The humpback whale (Megaptera novaeangliae) is a species of Baleen whale, which are characterized by having baleen plates for filtering food from water, rather than teeth. Baleen or whalebone is a filter-feeder system inside their mouths. Adults range in length from 12–16 metres (39–52 ft) and weigh approximately 36,000 kilograms (79,000 lb). The humpback has a distinctive body shape, with unusually long pectoral fins and a knobbly head. It is often seen breaching and slapping the water. Males produce a complex song which lasts for 10 to 20 minutes and is repeated for hours at a time. They only sing when in their calving grounds and only in the mating period. The purpose of the song is not yet clear, although it appears to have a role in mating. It has been suggested that the songs are used to communicate male fitness to female whales.
Humpbacks are found all around the world, they typically migrate up to 25,000 kilometres (16,000 mi) each year. Humpbacks feed only in summer, in polar waters, and migrate to tropical or sub-tropical waters to breed and give birth in the winter. During the winter, humpbacks do not feed, they live off their fat reserves. Their diet consists mostly of krill and small fish.
Once hunted to the brink of extinction, humpbacks are now sought by whale watchers all around the world, and the first humpback in Irish waters for 2012 has been spotted three miles south of Hook Head Co Wexford.