Humpback Whale

The Humpback Whale (Megaptera novaeangliae) is a mammal which belongs to the baleen whale suborder. It is a large whale: an adult usually ranges between 12–16 m (40–50 ft long and weighs approximately 36,000 kilograms (79,000 pounds), or 36 tonnes or metric tons (40 tons). more...

It is well known for its breaching (leaping out of the water), its unusually long front fins, and its complex whale song. The Humpback Whale lives in oceans and seas around the world, and is regularly sought out by whale-watchers.

Physical description

Humpback Whales can easily be identified by their stocky bodies with obvious humps and black upper parts. The head and lower jaw are covered with knobs called tubercles, which are actually hair follicles and are characteristic of the species. The tail flukes, which are lifted high in the dive sequence, have wavy rear edges.

The long black and white tail fin, which can be up to a third of body length and pectoral fins have unique patterns, which enable individual whales to be recognised, in a similar way to the bill markings on Bewick's Swans. Several hypotheses have been suggested to explain the evolution of the Humpback's pectoral fins, proportionally the longest fins of any cetacean. The two most enduring hypotheses are that the higher maneuverability afforded by long fins is a significant evolutionary advantage, or that the increased surface is useful for temperature control when migrating between warm and cold climates.

Humpbacks have 270 to 400 darkly coloured baleen plates on each side of the mouth. Ventral grooves run from the lower jaw to the umbilicus about halfway along the bottom of the whale. These grooves are less numerous (usually 16–20) and consequently more prominent than in other rorquals. The stubby dorsal fin is visible soon after the blow when the whale surfaces, but has disappeared by the time the flukes emerge. It has a distinctive 3 m (10 ft) bushy blow.

The calf is about 4–4.5 m (13–15 ft) long when born and weighs approximately 700 kg (1500 lbs). Calves are nursed by their mothers for their first six months, then are sustained through a mixture of nursing and independent feeding for a further six months. Calves leave their mothers at the start of their second year, when they are typically 9 m (30 ft) long. Both sexes reach sexual maturity at the age of five. Full adult size is achieved a little later. Grown size is commonly 15–16 m (49–52 ft) in males, 16–17 m (52–56 ft) in females, and a weight of 40,000 kg (or 44 tons); the largest ever recorded specimen was 19 m (62 ft) long and had pectoral fins measuring 6 m (20 ft) each.

Females have a lobe about 15 cm (6 inches) in diameter in their genital region that is not present in males. This allows males and females to be distinguished if the underside of the whale can be seen, even though the male's penis usually remains unseen in the genital slit. Females typically breed every two or three years. The gestation period is eleven months, yet some individuals can breed in two consecutive years.

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