Humpback whale
Megaptera novaeangeliae

Humpback whales are the acrobats and songsters of the great whales. A humpback leaping clear of the water in a full breach is a truly spectacular sight, and its haunting song is one of the most complex in the animal kingdom.

The humpback whale is the fifth largest of all whales. Fully-grown, it can be 16 metres long and weigh up to 40 tonnes. There are three good ways to identify a humpback. First of all, most of its chunky body is dark gray to black, except for two enormous, white and black pectoral flippers. No other whale has flippers like these, which can be almost 5 metres long. Second, as the whale begins to dive, it bends its back, showing a rounded hump underneath its short, nubby dorsal fin. This profile is how the humpback whale got its name. And third, as the whale slides beneath the surface, you may see the underside of its huge tail flukes. The natural black and white patterns and scars seen here, unique to humpbacks, are used by researchers to identify individual whales. Like human fingerprints, no two humpback tails are the same.

A close-up view of a humpback whale surprises many people. The head is large and, when seen from above, looks alligator-shaped. On top are small knobs that look like bolts on a piece of machinery. The mouthline runs high along the length of the head, dropping sharply below the eyes. The tip of the lower jaw has a fleshy bump, which is often covered with barnacles. The humpback has long folds, or pleats, running from its throat down its belly which expand when it is feeding. The humpback’s blow, or spout, is balloon-shaped and can be as high as 3 metres.

Range

Humpback whales are found in all the world’s oceans. Like many baleen whales, they are migrants, and follow predictable routes according to the season. In the north Pacific, humpbacks travel from their winter breeding grounds in the south to summer feeding grounds in the north. Humpbacks seen off B.C. spend their winters in the coastal waters of either Hawaii or Baja, Mexico. They do not eat there. Winter is the time for mating, and giving birth. In early spring, the whales head north in small groups to eat. Many go to the coastal inlets of southeast Alaska, and to the Bering and southern Chukchi Seas. Some humpbacks spend their summers off B.C.

Behaviour

Because of its many surface antics, the humpback whale is one of the most interesting whales to watch. Humpbacks like to breach, slap their tails, and wave their long flippers in the air. They are very lively in the winter breeding grounds, where males push and shove each other to get near a female. These wrestling matches can get so rough that the dorsal fins and head knobs of competing males can get ragged and bloody. One year later, females return to give birth to their 5-metre, 2-tonne calves.

It is on the breeding grounds that humpback whales sing their songs — an eerie blend of grunts, whistles and whines. Only the males sing, usually while hanging head-down some 20 metres below the surface. Why he sings is a mystery. How he knows what to sing is an even bigger puzzle. The song changes from season to season, yet all male humpbacks on each of the breeding grounds, sing the same song.

The humpback is a rorqual baleen whale. It eats by gulping in a huge mouthful of water and food. To contain the water, its throat expands like a pelican’s pouch, until its massive tongue squeezes the water out through the baleen. Its favourite foods are small schooling fish and krill. The humpback uses a variety of feeding techniques. Perhaps the most unusual is called bubble-netting. Several whales circle a school of fish from below and blow bubbles as they spiral toward the surface. The fish are frightened into a tight ball, and the whales surface, mouths wide open, to swallow them.

Status

Worldwide, humpback whales are endangered. In the north Pacific, they were heavily hunted by whalers for their oil and baleen. Where there were once perhaps 15,000, today there are an estimated 6,000 to 8,000. Even though humpbacks have been fully protected since 1965, their numbers are increasing very slowly.

Humpbacks were once quite plentiful on the B.C. coast, even in the inside waters of the Strait of Georgia. Several individuals have been seen in these waters in recent years. This is a hopeful sign that one day, the humpback whale may again be a common sight on the B.C. coast.