3d fine art render of a humpback whale.
Made with bryce 3d, post work in photoshop.
The humpback whale (Megaptera novaeangliae) is a baleen whale. One of the larger rorqual species, 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 an acrobatic animal, often breaching and slapping the water. Males produce a complex whale song, which lasts for 10 to 20 minutes and is repeated for hours at a time. The purpose of the song is not yet clear, although it appears to have a role in mating.
Found in oceans and seas around the world, humpback whales typically migrate up to 25,000 kilometres 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 fast and live off their fat reserves. The species’ diet consists mostly of krill and small fish. Humpbacks have a diverse repertoire of feeding methods, including the bubble net feeding technique.
Like other large whales, the humpback was and is a target for the whaling industry. Due to over-hunting, its population fell by an estimated 90% before a whaling moratorium was introduced in 1966. Stocks have since partially recovered; however, entanglement in fishing gear, collisions with ships, and noise pollution also remain concerns. There are at least 80,000 humpback whales worldwide. Once hunted to the brink of extinction, humpbacks are now sought by whale-watchers, particularly off parts of Australia, Canada, and the United States.
Humpback whales can easily be identified by their stocky bodies with obvious humps and black dorsal coloring. 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 some dive sequences, have wavy trailing edges.There are four global populations, all under study. North Pacific, Atlantic, and southern ocean humpbacks have distinct populations which complete a migratory round-trip each year. The Indian Ocean population does not migrate, stopped by that ocean’s northern coastline.
The long black and white tail fin, which can be up to a third of body length, and the pectoral fins have unique patterns, which make individual whales identifiable. Several hypotheses attempt to explain the humpback’s pectoral fins, which are proportionally the longest fins of any cetacean. The two most enduring mention the higher maneuverability afforded by long fins, and the usefulness of the increased surface area for temperature control when migrating between warm and cold climates. Humpbacks also have ‘rete mirable’ a heat exchanging system, which works similarly in humpbacks, sharks and other fish.
A humpback whale tail displaying wavy rear edges
A tail from a different individual – the tail of each humpback whale is visibly unique.Humpbacks have 270 to 400 darkly coloured baleen plates on each side of the mouth. The plates measure from a mere 18 inches (46 cm) in the front to approximately 3 feet (0.91 m) long in the back, behind the hinge. 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 disappears by the time the flukes emerge. Humpbacks have a 3 metres (9.8 ft) heart shaped to bushy blow, or exhalation of water through the blowholes. Early whalers also noted blows from humpback adults to be 10–20 feet (3.0–6.1 m) high. Whaling records reveal understanding of the species-specific shape and height of blows.
Newborn calves are roughly the length of their mother’s head. A 50-foot (15 m) mother would have a 20-foot (6.1 m) newborn weighing in at 2 short tons (1.8 t). They are nursed by their mothers for approximately six months, then are sustained through a mixture of nursing and independent feeding for possibly six months more. Humpback milk is 50% fat and pink in color. Some calves have been observed alone after arrival in Alaskan waters.
Females reach sexual maturity at the age of five with full adult size being achieved a little later. Males reach sexual maturity at approximately 7 years of age. Whale lifespan estimates range from 30–40 years to 70–80 years.
Fully grown the males average 15–16 metres (49–52 ft), the females being slightly larger at 16–17 metres (52–56 ft), with a weight of 40,000 kilograms (44 short tons)); the largest recorded specimen was 19 metres (62 ft) long and had pectoral fins measuring 6 metres (20 ft) each. The largest humpback on record, according to whaling records, was killed in the Caribbean. She was 88 feet (27 m) long, weighing nearly 90 short tons (82,000 kg).
Females have a hemispherical lobe about 15 centimetres (5.9 in) in diameter in their genital region. This allows males and females to be distinguished from the underside, even though the male’s penis usually remains hidden in the genital slit. Male whales have distinctive scars on heads and bodies, some resulting from battles over females.
The varying patterns on the humpback’s tail flukes are sufficient to identify an individual. Unique visual identification is not currently possible in most cetacean species (other exceptions include orcas and right whales), making the humpback a popular species for study. 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 more 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 currently maintained by Wheelock College. Similar photographic identification projects have begun in the North Pacific by SPLASH (Structure of Populations, Levels of Abundance and Status of Humpbacks), and around the world. Another organization (Cascadia Research) headed by well-known researcher John Calambokidis, along with Dr. Robin Baird, joined with others from NOAA, hoping to prepare a public online catalog of more than 3500 fluke identification pictures.
Humpbacks feed only in summer and lives off fat reserves during winter. They feed only rarely and opportunistically while in their wintering waters. The humpback is an energetic feeder, taking krill and small schooling fish, such as herring (Clupea harengus), salmon, capelin (Mallotus villosus) and sand lance (Ammodytes americanus) as well as Mackerel (Scomber scombrus), pollock (Pollachius virens) and haddock (Melanogrammus aeglefinus) in the North Atlantic. Krill and Copepods have been recorded from Australian and Antarctic waters. Humpbacks hunt fish by direct attack or by stunning them by hitting the water with its pectoral fins or flukes.
A pair of humpback whales feeding by lungingThe humpback has the most diverse repertoire of feeding methods of all baleen whales. Its most inventive technique is known as bubble net feeding: 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 bubble net, mouths agape, swallowing thousands of fish in one gulp. This ring can begin at up to 30 metres (98 ft) in diameter via the cooperation of a dozen animals. Some of the whales blow the bubbles, some dive deeper to drive fish toward the surface, and others herd other fish into the net by vocalizing. Humpbacks have been observed bubblenet feeding alone as well.
Humpback whales are preyed upon by Orcas. The result of these attacks is generally nothing more serious than some scarring of the skin, but it is likely that young calves are sometimes killed.
The humpback whale is found in all the major oceans, in a wide band running from the Antarctic ice edge to 65° N latitude, though not in the eastern Mediterranean or the Baltic Sea. There are at least 80,000 humpback whales worldwide, with 18,000-20,000 in the North Pacific, about 12,000 in the North Atlantic, and over 50,000 in the Southern Hemisphere, down from a pre-whaling population of 125,000.
Humpbacks are migratory, spending summers in cooler, high-latitude waters, but mating and calving in tropical and subtropical waters. An exception to this rule is a population in the Arabian Sea, which remains in these tropical waters year-round. Annual migrations of up to 25,000 kilometres (16,000 mi) are typical, making it one of the farthest-travelling of any mammalian species.
A 2007 study identified seven individual whales wintering off the Pacific coast of Costa Rica as those which had made a trip from the Antarctic of around 8,300 kilometres (5,200 mi). Identified by their unique tail patterns, these animals have made the longest documented migration by a mammal.
In Australia, two main migratory populations have been identified, off the west and east coast respectively. These two populations are distinct with only a few females in each generation crossing between the two groups.