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 40″“50 ft (12″“16 m) long and weighs approximately 79,000 pounds (36,000 kilograms, or 36 tons. It is well known for its breaching (leaping out of the water) and its unusually long front fins. The Humpback Whale lives in oceans and seas around the world, and is regularly sought out by whale-watchers.
The Humpback Whale feeds only in summer and lives off fat reserves during winter. It is an energetic feeder, taking krill and small schooling fish, such as herring, capelin and sand lance. It will hunt fish by direct attack or by stunning them by hitting the water with its flippers or flukes.
Humpback Whales are preyed upon by orcas. The result of these attacks is generally nothing more serious than some scarring of the skin. However, it is likely that young calves are sometimes killed.
Population and distribution
The Humpback Whale is found in all the major oceans, in a wide band running from the Antarctic ice edge to 65Â° N latitude. It is a migratory species, spending its summers in cooler, high-latitude waters, but mating and calving in tropical and sub-tropical waters. Annual migrations of up to 25,000 km (16,000 miles) are typical, making it one of the best traveled of any mammalian species. An exception to this rule is a population in the Arabian Sea, which remains in these tropical waters year-round. The species is not found in the eastern Mediterranean, the Baltic Sea or the Arctic Ocean.
Populations of nearly all-large whale species are currently on the increase, after decades of decline as a result of (now illegal) whaling. The Humpback Whale appears to be recovering even more strongly from the effects than the other large whales. Since its low point of about 20,000 individuals at the time of the 1966 moratorium, the species’ population has increased to about 35,000 today. There are estimated to be 11,600 Humpbacks in the North Atlantic, 10,000 in the North Pacific and at least 17,000 in the Southern Hemisphere.
Taxonomy and evolution
The is evidence that indicates that the fin and blue whales’ lineages separated more than 5 million years ago, and that these species split after the Humpback did. The Humpback Whale species is therefore between 5 and 12 million years old. Like other cetacean species, though, the Humpback fossil record becomes very patchy at times greater than 2.5 million years ago, and it is not currently possible to narrow this age range further.
Although much was known about the size, shape, and composition of Humpback Whales due to whaling, the migratory patterns and social interactions of the species were not well known until the problem was analyzed by R. Chittleborough and W. H. Dawbin in two separate studies in the 1960s. Roger Payne and Scott McVey studied the species in 1971.
Scientists realized that the varying patterns on the Humpback’s tail fluke were sufficient to identify an individual. Such unique identification is not possible in other species and so the Humpback has become the most-studied whale species. A study using data from 1973 to 1998 on whales in the North Atlantic gave researchers detailed information on gestation times, growth rates, and calving periods “” as well as allowing accurate population predictions by simulating the mark-release-recapture technique. A photographic catalogue of all known whales in the North Atlantic was developed over this period and is today maintained by Wheelock College. Similar photographic identification projects have subsequently begun in the North Pacific, specifically by SPLASH (Structure of Populations, Levels of Abundance and Status of Humpbacks), as well as in other areas around the world.