Difference between revisions of "Right whale"
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'''Right whales''' are three species of [[whale]] found in the Atlantic and Pacific Oceans, and so-named by early whalers who thought that it was the "right" whale to kill due to its
'''Right whales''' are three species of [[whale]] found in the Atlantic and Pacific Oceans, and so-named by early whalers who thought that it was the "right" whale to kill due to its the , as well when dead. The exploitation of the right whale began in the Bay of Biscay in Spain by the 12th century and continued, especially in the North Atlantic, for many centuries. Despite being protected since the 1930s, the right whale is today the most endangered of all the great whales.
Revision as of 01:53, 7 May 2013
|Species|| E. glacialis|
Right whales are three species of whale found in the Atlantic and Pacific Oceans, and so-named by early whalers who thought that it was the "right" whale to kill due to its slow swimming speed and habit of swimming at the surface, as well its tendency to float when dead. The exploitation of the right whale began in the Bay of Biscay in Spain by the 12th century and continued, especially in the North Atlantic, for many centuries. Despite being protected since the 1930s, the right whale is today the most endangered of all the great whales.
The right whale is a large, bulky baleen whale of unusual appearance. Its upper and lower jaws are highly curved, allowing its long baleen plates to be enclosed while swimming. Its rostrum (upper jaw) is narrow and is often covered by "callosities," hardened patches of skin that occur in the facial area.
Right whales are black all over except for the belly, where there is often a white patch. Wounds and scars may appear bright orange because they become infested with whale lice, or cyamids. The callosities, which are also found near the blowholes, above the eyes, and on the chin and upper lip, are black or gray but appear white because of cyamid coverage.
The right whale has no dorsal (upper) fin or ridge. Its flippers are large and paddle-shaped, and its flukes are very wide, with a deep notch in the center.
Adult right whales are generally 35-55 feet (10.7-16.8 m) long. The largest individuals known have measured 60 feet (18.3 m) long and weighed 117 tons (106,500 kg). Females are larger than males.
This whale's diet is less varied than that of many other baleen whales. They feed on planktonic organisms including shrimp-like krill and copepods, particularly copepods in the genus Calanus. As baleen whales, they have a series of 225-250 fringed overlapping plates hanging from each side of the upper jaw. These plates are made of a fingernail-like material called keratin that frays out into fine hairs on the ends and inside the mouth near to the tongue. The plates are black, with a maximum length of 7.2 feet (2.2 m). Right whales are "grazers of the sea," often swimming slowly with their mouths open. As water flows into the mouth and through the baleen, prey are trapped on the inside near the tongue to be swallowed.
Mating and Breeding
Males reach sexual maturity at 35-40 feet, and the age at which these lengths are achieved is not known. Females reach sexual maturity at 40-45 feet, as early as five years of age. The young right whale stays with its mother for 1 year. Right whales are commonly found alone or in small groups of 1-3 animals, but they may form groups of up to 30 whales for social, possibly courtship, behavior. In such groups there is much rolling and thrashing; actual mating has been observed several times. Much of their social behavior, however, is not for reproductive purposes; birthing is highly seasonal, but courtship takes place at all times of the year.
Distribution and Migration
Right whales are found worldwide but in very small numbers. Like most baleen whales, they are seasonally migratory. They inhabit colder waters for feeding, then migrate to warmer waters for breeding and calving. Although they may move far out to sea during their feeding seasons, right whales give birth in coastal areas. Interestingly, many of the females do not return to these coastal breeding areas every year, but visit the area only in calving years. Where they go in other years remains a mystery.
Right whales are among the slowest swimming whales, although they may reach speeds up to 10 mph in short spurts. They can dive to at least 1,000 ft. and can stay submerged up to 40 minutes. Since 1969, a population of right whales has been studied off the coast of Argentina by Dr.Roger Payne. He has used the pattern of right whale callosities to identify individual animals: he found that each animal has callosities of different shapes and sizes. Comparing photographs of the animals makes it possible to know which whale is being observed. Because of their coastal habitat, the whales can commonly be observed from the beach or nearby clifftops. Similar research programs also occur in other parts of the Southern Hemisphere and in the North Atlantic. Right whales can live for at least 70 years.
The right whale is extremely endangered, even after years of protected status. Best population estimates are 300 -350 in the North Atlantic, perhaps less than 100 in the eastern North Pacific and an unknown (but small) number in the western North Pacific, and 3,000-4,000 in the Southern Hemisphere. Full protection was granted in 1931, but despite over 50 years of protection, recovery has been questionable. Only in the past 15 years is there evidence of a population recovery in the Southern Hemisphere, and it is still not known if the right whale will survive at all in the Northern Hemisphere. Although not presently hunted, current conservation problems include collisions with ships, conflicts with fishing activities, habitat destruction, oil drilling, and possible competition from other whale species.