Right whale

Right whales or black whales are three species of large baleen whales of the genus Eubalaena: the North Atlantic right whale (E. glacialis), the North Pacific right whale (E. japonica) and the Southern right whale (E. australis). They are classified in the family Balaenidae with the bowhead whale. Right whales have rotund bodies with arching rostrums, V-shaped blowholes and dark gray or black skin. The most distinguishing feature of a right whale is the rough patches of skin on its head, which appear white due to parasitism by whale lice. Right whales can grow up to more than 18 m (59 ft) long with a highest-recorded length of 19.8 m (65 ft). Right whales are very robust whales, weighing 100 short tons (91 t; 89 long tons) or more. The largest known right whales can attain 20.7 m (68 ft) in length and weigh up to 135,000 kg (298,000 lb) or 21.3 m (70 ft) with uncertainty, Their immense bulk makes right whale significantly heavier than other whales of similar or greater length such as the humpback, gray, sperm and even fin whales. In fact, right whales rank only behind the blue whale in sheer body mass. One (apocryphal) explanation for their name is that whalers identified them as the 'right' whale to kill on a hunt due to the plentiful oil and baleen they could provide. All three species are migratory, moving seasonally to feed or give birth. The warm equatorial waters form a barrier that isolates the northern and southern species from one another although the southern species, at least, has been known to cross the equator. In the Northern Hemisphere, right whales tend to avoid open waters and stay close to peninsulas and bays and on continental shelves, as these areas offer greater shelter and an abundance of their preferred foods. In the Southern Hemisphere, right whales feed far offshore in summer, but a large portion of the population occur in near-shore waters in winter. Right whales feed mainly on copepods but also consume krill and pteropods. They may forage the surface, underwater or even the ocean bottom. During courtship, males gather into large groups to compete for a single female, suggesting that sperm competition is an important factor in mating behavior. Although the blue whale is the largest animal on the planet, the testes of the right whale are actually ten times larger than those of the blue whale – with each weighing up to 525 kilograms (1,157 lb), they are by far the largest of any animal on Earth. Gestation tends to last a year, and calves are born at 1 short ton (0.91 t; 0.89 long tons) in weight and 4–6 m (13–20 ft) in length. Weaning occurs after eight months. Right whales were a preferred target for whalers because of their docile nature, their slow surface-skimming feeding behaviors, their tendency to stay close to the coast, and their high blubber content (which makes them float when they are killed, and which produced high yields of whale oil). Today, the North Atlantic and North Pacific right whales are among the most endangered whales in the world, and both species are protected in the United States by the Endangered Species Act. The western populations of both are currently endangered, with their total populations numbering in the hundreds. The eastern North Pacific population, on the other hand, with fewer than 50 individuals remaining, is critically endangered – further still, the eastern North Atlantic population, which numbers in the low teens at best, may already be functionally extinct. Although the whales no longer face pressure from commercial whaling, mankind remains by far the greatest threat to these species: the two leading causes of death are being struck by ships and entanglement in fishing gear. Ingestion of plastic marine debris also presents a growing threat. For the North Atlantic right whale, for example, whose population was estimated at 411 in 2018 which was down from 451 in 2016 and 458 in 2015, these two anthropogenic factors alone account for 48% of all known right whale deaths since 1970. More than 85% of right whales have been entangled at least once. In 2017, at least 118 right whales were in the Gulf of St Lawrence, or roughly a quarter of the local population, which previously fed in summer and fall months in the Bay of Fundy and Roadway basin. The habitat shift moved this population away from existing conservation efforts and into the path of busy shipping lanes and also snow crab fisheries where Fisheries and Oceans Canada doubled the quotas in 2017. A popular explanation for the name right whales is that they were the right ones to hunt, as they float when killed and often swim within sight of shore. They are quite docile and do not tend to shy away from approaching boats. As such, they were hunted nearly to extinction during the active years of the whaling industry. This origin is apocryphal. In his history of American whaling, Eric Jay Dolin writes: The right whales were first classified in the genus Balaena in 1758 by Carl Linnaeus, who at the time considered all of the right whales (including the bowhead) as a single species. Through the 1800s and 1900s, in fact, the family Balaenidae has been the subject of great taxonometric debate. Authorities have repeatedly recategorized the three populations of right whale plus the bowhead whale, as one, two, three or four species, either in a single genus or in two separate genera. In the early whaling days, they were all thought to be a single species, Balaena mysticetus. Eventually, it was recognized that bowheads and right whales were in fact different, and John Edward Gray proposed the genus Eubalaena for the right whale in 1864. Later, morphological factors such as differences in the skull shape of northern and southern right whales indicated at least two species of right whale—one in the Northern Hemisphere, the other in the Southern Ocean. As recently as 1998, Rice, in his comprehensive and otherwise authoritative classification, Marine mammals of the world: systematics and distribution, listed just two species: Balaena glacialis (the right whales) and Balaena mysticetus (the bowheads). In 2000, two studies of DNA samples from each of the whale populations concluded the northern and southern populations of right whale should be considered separate species. What some scientists found more surprising was the discovery that the North Pacific and North Atlantic populations are also distinct, and that the North Pacific species is more closely related to the southern right whale than to the North Atlantic right whale. The authors of one of these studies concluded that these species have not interbred for between 3 million and 12 million years.