suggests that the large whales create 'infra sound' lower than we humans can hear.

Singing is more common and maybe confined to the breeding season. Only male humpbacks sing. The song may function as a sexual display, advertising the presence of a breeding mate and keeping a family group together, but the complexity of the song suggests there is more to it than that. In addition to the ritual announcement, there may be new information and/or the preservation of old information. These haunting sounds may travel kilometres under water and can be heard above the surface.

Humpback whale songs constantly evolve throughout the mating season. As a theme changes, all the whales of the given group make the same changes in time with the others. This is one of the remarkable mysteries of the animal world.

It was once thought that Humpbacks are stationary when singing but recent evidence suggests that Humpbacks which migrate along the Australian coastlines may sing as they are travelling. Humpbacks also produce a variety of social sounds made by males and females.

The larger baleen whales communicate with similar ability and produce sounds far outside the range of human hearing. Recently it was discovered that Blue whales also sing but their 'songs' are almost all below the range of human hearing and very long indeed. A blue whale song may last ten hours with as much as twenty minutes between notes. Why they do this is a mystery.