Aquafacts / Grey Whales

Grey Whales

You asked questions about grey whales and our biologists answered.

Quick info


Maximum number of baleen plates on upper jaw

450 kilograms

Average weight of a newborn

15 minutes

Maximum time between breaths

9,000 kilometres

Yearly migration

Where do grey whales live?

Winter Breeding:

Grey whales spend winters, from January to March, in the warm waters of Baja California, Mexico, where pregnant females give birth. By late February, they start swimming northward. Adult males, newly-pregnant females and juveniles leave first, followed by females and their calves. Some grey whales start feeding when they reach the waters along Vancouver Island, although in some years, some start feeding as far south as central California.

Summer Feasting:

During the summer months, most grey whales feed in the Bering Sea, the Chukchi Sea, the western Beaufort Sea and the Arctic Ocean. Here they gorge themselves on massive quantities of food! Grey whales rely almost entirely on their fat reserves as an energy source during their winters and migrations so they build up their blubber and other fat reserves by feasting through the summer months. They gain 16 to 30 percent of their body weight during this time. In October, as the northern winter begins, pregnant females lead the procession of migrating grey whales returning to the warmer waters of Baja California.

What do grey whales eat?

These enormous animals eat large quantities of tiny animals. Scientists believe an adult grey whale consumes an average of about 1,100 kg of food per day. The main component of their diet is small, shrimp-like animals called amphipods that live on muddy ocean floors. Amphipods are minute compared to grey whales. Grey whales also eat tubeworms, mysids (another shrimp-like animal), small fishes, ghost shrimps, herring eggs and crab larvae (especially larvae of porcelain crabs), which are a seasonally important food source for them in British Columbia.

How do grey whales eat?

Grey whales use suction to draw food into their mouths. A feeding grey whale turns so that one side of its mouth faces the ocean bottom. The whale opens its mouth slightly and pulls in its huge tongue. This draws in sediment and amphipods from the ocean bottom. The whale then pushes the sediment through the baleen plates on the opposite side of its mouth. The amphipods are caught in the baleen, which acts like a filter.
Grey whales are the only baleen (filter feeder) whale that regularly feeds on bottom-dwelling animals. Scientists think they can tell whether a grey whale is a right or left-handed feeder by looking at the barnacles and scraped skin on its head. There are more skin scratches, and fewer barnacles, on the side of the whale that faces the bottom when it feeds. Sometimes grey whales use other feeding techniques such as surface skimming for crab larvae.

Where can I see grey whales?

Each spring, thousands of people flock to Pacific Rim National Park on Vancouver Island hoping to catch a glimpse of migrating grey whales heading up to their summer feeding grounds. Since the whales often travel close to the shoreline, many park visitors spot the whales from the beach! There are summer residents that can be observed all through the summer off the Pacific Rim National Park. West Coast whale watching companies use small boats to bring people closer. Guidelines help ensure that these boats do not interrupt or disturb the whales. For more information about whale watching, phone the Tourism Association of Vancouver Island at 250-382-3551.

Were grey whales ever hunted?

Historically, grey whales were hunted by the Chukotka people of the US/Russian Arctic, as well as many coastal First Nations in B.C. and Washington. Grey whales were hunted commercially for their meat and oil by European, Japanese, and North American whalers, especially in the 17th and 18th century. Relentlessly hunted for their meat and oil, Atlantic grey whales became extinct in the 18th century. The eastern North Pacific population also plummeted but has since made a dramatic comeback.

Are grey whales still hunted today?

Not commercially; in the late 1940s, a convention under the International Whaling Commission (IWC) prohibited the commercial whaling of grey whales. These restrictions enabled grey whales to make a dramatic comeback to current population levels. However, subsistence hunting still occurs in Russia and the US Arctic. The Makah tribe of Washington State is also negotiating the right to hunt grey whales for subsistence purposes.


What is the future of grey whales?

The latest shore-based count in 2005 showed the population at 18,000 animals, down from 26,600 in 1998. The grey whale populations is likely to remain around this number, unless there is a change in the ocean ecosystem, because it is currently thought that it has reached carrying capacity. This means the number of grey whales is as high as the North Pacific Ocean can support. The number of western North Pacific (Korean) grey whales is very low—100 to 200 whales. They are listed as critically endangered.

How can I help?

If you see a whale or dolphin off the coast of British Columbia, we would love to hear about it. Report your sighting at


  1. American Cetacean Society. 2007. Grey Whale Fact Sheet
  2. Busch, Robert H. 1998. Grey Whales: Wandering Giants. Custer, WA: Orca Publishing.
  3. Gordon, David G., and Alan Baldridge. 1991. Grey Whales. Monterey Bay, CA: Monterey Bay Aquarium.
  4. Leatherwood, Stephen and Randall R. Reeves. 1992. The Sierra Handbook of Whales and Dolphins. San Francisco: Sierra Club Books.
  5. Jones, Mary Lou, Steven L. Swartz and Stephen Leatherwood, Eds. 1984. The Grey Whale Eschrichtius robustus. Orlando: Academic Press.
  6. Wild Whales - The B.C. Cetacean Sightings Network

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