Humpback Whale

These whales are relatively conspicuous because they often come quite close to shore, swim at the surface and jump above the waves.

Humpback whales spend their summers feeding far from shore, in the cold waters near the poles. They feed by taking in huge mouthfuls of sea water. Their baleen plates then strain out any fish or krill from the water. Pairs of humpback whales also corral shoals of fish by blowing curtains of bubbles around them. The fish will not swim through the bubbles, so they crowd together. The whales then rush up from beneath into the mass of fish with their mouths wide open.

The humpback whale has a distinctly curved lower jaw and an average of 22 throat grooves. Its most characteristic features are the many knobs on the body and the flippers, which are about 16 ft (5 m) long and scalloped at the front edges. Humpback whales are more gregarious than blue whales and are usually seen in family groups of 3 or 4, although they may communicate with many other groups.

As winter approaches, the whales stop feeding and head to warmer, shallow waters near coasts or groups of islands. For example, populations of humpbacks spend the winter near Baja California and the Hawaiian islands. During the winter the whales do not feed; instead they concentrate on reproduction. The males produce songs that they repeat for days on end. The remarkable song of the male humpback whale is uttered repeatedly for hours, each segment lasting up to 20 minutes. This probably helps them to keep in touch with one another when separated in the oceans, and also help to keep rival males away from each other. Their song patterns are distinctive and change over time. Humpback whales are quite often seen jumping above the water, with this behaviour described as breaching. Like singing, this may be part of their courtship ritual. Pregnant females stay feeding for longer than the other whales, and arrive in the wintering grounds just in time to give birth.

Humpback whales are so-called because of the dorsal fin (on the back), which may be swelled into a hump by deposits of fat. Humpback whales have the longest pectoral (arm) fins of any whale species, measuring about one-third of their body length.

Distribution: Occurs worldwide, migrating to temperate and polar waters to feed, and then mates and calves in the tropics. A resident population occurs in the Arabian Sea.

Habitat: Deep ocean water. They come closer to land to mate and calf.

Weight: 19.9 - 32.6 tonnes (22 - 36 tons); females are much heavier.

Length: 12 - 15 m (40 - 50 ft).

Maturity: 6 - 10 years.

Gestation Period: About 365 days; females give birth once every 2 - 3 years.

Breeding: Single young born every 2-3 years. Mating takes place in winter. Gestation is 11 months.

Diet: Use their baleen plates to obtain krill, which form the major part of their food intake; also eats small fish.

Lifespan: Up to 100 years.

Status: Vulnerable.

Hairy bumps

These swollen areas on the head have hairs on them.

Dorsal fin

The dorsal fin is a feature of the rorqual family of whales.

Fins

These are very long -equivalent to a third of the humpback whale’s body length.

Tail flukes

The patterning here is distinctive, serving to identify individual whales.

Eyes

These are small and relatively inconspicuous, set below the jaws.

VANISHING WRINKLES

When the whales are feeding by sucking water into their mouths, the wrinkles of skin on the throat will disappear.