For a long time, it was believed that whales cannot sing since they do not have functional vocal cords. Researchers believe that the sounds are produced by pushing one air stream in different directions within their respiratory tract, and another study suggests the thorax may be used. In the 1950's, their singing was discovered when the United States Navy experimented with hydrophones. From then on, their singing has been analyzed by scientists, who describe it like this: the whales go to a depth of between 45 & 130 feet and get into a certain position when they sing. They may remain motionless with their head downward, or are sometimes seen traveling, either alone, or with another male and a small percentage are observed traveling with a female and her calf. Kent Noonan, our engineer, made the following experiences: "There was a mother/baby/escort pod traveling toward me while I was out in my kayak with my hydrophone. The mother and baby veered to one side and swam by me underwater. The male swam directly under me only a few feet down and continued singing uninterrupted. I was listening as he approached and it became so loud I thought my ears would burst. I tore the headphones off and could still hear it very loud as he passed under me only about 8 feet down. Another time I saw a large male singing while I recorded nearby. He was slowly swimming in a large circle under a mother and baby. He went in a circle perhaps 100 yards across at a rate of about 15 minutes to go around it, about 50 to 100 feet down. This is the recording I call "Kalama Lullaby" because it seemed he was making a cradle of sound for the mother and baby to feel protected in, while they snuggled on the surface in the sun"

We can distinguish several kinds of sound, the so-called "social sounds", "communicative sounds between mothers and calves", the "feeding siren" or call" done in the feeding grounds, and the classic "whalesongs" we are engaged with. With all the studies being done each year, perhaps even more types will be uncovered!

• social sounds
  These are short, quick sounds which can hardly be heard (or not heard at all!) under water with the human ear. These sounds can only be picked up with special hydrophones which would have to be close to the whales and pointed directly at them. The social sounds are used to communicate, especially when they travel slowly on the surface or when resting - but not when traveling at higher speeds. The majority of this kind of communication (85%) takes place between mothers and their calves, according to Dr. Marsha Green, but another example may be whales within a group communicating with each other.

• whalesongs
  It has been defined that only the humpback whale males are singing. Unlike a pop song with a melody, a whalesong is more like a string of different sounds in different pitches that can sound like humming, snoring, groaning, sighing or chirping. Similar to classical music, a whalesong consists of different themes which develop and build over the years. The whale songs can even be heard from a distance of 100 miles or more. The whales are singing mainly in their breeding grounds or on the way from or to their feeding grounds in cooler waters. Although whale singing has been heard in the feeding grounds up north, other communicative sounds are much more common and are currently being studied. Perhaps we will be able to install a hydrophone in Alaska one day to learn more about that.

Although it is the best known and most studied large whale, nobody knows exactly why the humpback whale sings. As the songs are performed almost exclusively in the breeding grounds, researchers believe that singing and mating go together. But whether a male is trying to impress a female or get rid of competitors or show his social status still remains a secret. Another theory explains the singing as a kind of sonar to find other whales. A recent study by Dr. Darling and his team shows several hypotheses still being studied. One is females are chased by singing and non-singing males. Another is pairs of males around females take on different roles of blocking and chasing, and yet another is not all male-singer relationships are non-agnostic, that is, in many instances they witnessed highly agnostic reactions. The research team found that with adult male/male interactions that were mediated with song were extremely common in our breeding grounds and that the singing usually stopped with the interaction. They also found most interactions were with an adult male singer being joined by another adult male, and at some times two adult males. Also according to the team, several observations appear to tie in sequential behavioral patterns. Most common, they say, is a lone male singing, occasionally singers are accompanying a mom/calf, and a small percentage was a singing male accompanied by another adult, sex unknown. They feel the song might help in organizing the males and may provide a real time measure of association between the different males and maybe providing a means of mutual assistance in mating. Definitely more studies will need to be done. We look forward to reading the results of future work and will eagerly share it with you.

We do understand the importance of communication within the species. It is imperative these animals stay as a protected species, not just for our own studies and observations, but so the future generations can hear, first hand, the amazing voices of the deep. Building up a world-wide monitoring system would make it possible to learn much more about the migration patterns of these giants. We at Whalesong hope to reach more scientists with our website who could use our broadcast for their work and then discuss their experiences with us.

According to the experts, the song generally lasts from 5 to 20 minutes long and has a hierarchically organized sequence of sounds. There are specific sound units that are organized into phrases , and these phrases then are repeated several times as a theme. The song, often five to seven different themes, is often repeated without stopping, says Dr. Jim Darling.

The unique dynamics of the song changes collectively, which means all the singers within the population sing the same version. The song's rate change may change however, with a complete turnover to a new song varying by area. In Bermuda one study showed a complete turnover in five plus seasons. In Australia, it was two seasons. The songs differ from population to population - the humpback whales of the North Pacific (Hawaii, Mexico, Japan) have a different song than, for example, the humpback whales of the South Pacific (Australia and the Islands of the South Pacific). Is this is a version of different dialects?

Blue whales could once communicate from pole to pole - that means halfway around the world! But due to increasing noise pollution of the oceans, this is believed now to be nearly impossible. Researchers tell us noise under water travels five times faster than above. Years ago while doing a humpback singing study, researchers working together in Mexico, Japan, and Hawaii, found when the song altered slightly in Hawaii, within several days it also altered in Mexico and Japan to match the Hawaiian singers. What this means has baffled researchers who promise to continue their hard work toward a better understanding of these beautiful and mystifying animals.