Animal Info - North Atlantic Right Whale

(Other Names: Baleine de Biscaye, Baleine des Basques, Ballena, Ballena Franca del Norte, Ballenga, Biscayan Right Whale, Black Right Whale, Northern Right Whale, Right Whale)

Eubalaena glacialis (Balaena g.)

Status: Endangered

1. Profile (Picture)
2. Tidbits
3. Status and Trends (IUCN Status, Oceans and Seas Where Currently Found, Taxonomy, Population Estimates, History of Distribution, Threats and Reasons for Decline)
4. Data on Biology and Ecology (Size and Weight, Habitat, Age to Maturity, Gestation Period, Birth Season, Birth Rate, Early Development, Maximum Age, Diet, Behavior, Social Organization, Mortality and Survival)
5. References

Profile

Pictures: North Atlantic Right Whale #1 (7 Kb JPEG); North Atlantic Right Whale #2 (26 Kb JPEG) (Univ. Wash.); North Atlantic Right Whale #3 (55 Kb JPEG) (Swiss Cetacean Soc.); North Atlantic Right Whale #4 (58 Kb JPEG) (Oregon State Univ.)

The North Atlantic right whale weighs up to 100,000 kg (220,000 lb) and is up to 17 m (56') long. It can easily be distinguished from the other great whales by its lack of a dorsal fin or dorsal ridge; its stout, robust stature; and the presence of distinctive growths on the head known as "callosities". Right whales are individually identifiable by their pattern of callosities. The right whale is usually found in temperate waters. It is found closer to land than are most large whales, especially during the breeding season. Calves may be born in the protected waters of a shallow bay.

The North Atlantic right whale feeds alone or in small groups. Its food consists primarily of small marine crustaceans. Right whales are " skim feeders", moving slowly through the water with their mouths partially open, continuously straining the food items with their long baleen. The North Atlantic right whale migrates to more northerly latitudes for summer feeding, and back south to temperate waters in the fall and winter for breeding.

A relatively slow swimmer, the North Atlantic right whale averages about 8 km/h (6 mi/h). It usually does not fear boats and can be easily approached by them. North Atlantic right whales usually travel alone or in groups of 2 - 3 (up to about 12). The membership of groups of right whales does not seem to remain fixed. Identifiable individuals can be seen moving from one group to another. An individual female mates with multiple males. Apparently, mating pairs do not establish long-term social bonds.

The North Atlantic right whale occurs in the Atlantic Ocean: during the summer from Davis Strait, Denmark Strait, and the Norwegian Sea south to Massachusetts and the Bay of Biscay; during the winter it ranges south to Florida and the Golfo de Cintra (23°N), Western Sahara. The species is close to extinction in the Eastern North Atlantic. Overfishing by the whaling industry caused the North Atlantic right whale's decline. Its most serious threats are collisions with ships and entanglement in fishing gear. More than half of the living right whales in the Western North Atlantic have experienced at least one ship-strike or net entanglement.

Tidbits

*** The North Atlantic right whale is one of the world's rarest mammals.

*** Female right whales have a very strong protective maternal instinct. This was taken advantage of by early whalers, who captured the calf first, knowing that the mother was then unlikely to escape.

*** Right whales were so named because they were the "right" whale to hunt: they are slow; they float when killed; they are found in temperate waters; and they have a high yield of oil.

*** Loss of gene diversity experienced by North Atlantic right whales over the last century has been modest. Any significant reduction in genetic variation in the species most likely occurred prior to the late 19^th century. (Rosenbaum et al. 2000)

Status and Trends

Taxonomy:

Taxonomy and nomenclature of the right whales are in flux, but there is no doubt that the populations in the North Atlantic and North Pacific oceans are completely isolated from each other and from the population in the Southern Ocean. Recent genetic evidence supports the recognition of three species, North Atlantic right whale (Eubalaena glacialis), North Pacific right whale (Eubalaena japonica) and Southern right whale (Eubalaena australis). (Reeves et al. 2003)

IUCN Status:

1960's: Rare
1970's - 1994: Endangered
1996 - 2002: Endangered (Criteria: C1, D)
2004: Endangered (Criteria: D) (IUCN 2004)

Oceans and Seas Where the North Atlantic Right Whale Is Currently Found:

2004: Occurs in the Atlantic Ocean (northwest, western central). (IUCN 2004)

Countries Where the North Atlantic Whale Is Currently Found:

2004: Occurs in Bahamas, Belgium, Canada, France, Germany, Iceland, Ireland, Italy, Mexico, Morocco, Netherlands, Portugal, Spain, United Kingdom, and United States (IUCN 2004).

Population Estimates:

[Note: Figures given are for wild populations only.]

WORLD
- 19th century: About 10,000 (Oryx 1997i)
- 1965: Unknown, probably a few hundred (IUCN 1966)
- 1972: Possibly only a few hundred (Curry-Lindahl 1972)
- 1982: At least 70 - 100 (Reeves 1982)
- 1991: Maybe only a few hundred (Klinowska 1991)
- 1999: About 300 (Oryx 1999c)
- 2004: Around 350 (Focus 2004a)

History of Distribution:

The North Atlantic right whale was once abundant and distributed throughout the North Atlantic. It was hunted starting in the 10th - 11th centuries. Catches peaked between the 13th - 17th centuries but continued, at a low level, into the 20th century. By 1700 it was too rare to be of economic importance.

The North Atlantic right whale occurs in the Atlantic Ocean: during the summer from Davis Strait, Denmark Strait, and the Norwegian Sea south to Massachusetts and the Bay of Biscay; during the winter it ranges south to Florida and the Golfo de Cintra (23°N), Western Sahara. Although right whales are occasionally seen in European waters, the species is close to extinction in the Eastern North Atlantic. The Gulf of Maine, the Bay of Fundy and the Cape Cod area are now important feeding areas, and there is possibly a calving area off Florida. (Klinowska 1991, IUCN 2003a, Reeves et al. 2003)

Threats and Reasons for Decline:

Overfishing by the whaling industry caused the North Atlantic right whale's decline. Its most serious threats are collisions with ships and entanglement in fishing gear. More than half of the living right whales in the Western North Atlantic have experienced at least one ship-strike or net entanglement. The species is at risk from collisions with ships and entanglement in nets because it is relatively slow-moving, spends a fair amount of time near the surface, and lives in the midst of one of the world’s busiest shipping lanes. At least a third of the deaths in this population each year are thought to be directly linked to human activities. (Shine 2001, Reeves et al. 2003)

In addition, because the North Atlantic right whale is dependent on coastal habitat, it may be more vulnerable to impacts from human activity, such as pollution, than many other cetaceans. Furthermore, because the population is so small and slow-growing, even minor sources of mortality may have a significant impact.

Data on Biology and Ecology

Size and Weight:

Length: 13 - 17 m (43 - 56'); Weight: 60,000 - 100,000 kg (130,000 - 220,000 lb).

Habitat:

The North Atlantic right whale is usually found in temperate waters, although some move just north of the Arctic Circle or just south of the Tropic of Cancer. It is found closer to land than are most large whales, especially during the breeding season. Calves may be born in the protected waters of a shallow bay.

The North Atlantic right whale occurs in the Grand Banks Global 200 Ecoregion. (Olson & Dinerstein 1998, Olson & Dinerstein 1999)

Age to Maturity:

Estimates of the age at sexual maturity range from 5 - 10 years. Males are sexually mature at a length of 15 m (49') and females at a length of 15.5 m (51'). (Wilson & Ruff 1999)

Gestation Period:

Between 9 - 12 months.

Birth Season:

Most calves are born in winter. Since gestation lasts approximately one year, it is assumed that mating leading to conception also takes place in winter, although sexual activity has been observed year-round. (Wilson & Ruff 1999)

Birth Rate:

A single calf is born at a time. Females give birth every 3 - 4 years (Wilson & Ruff 1999).

Early Development:

Calves grow rapidly, attaining a length of 12 m (39') by the age of 18 months. (Wilson & Ruff 1999)

Maximum Age:

More than 60 years. (Wilson & Ruff 1999)

Diet:

The North Atlantic right whale feeds alone or in small groups, eating about 1000 - 2500 kg (2200 - 5500 lb) of food every day. Its food consists primarily of small marine crustaceans, mostly copepods from the genus Calanus and occasionally krill and other zooplankton. It may also feed on small fish on occasion. Right whales are "skim feeders", moving slowly through the water with their mouths partially open, continuously straining the food items with their long baleen. This feeding mechanism contrasts with that of other baleen whales such as blue whales and humpback whales, which are known as "gulp feeders". (Wilson & Ruff 1999)

Behavior:

The North Atlantic right whale migrates to more northerly latitudes for summer feeding, and back south to temperate waters in the fall and winter for breeding. It is a relatively slow swimmer, averaging about 8 km/h (6 mi/h). It usually makes a series of 5 or 6 shallow dives and then submerges for about 20 minutes. It usually does not fear boats and can be easily approached by them. Right whales emit a number of low frequency sounds, mostly during courtship. Breaching behavior and lobtailing are common in this species.

Social Organization:

North Atlantic right whales usually travel alone or in groups of 2 - 3 (up to about 12). When they were more numerous, groups of up to 100 were seen together on the feeding grounds. If prey are dense, the whales may feed together, although usually the groups break up to feed individually, probably because of the enormous food requirements of each individual whale. The membership of groups of right whales does not seem to remain fixed. Identifiable individuals can be seen moving from one group to another.

A calf and its mother appear to exhibit the same type of bonding behavior that is typical of other mammals. The calf maintains close contact with its mother, swimming up on her back or butting her with its head. The mother may roll over on her back and hold her calf in her flippers.

An individual female mates with multiple males. Apparently, mating pairs do not establish long-term social bonds.

Mortality and Survival:

Known mortality amounted to less than 1 whale per year in the 1970's (Reeves 1982).

The survival rate decreased from 0.99/year in 1980 to 0.94/year in 1994. (Oryx 1999)

References

Arkive, Bonner 1989, Burton & Pearson 1987, Curry-Lindahl 1972, Focus 2004a, IUCN 1966, IUCN 1994, IUCN 1996, IUCN 2000, IUCN 2003a, IUCN 2004, Klinowska 1991, Macdonald 1984, NMFS, Nowak & Paradiso 1983, Olson & Dinerstein 1998, Olson & Dinerstein 1999, Oregon State Univ., Oryx 1997i, Oryx 1999c, Reeves 1982, Reeves et al. 2003, Rosenbaum et al. 2000, Shine 2001, Swiss Cetacean Soc., Univ. Wash., Wilson & Ruff 1999

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Last modified: November 2, 2005;