The right whales are among the stockiest of all whales. The North Atlantic right whale has a massive head that can be up to nearly one-third of its body length. The jawline is arched and the upper jaw is very narrow in dorsal view. The flippers are broad and tend to be more fan-shaped than the pointed flippers of most other cetaceans. There is no dorsal fin or dorsal ridge on the broad back. The flukes are very wide (up to 35% or more of total length) and smoothly tapered, with a smooth trailing edge and a deep notch.
Most North Atlantic right whales are predominantly black, but there may be large white splotches of varying extent on the underside and sometimes elsewhere on the body. The head is covered with callosities, areas of roughened skin to which whale lice attach. The largest of these callosities, on the top of the rostrum, is called the bonnet. The widely separated blowholes produce a V-shaped blow up to 5 m high. Inside the mouth are 200-270 long thin baleen plates, which may reach nearly 3 m in length. They are brownish-gray to black in color. The fringes of these plates are very fine, reflecting the small prey taken by this species.
Adults range in length to 17 m, but may occasionally reach 18 m. Females are larger than males. Newborns are 4.5-6 m long. Adults may reach weights of 80-100 tons.
Can be Confused With
The North Atlantic right whale can be easily distinguished from other whale species in the Atlantic Ocean by its robust body, large head, long baleen plates, and V-shaped blow. Right and bowhead whales once overlapped in distribution, and may again if populations recover.
North Atlantic right whales from two populations primarily inhabit temperate and subpolar waters of the North Atlantic Ocean. Historically, the two populations were presumably largely isolated from each other, and the eastern stock is thought to be functionally extinct. The western North Atlantic stock breeds off the southeastern United States (Florida and Georgia) and feeds in the Gulf of Maine and off eastern Canada, as far north as Nova Scotia. The eastern Atlantic stock occurred in northern European waters, from Spain to Norway and Iceland, but records there in recent years have been extremely rare.
Ecology and Behavior
Right whales are mostly seen in groups of less than 12 (most often singles or pairs). Larger groups may form on areas of aggregation for feeding and breeding. They can be aerially active and generally raise their flukes before a deep dive.Right whale individuals can be identified by the patterns of scars and callosities (mainly on the head and back).
The mating system appears to involve sperm competition (males competing to inseminate females, not so much by physical aggression, as by delivering large loads of sperm, thereby displacing that of other males). Young are born in winter and spring on tropical/subtropical breeding areas.
Feeding and Prey
Right whales feed on calanoid copepods and other small invertebrates (smaller copepods, krill, pteropods, and larval barnacles), generally by slowly skimming through patches of concentrated prey at or below the surface. The most common prey species is the copepod Calanus spp.
Threats and Status
This was the first species of whale to be commercially hunted, starting in the 1100s. Heavy hunting left it severely depleted by the late 1600s, but some direct exploitation continued into the 20th century. Right whales are now fully protected, but current known threats include vessel collisions and entanglement in fishing gear. In addition, habitat destruction, pollution, and disturbance by vessel traffic may also be factors. This is probably the world’s most endangered large whale, with only a few hundred thought to remain.
Currently, right whales are listed as ‘Endangered’ (IUCN) and ‘Endangered’ (ESA).
Best, P.B., J.L. Bannister, R.L. Brownell, Jr. and G.P. Donovan (eds.). 2001. Right whales worldwide status. Journal of Cetacean Research and Management, Special Issue 2, 309 pp.
Cummings, W.C. 1985. Right whales Eubalaena glacialis (Muller, 1776) and Eubalaena australis (Desmoulins, 1822). pp. 275-304 in S.H. Ridgway and R. Harrison, eds. Handbook of marine mammals, Vol. 3: The sirenians and baleen whales. Academic Press.
National Marine Fisheries Service. 1991. Final recovery plan for the northern right whale Eubalaena glacialis. National Marine Fisheries Service, Silver Spring, Maryland.
Katona, S.K. and S.D. Kraus. 1999. Efforts to conserve the North Atlantic right whale. pp. 311-331 in J.R. Twiss and R.R. Reeves, eds. Conservation and management of marine mammals. Smithsonian Institution Press.
Perry, S.L., D.P. Demaster and G.K. Silber. 1999. The great whales history and status of six species listed as Endangered under the U.S. Endangered Species Act of 1973. Marine Fisheries Review 61:1-74.