text: right whale right 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 the maximum record of 19 . 8 m ( 65 ft ) and weigh up to 100 short tons ( 91 t ; 89 long tons ) or more ; 20 . 7 m ( 68 ft ) with 135 , 000 kg ( 298 , 000 lb ) or 21 . 3 m ( 70 ft ) with uncertainty , being significantly larger than other coastal species such as humpbacks , grays , or eden 's and 's , but smaller than blues . right whales were named by whalers who 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 . 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 on the ocean bottom . during courtship , males gather into large groups to compete for a single female , suggesting that sperm competition appears to be 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 tendencies 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 no longer facing a threat from whaling , mankind remains by far the greatest threat to these species : the two leading causes of death are from being struck by ships and from entanglement in fishing gear . regarding the north atlantic right whale , for example , these two anthropogenic factors alone account for 48 % of all known right whale deaths since 1970 . naming 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 . " taxonomy 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 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 . in 2001 , brownell et al. reevaluated the conservation status of the north pacific right whale as a distinct species , and in 2002 , the scientific committee of the international whaling commission ( iwc ) accepted rosenbaum 's findings , and recommended that the eubalaena nomenclature be retained for this genus . 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 two separate genera . the cladogram is a tool for visualizing and comparing the evolutionary relationships between taxa ; the point where each node branches is analogous to an evolutionary branching – the diagram can be read left - to - right , much like a timeline . the following cladogram of the family balaenidae serves to illustrate the current scientific consensus as to the relationships between the three right whales and the bowhead whale . whale lice , parasitic 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 rising temperatures of the equator then created a second split , into northern and southern groups , preventing them from interbreeding . " 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 . others the pygmy right whale ( caperea marginata ) , a much smaller whale of the southern hemisphere , was until recently considered a member of the family balaenidae . however , they are not right whales at all , and their taxonomy is presently in doubt . most recent authors place this species into the monotypic family neobalaenidae , but a 2012 study suggests that it is instead the last living member of the family cetotheriidae , a family previously considered extinct . yet another species of right whale was proposed by emanuel 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 , 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 debated , and further evidence for this species was discovered during the construction of a motorway in strömstad , sweden in 2009 . to date , however , scientific consensus still considers hunterius to be a north atlantic right whale . according to a dna analysis conducted by scientists , it was later confirmed that the fossil bones are actually from a bowhead whale . 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 . there is a deal of obscurity concerning the identity of the species thus baptised . ... some pretend to see a difference between the greenland whale of the english and the right whale of the americans . " in fact , there was indeed a difference between the two – melville 's " greenland whale " , or " greenland right whale " , was in fact the modern - day bowhead whale , balaena mysticetus . the following are junior synonyms for the genus eubalaena : , 1989 gray , 1873 hunterius gray , 1866 gray , 1864 marschall , 1873 macleayius gray , 1865 although the right whale is now officially in the eubalaena genus , the type species for a genus remains as it was first described – in the case of eubalaena the type species is balaena australis desmoulins , 1822 . some of the species - level synonyms are : for e. australis : b. antarctica lesson , 1828 b. mysticetus antarctica schlegel , 1841 b. gray , 1843 b. glacialis mueller , 1776 b. glacialis australis scheffer & rice , 1963 e. capensis gray , 1866 e. glacialis australis tomilin , 1962 gray , 1873 gray , 1864 macleayius australiensis gray , 1865 for e. glacialis : b. , 1860 b. glacialis glacialis scheffer & rice , 1963 b. mysticetus kerr , 1792 b. lacépède , 1804 glacialis , 1989 e. glacialis glacialis tomilin , 1957 hunterius , 1867 macleayius gray , 1870 for e. japonica : b. japonica lacépède , 1804 ( basionym ) b. gray , 1864 balaenoptera antarctica temminck , 1841 ( lapsus for balaena ) e. glacialis japonica imaizumi , 1958 e. gray , 1868 description 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 ( whale lice ) . each individual has a unique callosities pattern . in 2016 , a competitive effort resulted in the use of facial recognition software to derive a process to uniquely identify right whales with about 87 % accuracy based on their callosities . the primary role of callosities has been considered to be protection against predators . right whale declines might have also reduced barnacles . right whales are very large , robust whales that can grow up to more than 18 m ( 59 ft ) long and weigh up to 100 short tons ( 91 t ; 89 long tons ) , almost as big as bowhead whales and much larger than other species with high dependencies on shallow waters . an unusually large 40 % of their body weight is blubber , which is of relatively low density . consequently , unlike many other species of whale , dead right whales tend to float . right whales swim slowly , reaching only 5 kn ( 9 . 3 km / h ) at top speed . however , they are highly acrobatic and frequently breach ( jump clear of the sea surface ) , tail - slap and . anatomy adults may be between 11 – 18 m ( 36 – 59 ft ) in length and typically weigh 60 – 80 short tons ( 54 – 73 t ; 54 – 71 long tons ) . 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 ; 89 long tons ) . right whales have a distinctive wide v - shaped blow , caused by the widely spaced blowholes on the top of the head . the blow rises 5 m ( 16 ft ) above the surface . 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 to 2 m ( 6 . 6 ft ) in length , 78 cm ( 2 . 56 ft ) in diameter , and weighing up to 525 kg ( 1157 lbs ) , are also by far the largest of any animal on earth . the blue whale may be the largest animal on the planet , yet the testicles of the right whale are 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 . many of southern right whales are seen with rolls on fats behind blowholes that northern species often lack , and these are regarded as a sign of better health condition due to sufficient nutrition supply , and could have contributed in vast differences in recovery status between right whales in southern and northern hemisphere , other than direct impacts by mankind . life history and ecology courtship and reproduction during the mating season , which can occur at any time in the north atlantic , right whales gather into " surface - active groups " made up of as many as 20 males consorting a single female . the female has her belly to the surface while the males stroke her with their flippers or keep her underwater . the males do not compete as aggressively against each other as male humpbacks . the female may not become pregnant but she is still able to assess the condition of potential mates . the mean age of first parturition in north atlantic right whales is estimated at between 7 . 5 and 9 years . females breed every 3 – 5 years . both reproduction and calving take place during the winter months . calves are approximately 1 short ton ( 0 . 91 t ; 0 . 89 long tons ) 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 . lifespan 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 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 . diet and predation the right whales ' diets consist primarily of zooplankton , primarily the tiny crustaceans called copepods , as well as krill , and pteropods , although they are occasionally opportunistic feeders . as with other , 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 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 north atlantic right whales ( eubalaena glacialis ) live in the north atlantic ; 23 north pacific right whales have been identified in the eastern north pacific ( eubalaena japonica ) and 15 , 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 newfoundland . 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 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 . 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 whaling in the early centuries of shore - based whaling before 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 , some 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 hunt right whales commercially , beginning 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 before 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 . whale watching 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 dedicated to the whales . in winter in argentina , 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 . conservation 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 " endangered " by the iucn red list . in the united states , the national marine fisheries service ( nmfs ) , a of the national oceanic and atmospheric administration ( noaa ) has classified all three species as " endangered " under the endangered species act . under the marine mammal protection act , they are listed as " depleted " . the southern right whale is listed as " endangered " under the australian environment protection and biodiversity conservation act , as " nationally endangered " under the new zealand threat classification system , as a " natural monument " by the argentine national congress , and as a " state natural monument " under the brazilian national endangered species list . 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 institute greater protections . the defenders of wildlife , the humane society of the united states and the ocean conservancy sued the nmfs 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 within 20 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 made official when 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 , florida to brunswick , georgia 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 the 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 bank area has implemented an program to acoustically detect right whales in the boston approaches and notify mariners via the right whale listening network website . threats 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 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 . 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 . some are able to escape , but others remain tangled . whales can be successfully disentangled , if observed and aided . in july 1997 , the u.s. noaa introduced the atlantic large whale take reduction plan , which seeks to minimize whale entanglement in fishing gear and record large whale sightings in an attempt to estimate numbers and distribution . in 2012 , the u.s. navy proposed to create a new undersea naval training range immediately adjacent to northern right whale calving grounds in shallow waters off the florida / georgia border . legal challenges by leading environmental groups including the natural resources defense council were denied in federal court , allowing the navy to proceed . these rulings were made despite the extremely low numbers ( as low as 313 by some estimates ) of right whales in existence at this time , and a very poor calving season .