North Atlantic right whales might be vast, slow swimmers, but they still reveal moments of surprising agility at the surface. Sadly though, with under 400 remaining in the world today, these ocean giants are seen less frequently than ever before.
When did North Atlantic right whales first appear in oceans?
Ancestors of modern right whales likely evolved around 20–25 million years ago during the Miocene epoch, when early baleen whales diversified in the world’s seas.
When were they first discovered and documented by humans?
The species was formally described in 1776 by Danish zoologist Otto Friedrich Müller, who gave these whales the scientific name still used today: Eubalaena glacialis.
What oceans do they live in (and how has this evolved over time)?
North Atlantic right whales are found in Atlantic coastal waters and migrate seasonally, alone or in small groups. In spring, summer and autumn, most of the population is found off the coast of New England in the US, and, increasingly they are also found further north in Canadian waters, where they feed and mate.
In autumn, some right whales travel south along the mid-Atlantic coast to shallow coastal calving grounds off the Southeastern United States. While previously widespread through the North Atlantic (including off Scotland and Ireland), centuries of hunting reduced their numbers to the brink of extinction.
In recent years, the distribution patterns of the North Atlantic right whale have been changing in response to warming waters and shifting prey locations, contributing to reduced reproduction and increased susceptibility to human-caused threats.
Since 2010, right whales have been more frequently found feeding in Canada’s busy Gulf of St. Lawrence during the summer months.
Origins of the name “right whale”
The name “right whale” comes from early whalers, who considered them the “right” whale to hunt. As they are slow swimmers, float after being killed (due to the thickness of their blubber), and stay close to shore, they are easy targets for whalers.
What is the scientific name of the North Atlantic right whale?
The scientific name of the North Atlantic right whale is Eubalaena glacialis. The genus name Eubalaena means ‘good or true whale’.
The physical features of the North Atlantic right whale
North Atlantic right whales are very large, rotund and mostly black, while some may have white blotches on their belly. Unlike many other whales, dolphins and porpoises, North Atlantic right whales don’t have a dorsal fin. Their flippers are broad and paddle-shaped, and their tail flukes are wide. Right whales have enormous heads, which are about one-third of the total body length, and their mouths are large, containing hundreds of baleen plates, each up to 3m (8ft) in length.
The markings on a North Atlantic right whale
Right whales have large, rough skin growths on their heads called callosities (derived from the word “callus”). These patches are colonised by colonies of small crustaceans called whale lice, which make them appear white. The shape, size and position of callosities are unique on each whale’s head, so scientists can use these patterns to identify individuals. Right whales also have a distinctive v-shaped blow (spout) that can be spotted when they breathe out at the surface of the water.
How big are North Atlantic right whales?
Right whales are usually between 13-18 metres long and weigh between 40-90 tonnes. The females are usually slightly larger than males.
Do they have teeth?
No, North Atlantic right whales don’t have teeth. Instead, they have baleen plates, long bristle-like structures made of keratin that act as filters for catching tiny prey.
Are they solitary or social animals?
Right whales may be seen alone, in small groups, or actively socialising at the water surface. While a whale might appear to be travelling or feeding alone, sound recordings indicate they are frequently in acoustic contact with others. Research has revealed that mother right whales communicate to their calves using quieter calls, sometimes described as whispers, which are less audible over long distances and may help keep calves safe, reducing the risk of detection by predators.
What do they eat?
Right whales feed entirely on zooplankton – their favourite types are copepods (tiny crustaceans), which are about the size of a grain of rice. They also eat krill and small invertebrates.
The whales skim feed or graze, swimming slowly through large patches of copepods with their mouths open. The baleen plates in their mouths strain prey from seawater like a giant sieve. Scientists have found right whales can eat between 998 and 2495 kg of food every day.
How do they track their prey?
Right whales rely on sensitive hearing and possibly chemical cues to locate dense patches of prey. They often swim slowly through areas with high concentrations of copepods and feed continuously.
How do they breathe?
Like all whales, right whales breathe air through blowholes on top of their heads. When they surface, they release the distinctive v-shaped blow, which can help researchers to identify them at sea.
Do they come to the surface for long?
Right whales typically surface for short breathing intervals, then dive for several minutes. They tend to swim and rest at or just below the surface with very little of their body above water, which can make them hard to see. Their dives usually last between five and 20 minutes, though they sometimes remain underwater longer while feeding.
What is their lifespan?
Right whales are thought to live for 70 years or more, though many individuals today die much younger because of human-related threats.
How fast can they swim?
They are relatively slow swimmers, usually traveling at around 3–5 mph, although they can move faster for short bursts.
Are they intelligent animals?
Yes. Like many whales, they possess large, complex brains and show signs of intelligence, including communication, learning and social behaviour.
Do they interact with other whale or dolphin species?
Interactions with other whale species are rare, but there have been some reports of communications between right whales and both humpback whales and bottlenose dolphins. They may occasionally share feeding areas with other baleen whales including sei whales.
How long will the calf stay with its mother?
A calf usually stays with its mother for about a year, learning migration routes and feeding behaviour.
What sounds do right whales make?
Right whales communicate using low frequency moans, groans and pulses. Their most common call is an “up-call”, a rising “whoop” sound used as a contact call with other whales.
Do they have any natural predators?
Large sharks and killer whales (orcas) may occasionally attack calves, but natural predation is relatively rare.
How do they protect themselves?
Their main defence is size and strength. Mothers will also closely guard their calves and position themselves between the calf and potential threats.
What are the main threats to North Atlantic right whales?
Hunted since the 11th century, right whales were nearly extinct when they finally received protection from whaling in 1935. Even so, the population has struggled to recover as they face mounting modern-day threats from accidental entanglements in fishing gear, collision with ships, ocean noise pollution, and the effects of climate change on food supply.
Find out more about how noise pollution is affecting the lives of whales and dolphins here.
Are they endangered?
North Atlantic right whales are critically endangered, with fewer than 400 individuals remaining, and only about 70 reproductively active females. Human impacts threaten the survival of the species, specifically entanglements and vessel strikes. There is some cautious optimism that stronger protection measures will slow the number of deaths, so the population may recover.
Words by: Danny Groves, Whale and Dolphin Conservation
Top image: Northern Right whale breaching at sunset, off Grand Manan Island, Bay of Fundy, New Brunswick, Canada (Photo by: Francois Gohier/VW Pics/Universal Images Group via Getty Images)
