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Wildlife Guide · North Pacific — eastern population from Mexico to the Arctic & Small, severely depleted western population off Russia

Gray Whale

Eschrichtius robustus (Lilljeborg, 1861) — family Eschrichtiidae

One of the longest migrations of any mammal, and a whale that feeds by rolling on the seabed.

Least Concern overall; the western Pacific population is Critically Endangered
Gray whale with mottled barnacle-covered skin surfacing at sea

Image: AI-generated educational wildlife portrait — World Animal Rescue Network · AI visualisation, not a photograph

In brief

The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment.

By the WARN Research & Conservation TeamChecked against IUCN Red List & CITES sourcesLast updated

The gray whale makes one of the longest migrations of any mammal, travelling up to roughly 20,000 km a year between Arctic feeding grounds and the lagoons of Baja California where it calves. It is also the only baleen whale that feeds primarily by rolling onto its side on the seafloor and sucking up sediment, straining amphipods from the mud. The eastern North Pacific population recovered strongly after whaling ended, and is one of the clearest large-whale recovery stories. The western population did not, and remains Critically Endangered.

~20,000 km

Annual round-trip migration — among the longest of any mammal

Benthic

The only baleen whale that feeds mainly from the seafloor

~15 m

Adult length

Recovered

The eastern Pacific population rebounded after whaling ended

Figures sourced from IUCN Red List — Eschrichtius robustus, CITES Appendices .

Gray Whale: Quick Facts

Vital statistics and key facts about the Gray Whale
Length ~15 m
Migration Up to ~20,000 km per year
Feeding Benthic — filters seafloor sediment
Calving grounds Baja California lagoons, Mexico
Eastern population Recovered; delisted in the US in 1994
Western population Critically Endangered

Scientific Classification

Scientific classification of the Gray Whale
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Artiodactyla
Infraorder Cetacea
Family Eschrichtiidae
Species Eschrichtius robustus

Conservation Status

IUCN Status
Least Concern (species); western Pacific subpopulation Critically Endangered
Population
Tens of thousands in the eastern North Pacific
Trend
Eastern population recovered; recent unusual mortality events recorded
Assessed
2018
CITES
Appendix I

The North Atlantic population was hunted to extinction centuries ago. Recent mass strandings of emaciated whales point to prey availability in warming Arctic feeding grounds.

Did you know?

Most gray whales are right-sided: they roll onto the same flank to feed, wearing the baleen down more on that side.

Key Facts: Gray Whale

  • Gray whales migrate up to roughly 20,000 km a year.
  • They feed by rolling on the seabed and filtering amphipods from sediment.
  • The eastern North Pacific population recovered strongly after whaling protection.
  • The western Pacific population remains Critically Endangered.
  • Whalers called them devil fish for the ferocity with which mothers defended calves.

Feeding on the bottom

Gray whales are unique among baleen whales in feeding mainly from the seafloor. A whale rolls onto its side, usually the right, and suctions up sediment, then strains small crustaceans — principally amphipods — through short coarse baleen. The habit leaves visible feeding pits on the seabed and stirs nutrients into the water column, so gray whales physically rework the Arctic shelf where they feed. Most individuals show more wear on the right side of the baleen, in the same way people are right-handed.

The migration

Each autumn gray whales leave Arctic and sub-Arctic feeding grounds and travel south along the North American coast to shallow, warm, hypersaline lagoons in Baja California, where calves are born. In spring they return north. Because the route hugs the coast, the migration is visible from land and supports substantial whale-watching. It also concentrates the entire population into a narrow coastal corridor, which makes them exposed to vessel traffic, entanglement and coastal development along the whole route.

Recovery, and the population that did not recover

Commercial whaling reduced gray whales severely. After protection, the eastern North Pacific population rebounded to tens of thousands and was removed from the US endangered species list in 1994 — one of the strongest large-whale recovery cases on record. The western North Pacific population, which feeds off Sakhalin, did not recover in the same way and remains Critically Endangered, with tracking showing some individuals crossing to the eastern side. The North Atlantic population was hunted to extinction centuries ago, though occasional strays now appear as Arctic ice retreats.

Modern pressures

Gray whales face entanglement in fishing gear, vessel strikes along a coastal migration route, noise and disturbance from shipping and industrial activity, and changes in the Arctic benthic communities they depend on. Unusual mortality events have been recorded in recent years, with large numbers of emaciated whales stranding, and reduced prey availability in warming Arctic feeding grounds is a leading hypothesis. A recovered population is not a secure one when its food supply is shifting.

What WARN Does

WARN publishes free, sourced species education including conservation's genuine successes and their limits. The eastern gray whale shows that a heavily hunted large whale can recover once killing stops — and recent mortality events show that protection from hunting does not protect a species from what is happening to its food.

If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.

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Gray Whale: Frequently Asked Questions

How far do gray whales migrate?
Up to roughly 20,000 km on a round trip each year, between Arctic feeding grounds and calving lagoons in Baja California — among the longest migrations of any mammal.

How do gray whales feed?
By rolling onto their side on the seafloor and suctioning up sediment, then straining small crustaceans such as amphipods through short coarse baleen. They are the only baleen whale to feed mainly this way, and most show more baleen wear on the right side.

Are gray whales endangered?
The species is listed as Least Concern because the eastern North Pacific population recovered strongly after whaling ended. The western North Pacific population is Critically Endangered, and the North Atlantic population was hunted to extinction centuries ago.

Why were gray whales called devil fish?
Whalers gave them the name for the ferocity with which mothers defended their calves in the Baja calving lagoons, where hunting was concentrated and the whales fought back hard.

What do gray whales eat?
The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment. The guide's ecology sections give the prey or forage detail behind that summary.

Where do gray whales live?
Gray Whales live in North Pacific — eastern population from Mexico to the Arctic, Small, severely depleted western population off Russia. The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment.

Are gray whales dangerous?
Gray Whales are not generally dangerous to people. The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment. Give wild individuals space and do not corner or handle them.

How long do gray whales live?
A precise wild lifespan for gray whales is not firmly established in the sources cited on this guide. The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.

How big is a gray whale?
A Gray Whale is about ~15 m. The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment.

Sources & References

Population figures, conservation status and biological facts on this page are drawn from authoritative scientific and intergovernmental sources.

Terms used on this page

Plain-English definitions, from our wildlife and conservation glossary.

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