The Great Migrators

Whales travel tens of thousands of kilometres during their lifetime, and they usually make these epic migrations twice a year. The reasons why they undertake such lengthy journeys is that they need to forage for food and later in the year, they move to breeding grounds.  

It’s vital that whales’ migratory routes all over the planet are protected and threats to the animals are eradicated, ensuring they can live safe and long lives.  

We take a closer look at four whale species who can definitely be called ‘The Great Migrators’.  

Grey whales (Eschrichtius robustus) make one of the longest annual migrations of any mammal, travelling between 15,000 to 20,000 kilometres.   

The baleen whales were once commonly found through the Northern Hemisphere but are now only regularly found in the North Pacific Ocean. There are two populations in this region: the Eastern Pacific grey whale (living along the Pacific coast of North America) and the Western Pacific grey whale (living around Korea, China and Japan).   

In the case of the Eastern Pacific grey whale, it feeds in the summer in the Bering and Chukchi Seas between Alaska and Russia. In the autumn, it migrates south along the west coast of the U.S., as far as the Baja Peninsula in Mexico and the south eastern Gulf of California. In the beautifully warm waters there, they breed and give birth to calves.  

Interestingly, research since 2004 has detected some members of the Western Pacific grey whale population making a migration to the Pacific coast of North America to visit feeding and wintering grounds used by their Eastern Pacific grey whale counterparts. You could call it checking out where their cousins live!  

Grey whales usually migrate for about two to three months annually in large groups and they pace themselves, swimming up to 8 kilometres per hour.  

There’s still a lot to be learnt about how this species lives as they’re usually found out in the open ocean as opposed coastal waters. But like other large whales, fin whales migrate between feeding and breeding grounds.  

They make quick work of their migrations as they are called the ‘greyhounds of the sea’. Fin whales can cruise at up to 15 kilometres per hour and can accelerate in short bursts of speed of up to 28 kilometres per hour. The largest population of fin whales is thought to be in the North East Atlantic with an estimated 25,000 – 30,000 fin whales living there.  

Fin whales are generally solitary or found in pairs, so they aren’t a species that migrate in a group. A study published in 2022 found that Antarctic fin whales could be migrating as far south as Chile – quite a journey!  

Blue whales are found in all of the world’s oceans. They’re generally more common in the Southern Hemisphere (Antarctica, Australian and New Zealand waters). There’s also a resident population in the northern Indian Ocean.  
 
In the North Atlantic Arctic, the blue whale can be spotted around Norway, Iceland, the Faroe Islands, in southern Greenland, and in southern Svalbard. They’ve also been occasionally spotted in North Atlantic waters west of Ireland and Scotland and have been spotted off Galicia in Spain.  
 
Generally speaking, blue whales spend their summers feeding in cold waters and then migrate long distances to warmer waters (nearer the equator) for mating season.   
 
The Eastern North Pacific population of blue whales mostly feed off California from summer to autumn and then move north to colder waters off Oregon, Alaska and Washington State to continue feeding. During winter and spring, they migrate south to the waters of Mexico (mostly the Gulf of California) and the Costa Rica Thermal Dome.  
 
Blue whales are occasionally seen swimming in small groups but are more often found migrating alone or in pairs (particularly with offspring). 

Humpback whales make one of the longest migrations of all animals, with some individuals travelling up to 8,000 kilometres between their feeding and breeding grounds.   

Humpbacks are found in oceans all over the world, with major populations found in the North Atlantic, North Pacific and in the Southern and Indian oceans.   

In the northern hemisphere, whales feed in the colder polar areas between June and October before heading south to breed in warmer waters in the months between December and April.   

In the southern hemisphere, the populations feed around the Antarctic between November and March and migrate north towards the equator where they mate and give birth between July and October. 

In the North Pacific, some humpback whales migrate from Alaska to Hawaii (4,800 kilometres) in as few as 32 days.   

Along the coast of South America, scientists tracked one whale travelling just under 19,000 kilometres over 265 days. It travelled from its summer foraging area near the Antarctic Peninsula, up to its winter breeding area off Colombia and then back to the Antarctic Peninsula.