Humpback whales are known for their magical songs that travel for great distances through the world’s oceans. These melodic sequences of moans, howls, cries, and squeals are complex, each song lasting about ten to twenty minutes and typically repeated for hours on end. Scientists studying whale songs think that humpbacks sing to communicate with others and to attract potential mates, although this may be oversimplifying their significance.
There are two distinct humpback whale populations in the North Pacific Ocean, and two in the North Atlan-tic. Additionally there are seven isolated groups in the southern hemisphere. Whales within each oceanic group sing an identical song, and each population’s song differs depending on its location. Singing is con-sistently done by the males.
Humpback whales are frequently seen near coastlines where they feed on tiny shrimp-like krill, plankton and small fish. Migrating annually, they move from their summer feeding grounds near the poles to warmer winter breeding waters closer to the equator. Mothers swim close to their young, often touching with their flippers in what appear to be gestures of affection. Females nurse their calves for almost a year, though it takes far longer than that for a humpback whale to reach full adulthood. Calves don’t stop growing until they’re ten years old.
These whales are powerful swimmers, and use their massive tail fin (called a fluke) to propel themselves through the water – and sometimes completely out of it. Observers aren’t sure if this breaching behaviour serves some practical purpose, such as cleaning parasitic pests from the skin, or whether the whales sim-ply do it because they can. Other aquatic manoeuvres include swimming on their backs with both flippers in the air; raising their flukes out of the water then slapping the water surface (‘lobtailing’); and ‘flipper slapping’ which is exactly as it sounds! ‘Spyhopping’ – poking their heads out of the water and taking a good look around – is another favourite move. When they’re not performing aerial feats, humpbacks cruise through the water at about 5 to 14 kph. They’re capable of diving over 200 metres and staying underwater for 30 minutes. Most of their dives, however, last about half that long.