Humpback whales range in size from 12 – 16 metres and weigh approximately 36,000kg.
It is an acrobatic animal, often breaching and slapping its tail on the surface. Males produce a complex song which lasts for approximately fifteen minutes, but sung repeatedly for hours on end – this can often be heard by divers during migration. They migrate up to 25,000 kilometres each year.
They feed primarily in summer, in polar waters, usually on krill and small fish, then live off fat reserves in winter. Its most inventive form of hunting is known as “bubble-net feeding.” This is when a group of whales swims in a shrinking circle blowing bubbles below a school of prey. The shrinking ring of bubbles encircles the school and confines it in an ever-smaller cylinder. The whales then suddenly swim upward, through the bubbles, mouths agape and swallowing thousands of fish in one gulp.
During winter they move to tropical waters to breed and give birth. Newborn calves are roughly the length of their mother’s head. Calves nurse with their mothers for about six months. Most monitored humpback whales have rebounded well since the end of commercial whaling in 1966.