Gray Whale
Eschrichtius robustus
Swims the length of a continent twice a year — and sometimes asks to be petted.
Gray whales make one of the longest migrations of any mammal, from Arctic feeding grounds all the way to warm Mexican lagoons and back. They feed by rolling onto their side and vacuuming the seafloor, and they came back from the edge of extinction.
On the conservation status
The eastern North Pacific population recovered and left the US endangered list in 1994. The western population is listed as Endangered by the IUCN, with only about 100 to 150 adults, though it's slowly growing. The Atlantic gray whale went extinct centuries ago.
- Length
- 12–15 m (39–49 ft)
- Weight
- Up to 41,000 kg (45 tons)
- Lifespan
- 50–70 years
- Diet
- Amphipods sifted from seafloor mud
- Migration
- Alaska ⇄ Baja California
- Passengers
- Hundreds of kg of barnacles
The good stuff.
They eat the seafloor
A gray whale rolls onto its side, drags its head through the mud, and sucks up sediment full of tiny shrimp-like amphipods. Then it strains the mud back out through its baleen, leaving long feeding trails on the seabed.
Most are right-handed
Individual whales prefer to roll to one particular side, and their baleen wears down faster on that side. Far more of them are right-side feeders than left.
They're moving ecosystems
A gray whale's skin hosts barnacles found nowhere else, plus swarms of pale whale lice living in the cracks. An adult can carry a few hundred kilos of passengers.
Whalers called them devilfish
Mothers defend their calves with everything they have and were known for smashing whaleboats. The name stuck for a hundred years.
Now some of them come say hi
In San Ignacio Lagoon in Mexico, gray whales — often mothers with calves — deliberately swim up to small boats and hold still to be touched. In the very lagoons where they were hunted.
Newborns can't float well
Calves are born with very little blubber, which is why mothers make the enormous swim to warm shallow lagoons to give birth instead of staying in the food-rich Arctic.
Wait, really?
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One gray whale was tracked swimming from Russia to Mexico and back — nearly 23,000 km, the longest migration ever recorded for a mammal.
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They have no dorsal fin, just a low hump followed by a row of bumps called knuckles.
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Baby gray whales drink around 190 litres of milk a day.
What it sounds like
Low rumbles, croaks and a distinctive metallic knocking, plus grunts while feeding.
We haven't found a recording we're allowed to share yet, so for now this one is a description.
Where you might see one
The California coast from December to April, and the lagoons of Baja California Sur — San Ignacio, Ojo de Liebre and Magdalena Bay.
The trouble
- Entanglement in fishing gear
- Ship strikes along a coastline crowded with traffic
- Warming Arctic changing the seafloor food they depend on
One real thing
Their migration hugs the coast, so coastal habitat matters. Join a beach clean-up on a migration route — you're cleaning their highway.
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