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: "Despite this highly plausible rationale, nobody actually knows how the right whale got its name. The earliest references to the right whale offer no indication why it was called that, and some who have studied the issue point out that the word 'right' in this context might just as likely be intended "to connote 'true' or 'proper,' meaning typical of the group.""
Genetic evidence appears to have settled a long-standing question about whether to include the largest, the Arctic-dwelling bowhead whale, with the rest. Although all four are included in the taxonomic family Balaenidae, that whale is not included in the genus Eubalaena, and will therefore not be covered here.
Authorities have repeatedly recategorized the three populations of Eubalaena right whales, in one, two or three species. In the whaling era, they were thought to be a single species. Later, morphological factors such as differences in the skull shape of northern and southern animals indicated at least two species—one in the Northern Hemisphere, the other in the Southern Ocean. Right whales are not thought to cross equatorial waters to make contact with the other (sub)species or (inter)breed.
Three Eubalaena species theory
Genetic evidence demonstrates the northern and southern populations have not interbred for between 3 million and 12 million years, confirming the southern right whale is a distinct species. More surprising was the discovery that the Northern Hemisphere Pacific and Atlantic populations are also distinct, and that the Pacific species (now known as the North Pacific right whale) is more closely related to the southern right whale than to the North Atlantic right whale. While Rice continued to list two species in his 1998 classification, Rosenbaum et al. disagreed in 2000 and Brownell et al. in 2001. In 2005, Mammal Species of the World listed three species, indicating a shift to this conclusion.
Whale lice, parasitic cyamid crustaceans that live off skin debris, offer further information through their own genetics. Because these lice reproduce much more quickly than whales, their genetic diversity is greater. Marine biologists at the University of Utah examined these louse genes and determined their hosts split into three species 5–6 million years ago, and these species were all equally abundant before whaling began in the 11th century. The communities first split because of the joining of North and South America. The heat of the equator then created a second split, into northern and southern groups. "This puts an end to the long debate about whether there are three [Eubalaena] species of right whale. They really are separate beyond a doubt", Jon Seger, the project's leader, told BBC News.
A 2007 study by Churchill provided further evidence to conclude the three living right whale species do comprise a phylogenetic lineage, distinct from the bowhead, and are rightly classified into a separate genus.
The pygmy right whale (Capera marginata), a much smaller whale of the Southern Hemisphere, was also included in the Balaenidae family, but has recently been found to warrant a separate family, Neobalaenidae.
Yet another species of right whale was proposed by Emmanuel Swedenborg in the 18th century - the so called "Swedenborg whale". The description of this species was based on a collection of fossil bones unearthed at Norra Vånga, Sweden, in 1705 and believed to be those of giants. The bones were examined by Swedenborg, who realized they belong to a species of whale. The existence of this species has been and is currently debated. Further evidence for this species was discovered during the construction of a motorway in Strömstad, Sweden in 2009.
Synonyms and common names
Due to their familiarity to whalers over a number of centuries, the right whales have had many names. These names were used throughout the world, reflecting the fact that only one species was recognized at the time. In his novel Moby-Dick, Herman Melville writes:
- "Among the fishermen, the whale regularly hunted for oil is indiscriminately designated by all the following titles: The Whale; the Greenland whale; the black whale; the great whale; the true whale; the right whale."
The species-level synonyms are:
- For E. australis: antarctica (Lesson, 1828), antipodarum (Gray, 1843), temminckii (Gray, 1864)
- For E. glacialis: biscayensis (Eschricht, 1860), nordcaper (Lacepede, 1804)
- For E. japonica: sieboldii (Gray, 1864)
Unlike other whales, a right whale has distinctive callosities (roughened patches of skin) on its head, along with a broad back without a dorsal fin, occasionally with white belly patches, and a long, arching rostrum, or upper jaw, that begins above the eye. The callosities appear white due to large colonies of cyamids (whale lice). Right whales can grow up to 18 m (59 ft) long and weigh up to 100 short tons (91 t), significantly larger than humpbacks or grays, but smaller than blues.
Adults may be between 11–18 m (36–59 ft) in length and typically weigh 60–80 short tons (54–73 t). The most typical lengths are 13–16 m (43–52 ft). The body is extremely thick with girth as much as 60% of total body length in some cases. The tail fluke is broad (up to 40% of body length). The North Pacific species is on average the largest of the three species. The largest specimens may weigh 100 short tons (91 t).
Right whales have between 200 and 300 baleen plates on each side of their mouths. These are narrow and approximately 2 m (6.6 ft) long, and are covered in very thin hairs. The plates enable the whale to filter feed.
The penis on a right whale can be up to 2.7 m (8.9 ft) – the testes, at up to2 m (6.6 ft) in length, 78 cm (2.56 ft) in diameter, and weighing up to525 lb (238 kg), are also by far the largest of any animal on Earth. The blue whale may be the largest animal on the planet, but the testicles of the right whale are actually ten times the size of those of the blue whale. They also exceed predictions in terms of relative size, as well – they are six times larger than would be expected on the basis of body mass. Together, the testicles make up nearly 1% of the right whale's total body weight. This strongly suggests sperm competition is important in mating, which correlates to the fact that right whales are highly promiscuous.
The mean age of first parturition in North Atlantic right whales is estimated at between 7.5 and 9 years. Females breed every 3–4 years. Both reproduction and calving take place during the winter months. Calves are approximately 1 short ton (0.91 t) in weight and 4–6 m (13–20 ft) in length at birth following a gestation period of 1 year. The right whale grows rapidly in its first year, typically doubling in length. Weaning occurs after eight months to one year and the growth rate in later years is not well understood—it may be highly dependent on whether a calf stays with its mother for a second year.
Very little is known about the life span of right whales. One of the few well-documented cases is of a female North Atlantic right whale that was photographed with a baby in 1935, then photographed again in 1959, 1980, 1985, and 1992. Consistent callosity patterns ensured it was the same animal. She was last photographed in 1995 with a seemingly fatal head wound, presumably from a ship strike. By conservative estimates (e.g. she was a new mother who had just reached sexual maturity in 1935), she was nearly 70 years of age, if not older. Research on the closely related bowhead whale suggests this lifespan is not uncommon and may even be exceeded.
|This section does not cite any references or sources. (May 2012)|
Right whales swim slowly, reaching only 5 kn (9.3 km/h) at top speed, but are highly acrobatic and frequently breach (jump clear of the sea surface), tail-slap and lobtail. Like other baleen whales, the species is not gregarious and the typical group size is only two. Groups of up to 12 have been reported, but these were not close-knit and may have been transitory.
|This section does not cite any references or sources. (May 2012)|
Right whales are often marked by large scaly gray-white patches on their skin, whose patterns are unique from animal to animal. These patches, called callosities, are colonies of crustaceans known as whale lice which can exist in the tens of thousands upon each whale. The parasitic creatures subsist on algae and dead skin, and while they are irritants, they do not cause significant harm to the whale.
As with other baleens, they feed by filtering prey from the water. They swim with an open mouth, filling it with water and prey. The whale then expels the water, using its baleen plates to retain the prey. Prey must occur in sufficient numbers to trigger the whale's interest, be large enough that the baleen plates can filter it, and be slow enough that it cannot escape. The "skimming" may take place on the surface, underwater, or even at the ocean's bottom, indicated by mud occasionally observed on right whales' bodies.
The right whales' three known predators are humans, orcas, and sharks. When danger lurks, a group of right whales may cluster into a circle, and thrash their outwards-pointing tails. They may also head for shallow water, which sometimes proves to be an ineffective defense. The sheer size of this animal is its best defense, although a young calves are the most vulnerable to orca and shark attacks.
Range and habitat
The three Eubalaena species inhabit three distinct areas of the globe: the North Atlantic in the western Atlantic Ocean, the North Pacific in a band from Japan to Alaska and all areas of the Southern Ocean. The whales can only cope with the moderate temperatures found between 20 and 60 degrees in latitude. The warm equatorial waters form a barrier that prevents mixing between the northern and southern groups. Although the southern species in particular must travel across open ocean to reach its feeding grounds, the species is not considered to be pelagic. In general, they prefer to stay close to peninsulas and bays and on continental shelves, as these areas offer greater shelter and an abundance of their preferred foods.
Because the oceans are so large, it is very difficult to accurately gauge whale population sizes. Approximate figures:
- 400 to 450 North Atlantic right whales (Eubalaena glacialis) live in the North Atlantic;
- 30-50 North Pacific right whales live in the eastern North Pacific (Eubalaena japonica) and perhaps 100-200 more in the Sea of Okhotsk; and
- 12,000 southern right whales (Eubalaena australis) are spread throughout the southern part of the Southern Hemisphere.
North Atlantic right whale
Almost all of the 400 North Atlantic right whales live in the western North Atlantic Ocean. In northern spring, summer and autumn, they feed in areas off the Canadian and northeast U.S. coasts in a range stretching from New York to Nova Scotia. Particularly popular feeding areas are the Bay of Fundy and Cape Cod Bay. In winter, they head south towards Georgia and Florida to give birth.
There have been a smattering of sightings further east over the past few decades; several sightings were made close to Iceland in 2003. These are possibly the remains of a virtually extinct eastern Atlantic stock, but examination of old whalers' records suggests they are more likely to be strays. However, a few sightings are regular between Norway, Ireland, Spain, Portugal, the Canary Islands and even Italy and Sicily; at least the Norway individuals come from the Western stock.
North Pacific right whale
The North Pacific right whale appears to occur in two populations. The population in the eastern North Pacific/Bering Sea is extremely low, numbering about 30 individuals. A larger western population of 100-200 appears to be surviving in the Sea of Okhotsk, but very little is known about this population. Thus, the two northern right whale species are the most endangered of all large whales and two of the most endangered animal species in the world. Based on current population density trends, both species are predicted to become extinct within 200 years. The Pacific species was historically found in summer from the Sea of Okhotsk in the west to the Gulf of Alaska in the east, generally north of 50°N. Today, sightings are very rare and generally occur in the mouth of the Sea of Okhotsk and in the eastern Bering Sea. Although this species is very likely to be migratory like the other two species, its movement patterns are not known.
Southern right whale
The last major population review of southern right whales by the International Whaling Commission (IWC) was in 1998. Researchers used data about adult female populations from three surveys (one in each of Argentina, South Africa and Australia) and extrapolated to include unsurveyed areas and estimated counts of males and calves (using available male:female and adult:calf ratios), giving an estimated 1997 population of 7,500 animals. More recent data from 2007 indicate those survey areas have shown evidence of strong recovery, with a population approaching twice that of a decade earlier. However, other breeding populations are still very small, and data are insufficient to determine whether they, too, are recovering.
The southern right whale spends the summer months in the far Southern Ocean feeding, probably close to Antarctica. It migrates north in winter for breeding, and can be seen around the coasts of Argentina, Australia, Brazil, Chile, Mozambique, New Zealand and South Africa.
Since hunting of the southern right whale ceased, stocks are estimated to have grown by 7% a year. The South American, South African and Australasian groups apparently intermix very little, if at all, because of the strong fidelity of mothers to their feeding and calving grounds. The mother passes these instincts to her calves.
In Brazil, more than 300 individuals have been cataloged through photo identification (using their distinctive head callosities) by the Brazilian Right Whale Project, maintained jointly by Petrobras (the Brazilian state-owned oil company) and the International Wildlife Coalition. The State of Santa Catarina hosts a concentration of breeding and calving right whales from June to November, and females from this population are also known to calve off Argentinian Patagonia.
Vocalization and hearing
Vocalizations made by right whales are not elaborate compared to those made by other whale species. The whales make groans, pops and belches typically at frequencies around 500 Hz. The purpose of the sounds is not known but may be a form of communication between whales within the same group.
Northern right whales responded to sounds similar to police sirens—sounds of much higher frequency than their own. On hearing the sounds, they moved rapidly to the surface. The research was of particular interest because northern rights ignore most sounds, including those of approaching boats. Researchers speculate this information may be useful in attempts to reduce the number of ship-whale collisions or to encourage the whales to surface for ease of harvesting.
Relationship to humans
In the early centuries of shore-based whaling prior to 1712, right whales were virtually the only catchable large whales, for three reasons:
- They often swam close to shore where they could be spotted by beach lookouts, and hunted from beach-based whaleboats.
- They are relatively slow swimmers, allowing whalers to catch up to them in their whaleboats.
- Once killed by harpoons, they were more likely to float, and thus could be retrieved. However, many did sink when killed (10-30% in the North Pacific) and were lost unless they later stranded or surfaced.
Basque people were the first to commercially hunt right whales. They began as early as the 11th century in the Bay of Biscay. They initially sought oil, but as meat preservation technology improved, the animal was also used for food. Basque whalers reached eastern Canada by 1530 and the shores of Todos os Santos Bay (in Bahia, Brazil) by 1602. The last Basque voyages were made prior to the Seven Years' War (1756–1763). All attempts to revive the trade after the war failed. Basque shore whaling continued sporadically into the 19th century.
"Yankee whalers" from the new American colonies replaced the Basques. Setting out from Nantucket, Massachusetts and Long Island, New York, they took up to 100 animals in good years. By 1750, the commercial hunt of the North Atlantic right whale was basically over. The Yankee whalers moved into the South Atlantic before the end of the 18th century. The southernmost Brazilian whaling station was established in 1796, in Imbituba. Over the next hundred years, Yankee whaling spread into the Southern and Pacific Oceans, where the Americans were joined by fleets from several European nations. The beginning of the 20th century saw much greater industrialization of whaling, and the harvest grew rapidly. By 1937, there had been, according to whalers' records, 38,000 takes in the South Atlantic, 39,000 in the South Pacific, 1,300 in the Indian Ocean, and 15,000 in the north Pacific. The incompleteness of these records means the actual take was somewhat higher.
As it became clear the stocks were nearly depleted, the world banned right whaling in 1937. The ban was largely successful, although violations continued for several decades. Madeira took its last two right whales in 1968. Japan took 23 Pacific right whales in the 1940s and more under scientific permit in the 1960s. Illegal whaling continued off the coast of Brazil for many years and the Imbituba land station processed right whales until 1973. The Soviet Union illegally took at least 3,212 southern right whales during the 1950s and '60s, although it reported taking only four.
The southern right whale has made Hermanus, South Africa one of the world centers for whale watching. During the winter months (July–October), southern right whales come so close to the shoreline, visitors can watch whales from strategically placed hotels. The town employs a "whale crier" (cf. town crier) to walk through the town announcing where whales have been seen. Southern right whales can also be watched at other winter breeding grounds.
In Brazil, Imbituba in Santa Catarina has been recognized as the National Right Whale Capital and holds annual Right Whale Week celebrations in September, when mothers and calves are more often seen. The old whaling station there has been converted to a museum documenting the history of right whales in Brazil. In winter in Argentina, Península Valdés in Patagonia hosts the largest breeding population of the species, with more than 2,000 animals catalogued by the Whale Conservation Institute and Ocean Alliance.
The leading cause of death among the North Atlantic right whale, which migrates through some of the world's busiest shipping lanes while journeying off the east coast of the United States and Canada, is from being struck by ships. At least 16 ship-strike deaths were reported between 1970 and 1999, and probably more remain unreported. According to NOAA, 25 of the 71 right whale deaths reported since 1970 resulted from ship strikes. Recognizing this toll could tip the delicately balanced species towards extinction, in July 1997, the U.S. National Oceanic and Atmospheric Administration's (NOAA) introduced the Atlantic Large Whale Take Reduction Plan. A key part of the plan was the introduction of mandatory reporting of large whale sightings by ships using US ports.
A second major cause of morbidity and mortality in the North Atlantic right whale is entanglement in fishing gear. Right whales ingest plankton with wide-open mouths, risking entanglement in any rope or net fixed in the water column. Rope wraps around their upper jaws, flippers and tails. Most manage to escape with minor scarring, but some are seriously and persistently entangled. If observers notice, they can be successfully disentangled, but others die over a period of months. Animal welfare and extinction concerns align in emphasizing the harm of such entanglements.
Both the North Atlantic and North Pacific species are listed as a "species threatened with extinction which [is] or may be affected by trade" (Appendix I) by CITES, and as Conservation Dependent by the IUCN Red List, and as endangered under the US Endangered Species Act.
The US and Brazil added new protections for right whales in the 2000s to address the two primary hazards. While environmental campaigners were, as reported in 2001, pleased about the plan's positive effects, they attempted to force the US government to do more. In particular, they advocated 12 knots (22 km/h) speed limits for ships within 40 km (25 mi) of US ports in times of high right whale presence. Citing concerns about excessive trade disruption, it did not comply. The Defenders of Wildlife, the Humane Society of the United States and the Ocean Conservancy sued the National Marine Fisheries Service (a NOAA subagency) in September 2005 for "failing to protect the critically endangered North Atlantic Right Whale, which the agency acknowledges is 'the rarest of all large whale species' and which federal agencies are required to protect by both the Marine Mammal Protection Act and the Endangered Species Act", demanding emergency protection measures. According to NOAA researchers, about 83% of right whale sightings in the mid-Atlantic region occur within20 nautical miles (37 km) of shore.
The southern right whale, listed as "endangered" by CITES and "lower risk - conservation dependent" by the IUCN, is protected in the jurisdictional waters of all countries with known breeding populations (Argentina, Australia, Brazil, Chile, New Zealand, South Africa and Uruguay). In Brazil, a federal Environmental Protection Area encompassing some 1,560 km2 (600 sq mi) and 130 km (81 mi) of coastline in Santa Catarina State was established in 2000 to protect the species' main breeding grounds in Brazil and promote whale watching.
On February 6, 2006, NOAA proposed its Strategy to Reduce Ship Strikes to North Atlantic Right Whales. The proposal, opposed by some shipping interests, limited ship speeds during calving season. The proposal was implemented in 2008. On December 8, 2008, NOAA issued a press release that included the following:
- Effective January 2009, ships 65 feet (20 m) or longer are limited to 10 knots (19 km/h) in waters off New England when whales begin gathering in this area as part of their annual migration. The restriction extends to 20 nautical miles (37 km) around major mid-Atlantic ports.
- The speed restriction applies in waters off New England and the southeastern US, where whales gather seasonally.
- Southeastern US from St. Augustine, Fla. to Brunswick, Ga. from Nov 15 to April 15
- Mid-Atlantic U.S. areas from Rhode Island to Georgia from Nov 1 to April 30.
- Cape Cod Bay from Jan 1 to May 15
- Off Race Point at northern end of Cape Cod from March 1 to April 30
- Great South Channel of New England from April 1 to July 31
- Temporary voluntary speed limits in other areas or times when a group of three or more right whales is confirmed
- Scientists will assess the rule's effectiveness before the rule expires in 2013."
The Stellwagen Bank area has implemented an autobuoy program to acoustically detect right whales in the Boston Approaches and notify mariners via the Right Whale Listening Network website.
- Mead, James G.; Brownell, Robert L., Jr. (16 November 2005). "Order Cetacea (pp. 723–743)". In Wilson, Don E., and Reeder, DeeAnn M., eds. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). ISBN 978-0-8018-8221-0. OCLC 62265494. http://www.bucknell.edu/msw3/browse.asp?id=14300006.
- Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. (2008). "Eubalaena australis". IUCN Red List of Threatened Species. Version 2011.2. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/8153. Retrieved 18 May 2012.
- Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. (2008). "Eubalaena glacialis". IUCN Red List of Threatened Species. Version 2011.1. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/41712. Retrieved 18 September 2011.
- Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. (2008). Eubalaena japonica. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 7 October 2008.
- "North Atlantic Right Whale | Basic Facts About Right Whales | Defenders of Wildlife". Defenders.org. http://www.defenders.org/north-atlantic-right-whale/basic-facts. Retrieved May 10, 2012.
- Dolin, Eric Jay (2007). Leviathan: The History of Whaling in America. W.W. Norton & Co.. p. 22. ISBN 0-393-06057-8. http://books.google.com/books?id=KlVe8hYUpU4C&lpg=PP1&dq=leviathan&pg=PA22#v=onepage&q&f=false.
- Kenney, Robert D. (2008). "Right Whales (Eubalaena glacialis, E. japonica, and E. australis)". In Perrin, W. F.; Wursig, B.; Thewissen, J. G. M.. Encyclopedia of Marine Mammals. Academic Press. p. 963. ISBN 978-0-12-373553-9. http://books.google.com/books?id=2rkHQpToi9sC&pg=PA963. Retrieved 20 May 2012. ""The study by Churchill (2007) now has provided the evidence to conclude that the three living right whale species do comprise a phylogenetic lineage distinct from the bowhead and are rightly classified into a separate genus." (emphasis added)"
- J. Müller (1954). "Observations of the orbital region of the skull of the Mystacoceti". Zoologische Mededelingen 32: 239–290. 
- Palaeobiology and Biodiversity Research Group, University of Bristol
- Rice, Dale W. (1998). "Marine mammals of the world: systematics and distribution". Society of Marine Mammalogy Special Publication Number 4: 231pp.
- Rosenbaum, H. C., R. L. Brownell Jr., M. W. Brown, C. Schaeff, V. Portway, B. N. White, S. Malik, L. A. Pastene, N. J. Patenaude, C. S. Baker, M. Goto, P. Best, P. J. Clapham, P. Hamilton, M. Moore, R. Payne, V. Rowntree, C. T. Tynan, J. L. Bannister and R. Desalle (2000). "World-wide genetic differentiation of Eubalaena: Questioning the number of right whale species" (PDF). Molecular Ecology 9 (11): 1793–802. DOI:10.1046/j.1365-294x.2000.01066.x. PMID 11091315. ftp://swfscftp.noaa.gov/users/bhhanser/Papers%20included%20in%20table%20of%20Genetics%20working%20paper/Rosenbaum%20HC%20et%20al%202000%20right%20whale%20species.pdf.
- Brownell, R. L. Jr., P.J. Clapham, T. Miyashita and T. Kasuya (2001). "Conservation status of North Pacific right whales". Journal of Cetacean Research and Management (Special Issue) 2: 269–286.
- Kaliszewska, Z. A., J. Seger, S. G. Barco, R. Benegas, P. B. Best, M. W. Brown, R. L. Brownell Jr., A. Carribero, R. Harcourt, A. R. Knowlton, K. Marshalltilas, N. J. Patenaude, M. Rivarola, C. M. Schaeff, M. Sironi, W. A. Smith & T. K. Yamada (2005). "Population histories of right whales (Cetacea: Eubalaena) inferred from mitochondrial sequence diversities and divergences of their whale lice (Amphipoda: Cyamus)". Molecular Ecology 14 (11): 3439–3456. DOI:10.1111/j.1365-294X.2005.02664.x. PMID 16156814.
- Ross, Alison (September 20, 2005). "Whale riders' reveal evolution". BBC News. http://news.bbc.co.uk/2/hi/science/nature/4260498.stm.
- "Prehistoric Whale Discovered On The West Coast Of Sweden". Sciencedaily.com. June 5, 2009. http://www.sciencedaily.com/releases/2009/06/090605110420.htm. Retrieved May 10, 2012.
- Carwardine MH, Hoyt E (1998). Whales, Dolphins and Porpoises. Surry Hills, NSW: Reader's Digest. ISBN 0-86449-096-8.
- J. Müller (1954). "Observations of the orbital region of the skull of the Mystacoceti". Zoologische Mededelingen 32: 239–290. http://www.repository.naturalis.nl/record/318263.
- Woodward, Becky L.; Winn, Jeremy P.; Fish, Frank E. (2006). "Morphological Specializations of Baleen Whales Associated With Hydrodynamic Performance and Ecological Niche". Journal of Morphology 267 (11): 1284–1294. DOI:10.1002/jmor.10474. PMID 17051544. http://darwin.wcupa.edu/~biology/fish/pubs/pdf/2006jmorph.pdf. "The true buoyancy of a particular whale is dependent upon its body composition, particularly the relative quantities of muscle and blubber tissues. Balaenopterid whales have a higher proportion of muscle tissue and tend to be negatively buoyant while the opposite is true for right whales (Lockyer, 1976)."
- Lockyer, C. (1976). "Body weights of some species of large whales". Journal du Conseil Conseil International pour l'Exploration de la Mer 36 (3): 259–273. DOI:10.1093/icesjms/36.3.259.
- Crane, J.; Scott, R. (2002). "Eubalaena glacialis: North Atlantic right whale: Information". Animal Diversity Web. University of Michigan Museum of Zoology. http://animaldiversity.ummz.umich.edu/site/accounts/information/Eubalaena_glacialis.html. Retrieved April 30, 2006.
- Feldhamer, George A.; Thompson, Bruce C.; Chapman, Joseph A. (2003). Wild mammals of North America : biology, management, and conservation (2nd ed. ed.). Baltimore, Md.: Johns Hopkins University Press. p. 432. ISBN 9780801874161. http://books.google.com/books?hl=en&lr=&id=-xQalfqP7BcC&oi=fnd&pg=PA432#v=onepage&q&f=false.
- Brownell, Jr., Robert L.; Ralls, K. (1986). "Potential for sperm competition in baleen whales". Report of the International Whaling Commission 8 (8): 97–112.
- A.R. Knowlton, S.D. Kraus and R.D. Kenney (1994). "Reproduction in North Atlantic right whales (Eubalaena glacialis)". Canadian Journal of Zoology 72 (7): 1297–1305. DOI:10.1139/z94-173.
- P.K. Hamilton, A.R. Knowlton, M.K. Marx and S.D. Kraus (1998). "Age structure and longevity in North Atlantic right whales (Eubalaena glacialis) and their relation to reproduction". Marine Ecology Progress Series 171: 285–292. DOI:10.3354/meps171285.
- R. Payne, V. Rowntree, J.S. Perkins, J.G. Cooke and K. Lankester (1990). "Population size, trends and reproductive parameters of right whales (Eubalaena australis) off Peninsula Valdez, Argentina". Report - International Whaling Commission (Special Issue) 12: 271–278.
- P.B. Best (1994). "Seasonality of reproduction and the length of gestation in southern right whales Eubalaena australis". Journal of Zoology (London) 32 (2): 175–189. DOI:10.1111/j.1469-7998.1994.tb01567.x.
- Kenney, Robert D. (2002). "North Atlantic, North Pacific and Southern Right Whales". In William F. Perrin, Bernd Wursig and J. G. M. Thewissen. The Encyclopedia of Marine Mammals. Academic Press. pp. 806–813. ISBN 0-12-551340-2.
- Katona, S. K. and S. D. Kraus (1999). "Efforts to conserve the North Atlantic right whale". In J. R. Twiss and R. R. Reeves. Conservation and Management of Marine Mammals. Smithsonian Press. pp. 311–331.
- Notarbartolo di Sciara, G., E. Politi, A. Bayed, P.-C. Beaubrun and A. Knowlton (1998). "A winter cetacean survey off Southern Morocco, with a special emphasis on suitable habitats for wintering right whales". Sci. Rep. Int. Whaling Commission, SC/49/O3, 48: 547–550.
- Martin AR, Walker FJ (May 16, 1996). "SIGHTING OF A RIGHT WHALE (Eubalaena glacialis) WITH CALF OFF S. W. PORTUGAL". Marine Mammal Science 13 (1): 139–140. DOI:10.1111/j.1748-7692.1997.tb00617.x. http://www3.interscience.wiley.com/journal/119947961/abstract?CRETRY=1&SRETRY=0. Retrieved October 26, 2006.
- Jacobsen KO, Marx M, Øien N (May 21, 2003). "TWO-WAY TRANS-ATLANTIC MIGRATION OF A NORTH ATLANTIC RIGHT WHALE (Eubalaena glacialis)". Marine Mammal Science 20 (1): 161–166. DOI:10.1111/j.1748-7692.2004.tb01147.x. http://www3.interscience.wiley.com/journal/119922229/abstract. Retrieved October 26, 2006.
- Viegas, Jennifer (June 30, 2010). "Smallest whale population identified". Discovery News. http://www.msnbc.msn.com/id/38016305/ns/technology_and_science/?gt1=43001. Retrieved May 19, 2012.
- Rincon, Paul (December 3, 2003). "Northern Right Whales respond to emergency sirens". BBC News. http://news.bbc.co.uk/1/hi/sci/tech/3256406.stm. Retrieved May 10, 2012.
- Gaines CA, Hare MP, Beck SE, Rosenbaum HC (March 7, 2005). "Nuclear markers confirm taxonomic status and relationships among highly endangered and closely related right whale species". Proceedings of the Royal Society of LondonSeries B 272 (1562): 533–542. DOI:10.1098/rspb.2004.2895. PMC 1578701. PMID 15846869. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1578701.
- Scarff, JE (2001). "Preliminary estimates of whaling-induced mortality in the 19th century Pacific northern right whale (Eubalaena glacialis) fishery, adjusting for struck-but-lost whales and non-American whaling". J. Cetacean Res. Manage (Special Issue 2): 261–268.
- Tonnessen, J. N. and A. O. Johnsen (1982). The History of Modern Whaling. United Kingdom: C. Hurst & Co.. ISBN 0-905838-23-8.
- Reeves, Randall R., Brent S. Stewart, Phillip J. Clapham and James. A Powell (2002). National Audubon Society: Guide to Marine Mammals of the World. United States: Alfred A. Knopf, Inc.. ISBN 0-375-41141-0.
- "Ocean Alliance website". Oceanalliance.org. http://www.oceanalliance.org. Retrieved May 10, 2012.
- Vanderlaan & Taggart (2007). "Vessel collisions with whales: the probability of lethal injury based on vessel speed" (PDF). Mar. Mam. Sci. http://www.phys.ocean.dal.ca/~taggart/Publications/Vanderlaan_Taggart_MarMamSci-23_2007.pdf. Retrieved May 10, 2008.
- NOAA (December 8, 2008). "Press Release on Effective Date of Speed Regulations" (PDF). http://www.nmfs.noaa.gov/pr/pdfs/shipstrike/pressrelease_effective.pdf. Retrieved December 21, 2008.
- Author not specified (1997). "Atlantic Large Whale Take Reduction Plan". NOAA. NOAA. http://www.nero.noaa.gov/whaletrp/. Retrieved May 2, 2006.
- Author not specified (November 28, 2001). "Right whales need extra protection". BBC News (BBC News). http://news.bbc.co.uk/2/hi/science/nature/1681532.stm. Retrieved May 2, 2006.
- The Southeast United States Right Whale Recovery Plan Implementation Team and the Northeast Implementation Team (November 2005). "NMFS and Coast Guard Inactions Bring Litigation" (PDF). Right Whale News 12 (4). http://www.narwc.org/pdf/rwn/rwnov05.pdf. Retrieved May 2, 2006.
- Petrobras, Projeto Baleia Franca. More information on Brazilian right whales is available in Portuguese.
- NOAA. Proposed Strategy to Reduce Ship Strikes to North Atlantic Right Whales.