Without a doubt, the most interesting aspect of the Humpback whale is it’s song. Only males sing! So it is assumed they use their songs to attract females and discourage other males. These songs last upwards of 30 minutes and are composed of 2 to 10 main components – always repeated in the same order. The song changes slowly over many months but the songs remain recognizable to the one sung last year. Over a period of five years, or so, the songs are completely different.

In any given breeding ground, there’s an almost infinite variety of timbre, volume and frequencies to be heard. All of the males in the area sing the same song. Small variations sometimes occur which are picked up by the other males allowing the songs to evolve over many years into new tunes.

If you watch a male singer, you’ll see him surface for air, then dive under the surface to a depth of 15 metres or so. There with head pointed slightly downwards he begins his song.

Why do they sing? No one has yet deciphered the exact message, but it seems likely that songs attract mates. In the breeding grounds one often sees a female, a calf and an ‘escort’. Many scientists believe that the ‘escort’ is the male singer who accompanies the female waiting for her to come into heat after the recent birth of the calf. If one theory is correct, the etherial songs are mostly designed to sooth and woo the female and only secondarily to warn off other males. Other observations seem to suggest that the songs are a method of establishing a “dominance hierarchy in the breeding grounds.”

SOUND IS EVERYTHING:

All of this is hidden from your eyes. To understand the whale and all other sea creatures you must listen to their sounds. In the sea, you might say that senses are reversed. On land, sight is the most important. You can see much further than you can hear. In the sea the opposite is true – you can hear much further than you can see. So whales, dolphins, fish and other creatures that inhabit the depths have developed very sophisticated sound transmission and receiving organs. That’s why marine biologists make use of hydrophones to study and record underwater sounds.

It has been said, but is still unproven, that humpback whales can communicate from ‘equator to pole’. Not their songs necessarily, but other sounds – grunts, bellows, moans – some sounds that we can hear and some that are below the range of human hearing but which carry great distances – thousands of miles – in deep underwater sound channels. If they do, who are they communicating with? Can a whale in a northern hemisphere breeding ground signal its distant cousin in Antarctica? These are questions that are still to be answered.

One thing that is more likely, is that humpback whales are probably the source of the many legends and myths about sea monsters. Early sailors would have encountered the the eerie songs of the Humpback whale and heard them through the hulls of their ships. The Humpback whale’s voice is very strong – much greater than that of the Gray whale. If you happened to be swimming near a singing whale your whole body would vibrate – an encounter that would be guaranteed to feed a myth for centuries!