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Eubalaena glacialisNorth Atlantic right whale

By Jonathan Crane and Rebecca Scott

Geographic Range

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). (Rosenbaum, et al., 2000)

Habitat

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)

Physical Description

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).

  • Sexual Dimorphism
  • female larger
  • Range mass
    55000 to 95000 kg
    121145.37 to 209251.10 lb
  • Range length
    17 (high) m
    55.77 (high) ft

Reproduction

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.

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 number of offspring
    1
    AnAge
  • Average gestation period
    12 months
  • Average gestation period
    350 days
    AnAge
  • Range age at sexual or reproductive maturity (female)
    5 to 10 years
  • Range age at sexual or reproductive maturity (male)
    5 to 10 years

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

Lifespan/Longevity

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.

(Katona 1999)

  • Range lifespan
    Status: wild
    67 (high) years
  • Average lifespan
    Status: captivity
    67 years
    AnAge

Behavior

Northern right whales are migratory animals, spending the winter in warmer waters such as those found off Cape Hatteras, and migrating to the poles for cooler waters in late summer and early fall. It is rare to see a whale off the coast of Cape Cod from June to October because they have all headed north.

Right whales are not known for being gregarious, but they can be found in small groups. The typical group size ranges from a single whale to a group of 12 but usually two. The group composition varies from female-calf, all males, or mixed. It is difficult to determine group size because of the dispersion. A larger group may be formed at far distances staying in contact by acoustics. Composition of groups is rarely known because of the difficulty in sexing individuals (Evans 1987).

They are fairly social in that they will swim with other types of cetaceans. It was reported that one mother that was fed up with the playful antics of her calf swam underneath the calf, then surfaced, cradling the calf in her flippers.

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)

Food Habits

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).

Predation

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.

Ecosystem Roles

Baleen whales, like northern right whales, are important as predators on krill and other planktonic invertebrates in marine environments.

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

Economic Importance for Humans: Negative

There are no negative effects of northern right whales on humans.

Conservation Status

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).

Other Comments

An article by R. Reeves quoted some Pilgrims who arrived in North America in 1620. They wrote at that time, "Cape Cod was like to be a place of good fishing; for we saw daily great whales, of the best kind for oil and bone, come close aboard our ship, and, in fair weather, swim and play about with us." They are most likely refering here to northern right whales. What must it have been like to be able to sail among these large mammals as they ambled through the water? Unfortunately most of us will probably never again be able to experience this. Whales are not like California condors, where captive breeding efforts can be employed. Because they are surface feeders, they are especially vulnerable to pollution. An oil refinery in the Bay of Fundy, for example, puts right whales and countless other wildlife species at risk of experiencing the toxic effects of an oil spill.

Northern right whales tend to be docile creatures (despite their size of about 17 m, and 78.5 to 106 metric tons). They do not attack a human unless they feel threatened. They also appear to be playful creatures, breaching out of the water (imagine the power needed to get 100 tons airborne), and slapping the surface with their large fins. Some observers even suggest that they stick their tails up out of the water so that their large tail flukes catch a breeze, allowing them to sail. We can not afford to lose this great creature.

Recent work on genetic variation in right whales suggests that Pacific populations of what has been considered Eubalaena glacialis represent a distinct species which is more closely related to southern right whales, Eubalaena australis. Therefore, northern right whales, Eubalaena glacialis, should not be considered to occur in the Pacific ocean. (Rosenbaum, et al., 2000)

Contributors

Brian Arbogast (editor), Humboldt State University.

Jonathan Crane (author), University of Michigan-Ann Arbor.

Rebecca Scott (author), Humboldt State University.

Glossary

Arctic Ocean

the body of water between Europe, Asia, and North America which occurs mostly north of the Arctic circle.

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

filter-feeding

a method of feeding where small food particles are filtered from the surrounding water by various mechanisms. Used mainly by aquatic invertebrates, especially plankton, but also by baleen whales.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

planktivore

an animal that mainly eats plankton

polar

the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

ultrasound

uses sound above the range of human hearing for either navigation or communication or both

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

young precocial

young are relatively well-developed when born

zooplankton

animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)

References

Bonner, N. (1989) Whales of the world. pp. 48-58.

Chapman, J.A., Feldhamer, G.A., (1982) Wild Mammals of north america. pp. 415-30.

Mayo, C.A., Marx, M.K. (1990) Surface foraging behavior of the North Atlantic right whale, Eubalaena glacialis, and associated zooplankton characteristics. Canadian Journal of Zoology, (68), pp. 2214-20.

Murison, L.D., Gaskin, D.E. (1989) The distribution of right whales and zooplankton in the Bay of Fundy, Canada. Canadian Journal of Zoology, (67), pp. 1411- 20.

Payne, R. (1994) Among whales. Natural History, (1), pp. 40-47.

Reeves, R.R. (1979) Right whale: Protected but still in trouble. National Parks and Conservation Magazine, (2), pp. 10-15.

Reeves, R.R., Kraus, S., Turnbull, P. (1983) Right whale refuge? Natural History, (4), pp. 40-44.

Leatherwood, S. and R. R. Reeves. 1983. The Sierra Club Handbook of Whales and Dolphins. Sierra Club Press, San Francisco.

Cummings, W. 1985. Right Whales. New York, N.Y.: Academic Press.

Ellis, R. 1985. The Book of Whales. New York, N.Y.: Alfred A. Knopf, Inc..

Evans, P. 1987. The Natural History of Whales and Dolphins. New York, N.Y.: Facts on File Publications.

Katona, S., S. Kraus. 1999. Efforts to Conserve the North Atlantic Right Whale. Washington, D.C.: Smithsonian Institution Press.

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.

Slijper, E. 1979. Whales. Ithaca, N.Y.: Cornell University Press.

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