North Atlantic Right Whale (Eubalaena glacialis): Facts

What does a North Atlantic right whale look like?

Right whales are easy to recognize once you know what to look for. The body is very thick and mostly black, with a broad, smooth back and no dorsal fin at all. The flippers are short, wide and paddle-shaped, and the deeply notched tail flukes are all black. Some whales have irregular white patches on the belly.

The head is enormous, roughly a quarter to a third of the body length, with a strongly arched upper jaw and a long, curving lower lip. The two blowholes sit wide apart, so the spout forms a V shape up to about 5 m (16 ft) high when seen from in front or behind.

The most distinctive feature is the callosities: rough, raised patches of thickened skin on the head, chin, lips and above the eyes. The skin itself is dark, but dense colonies of tiny crustaceans called whale lice (cyamids) live on the patches and make them look white, yellow or orange. Callosities are already present before birth, and every whale’s pattern is unique. Researchers use photographs of these patterns to recognize individuals, and most of the population is listed by name or number in a photo catalog kept by the New England Aquarium.

How big is a North Atlantic right whale?

Adults are usually about 13–16 m (43–52 ft) long, and NOAA Fisheries gives a maximum weight of about 64 tonnes (140,000 lb). Females are slightly larger than males. Right whales are also extremely broad for their length, and much of their bulk is blubber, which makes up roughly 40% of body weight. Because blubber is lighter than water, a dead right whale usually floats.

The baleen is long as well. Each side of the upper jaw holds about 200–270 narrow plates up to about 2.8 m (9 ft) long, with fine hair-like fringes that trap food. Calves are about 4.3 m (14 ft) long at birth and weigh roughly a tonne, and they grow quickly on their mother’s fat-rich milk.

Where do North Atlantic right whales live?

Almost all surviving right whales live in the western North Atlantic, mostly over the continental shelf and often within sight of land, although some travel far offshore over deep water. In spring, summer and fall many feed off New England and in Canadian waters, including Cape Cod Bay, the Gulf of Maine, the Bay of Fundy and, since about 2015, the Gulf of St. Lawrence. Underwater recorders show that some whales stay off New England and the mid-Atlantic coast all year.

Each fall, some whales, especially pregnant females, travel more than 1,600 km (1,000 mi) south to shallow coastal waters off the Carolinas, Georgia and northeast Florida, the species’ main known calving ground. The United States protects two areas as critical habitat: a feeding area off New England, and a calving area from Cape Fear, North Carolina, to south of Cape Canaveral, Florida.

A second population once lived in the eastern Atlantic, from Norway and the British Isles to the Bay of Biscay and northwest Africa. Centuries of whaling destroyed it, and scientists consider it functionally extinct. The few right whales seen off Iceland, Norway, Ireland, Portugal or the Azores in recent decades are rare visitors, and some have been identified from photographs as wanderers from the western population.

What do right whales eat?

Right whales are filter feeders that live mainly on copepods, rice-sized crustaceans that drift in dense swarms. In the North Atlantic their most important prey is a fatty copepod called Calanus finmarchicus. They also eat krill, pteropods (tiny swimming snails) and the larvae of barnacles and other small animals.

Unlike humpback and blue whales, which gulp huge mouthfuls of water, right whales are skim feeders. They swim slowly forward with the mouth open, sometimes with the top of the head showing at the surface, so that water flows in at the front and out at the sides while the fine baleen fringes catch the copepods. They also feed deep in the water column and even close to the seabed, and whales sometimes surface with mud on their heads. The different feeding styles of these giants are explained in What are baleen whales?

A single whale needs enormous numbers of copepods every day, so right whales depend on places where currents pack their prey into very dense patches. When warming water changed where copepods gather in the Gulf of Maine in the 2010s, many whales shifted their feeding areas north and east. Sei whales and basking sharks often feed on the same swarms nearby.

Behavior and communication

Right whales usually travel alone or in small, loose groups and spend much of their time at or just below the surface. That habit, together with their dark color and missing dorsal fin, makes them hard to see from a ship. They are slow swimmers, usually moving at about 4 km/h (2 knots) and rarely faster than about 9 km/h (5 knots), yet they can be surprisingly lively, breaching, slapping their flippers and lifting their flukes high out of the water.

The most striking social behavior is the surface-active group, or SAG: a female at the surface surrounded by a crowd of males, sometimes as many as 20, which jostle, roll and touch her with their flippers. These groups are seen in all seasons and are linked to mating and social bonding. Males do not fight hard over females; instead, competition seems to happen through sperm, and right whales have the largest testes of any animal.

Right whales communicate with low-frequency moans, groans and pulses. The best-known call is the “upcall”, a short rising whoop that seems to help whales keep in contact. Because it is so recognizable, underwater microphones and listening buoys detect upcalls to warn ships and managers when right whales are nearby. Adult males also make a loud, sharp sound known as the “gunshot” call.

Reproduction and calves

Female North Atlantic right whales usually have their first calf at about 9–10 years of age. Pregnancy lasts about a year, and a single calf is born in winter, mainly off the southeastern United States, where the calving season runs from mid-November to mid-April.

Mother and calf stay close together for roughly a year, and calves are weaned at about 8–12 months. Males provide no care. A healthy female can give birth about every three years, but NOAA Fisheries reports that females now calve only every 7–10 years on average. Injuries from fishing gear and ships, together with poorer feeding conditions, leave many females without the energy reserves needed for pregnancy and nursing.

Births swing widely from year to year, from 39 calves in 2009 to none at all in 2018. The 2026 season produced 23 calves, the most in 17 years, a reminder that the species can still respond when females are healthy.

How long do right whales live?

Right whales can live at least 70 years. One female photographed with a calf in 1935 was still being seen in the 1990s, and related baleen whales can live much longer, as described in How long do whales live? Human-caused deaths now cut most lives short, though. NOAA Fisheries estimates that females today live only to about 45 years and males to about 65 on average.

Threats: ships and fishing gear

Whaling no longer threatens right whales, but two other human activities do. The first is collisions with vessels. Right whales feed, rest and migrate close to some of the busiest ports and shipping lanes on the Atlantic coast, and they often lie just under the surface. Vessels of almost any size can kill or injure them, and the chance of a fatal blow rises sharply with speed.

The second is entanglement in fishing gear, especially the vertical ropes that link lobster and crab traps on the seabed to buoys at the surface, and gillnets. Whales can drag rope and gear for months, which cuts into their skin, makes feeding harder and drains their energy. More than 85% of North Atlantic right whales carry scars showing they have been entangled at least once, and many have been entangled several times.

Other pressures add up: underwater noise from shipping and construction can mask calls and raise stress levels, and climate-driven changes in prey have pushed whales into areas with fewer protections. Natural predators matter far less. Orcas and large sharks occasionally attack calves, but healthy adults are rarely targeted.

Conservation status

The IUCN Red List moved the North Atlantic right whale from Endangered to Critically Endangered in 2020. It is listed as endangered under the US Endangered Species Act and Canada’s Species at Risk Act, and international trade in its products is banned under CITES Appendix I.

After commercial whaling ended, the population grew slowly to roughly 480 whales around 2010, then fell as deaths rose and births dropped. Since 2017, NOAA has tracked an Unusual Mortality Event covering dead, seriously injured and sick whales, which together amount to more than 20% of the population. The latest estimate, 384 whales at the start of 2024, is the third yearly rise in a row, but there are still only about 70 breeding females. The numbers are explained in more detail in How many right whales are left?

Protection measures include seasonal 10-knot speed limits for larger vessels in key US areas since 2008, speed limits and temporary fishing closures in Canada’s Gulf of St. Lawrence since 2017, shipping lanes moved away from whale hotspots, rules for weaker rope and fewer buoy lines, and trials of “ropeless” traps that stay on the seabed until a signal brings the buoy line up.

Right whales and people

The species’ name comes from whaling. Whalers are said to have considered it the right whale to hunt because it was slow, coastal and floated when killed, a story explored in Why are they called right whales? Basque whalers hunted right whales in the Bay of Biscay from around the 11th century, and colonial shore whalers took them off New England in the 1600s and 1700s. By the early 20th century very few were left, and international agreements have protected right whales from commercial whaling since 1935.

Today the right whale is a symbol of ocean conservation along the US East Coast, and both Massachusetts and Georgia have named it their state marine mammal. In US waters it is illegal to approach within 500 yards (460 m) of a right whale by boat, kayak, paddleboard or drone, and anyone who spots one is encouraged to report the sighting so ships in the area can slow down.