North Atlantic Right Whales were hunted for at least 800 years, until they became so rare that it was no longer commercially viable to exploit them. Now numbering only in the hundreds, and showing no signs of recovery, Northern right whales are nearly extinct. Some populations have not shown any significant reproduction, even after becoming protected by law.
Today, the North Atlantic right whale is a rarely observed species, but its name derives from an era when they were more frequently sighted, when they swam slowly, close to shore, thus making them an easy target for whalers. Not only did this swimming behaviour make this whale the right one to hunt, but this whale also floats when dead and yielded vast quantities of valuable oil and baleen.
Despite its bulky size, the North Atlantic right whale is able to perform acrobatic acts such as jumping out of the water, known as breaching, violently slapping the water surface with the tail and/or a pectoral fin. Although the purpose of these behaviours is not fully understood, they may be used in communication. Similarly, the range of low frequency groans, moans and belches that the North Atlantic right whale makes are hypothesised to be used to communicate with other individuals, or signal aggression.
Remarkable for massive size, North Atlantic right whales feed chiefly on minute planktonic prey, including large copepods, the size of a grain of rice; krill, a shrimp-like crustacean; tiny planktonic snails and the drifting larval stages of barnacles and other crustaceans. North Atlantic right whales are skim feeders, meaning they consume prey by swimming forward with mouths open, allowing water to flow into the mouth and out through the baleen. Tiny prey are strained from the water as it becomes caught in the fringed baleen, where it is then dislodged by the tongue and swallowed. Although this whale often feeds at or immediately below the ocean surface, the North Atlantic right whale is also believed to sometimes feed close to the bottom, since it has been seen surfacing after a 10 to 20 minute dive with mud on its head.
After feeding at northern latitudes during the summer, the North Atlantic right whale migrates south for winter. Pregnant females head for the inshore calving grounds, whilst the location of the remaining majority of the population is not known. Wherever they move, this is the season at which mating takes place.
North Atlantic right whale females typically first calve at nine to ten years of age, therafter giving birth to a single young every three years. The gestation period lasts for about one year, and following birth, the mother and her young remain close until the calf is weaned at the age of one. During its first year of life the calf learns the location of critical feeding grounds from its mother, which it will continue to visit for the remainder of its life. The female then takes a third year to replenish her energy stores before breeding again.
- * Encyclopedia of Earth. Author: Encyclopedia of Life. 2011. Topic ed. C.Michael Hogan. Ed.-in-chief Cutler J.Cleveland. National Council for Science and the Environment http://www.eoearth.org/article/North_Atlantic_Right_Whale?topic=49540
- * D.W.Macdonald. 2006. The Encyclopedia of Mammals. Oxford University Press, Oxford.
- * C.A.Mayo and M.K.Marx. 1990. Surface foraging behavior of the North Atlantic right whale, Eubalaena glacialis, and associated zooplankton characteristics. Canadian Journal of Zoology, (68), pp. 2214-20.
- ARKive. 2008. North Atlantic right whale (Eubalaena glacialis)
- * A.R.Martin and F.J.Walker. 1997. Sighting of a right whale (Eubalaena glacialis) with calf off S. W. Portugal. Marine Mammal Science 13(1): 139-141.
The North Atlantic right whale differs in skin color from the North Pacific right whale and the cold waters of the Arctic Circle are a natural impediment to the mingling of these two groups."
Adaptation: This skull of a Right whale (Eubalaena) is shown with the mandible dropped into the open position, illustrating how the baleen plates hang like a curtain of filters to strain and separate food from a mouthful of water.
Mammal Species of the World
More images, video and sound
- Original description: Linnaeus, C., 1758. Systema Naturae per regna tria naturae, secundum classis, ordines, genera, species cum characteribus, differentiis, synonymis, locis. Tenth Edition, Laurentii Salvii, Stockholm, 1:75, 824 pp.
North Atlantic Right Whales (Eubalaena glacialis) inhabit the Atlantic Ocean, especially between 20o and 60o N latitude. Most individuals in the western North Atlantic population range from wintering and calving areas in coastal waters off the southeastern United States to summer feeding and nursery grounds in New England waters and north to the Bay of Fundy and Scotian Shelf. In 1991, five "high use" areas were identified by the National Marine Fisheries Service: (1) coastal Florida and Georgia, (2) Great South Channel, (3) Massachusetts Bay and Cape Cod Bay, (4) Bay of Fundy, and (5) Scotian Shelf (NOAA Fisheries Office of Protected Resources Website, accessed 10 December 2009, http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/rightwhale_northatlantic.htm).
The eastern North Atlantic population may originally have migrated along the coast from northern Europe to the northwest coast of Africa. Historical records suggest these animals were heavily exploited by whalers from the Bay of Biscay (off southern Europe) and Cintra Bay (off the northwestern coast of Africa), as well as off coastal Iceland and the British Isles. During the early to mid 1900s, right whales were intensely harvested in the Shetlands, Hebrides, and Ireland. Recent surveys suggest right whales no longer frequent Cintra Bay or northern European waters. Due to a lack of sightings, current distribution and migration patterns of the eastern North Atlantic right whale population are unknown (NOAA Fisheries Office of Protected Resources Website, accessed 10 December 2009, http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/rightwhale_northatlantic.htm).
What was long treated as a single right whale species is now recognized as three distinct species by both scientists and federal regulatory agencies (Rosenbaum et al. 2000; Gaines et al. 2005; http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/). The North Pacific right whale (Eubalaena japonica), which inhabits the Pacific Ocean, especially between 20o and 60o N latitude, is now widely recognized as a species distinct from the North Atlantic right whale. Similarly, the Southern right whale (Eubalaena australis) is now recognized as a distinct species occurring in the southern hemisphere between around 20o and 60o S latitude.
occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (20,000-2,500,000 square km (about 8000-1,000,000 square miles)) Remnant populations occur in the North Atlantic (mainly Florida and Gulf of Mexico to Labrador). Very rare in the eastern North Atlantic (fewer than 10 reliable sightings within the past 50 years, but including a female and calf were observed off Portugal in 1995 (Martin and Walker 1997). North Atlantic high-use areas include coastal Florida and Georgia (winter calving); Great South Channel east of Cape Cod, Massachusetts (spring feeding); Massachusetts Bay and Cape Cod Bay (winter-spring feeding); Bay of Fundy (summer and fall feeding and nursery area); and Browns and Baccaro banks south of Nova Scotia (Roseway Basin, summer and fall feeding) (Right Whale Recovery Team 1990, Malik et al. 1999). See Right Whale Recovery Team (1990) and IUCN (1991) for further details. The Bay of Fundy is the important nursery area, but at least one other nursery area (as yet unidentified) must exist (Schaeff et al. 1993, Malik et al. 1999).
- North-West Atlantic Ocean species (NWARMS)
- UNESCO-IOC Register of Marine Organisms
The range map shows where the species may occur, based on oceanography. The species has not been recorded for all the states within the hypothetical range as shown on the map. States for which confirmed records of the species exist are included in the list of native range states.
Northern right whales were once found throughout the Northern Hemisphere. These whales inhabit the temperate and subpolar waters of the north Atlantic and north Pacific oceans. In the North Pacific they are found from about 25 to 60 degrees north and in the North Atlantic from about 30 to 75 degrees north. Northwest Atlantic populations occur from Iceland to the Gulf of Mexico, with largest concentrations occurring between Nova Scotia, Canada, and Florida. Winter calving grounds occur off the coasts of Florida and Georgia.
Right whales move from subpolar regions with the onset of winter to lower latitudes, staying near land masses. Some good areas to see them are from Cape Cod north to the Bay of Fundy, Nova Scotia and Grand Manan Island, New Brunswick.
Northern Pacific populations are isolated from Northern Atlantic populations and are genetically distinct. These populations are sometimes referred to as Eubalaena japonica, Northern Pacific right whales, and occur from the southeastern Bering Sea to the Okhotsk Sea off western Russia. Northern Pacific populations may be more closely related to southern right whales, Eubalaena australis, than to Northern Atlantic populations of northern right whales (Northern Atlantic right whales).
Biogeographic Regions: arctic ocean (Native ); atlantic ocean (Native ); pacific ocean (Native )
- Rosenbaum, H., R. Brownell, M. Brown, C. Schaeff, V. Portway, B. White, S. Malik, L. Pastene, N. Patenaude, C. Baker, M. Goto, P. Best, P. Clapham, P. Hamilton, M. Moore, R. Payne, V. Rowntree, C. Tynan, J. Bannister, R. DeSalle. 2000. World-wide genetic differentiation of Eubalaena: questioning the number of right whale species.. Molecular Ecology, 9: 1793-1802. Accessed December 01, 2003 at http://www.nefsc.noaa.gov/psb/pubs/rosenbaummolecol.pdf.
Eubalaena glacialis is typically uniformly dark in color except for scars, belly patches, parasites and head excrescences or callosities, most of which are light. Callosities are prominent on the rostrum, near blowholes, near eyes, and on the chin and lower lip. These large crusty growths often harbor crustaceans called whale lice, and may therefore appear white, orange, yellow, or pink. Hair can be found on the tips of the chin and upper jaw and is also associated with the callosities. Right whales have no dorsal fin, nor do they have the grooved throat. The flippers are very broad and short.
Compared to other mysticetes, right whales are very large in girth relative to their length giving them a rotund appearance. The jaws are greatly arched in order to fit the exceptionally long baleen. Baleen can reach a maximum length of 5 m with an average of 300 plates on either side. The head is enormous, close to one-third the body length. There is sexual dimorphism; females are larger than males. Young are 4.5 to 6m long at birth. Adults can be up to 17m long and weigh up to 100 tons.
The blowholes are well partitioned on the exterior surface, resulting in a vertical V-shaped blow that may be up to 5m high. The largest amount of blubber found in whales is that of right whales. The average thickness is 20 inches and can be as thick as 28 inches. It comprises 36-45% of the total body weight. All seven cervical vertebrae are fused into one osseous unit. They are extremely slow swimmers, swimming at an average of 2 knots and rarely exceeding 5 knots.
(Cummings 1985, Slijper 1979).
Range mass: 55000 to 95000 kg.
Range length: 17 (high) m.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: female larger
Length: 1400 cm
Weight: 2.3E7 grams
Size in North America
Average: 17 m
Range: up to 18 m
Right whales differ from other large whales in having callosities on the head; also, the absence of a dorsal fin distinguishes right whales from many other large whales. Lacks the knuckled ridge along the spine and the more elongate body and flippers of the gray whale. There are no known external morphological differences between E. GLACIALIS and E. AUSTRALIS, though it has been suggested that callosities along the upper surface of the lower lips are present more consistently in AUSTRALIS (see Leatherwood and Reeves 1983); of course, the two taxa cannot be mistaken in the field since their ranges are far apart.
- North-West Atlantic Ocean species (NWARMS)
Catalog Number: USNM 301637
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals
Preparation: Skull; Skeleton; Photograph
Collector(s): G. Davidson
Year Collected: 1861
Locality: Delaware River, Near Philadelphia On Coast Of New Jersey, *, New Jersey, United States, Delaware Bay, North America, North Atlantic Ocean
- Type: Cope, E. D. 1865. Proc. Acad. Nat. Sci. Philadelphia. 1865: 168.
Habitat Type: Marine
Comments: Inhabits nearshore and offshore waters. Mainly coastal in the North Atlantic, occurs over the continental shelf in the North Pacific (Right Whale Recovery Team 1990). Tynan et al. (2001) found a few of the remaining North Pacific animals concentrated in relatively warm (10.4 C SST), shallow (50 to 80 m deep), well-stratified water in an extensive coccolithophore bloom of EMILIANIA HUXLEYI. Mother-calf pairs generally concentrate their summer feeding activities in relatively secluded areas away from sites frequented by other whales (Schaeff et al. 1993).
- North-West Atlantic Ocean species (NWARMS)
Habitat and Ecology
Depending on the time of year and which hemisphere they're found, right whales will spend much of their time near bays and peninsulas and in shallow, coastal waters. This can provide shelter, food abundance, and security for females rearing young or avoiding the mating efforts of males. Four critical habitats for northern right whales are the Browns-Baccaro Bank, Bay of Fundy, Great South Channel, and the Cape Cod Bay. Each of these is distinguished by high densities of copepod populations. The first three have deep basins (150 m) flanked by relatively shallow water. Copepods are concentrated here because of convergences and upwellings driven by tidal currents. This also occurs in the Cape Cod Bay even though a deep basin isn't present.
(Cummings 1985, Katona 1999)
Habitat Regions: temperate ; polar ; saltwater or marine
Aquatic Biomes: coastal
Water temperature and chemistry ranges based on 433 samples.
Depth range (m): 0 - 8
Temperature range (°C): 3.976 - 26.026
Nitrate (umol/L): 0.286 - 4.522
Salinity (PPS): 31.523 - 36.280
Oxygen (ml/l): 4.690 - 7.680
Phosphate (umol/l): 0.092 - 0.673
Silicate (umol/l): 0.868 - 3.669
Depth range (m): 0 - 8
Temperature range (°C): 3.976 - 26.026
Nitrate (umol/L): 0.286 - 4.522
Salinity (PPS): 31.523 - 36.280
Oxygen (ml/l): 4.690 - 7.680
Phosphate (umol/l): 0.092 - 0.673
Silicate (umol/l): 0.868 - 3.669
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.
Stellwagen Bank Pelagic Community
The species associated with this page are major players in the pelagic ecosystem of the Stellwagen Bank National Marine Sanctuary. Stellwagen Bank is an undersea gravel and sand deposit stretching between Cape Cod and Cape Ann off the coast of Massachussets. Protected since 1993 as the region’s first National Marine Sanctuary, the bank is known primarily for whale-watching and commercial fishing of cod, lobster, hake, and other species (Eldredge 1993).
Massachusetts Bay, and Stellwagen Bank in particular, show a marked concentration of biodiversity in comparison to the broader coastal North Atlantic. This diversity is supported from the bottom of the food chain. The pattern of currents and bathymetry in the area support high levels of phytoplankton productivity, which in turn support dense populations of schooling fish such as sand lance, herring, and mackerel, all important prey for larger fish, mammals, and seabirds (NOAA 2010). Sightings of many species of whales and seabirds are best predicted by spatial and temporal distribution of prey species (Jiang et al 2007; NOAA 2010), providing support for the theory that the region’s diversity is productivity-driven.
Stellwagen Bank is utilized as a significant migration stopover point for many species of shorebird. Summer visitors include Wilson’s storm-petrel, shearwaters, Arctic terns, and red phalaropes, while winter visitors include black-legged kittiwakes, great cormorants, Atlantic puffins, and razorbills. Various cormorants and gulls, the common murre, and the common eider all form significant breeding colonies in the sanctuary as well (NOAA 2010). The community of locally-breeding birds in particular is adversely affected by human activity. As land use along the shore changes and fishing activity increases, the prevalence of garbage and detritus favors gulls, especially herring and black-backed gulls. As gull survivorship increases, gulls begin to dominate competition for nesting sites, to the detriment of other species (NOAA 2010).
In addition to various other cetaceans and pinnipeds, the world’s only remaining population of North Atlantic right whales summers in the Stellwagen Bank sanctuary. Right whales and other baleen whales feed on the abundant copepods and phytoplankton of the region, while toothed whales, pinnipeds, and belugas feed on fish and cephalopods (NOAA 2010). The greatest direct threats to cetaceans in the sanctuary are entanglement with fishing gear and death by vessel strikes (NOAA 2010), but a growing body of evidence suggests that noise pollution harms marine mammals by masking their acoustic communication and damaging their hearing (Clark et al 2009).
General threats to the ecosystem as a whole include overfishing and environmental contaminants. Fishing pressure in the Gulf of Maine area has three negative effects. First and most obviously, it reduces the abundance of fish species, harming both the fish and all organisms dependent on the fish as food sources. Secondly, human preference for large fish disproportionately damages the resilience of fish populations, as large females produce more abundant, higher quality eggs than small females. Third, by preferentially catching large fish, humans have exerted an intense selective pressure on food fish species for smaller body size. This extreme selective pressure has caused a selective sweep, diminishing the variation in gene pools of many commercial fisheries (NOAA 2010). While the waters of the SBNMS are significantly cleaner than Massachusetts Bay as a whole, elevated levels of PCBs have been measured in cetaceans and seabird eggs (NOAA 2010). Additionally, iron and copper leaching from the contaminated sediments of Boston Harbor occasionally reach the preserve (Li et al 2010).
- Clark CW, Ellison WT, Southall BL, Hatch L, Van Parijs SM, Frankel A, Ponirakis D. 2009. Acoustic masking in marine ecosystems: intuitions, analysis and implication. Inter-Research Marine Ecology Progress Series 395:201-222.
- Eldredge, Maureen. 1993. Stellwagen Bank: New England’s first sanctuary. Oceanus 36:72.
- Jiang M, Brown MW, Turner JT, Kenney RD, Mayo CA, Zhang Z, Zhou M. Springtime transport and retention of Calanus finmarchicus in Massachusetts and Cape Cod Bays, USA, and implications for right whale foraging. Marine Ecology 349:183-197.
- Li L, Pala F, Mingshun J, Krahforst C, Wallace G. 2010. Three-dimensional modeling of Cu and Pb distributions in Boston Harbor, Massachusetts and Cape Cod Bays. Estuarine Coastal & Shelf Science. 88:450-463.
- National Oceanographic & Atmospheric Administration. 2010. Stellwagen Bank National Marine Sanctary Final Management Plan and Environmental Assessment. “Section IV: Resource States” pp. 51-143. http://stellwagen.noaa.gov/management/fmp/pdfs/sbnms_fmp2010_lo.pdf
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Migrates seasonally between high latitudes (summer) and lower latitudes (winter), though migrations are less regular and coherent than those of humpback or gray whale (Leatherwood and Reeves 1983).
North Atlantic: generally most spend early summer off the coast of New England, move to waters off southern Canada (lower Bay of Fundy or area between Browns and Baccaro banks) in late summer and fall; some remain in northern waters in winter but most leave (beginning as early as October); pregnant females move south to winter calving areas off Georgia and Florida; wintering area for the rest of the population is unknown; northward movement occurs in late winter and early spring; perhaps most of the population moves through the Cape Cod-Massachusetts Bay area and Great South Channel March-May (Right Whale Recovery Team 1990). Females usually and males commonly return to their natal area in subsequent summers (Schaeff et al. 1993).
North Pacific: may be nomadic in summer, movements depending on where food resources are abundant; winter range is largely unknown (Right Whale Recovery Team 1990).
Comments: Diet mainly calanoid copepods and juvenile euphausiids. Feeds by skimming--swims with mouth open usually below the surface, sometimes at the surface. Depends on concentrations of zooplankton. In Bay of Fundy, appeared to exploit patches of copepods at densities greater than about 820 per cubic m (Murison and Gaskin 1989). In Cape Cod Bay, rarely fed where total zooplankton density was less than 1000 organisms per cubic meter (Mayo and Marx 1990). In the southeastern Bering Sea, fed primarily on later copepodite stages of the calanoid copepod CALANUS MARSHALLAE. Historically (1940s-1960s), this population had concentrated on the oceanic copepod NEOCALANUS CRISTATUS in deeper waters (Tynan et al. 2001).
Northern right whales tend to skim near the surface of the water feeding on small copepods, krill, and euphausiids. The whales swim along the surface, or just below, with their mouth open, skimming the zooplankton from the water. The water passes through a series of large baleen plates which filter out the food. The whale will skim the surface for a while, then close its mouth and push its tongue against the baleen to collect its meal. Whales tend not to feed until they find large concentrations of food. When they find these concentrations, they swim through the mass, making accurate adjustments to their course in order to maximize their intake (Slijper 1979, Evans 1987).
Animal Foods: aquatic crustaceans; zooplankton
Foraging Behavior: filter-feeding
Primary Diet: planktivore
Baleen whales, like northern right whales, are important as predators on krill and other planktonic invertebrates in marine environments.
Although they typically don't live together in groups, they may temporarily cluster together to form a defensive circle when threatened by a potential predator. In those circumstances, the whales form a circle with flailing tails pointed outwards. They may also move into shallow waters to attempt to overt the predator but sharks and killer whales (orcas) are able to continue to stalk in these depths. The right whale was hunted by man easily because it comes close to shore, is slow-moving and floats when killed (Evans 1987).
These whales are protected from most predators by their formidable size, calves may be targeted by killer whales (orcas) and sharks.
This list may not be complete but is based on published studies.
Known prey organisms
This list may not be complete but is based on published studies.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 1 - 5
Comments: Probably fewer than five nursery areas; only three or four populations.
250 - 1000 individuals
Comments: Total population is estimated at 200-350 in the North Atlantic (NMFS 1987, Right Whale Recovery Team 1990, Mayo and Marx 1990). North Atlantic population produced 8-13 calves per year in the 1980s (Matthews and Moseley 1990).
Travels singly or in small groups of 2-3, though may aggregate in areas with high concentration of food.
Life History and Behavior
- North-West Atlantic Ocean species (NWARMS)
Communication and Perception
Right whales make simple and complex low-frequency noises and a "belch-like utterance" that is their most common sound. These low-frequency sounds are chacteristic of balleen whales while high-frequency sounds are more typical of toothed whales. Other sounds are described as grunting, mooing, moaning, sighing, and bellowing. The maximum energy (Hz) recorded in southern right whales ranged from 50-500 and the duration ranged from 0.5 to 6.0 seconds. (Slijper 1979)
Communication Channels: tactile ; acoustic
Perception Channels: acoustic ; ultrasound
Comments: Active day/night.
Lifespan, longevity, and ageing
Data on mean longevity are not yet available. An indication that potential longevity can be very long was obtained by serendipity. A picture was taken of a female and her calf in 1935 in Florida. The animal was seen in 1959 off Cape Cod and irregularly until the summer of 1995. Assuming it was her first calf in the original picture and she was at the age of sexual maturity or eight years old, she would have been 67 years old when last seen.
Their close relatives, bowhead whales, have been recorded with lifespans approaching 200 years, so it's likely that right whales have very long lifespans.
Status: wild: 67 (high) years.
Status: captivity: 67 years.
Gestation may be about 16 months (Right Whale Recovery Team 1990) (also reported as 11-12 months and 13-14 months). Peak in calving apparently occurs from December through March off the southeastern U.S. (Right Whale Recovery Team 1990). Young nurse for at least 9 months (Right Whale Recovery Team 1990) (another report: weaned in 6-7 months). During their first year, calves accompany their mothers during the spring migration and summer feeding (Schaeff et al. 1993). Sexually mature in 5-9 years. Mean age of first parturition is 7.6 years (Knowlton et al. 1994). One calf is produced generally every 3-5 years.
Eubalaena glacialis copulates from December to March, when most of the young are born. After much nuzzling and caressing, mating right whales roll about randomly exposing flippers, flukes, backs, bellies, and portions of their heads. It has been noted that the male would sometimes begin precopulatory behavior by placing his chin on the exposed hindquarters of the female. It is believed that most right whales are polygamous and no permanent pair bonds are formed. Females probably mate with multiple males. No aggression has been observed between competing males, which is a rare behavior in mammals. Courting bouts may last for an hour or two, after which participants go their own way. Both males and females are seen on their back at the water's surface but females may show this posture to move her genitalia away from a pursuing male. Males tend to have the largest testes of an living mammal (weighing up to about 525 kg.), suggesting that sperm competition may play a significant role in determining mating success.
Mating System: polygynandrous (promiscuous)
Northern right whales mate in the winter and give birth in the spring to a single young. Females give birth to up to one calf every three to four years. Young are typically born in winter.
Males are sexually mature at a length of 15 m and females at 15.5 m, these sizes may be reached between 5 and 10 years of age.
Breeding interval: Females give birth to a single calf every 3 to 4 years.
Breeding season: Mating and births occur in the winter.
Average number of offspring: 1.
Average gestation period: 12 months.
Range age at sexual or reproductive maturity (female): 5 to 10 years.
Range age at sexual or reproductive maturity (male): 5 to 10 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization (Internal ); viviparous
Average gestation period: 350 days.
Average number of offspring: 1.
Right whales are 4.5 to 6 meters in length when they are born. They grow rapidly thereafter, attaining a size of 12 meters by 18 months old. The length of lactation and dependence are not well known.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
Evolution and Systematics
Systematics and Taxonomy
What was long treated as a single right whale species is now recognized as three distinct species by both scientists and federal regulatory agencies (Rosenbaum et al. 2000; Gaines et al. 2005; http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/). The North Pacific right whale (Eubalaena japonica), which inhabits the Pacific Ocean, especially between 20o and 60o N latitude, is now widely recognized as a species distinct from the North Atlantic right whale. Similarly, the Southern right whale (Eubalaena australis) is now recognized as a distinct species occurring in the southern hemisphere betwen around 20o and 60o S latitude.
Molecular Biology and Genetics
Barcode data: Eubalaena glacialis
Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen.
Other sequences that do not yet meet barcode criteria may also be available.
-- end --
Download FASTA File
Statistics of barcoding coverage: Eubalaena glacialis
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N1 - Critically Imperiled
Rounded National Status Rank: N1 - Critically Imperiled
NatureServe Conservation Status
Rounded Global Status Rank: G1 - Critically Imperiled
Reasons: Remnant populations occur in the North Atlantic; extremely low numbers; populations have failed to increase significantly even with protection; threats include collisions with boats, entanglement in fishing gear, disturbance by human activity, and general marine environmental deterioration.
Intrinsic Vulnerability: Highly vulnerable
Comments: Slow to mature, reproduces infrequently.
Other Considerations: Low reproductive rate; lack of recovery despite full protection.
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1994Endangered(Groombridge 1994)
- 1994Endangered(Groombridge 1994)
- 1990Vulnerable(IUCN 1990)
- 1990Endangered(IUCN 1990)
- 1988Endangered(IUCN Conservation Monitoring Centre 1988)
- 1986Endangered(IUCN Conservation Monitoring Centre 1986)
Date Listed: 06/02/1970
Lead Region: National Marine Fisheries Service (Region 11)
Where Listed: Entire
Population location: Entire
Listing status: E
For most current information and documents related to the conservation status and management of Balaena glacialis, see its USFWS Species Profile
Northern right whales tend to move through the ocean at a fairly slow pace for an animal of their size, they feed near the surface, and they float when killed; thus they were considered the "right" catch for whalers. Hunting of right whales began as early as the 10th century. These whales were hunted extensively during the 19th century, with as many as 100,000 whales slaughtered during this time. Right whales were driven close to extinction early in the 20th century and were one of the first whales to be given international protection in 1935. At the first international Convention for the Regulation of Whaling in 1935, a total ban on hunting right whales was established. The protection of this species was broadened in 1972 with the passing of the Marine Mammal Protection Act. A major issue revolving around the conservation of the right whale is habitat modification. Especially since they use shallow coastal lagoons and bays for breeding. Their numbers are stable and may even be increasing slightly in the Northwest Atlantic and off South Africa. The most current population estimate of 295 whales may represent the approximate carrying capacity. The carrying capacity could be increased though if collisions with ships and entanglement in fishing gear was decreased. It may be decades before the health of the right whale population is recovered. A recovery plan has been established with the difficult duty of managing a species that is hard to track. Luckily, activity modifications are taking place by people like the U.S. Coast Guard, U.S. Navy, ship traffic controllers in major shipping lanes, and others. Funding is always a major obstacle but support is being seen by individual institutions, states, and relevant sectors of the federal government (Cummings 1985, Katona 1999).
Northern Atlantic right whales are the most critically endangered great whale, with fewer than 300 individuals estimated. Populations of this species don't show significant signs of increasing in number, despite a ban on hunting. At the current population numbers species extinction is expected in 190 years.
Current threats to right whales include collisions with boats, since they tend to rest and feed at the surface frequently, pollution, becoming entangled in fish nets, and sonic pollution and disruption caused by military practices.
The history of research and conservation of northern right whales provides a number of lessons that may be applicable to other endangered species. First, sufficient funding must be provided to carry out an effective management program. Second, persistence and patience is needed to develop and implement a slow moving research program. Third, studies may not meet traditional scientific standards of proof because sample sizes are so small. Fourth, effective conservation will require cooperation from federal and state agencies as well as nongovernmental groups. Fifth, incidental take of a species is much harder to regulate than directed take like hunting. Lastly, we should never become complacent about the state of our knowledge (Katona 1999).
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: endangered
Global Short Term Trend: Decline of 10-30%
Global Long Term Trend: Decline of >90%
Comments: Formerly abundant, but hunted to near-extinction. North Atlantic population thought to have increased somewhat after the cessation of whaling, but apparently began declining once more after about 1990 (Caswell et al. 1999, Fugiwara and Caswell 2001).
It is not clear when Basque whaling began in the northwestern North Atlantic, but it had been established no later than 1530. It has long been thought that large numbers (tens of thousands) of Right Whales were taken off Labrador and Newfoundland by the Basques between 1530 and 1610 (Aguilar 1986, Reeves 2001) but recent genetic evidence suggest that many if not most of these were Bowheads (Rastogi et al. 2004). Shore-based whaling along the US east coast began in the mid 17th century and continued at least sporadically over the next two and a half centuries (Reeves et al. 1999, IWC 2001a). Reeves et al. (2007) estimated as a lower bound that some 5,500 Right Whales (and âpossibly twice that numberâ) were removed by whaling in the western North Atlantic between 1634â1951.
The current population is of about 300â350 individuals off the east coast of North America. IWC (2001a) obtained a minimum estimate of 263 in 1996 from identified animals known to be alive at that time, and indicated that the true population was probably not much higher. Kraus et al. (2001) provided a minimum estimate of 299 in 1998 based on animals presumed to be alive at that time (and not missing for more than five years). Preliminary analysis of more recent data have yielded estimates similar to those above. The whales are regularly surveyed in the winter calving ground off Florida and Georgia, and in spring/summer feeding grounds in Cape Cod Bay, the Great South Channel off Massachusetts, the Gulf of Maine, the Scotian Shelf, and the Bay of Fundy, but not all the whales using the wintering ground are seen in these major summering areas (IWC 2001b). There have been a few sightings in recent years in the Gulf of St Lawrence, two off Iceland in 2003, and one in the former whaling ground off Cape Farewell in 2004 (IWC 2005). A sighting off Norway in 1999 was identified as a well-known animal from the western North Atlantic population (Jacobsen et al. 2004).
Calf counts have been collected since 1980 but counts in the 1980s were probably underestimates, due to non-coverage of the winter calving grounds. Calf production has fluctuated, possibly linked to environmental conditions (Greene et al. 2003). It was low during 1998â2000 (average of three per year, with an associated calving interval of 5.7 years, Kraus et al. 2001) but high during 2001â2005 (average of 23 per year) (Clapham 2005). Nineteen calves were recorded in 2006, and the average inter-birth interval of the mothers concerned was 3.2 years (Anon. 2006).
An analysis of survival and reproductive rates (Caswell et al. 1999) concluded that survival rates had declined and that, as of 1995, the population was in decline. However, the finding of population decline was based on the assumption that only 38% of mature females were reproductively active, whereas the true figure appears to be over 70% (IWC 2001b). A subsequent review of survival rates concluded that survival rates probably were lower in the 1990s than in the 1980s (Clapham 2003). No more recent data on survival rates have been published to date; while reproduction has noticeably increased in this population, mortality has remained high and is a source of serious concern (IWC 2006).
Increase, if any, in this population is at a much lower rate than in the Southern Right Whale. Per capita calf production and calving intervals have been highly variable over the last decade. The occurrence of skin lesions, of a kind not seen in Southern Hemisphere Right Whales, was recorded during the period 1995 to 2002, and appeared to be correlated with the failure to reproduce of females that would normally be ready to calve (Reeves et al. 2001, Rolland et al. 2007). Over the same period, body condition as measured by blubber thickness was poorer in the North Atlantic than in Southern Hemisphere Right Whales (IWC 2001c). Mortality rates are higher than in Southern Hemisphere Right Whales, due largely to human-caused deaths (IWC 2001b) (see Threats section).
The first records of Basque whaling in the Bay of Biscay are from the 11th century. At least dozens of whales were taken each year in the Bay of Biscay until a marked decline was evident by 1650, and whaling declined during the 18th century. Basque whalers arrived in Iceland as early as 1412, and participated in the Right Whale fishery around the British Isles and Norway from the 14th to the 18th century, but probably many more whales were taken by Dutch, Danish, British and Norwegian whalers. Quantitative estimates of catches are not available. Historic Right Whale catches as far north as Iceland and Norway appear to have been mainly E. glacialis, with Balaena mysticetus (Bowhead) being the main species only in the far north (Greenland and Svalbard) (Aguilar 1986). Smith et al. (2006) documented extensive whaling for E. glacialis in the North Cape area (northern Norway) in the 17th century. Right whaling in the northeastern Atlantic seems to have declined from the mid-17th century and all but disappeared by the mid-18th century, but there was a brief period of Right Whale catches by modern whalers operating from shore stations in the British Isles and off Iceland, with at least 120 Right Whales were taken during 1881â1924 (Collett 1909, Brown 1986). The last recorded catch was a cow-calf pair off Madeira in 1967, accompanied by a third individual that escaped.
It is not clear whether there is a remnant Northeast Atlantic population or whether the animals seen there in modern times are strays from the west. There have been only eight confirmed sightings from 1960 to 1999, including the animal sighted in Norway in 1999, which was matched with the western north Atlantic population (IWC 2001b). A possible Right Whale was sighted in the Bay of Biscay in 1977 (Aguilar 1981) and a cow-calf pair was sighted off Cape Vincent, Portugal in 1995 (Martin and Walker 1997). A recent survey of the former Cintra Bay calving ground off Western Sahara failed to locate any Right Whales (Notarbartolo di Sciara et al. 1998), although survey conditions were often poor.
Degree of Threat: Very high - high
Comments: Initial large decline due primarily to hunting that occurred through the mid-1930s. Lack of population recovery has been attributed to mortality caused by collisions with ships and entanglement in fishing gear, degradation of feeding habitat (e.g., through effects of pollution on zooplankton), human disturbance (ships) (Right Whale Recovery Team 1990). Fujiwara and Caswell's (2001) analysis points to mortality of adult females caused by collisions as the primary factor in the decline. In fact, they suggest that reducing the death rate by only two adult females per year would reverse the decline. MtDNA data, in conjunction with behavioral and population data that indicate that the North Atlantic population may be suffering from reduced fertility, fecundity, and juvenile survivorship, support the hypothesis that inbreeding depression is also a cause of the lack of recovery (Schaeff et al. 1997). However, the data analysis and modelling of Fujiwara and Caswell (2001) do not support this hypothesis.
During 1999â2003, the recorded human-caused mortality and serious injury averaged 2.6 animals per year, of which 1.6 per year were fishery entanglements and 1.0 vessel collisions. A further 11 deaths (eight ship strikes, one entanglement, and two of unknown cause) were reported between 2004 and the end of 2006. Based on scarring from fishing gear it is estimated that at least 72% of the Right Whale population had been involved in an entanglement event at some point in their lives, and that 10â30% of the population is entangled each year (Clapham 2005). Because some anthropogenic deaths probably pass undetected, reported rates are considered minimal.
Hypotheses that have been advanced to explain the low reproductive rates observed for several years include: genetic factors, poor nutrition, chemical contaminants, biotoxins, disease. (IWC 2001c, Reeves et al. 2001). However, reproduction has increased in recent years.
Restoration Potential: No signs of recovery despite over 60 years of protection.
Management Requirements: In 1996, NMFS proposed rules that would prohibit vessels from approaching a right whale closer than 460 m (Federal Register, 7 August 1996). To avoid jeopardy to right whales, NMFS (Federal Register, 3 November 1997) proposed closing the Mid-Atlantic and Northeast Coastal segments of the Atlantic pelagic drift gillnet fishery for swordfish, tuna, and shark through 31 July 1998.
Biological Research Needs: Determine reasons for lack of recovery.
Global Protection: Many to very many (13 to >40) occurrences appropriately protected and managed
Comments: Species has had almost complete protection since 1937; but needs more protected habitat. NMFS (Federal Register, 3 June 1994, p. 28793) designated Critical Habitat as follows: portions of Cape Cod Bay and Stellwagen Bank, and Great South Channel (off coast of Massachusetts) and waters adjacent to the coast of Georgia and the east coast of Florida.
Needs: Continue to protect from hunting; protect habitat; promote and enforce regulations that reduce collisions with vessels. See recovery plan (1990).
Efforts are underway in both the US and Canada aimed at limiting deaths and injuries due to ship strikes and entanglements. In both countries, recovery plans have been developed involving collaboration among the various stakeholders.
Regulations are in place in the US requiring modifications to fishing gear and restrictions on certain types of gear in areas and times where Right Whales are common (Clapham 2005). A Mandatory Ship Reporting Scheme has been in place since 1999 in two areas in the Right Whale calving and summering grounds to enable vessels to be warned of Right Whales in the area. Regulations specify minimum approach distances for whale-watching and other vessels.
Shipping lanes in the Bay of Fundy have been moved, with the approval of the International Maritime Organization (IMO), to take them away from the major summer concentrations of Right Whales. A regulatory proposal to enforce maximum transit speeds on vessels passing through Right Whale habitats off the US east coast was still under review in 2007.
There is as yet no indication of a decrease in the rate of anthropogenic mortality, hence it is unclear whether the measures taken to date are sufficient.
The species is listed in Appendix I of both CITES and CMS.
Relevance to Humans and Ecosystems
Comments: Tens of thousands were harvested during the past few centuries; main exploitation ended around the 1920s; see IUCN (1991) for a review of exploitation history.
Economic Importance for Humans: Negative
There are no negative effects of northern right whales on humans.
Economic Importance for Humans: Positive
At least 1,000 years ago, the exploitation of this species began by hunters. Mainly, these whales were taken for blubber, used for oil for illumination, and for meat. No longer is this the primary threat to right whales. The main economic gain comes from eco-tourism which continues to be a fast growing industry (Katona 1999).
Positive Impacts: body parts are source of valuable material; ecotourism
IUCN Red List Category
- IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species.
North Atlantic right whale
The North Atlantic right whale (Eubalaena glacialis, which means "good, or true, whale of the ice"), is a baleen whale, one of three right whale species belonging to the genus Eubalaena, all of which were formerly classified as a single species. 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), right whales were once a preferred target for whalers, who reportedly considered them the "right" whales to hunt.
At present, they are among the most endangered whales in the world, and they are protected under the U.S. Endangered Species Act and the Marine Mammal Protection Act. There are about 400 individuals in existence in the western North Atlantic Ocean. In the eastern North Atlantic, on the other hand – with a total population reaching into the low teens at best – scientists believe that they may already be functionally extinct. Vessel strikes and entanglement in fixed fishing gear, which together account for nearly half of all North Atlantic right whale mortality since 1970, are their two greatest threats to recovery. They migrate between feeding grounds in the Gulf of Maine and their winter calving areas off Georgia and Florida, an ocean area with heavy shipping traffic.
- 1 Description
- 2 Behavior
- 3 Taxonomy
- 4 Whaling
- 5 Threats
- 6 Population and distribution
- 7 Conservation status
- 8 Whale watching
- 9 See also
- 10 References
- 11 External links
Like other right whales, the North Atlantic right whale, also known as the northern right whale or black right whale, is readily distinguished from other whales by the callosities on its head, a broad back without a dorsal fin, and a long arching mouth that begins above the eye. The body of the whale is very dark grey or black, occasionally with white patches on the belly. The right whale's callosities appear white due to large colonies of cyamids or whale lice.
Adult North Atlantic right whales average 13–16 m (43–52 ft) in length and weigh approximately 40,000 to 70,000 kg (44 to 77 short tons), they are slightly smaller on average than the North Pacific species. The largest measured specimens have been 18.2 m (60 ft) long and 106,000 kg (234,000 lb). Females are larger than males.
Forty percent of a right whale's body weight is blubber, which is of relatively low density. Consequently, unlike many other species of whale, dead right whales float.
There is little data on their life span, but it is believed to be at least fifty years, and some may live more than a century.
Aside from mating activities performed by groups of single female and several males, so called SAG (Surface Active Group), North Atlantic right whales seem less active compared to subspecies in southern hemisphere. However, this could be due to intense difference in number of surviving individuals especially calves that are tend to be more curious and playful than adults, and small amount of observations. They are also known to interact with other baleen whales especially with Humpback whales.
North Atlantic right whales recordings are available online. Many effective automated methods, such as Signal Processing, Data Mining and Machine Learning techniques have been developed to detect and classify their calls.
They first give birth at age nine or ten after a year-long gestation; the interval between births seems to have increased in recent[when?] years and now averages three to six years. Calves are 13–15 feet (4.0–4.6 m) long at birth and weigh approximately 3,000 pounds (1,400 kg).
Right whales feed mainly on copepods and other small invertebrates such as krill, pteropods, and larval barnacles, generally by slowly skimming through patches of concentrated prey at or below the ocean surface. Sei whales and Basking sharks (sometimes Minke whales as well) are in positions as food competitors and are known to feed in the same areas, swimming next to each other, but there have not been any conflicts observed between these species.
The cladogram is a tool for visualizing and comparing the evolutionary relationships between taxa. The point where a node branches off is analogous to an evolutionary branching – the diagram can be read left-to-right, much like a timeline. The following cladogram of the Balaenidae family serves to illustrate the current scientific consensus as to the relationships between the North Atlantic right whale and the other members of its family.
|The right whale family, Balaenidae|
Another so-called species of right whale, the "Swedenborg whale" as proposed by Emanuel Swedenborg in the 18th century, was by scientific consensus once thought to be the North Atlantic right whale. However, the 2013 results of DNA analysis of those fossil bones revealed that they were in fact those of the bowhead whale.
Right whales were so-named because whalers thought they were the "right" whale to hunt. As the "right" whale continued to float long after being killed, it was possible to 'flech' or strip the whale of blubber without having to take it onboard ship. Combined with the right whale's lack of speed through water, feeding habits, and coastal habitat, they were easy to catch, even for whalers equipped only with wooden boats and hand-held harpoons.
Basques were the first to commercially hunt this species. They began whaling in the Bay of Biscay as early as the eleventh century. The whales were hunted initially for whale oil but, as meat preservation technology improved, their value as food increased. Basque whalers reached eastern Canada by 1530. The last Basque whaling voyages were made prior to the commencement of the Seven Years' War (1756–1763). A few attempts were made to revive the trade, but they failed. Shore whaling continued sporadically into the 19th century. It had previously been assumed that Basque whaling in eastern Canada had been the primary cause for the depletion of the sub-population in the western North Atlantic, but later genetic studies disproved this.
Setting out from Nantucket and New Bedford in Massachusetts and from Long Island, New York, Americans took up to one hundred right whales each year, with the records including one report of 29 whales killed in Cape Cod Bay in a single day during January 1700. By 1750, the North Atlantic right whale population was, for commercial purposes, depleted. Yankee whalers moved into the South Atlantic before the end of the 18th century. The population was so low by the mid-19th century that the famous Whitby whaler Rev. William Scoresby, son of the successful British whaler William Scoresby senior (1760–1829), claimed to have never seen a right whale (although he mainly hunted bowhead whales off eastern Greenland, outside the normal range of right whales).
Based on back calculations using the present population size and growth rate, the population may have numbered fewer than 100 individuals by 1935. As it became clear that hunting right whales was unsustainable, international protection for right whales came into effect, as the practice was banned globally in 1937. The ban was largely successful, although violations continued for several decades. Madeira took its last two right whales in 1968.
For the period of 1970 to October 2006, humans have been responsible for 48% of the 73 documented mortalities of the North Atlantic right whale. A 2001 forecast showed a declining population trend in the late 1990s, and indicated a high probability that North Atlantic right whales would go extinct within 200 years if the then-existing anthropogenic mortality rate was not curtailed. The combined factors of small population size and low annual reproductive rate of right whales mean that a single death represents a significant increase in mortality rate. Conversely, significant reduction in mortality rate can be obtained by preventing just a few deaths. It was calculated that preventing the deaths of just two females per year would enable the population to stabilize. The data suggests, therefore, that human sources of mortality may have a greater effect relative to population growth rates of North Atlantic right whales than for other whales. The principal factors known to be retarding growth and recovery of the population are ship strikes and entanglement with fishing gear.
The single greatest danger to this species is injury sustained from ship strikes. Between 1970 and October 2006, 37% of all recorded North Atlantic right whale deaths were attributed to collisions. During the years 1999–2003, incidents of mortality and serious injury attributed to ship strikes averaged 1 per year. For the years 2004–2006, that number increased to 2.6. Additionally, it is possible that the official figures actually underestimate the actual ship-strike mortality rates, since whales struck in offshore areas may never be sighted due to low search effort.
In 2002, the International Maritime Organization shifted the location of the Traffic Separation Scheme (TSS, i.e. shipping lanes) in the Bay of Fundy (and approaches) from an area with the highest density of North Atlantic right whales to an area of lower density. This was the first time the IMO had changed a TSS to help protect marine mammals. In 2006, the US National Oceanic and Atmospheric Administration (NOAA) established a set of recommended vessel routes to reduce ship strikes in four important eastern-US right whale habitats. In 2007, and again on June 1, 2009, NOAA changed the TSS servicing Boston to reduce vessel collisions with right whales and other whale species. NOAA estimated that implementing an "Area To Be Avoided" (ATBA) and narrowing the TSS by 1 nautical mile (1.9 km) would reduce the relative risk of right whale ship strikes by 74% during April–July (63% from the ATBA and 11% from the narrowing of the TSS).
Fishing gear entanglement
The next greatest source of human-induced mortality is entanglement in fixed fishing gear such as bottom-set groundfish gillnet gear, cod traps and lobster pots. Between 1970 and October 2006, there have been 8 instances where entanglements have been the direct cause of death of North Atlantic right whales. This represents 11% of all deaths documented during that period. From 1986 to 2005, there were a total of 61 confirmed reports of entanglements, including the aforementioned mortalities. It is likely that official figures underestimate the actual impacts of entanglement. It is believed that chronically entangled animals may in fact sink upon death, due to loss of buoyancy from depleted blubber reserves, and therefore escape detection.
Beyond direct mortality, it is believed that whales that survive entanglement episodes may suffer other negative effects that may weaken it, reduce fertility, or otherwise affect it so that it is more likely to become vulnerable to further injury. Because whales often free themselves of gear following an entanglement event, scarring may be a better indicator of fisheries interaction than entanglement records. Recent[when?] analysis of the scarification of right whales showed that over 75% of whales examined during 1980-2002 were scarred at least once by fishing gear. Further research has indicated that between 14% and 51% of right whales are involved in entanglement each year.
In 2007, so as to protect northern right whales from serious injury or mortality from entanglement in gillnet gear in their calving area in Atlantic Ocean waters off the southeast United States, the National Marine Fisheries Service (NMFS) revised regulations implementing the Atlantic Large Whale Take Reduction Plan (ALWTRP). This plan expands the restricted area to include the waters off of South Carolina, Georgia, and Northern Florida. It also prohibits gillnet fishing or even gillnet possession in those waters for a period of five months, beginning on November 15 of each year, which coincides with the annual right whale calving season.
When entanglement prevention efforts fail, disentanglement efforts occasionally succeed, despite the fact that such efforts are more frequently impossible or unsuccessful. Nevertheless, they do in fact make a significant difference. During the period 2004-2008 there were at least four documented cases of entanglements for which the intervention of disentanglement teams averted a likely death of a right whale. For the first time in 2009 and again in 2011, scientists successfully used chemical sedation of an entangled whale to reduce stress on the animal and to reduce the time spent working with it. After disentangling the whale, scientists attached a satellite tracking tag, administered a dose of antibiotics to treat entanglement wounds and then another drug to reverse the sedation. Despite concerns that the trauma might impair reproduction, researchers confirmed in January 2013 that three disentangled whales had given birth.
Recently,[when?] the US Navy proposed plans to build a new undersea naval sonar training range immediately adjacent to northern right whale calving grounds in shallow waters off the Florida/Georgia border. In September 2012, legal challenges by leading environmental groups including the Natural Resources Defense Council were denied in federal court, allowing the Navy to proceed.
Climate change poses a threat to the North Atlantic right whale as global temperatures increase and ocean processes change. Long migratory periods, gestations, and time gaps between calves results in slow-growing right whale populations. A brief change in food availability can affect right whale populations for years after. Females must have access to plenty of food to successfully make it through pregnancy and produce enough milk to rear a calf. To illustrate the species’ sensitivity to food availability, in 1998 zooplankton populations dropped dramatically following a climate shift. Even though zooplankton abundance began to rise again in 1999, right whales have such a long reproduction and migratory cycle that the population was greatly affected by the minimal food availability from the year before. In 1999, only one right whale calf was born, compared to the 21 that were born in 1996, before the climate shift. In 2001, after the zooplankton populations greatly recovered, 30 calves were born.
Zooplankton abundance has been found to be associated with the North Atlantic Oscillation (NAO), the most influential climate force in the Northern Hemisphere. Periodically, pressure anomalies in the system shift from positive to negative as determined by the NAO Index, affecting temperatures and wind patterns. Abundant zooplankton populations have been linked to a positive NAO Index. As global temperatures increase, the NAO is predicted to shift more often and to greater intensities. These shifts will likely greatly affect the abundance of zooplankton, posing a great risk for right whale populations that cannot rapidly adapt to a new food source.
Population and distribution
It is not known how many populations in North Atlantic existed prior to whaling, but the majority of studies usually consider that there were historically two populations in the eastern and western North Atlantic. There are however two other hypotheses which claim, respectively, one super-population among the entire North Atlantic (with mixing of eastern and western migratory routes occurring at locations in relatively high latitudes such as in the Denmark Strait), and three sub-populations of eastern, western, and central Atlantic right whales (with the central stock ranging from Greenland's Cape Farewell in summer to the Azores and Bermuda in winter, although recent study indicates that the Azores had probably been a migratory corridor rather than a wintering ground).
Recent studies revealed that modern counterparts of the eastern and western populations are much closer genetically to each other than previously thought. Right whales' habitat can be affected dramatically by climate changes along with Bowhead whales.
In spring, summer and autumn, the western North Atlantic population feeds in a range stretching from New York to Nova Scotia. Particularly popular feeding areas are the Bay of Fundy, the Gulf of Maine and Cape Cod Bay. In winter, they head south towards Georgia and Florida to give birth. According to census of individual whales identified using photo-identification techniques, the latest available stock assessment data (August 2012) indicates that a minimum of 396 recognized individuals were known to be alive in the western North Atlantic in 2010, up from 361 in 2005. Distributions within other parts of Bay of Fundy is rather unknown although whales are occasionally observed at various locations in northern parts such as at Baxters Harbour.
Though their numbers are still scarce, some right whales migrate regularly into the Gulf of St. Lawrence, notably around the Gaspé Peninsula and in the Chaleur Bay and sometimes up to Anticosti Island, Tadoussac and in the St. Lawrence River. Some whales including cow and calf pairs also appear around Cape Breton Island. Further, the whales' regular range is known to reach up to off Newfoundland and the Labrador Basin.
Parts of the western group, especially for those seen regularly in the Gulf of St. Lawrence display different migratory or calving routines than the normal whales and these are so-called "Offshore Whales".
In early 2009, scientists recorded a record number of births among the western North Atlantic population. 39 new calves were recorded, born off the Atlantic coast of Florida and Georgia:
"Right whales, for the first time in a long time, are doing their part: they're having the babies; they're having record numbers of babies. We need to be vigilant and still do our part to prevent the whales from being killed."
— Monica Zani, New England Aquarium, Endangered right whales appear to be on the rebound, CNN.com
In contrast, 2012 appears to have been the worst calving season since 2000, with only seven calves sighted – and one of those is believed to have died. This is significantly below the annual average of 20 calves per year over the last decade. As the gestation period for right whales is a year long, researchers believe that a lack of food in the whales' summer feeding grounds in the Bay of Fundy during the summer of 2010 may be linked to the poor season in 2012.
The right whale was purported to have reached a population of 500 in the North Atlantic, which was assumed to have been achieved for the first time in centuries, when counted in 2013. The population of the whale has been increasing at about 2.5 percent per year, but this is below the optimal goal of 6 or 7 percent that researchers were hoping to attain.
In the eastern North Atlantic, the right whale population probably numbers in the low tens at best, with little information known about their distribution and migration pattern. Scientists believe that this population may be functionally extinct. The last catch occurred in 1967 from a pod? of three animals including a cow-calf pair: one escaped in Madeira and one was taken in the Azores.
Cintra Bay in the Western Sahara, the only known historical calving ground for this group, hosts no animals (or if any, then likely very few) nowadays, a situation similar to the Bay of Biscay where many whales once congregated throughout years. Although there were several sightings in the late 20th century (see Bay of Biscay) and catch records indicate whales used to use the bay for both feeding and wintering, it is still unclear whether or not the Biscayne coasts were ever used as a calving ground. Other parts of coastlines or oceanic islands from Iberian Peninsula and Portugal to Morocco in north to south possibly reaching even Mauritania. Locations such as Dakhla Peninsula and Bay of Arguin had been served potentially as wintering grounds similar to the Cintra Bay region. Historic presence of any wintering grounds in Mediterranean Sea is unknown.
Any calm waters in north such as Porth Neigwl, the Wadden Sea region, Cornwall coasts, Moray Firth and in Irish Sea could have been migratory colliders/feeding or resting grounds, or seasonal habitats to stay for less-migrating or resident (fully or partially) individuals. Some might have reached to entrance of Baltic Sea and northern Scandinavian.
Sightings and confirmations in recent years
There have been a few sightings further east over the past few decades, with several sightings close to Iceland in 2003. There was speculation that these could be the remains of a virtually extinct Eastern Atlantic stock, but examination of old whalers' records suggest that they are more likely to be strays from further west. A few have been sighted in waters adjacent to Norway, Ireland, Irish Sea, the Bay of Biscay in Spain, off the Iberian Peninsula, a cow-calf pair at Cape St. Vincent in Portugal, and continuous sightings of a single animal in the Canary Islands. A whale of unknown species, thought to be a right whale, was seen off Steenbanken, Schouwen-Duiveland (Netherlands) in July 2005 and was possibly the same animal previously seen off Texel in the West Frisian Islands. (See Wadden Sea.) Another possible sighting was made along Lizard Point, Cornwall in May 2012.
Vagrants from the Western Population
Some eastern sightings have been officially confirmed to be of vagrants from the western population. A right whale seen off Cape Cod in May 1999 was later seen in the Kvaenangen fjord in Troms, Northern Norway in September 1999. This individual was later confirmed to be "Porter", an adult male in the catalog (No.1133). He was seen again back in Cape Cod in winter 2000, having traveled for over 7,120 miles (=11500 km), making this the longest ever traveling record of right whales. The area vicinity to Scandinavian Peninsula was once in the historical "North Cape Ground", one of the major whaling grounds for this species in the 17th century.
In January 2009, one animal was sighted off Pico Island, Azores, the first confirmed appearance there since 1888. This animal was later identified as the a female from the western Atlantic group, and nicknamed as "Pico" according to this event.
Some individuals are known to show interesting patterns of movements which may possibly help researchers to deepen understandings of future re-colonization to eastern Atlantic, if possible.
Right whales have also on rare occasion been observed in the Mediterranean Ocean. In May 1991, a petty officer of the Italian Navy happened to be in the water with his camera about 13 km (8.1 mi) off the small island of Sant' Antioco (southwestern Sardinia), when a right whale happened to swim by – his photos comprise the only confirmed sighting in the 20th century. Earlier known occurrences of right whales in the Mediterranean include the stranding of a juvenile near Taranto (southeastern Italy) in 1877 and the sighting of two (one of which was later captured) in the bay of Castiglione (Algiers) in 1888 and Portugal. The Norway sightings appear to be of vagrants, or strays from the western Atlantic stock. Catch records at Cape Verde Islands in spring-summer seasons are highly doubtful.
Possible central population
As above mentioned, the existence of a possible third population, ranging from near Iceland or Greenland in the north to Bermudas in the south, has been mentioned by several biologists. Some right whales are now said to live primarily in Icelandic waters and occasionally join to the western population. In July 2003, during a search for the possibility of right whales inhabiting the historical Cape Farewell region carried out by the research team of the New England Aquarium with Jean Lemire and a Quebec film company, a female right whale - later named "Hidalgo" due to a scar mark on her head resembling a horse – was recorded in the Irminger Sea, southwest of the Iceland coast.
In 2009, right whales appeared in waters around Greenland although their origin was not confirmed. Prior to this, no right whales had been killed or confirmed present off the coast of Greenland for around 200 years except for the sighting of "1718", a unique animal seen only twice (off Cape Farewell in July 1987 and at the Nova Scotian Shelf in June 1989). Several sightings in the area made in the 1970s may or may not be of right whales, as the critically endangered population of Bowhead whales are also present in the area.
On a global level, the Convention on the Conservation of Migratory Species of Wild Animals (CMS, or the “Bonn Convention”) is a multilateral treaty specializing in the conservation of migratory species, their habitats and migration routes. CMS has listed the North Atlantic right whale on Appendix I, which identifies it as a migratory species threatened with extinction. This obligates member nations to strive towards strict protection of these animals, habitat conservation or restoration, mitigation of obstacles to migration, and control of other factors that might endanger them.
Additionally, CMS encourages concerted action among the range states of many Appendix I species. To that end, a small portion of the eastern Atlantic population's range is covered by the Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS). The Atlantic area bounded on the west by a line running from Cape St. Vincent in southwest Portugal to Casablanca, Morocco, and on the east by the Straight of Gibraltar.
Another multilateral treaty, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, (CITES, or the “Washington Convention”), also lists the North Atlantic right whale on its own Appendix I. Being so listed prohibits international trade (import or export) in specimens of this species or any derivative products (e.g. food or drug products, bones, trophies), except for scientific research and other exceptional cases with a permit specific to that specimen.
Either land based or organized Whale watching activities are available along east coasts from Canada in north to Florida. Onlookers lucky enough can spot them from shores time to time on whales' migration seasons especially for feeding (vicinity to Cape Cod such as at Race Point), and breeding/calving (off Georgia to Florida coasts) when whales strongly approach shores.
Due to the species' status, as of 2014, there is no whale watching location in eastern and mid Atlantic, and oceanic islands feasible to observe right whales regularly. Among these, only off Iceland right whales have been encountered during watching tours (save for expeditions and land-based observations targeting for birds and other faunas), and several observations were made in Iceland during the 2000s.
- Mead, J. G.; Brownell, R. L., Jr. (2005). "Order Cetacea". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. pp. 723–743. ISBN 978-0-8018-8221-0. OCLC 62265494.
- 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., Urbán, J. & Zerbini, A.N. (2012). "Eubalaena glacialis". IUCN Red List of Threatened Species. Version 2012.2. International Union for Conservation of Nature. Retrieved 18 January 2013.
- "Appendices I, II and III". Convention on International Trade in Endangered Species of Wild Fauna and Flora. CITES. 15 September 2012. Retrieved 20 January 2013.
- "ITIS Standard Report: Eubalaena glacialis (Müller, 1776)". ITIS on-line database. Integrated Taxonomic Information System. Retrieved 6 September 2012.
- Perrin, W.F. (2012). "Eubalaena glacialis Müller, 1776". World Cetacea Database. Retrieved 29 September 2012.
- "North Atlantic right whale (Eubalaena glacialis) 5-year review: Summary and Evaluation" (PDF). Gloucester, MA: National Oceanic and Atmospheric Administration Fisheries Service. August 2012. Retrieved 9 December 2012. "The western North Atlantic population numbered at least 361 individuals in 2005 and at least 396 in 2010 (Waring et al. 2012)."
- Fisheries and Oceans Canada (2007). "Recovery potential assessment for right whale (Western North Atlantic population)" (PDF). Canadian Science Advisory Secretariat Science Advisory Report 2007/027. Retrieved 17 June 2011.
- National Oceanic and Atmospheric Administration (2011-01-23). "Scientists Successfully Use Sedation to Help Disentangle North Atlantic Right Whale". ScienceDaily. Retrieved 2011-01-27.
- Burnie D and Wilson DE (Eds.), Animal: The Definitive Visual Guide to the World's Wildlife. DK Adult (2005), ISBN 0789477645
- http://www.coastalstudies.org/what-we-do/right-whales/fieldnotes.htm. retrieved on 13-05-2014
- Right Whale's "Up-Calls" - Cornell Bioacoustics Research
- More Right Whale calls - "moans", "screams" and "gunshot" - Cornell Bioacoustics Research
- M. Pourhomayoun, P. Dugan, M. Popescu, and C. Clark (2013). Bioacoustic Signal Classification Based on Continuous Region Features, Grid Masking Features and Artificial Neural Network. International Conference on Machine Learning (ICML).
- John D. Sutter (April 3, 2009). "Endangered right whales appear to be on the rebound". CNN. Retrieved 2009-12-29.
- http://teacheratsea.wordpress.com/2012/05/22/ellen-odonnell-theres-a-lot-of-food-in-the-ocean-and-one-more-whale-to-feed-may-20-2012/. retrieved on 13-05-2014
- 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.
- "Whale bones found in highway were not from mystery whale". ScienceNordic.com. February 7, 2013. Retrieved March 26, 2013.
- Ward-Geiger, L.I.; Silber, G.K.; Baumstark, R.D.; Pulfer, T.L. (3 March 2005). "Characterization of Ship Traffic in Right Whale Critical Habitat" (PDF). Coastal Management (Taylor & Francis Inc.) 33 (3): 263–278. doi:10.1080/08920750590951965. ISSN 0892-0753. Retrieved 22 August 2009.
- Aguilar A (1986). "A review of old Basque whaling and its effect on the right whales (Eubalaena glacialis) of the North Atlantic". Rep. Int. Whal. Commn (Special Issue 10): 191–99.
- 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.
- Rastogi, T., Brown, M. W., Mcleod, B. A., Frasier, T. R., Grenier, R., Cumbaa, S. L., Nadarajah, J. and White, B. N. (2004). Genetic analysis of 16th-century whale bones prompts a revision of the impact of Basque whaling on right and bowhead whales in the western North Atlantic. Canadian Journal of Zoology 8(10):1647-1654, 10.1139/z04-146
- Frasier, T. R., Mcleod, B. A., Bower, R., Brown, M., and White, B. N. (2007). Right Whales Past and Present as Revealed by their Genes in: Urban Whale: North Atlantic Right Whales at the Crossroads pp. 200-231, edited by Kraus, S. and Rolland, R.
- Waring, G.T.; Josephson E, Maze-Foley K, Rosel, PE, Editors (December 2010). "NORTH ATLANTIC RIGHT WHALE (Eubalaena glacialis): Western Atlantic Stock" (PDF). U.S. Atlantic and Gulf of Mexico Marine Mammal Stock Assessments. NOAA Tech Memo (National Marine Fisheries Service). NMFS NE 219: 8–18.
- Scarff JE (1986b). "Occurrence of the barnacles Coronula diadema, C. reginae and Cetopirus complanatus (Cirripedia) on right whales" (PDF). Scientific Reports of the Whale Research Institute 37: 129–153.
- Fujiwara, M.; Caswell, H. (29 November 2001). "Demography of the endangered North Atlantic right whale" (PDF). Nature 414 (6863): 537–541. doi:10.1038/35107054. PMID 11734852. Retrieved 17 June 2011.
- Schreiber, Laurie (February 2012). "Right Whale Mother and Fetus Skeletons Reconstructed". Fishermen's Voice. Retrieved 2013-10-09.
- "Vessel collisions and cetaceans: What happens when they don’t miss the boat". Whale and Dolphin Conservation Society website. p. 4.
- Vanderlaan & Taggart (2007). "Vessel collisions with whales: the probability of lethal injury based on vessel speed" (PDF). Mar Mam. Sci. Retrieved 2008-05-10.
- "North Atlantic Right Whale Ship Strike Reduction". Office of Protected Resources – NOAA Fisheries. Retrieved 2009-08-22.
- National Oceanic and Atmospheric Administration (2009-05-26). "Changes in Vessel Operations May Reduce Risk of Endangered Whale Shipstrikes". Retrieved 2009-08-22.
- NOAA (June 25, 2007). "NOAA announces rule to protect North Atlantic right whales from gillnet entanglement in Southeast U.S.". Retrieved 17 June 2011.
- "3 endangered right whales rescued from fishing gear reach rare milestone of motherhood". Associated Press (FOX News). January 24, 2013.
- Rolland et al. "Evidence that ship noise increases stress in right whales". Proceedings of the Royal Society B. The Royal Society. Retrieved 11 February 2012.
- Whale Defenders Lose Navy Training Challenge, courthousenews.com, accessed on 9/20/2012
- "Right Whales Wronged: Judge allows Navy to expand sonar use in calving ground". Natural Resources Defense Council. September 10, 2012.
- National Geographic
- New England Aquarium
- NOAA Climate Prediction Center
- Woods Hole Oceanographic Institution
- Reeves, R.R. and Mitchell, E. (1986). "American pelagic whaling for right whales in the North Atlantic.". Report of the International Whaling Commission Special Issue 10. pp. 221–254. Retrieved 27 January 2014.
- "Right Whale Special Issue 10: Abstracts" (PDF). Journal of Cetacean Research and Management (North Atlantic Right Whale Consortium): 5. December 1986. ISBN 0906975166. Retrieved 27 January 2014.
- Silvia A M., Steiner L.,Cascao I., Cruz J.M., Prieto R., Cole T., Hamilton K.P.and Baumgartner M. (2012). "Winter sighting of a known western North Atlantic right whale in the Azores" (PDF). Journal of Cetacean Research and Management.12. pp. 65–69. Retrieved 2013-04-28.
- nicola.hodgins's blog. "A whale named Pico". Whale and Dolphin Conservation. 11 April 2014. Retrieved 2014-04-28.
- "Endangered whale begins to recover after Bay of Fundy shipping lanes moved". Retrieved 6 July 2012.
- Whale sighting off Baxters' Harbour, Nova Scotia August 16, 2012 on YouTube. Retrieved on 11 July 2014
- Whale Facts - Gaspé Peninsula, right whale. ca, Canadian Whale Institute
- "Hear them coming: right whales return to the Gulf of St. Lawrence". Fisheries and Oceans Canada Homepage. 2013-04-22. Retrieved 2013-10-15.
- Poor Calving Season for Right Whales, Savannah Morning News Savannahnow.com, April 1, 2012
- Beth Daley (March 17, 2013). "Right whales in the midst of a revival". Boston Globe. Retrieved June 12, 2013.
- Brown.G.S. (1986). "Twentieth-century Records of Right Whales(Eubalaena glacialis) in the Northeast Atlantic Ocean" (PDF). Report of the International Whaling Commission Special Issue 10. pp. 121–127. Retrieved 2013-10-10.
- Lotze K.H., 2005. Radical changes in the Wadden Sea fauna and flora over the last2,000 years. Helgol Mar Res (2005) 59: pp.71–83. Retrieved on 29 July 2014
- Kees (C.J.) Camphuysen. "Who has an idea what animal we are looking at here?". Retrieved 2013-06-01.
- "North Atlantic right whale spotted off Cornwall?". WildlifeExtra.com.
- Porter's Biography. New England Aquarium Website
- Habitats-Migration Mystery. The North Atlantic Right Whale Consortium Website
- "First North Atlantic right whale sighting in Azores since 1888". WildlifeExtra.com.
- North Atlantic Right Whale Consortium (1997) Are there right whales in the eastern North Atlantic? Right Whale News Volume 4.
- Marine Mammal Society Newsletter, Winter 1996 (Vol 4, No 4).
- 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 (1996-05-16). "SIGHTING OF A RIGHT WHALE (EUBALAENA GLACIALIS) WITH CALF OFF S. W. PORTUGAL". Marine Mammal Science 13 (1): 139. doi:10.1111/j.1748-7692.1997.tb00617.x. Retrieved 2006-10-26.
- Jacobsen, K.O.; Marx, M.; Øien, N. (2003-05-21). "Two-way Trans-Atlantic migration of a North Atlantic right whale (Eubalaena glacialis)". Marine Mammal Science 20 (1): 161. doi:10.1111/j.1748-7692.2004.tb01147.x. Retrieved 2006-10-26.
- "No. 1412's Biography". New England Aquarium Homepage.
- "Whale Facts - Migration". Right Whale.Ca, Canadian Whale Institute.
- National Oceanic and Atmospheric Administration (May 20, 2009). "NOAA Expedition Hears Endangered North Atlantic Right Whales off Greenland".
- Newman, Dennis (May 20, 2009). "OSU Researchers Discover 'Extinct' Whales". Natural Oregon.
- SaraJean (2009-05-25). "Greenland: New Home for Right Whales". Retrieved 2009-12-29.
- "Appendices I and II". Convention on the Conservation of Migratory Species of Wild Animals (CMS). Amended by the Conference of the Parties in 1985, 1988, 1991, 1994, 1997, 1999, 2002, 2005, 2008 and 2011. Effective 23 February 2012. p. 1. Retrieved February 20, 2013.
- Official website of the Convention on the Conservation of Migratory Species of Wild Animals (CMS or Bonn Convention)
- Official website of the Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area
Names and Taxonomy
Comments: Bowhead whales and right whales often have been included in the same genus (Balaena) (e.g., Rice 1998), but most recent classifications recognize them as distinct genera (Balaena for bowhead whale, Eubalaena for right whales) (e.g., Baker et al. 2003; Mead and Brownell, in Wilson and Reeder 2005). MtDNA data are consistent with recognition of Balaena and Eubalaena as distinct genera (Rosenbaum et al. 2000).
A strong consensus does not exist regarding the taxonomic status of the various populations of right whales. Based on mtDNA data, Rosenbaum et al. (2000) proposed that the North Atlantic, North Pacific, and Southern Hemisphere populations could be recognized as distinct species (E. glacialis, E. japonica, and E. australis, respectively). Baker et al. (2003) argued against this proposal, noting among other things that no other consistent differences have been found among the three populations. The recovery plan for this species and Mead and Brownell (in Wilson and Reeder 1993) regarded the southern right whale (E. australis) as a distinct species, but Rice (1998) and Baker et al. (2003) included australis in Eubalaena (or Balaena) glacialis. Mead and Brownell (in Wilson and Reeder 2005) cited Rosenbaum et al. (2000) in recognizing E. glacialis, E. australis, and E. japonica as distinct species.
Sighting and mtDNA data indicate that western North Atlantic right whales segregate between separate nursery areas but probably represent a single breeding population (Schaeff et al. 1993).
To request an improvement, please leave a comment on the page. Thank you!