Whale of the Month - North Atlantic Right Whale

Species fact file

Common names: North Atlantic right whale, northern right whale, black right whale

Icelandic name: sléttbakur

Scientific name: Eubalaena glacialis

Family: Balaenidae (right and bowhead whales)

Max length: 18.5m (females), 16m (males)

Distribution: coastal regions in the North Atlantic

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North Atlantic right whales are the most endangered of all baleen whales, and are currently listed as critically endangered on the IUCN Red List. The western population ranges the length of the North American eastern seaboard, from winter calving grounds in Florida to summer grounds in Newfoundland and the Gulf of St Lawrence. It is estimated that there are now fewer than 300 individuals in this population. In the eastern Atlantic, right whales could once be found from the coastal waters of north-west Africa to Iceland, Norway, and Greenland – but now, this population is probably made up of less than 20 whales. There have been a few occasional sightings in Iceland in recent years, but the population is now so small it is not expected to recover.

The reason North Atlantic right whales are so endangered is because they were so favoured by whalers. They were the first whale to be commercially hunted – Basque whaling in the Bay of Biscay began as early as the 11th century and nearly wiped out right whales in the Atlantic. Their large size, slow swimming speed and large oil yield (up to 40% of their bodies are blubber) made them a hugely profitable target. These whales were actually named by whalers, because they were considered the ‘right’ whale to hunt.

There are two other species of right whale: the southern right whale (Eubalaena australis) and the North Pacific right whale (Eubalaena japonica). Neither of these species are critically endangered like the North Atlantic right whale, but there are only around 500 North Pacific right whales left in the world so they are considered endangered by the IUCN. Southern right whale populations have recovered well in the aftermath of heavy exploitation and are now listed as least concern – their success story gives us some hope for the future of the other right whales.

The wide difference in recovery of these three species is probably due to the differences in the impacts of human activities between the Northern and Southern hemispheres. The ranges of North Atlantic and North Pacific right whales overlap with areas of very high human population – both of these species are exposed to heavy shipping traffic, fisheries, and high noise levels. The combination of all these factors is hampering their recovery. The biggest threat to North Atlantic right whales is ship strikes, as much of their critical feeding habitat lies in the middle of the world’s busiest shipping lanes.

Because of their critically endangered status, there is currently a huge international effort to save the North Atlantic right whale. Conservation strategies so far have included implementing speed restrictions in shipping lanes, changing the route of shipping lanes, seasonally closing some kinds of commercial fisheries, requiring weak links in fishing gear to allow whales to break free, and testing new, ropeless fishing systems. Since conservation efforts for this species began, the risk of a fatal ship strike in US waters has decreased by 80-90%. The calving season of 2021/2022 has been particularly successful, with 15 mother-calf pairs observed so far. So, things may be looking up for this majestic but vulnerable ocean giant! You can read more about what is being done to save the North Atlantic right whale here.

All right whales are characterised by their stocky shape, arched jaw, and lack of a dorsal fin. However, their most distinguishing feature is their callosities. These are patches of tough, thick skin on the whale’s head which are colonised by parasites – mainly barnacles and whale lice. The patterns of callosities on each right whale are unique and can be used for to identify that individual from a photograph.  

Many baleen whales have very tiny sensory hairs on their face: on humpback whales, these hairs are mounted on the bumps on their head called tubercles, and on right whales they grow on their chin and from craters in the callosities. It is thought that these hairs can detect changes in the density of their prey in the water, which helps the whales to feed from the densest patch.

North Atlantic right whales feed mainly on copepods, which are a kind of zooplankton. Their hunting technique is described as ‘skim feeding’: they swim with their mouths open, collecting food inside their baleen plates as they go. Right whales will skim feed both at the surface – in which case, the top of their heads can be seen above the water – or at depth while completely submerged. Check out a video of skim feeding in action!

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Learn more about...

The historical distribution of right whales in the eastern Atlantic, including the Mediterranean Sea

How facial sensory hairs could be used while feeding