Mammals
Humpback Whale
Megaptera novaeangliae · also called humpback
The humpback whale is the acrobat and the composer of the whale world — a stocky baleen whale famous for breaching clear of the water, for the haunting, ever-changing songs of its males, and for the ingenious teamwork it uses to catch fish.
Overview
Humpback whales are found in every ocean. Their year is split between two very different homes: cold, plankton-rich polar and temperate seas in summer, where they feed intensively, and warm, calm tropical waters in winter, where they mate and give birth. The migration between the two is one of the longest of any animal. Distinct populations use different feeding and breeding grounds, and individuals return faithfully to the same areas their mothers used.
The “big wing”
The humpback’s scientific name means “big-winged New Englander,” a reference to its enormous pectoral flippers — up to five metres, the longest of any whale, scalloped along the leading edge with bumps (tubercles) that improve lift and reduce drag, a design now copied in some wind-turbine blades. The knobbly head, the humped back, and the pattern on the underside of the broad tail flukes — unique to each whale, like a fingerprint — are its other identifying features.
Song
Male humpbacks produce songs of extraordinary length and structure, built from repeating phrases and themes, lasting up to 20 minutes and sung for hours. All the males in a population sing essentially the same song at any one time, and that song evolves continuously — and sometimes a new song sweeps across from one ocean region to the next, a documented case of culture spreading between animal populations. The function is still debated, but its link to the breeding season points to a role in courtship and male competition.
Bubble-net feeding
Humpbacks are lunge feeders, engulfing a huge mouthful of water and prey and straining it through baleen plates. In some populations they add a cooperative twist: several whales dive under a shoal and blow a spiralling wall of bubbles that pens the fish into a tight ball, then surge up through the centre together with mouths agape. The technique, and its regional variations, are learned socially.
Reproduction
On the breeding grounds, males compete in boisterous “heat runs,” jostling and striking one another to escort a female. After an 11-month pregnancy a female gives birth to a single calf in warm water and nurses it on extremely rich milk; the calf doubles its length in the first year. Females breed about every two to three years.
Recovery
Hunted to near-extinction — perhaps 95% killed — the humpback has become one of the great conservation success stories. Protected since the 1960s, most populations have rebounded strongly, and the species is now Least Concern and still increasing. Remaining threats are ship strikes, entanglement in fishing gear, underwater noise, and localised food-web disruption, and a handful of small, isolated populations remain at risk.
Humpback Whale: common questions
Why do humpback whales sing?
Only male humpbacks sing, mostly on the breeding grounds and on migration, so the song is thought to be related to mating — advertising to females, sorting out status among males, or both. A song is a long, structured sequence of moans, cries, and chirps lasting 10–20 minutes and repeated for hours. All the males in a population sing the same song at a given time, and it steadily changes; occasionally a completely new song spreads from one ocean population to a neighbouring one, a rare example of large-scale cultural transmission in animals.
What is bubble-net feeding?
A cooperative hunting technique. A group of humpbacks dives beneath a school of fish or krill and one or more whales swim in an upward spiral while releasing a steady stream of bubbles from the blowhole. The rising bubbles form a cylindrical "net" that the prey will not swim through, concentrating them into a dense column. The whales then lunge up through the middle with mouths wide open, engulfing huge volumes of water and prey, and strain the water out through their baleen. Different populations have their own variations, learned and passed between individuals.
How far do humpback whales migrate?
Some of the farthest of any mammal — routinely 5,000 to 8,000 km each way. Whales that feed all summer in the rich cold water off Antarctica, Alaska, or Norway travel to breed and give birth in warm, sheltered tropical waters (Hawaii, the Caribbean, Tonga, the coast of Colombia, Madagascar) where newborn calves, which have little blubber, are less at risk from cold and from killer whales. The adults eat little or nothing during the months on the breeding grounds and the journey, living off fat reserves.
Have humpback whales recovered from whaling?
Remarkably well, in most places. Commercial whaling killed an estimated 90–95% of humpbacks before they were protected in the 1960s. Since then most populations have grown strongly — the ones off eastern Australia and in the North Atlantic have rebuilt to near their pre-whaling numbers — and in 2008 the species was moved to Least Concern, with the US removing most populations from its endangered list in 2016. A few small populations, such as the Arabian Sea humpbacks, remain endangered.