Gray whale feeding in Crescent Harbor, Whidbey Island, April 10, 2010

Gray Whale Tutorial

Gray Whales Eschrichtius robustus

The Saratoga Gray Whale Field Guide produced by Cascadia Research Collective.


Along with the arrival of spring comes the passage of Gray whales through Puget Sound and the Salish Sea. Here are a few Gray whale facts and resources to help you get to know Gray whales better. If you aren't lucky enough to see any live Gray whales this spring, visit "Rosie" the Gray whale skeleton at the Coupeville Wharf (complete with baleen), or the Gray whale skeletons at the Whale Museum in Friday Harbor, the Poulsbo Marine Science Center, or the Port Townsend Marine Science Center.

The Gray whale gets its name from its mottled gray skin, which is covered with barnacles and whale lice. Many biologists believe Gray whales may have been among the first of the great whales to have evolved into their present form.

They are 15' - 16' at birth, live to be 50 years or more, and grow to a length of 40' - 45' and a weight of approx. 30 tons, reaching sexual maturity at five to eleven years of age.

The Gray whale has two blowholes, and its spout resembles a heart shape (see photo above).

California Gray whales travel along shallow coastal waters of the eastern North Pacific.

In late winter or early spring gray whales begin to arrive along Pacfic Northwest coastal waters from winter migrations. In various fertile mudflats from Oregon to the Bering Sea they find invertebrates burrowing in the mud. By digging up the mudflats for shrimp and worms and leaving pits that attract all sorts of detritus and prey items, gray whales increase the productivity of the mudflats for sea ducks such as scoters, and for themselves a year later.

In October, the whales begin to leave their feeding grounds, usually in the Bering and Chukchi Seas, and head south to their calving grounds in the lagoons of Baja California. The journey takes two to three months.

The whales remain in the lagoons for several months, allowing the calves to build up enough blubber to sustain them during the northward migration and keep them warm in the colder waters.

During their time in Mexican waters, adult Grays seldom, if ever, eat, although they seem to dig into bottom sediments as if feeding or possibly just practicing feeding techniques. Overall, however, they live off the energy stored in their blubber layer.

Gray whale calf in Baja
©Judy Lochire
Judy Lochrie (wearing the blue wrist band), March, 2002


Gray whales are appreciated for their friendly approaches to people in small boats in their mating and calving grounds, where they are often seen spy-hopping, lobtailing and breaching.

There are 200-300 "seasonal resident" Gray whales that spend the spring, summer, and fall feeding from California to SE Alaska.

In Washington, Gray whales were once thought to be strictly seasonal travelers along the outer coast. We now know that these waters are more than just a stop on a migratory route for some. Two small groups of Grays often turn east into Washington's inland waters, usually during the spring northern migration. Some of them stay all summer.

graypits1
Gray whale feeding pits at low tide in Saratoga Passage.
The first group seems to know where the best feeding grounds are. From ten to twelve Grays return most years to northwestern Whidbey Island or southeastern Whidbey Island and Port Susan, Camano Island, feeding on ghost shrimp and tubeworms for several months. In recent years (2008-2009) more gray whales have been reported feeding in more areas around Whidbey Island, including Holmes Harbor and along Whidbey Naval Air Station and Joseph Whidbey State Park near Oak Harbor. They also appear to be arriving earlier - some in January - and staying later - some not leaving until July.

feedingmap

The second group visiting inland waters seems unfamiliar with the feeding areas, and are often emaciated when they arrive, possibly already dying of starvation. Hungry Grays usually arrive in Puget Sound in spring and summer, after four or five months in southern waters with little to eat.

364 Gray whales stranded in 1998/1999, mostly along the Pacific coast from California to Alaska, most of them with thin or dessicated blubber layers. Researchers believe the deaths were caused by a decline in amphipods which Gray whales feed upon in the Bering and Chukchi Seas. This decline is due in part to the combined effects of rising sea temperature and increased predation from the growing population of Gray whales themselves.

The number of Gray whale deaths along the Pacific coast in 1999 was twice as high as any year dating back to 1985, and the highest in the 24 years records have been kept.

Gray whales need enough food to survive the 10,000+ mile round-trip migration from Alaska to Baja. Along with humpback whales, Gray whales make the longest migration of any marine mammal.

Much has been learned just since 2010 about gray whale migrations. See Scientists see big 'scientific event' as Pacific whales turn up far from home for more.

At one time there were three Gray whale populations worldwide: a north Atlantic population, now extinct, the victims of over-hunting by the early 1700's; a Korean or western north Pacific population now extremely depleted, also from over-hunting; and the eastern north Pacific population, the only large surviving population, known as California Gray whales. They, too, were hunted to the edge of extinction in the 1850's after the discovery of their calving lagoons, and again in the early 1900's with the introduction of floating factories.

Gray whales were given partial protection in 1937 and full protection in 1947 by the International Whaling Commission. Since that time the eastern North Pacific Gray whale population has made a remarkable recovery and is now probably close to their population size before commercial whaling began.

More on Gray Whales:

Websites:

Cascadia Research - Gray Whale Hotline #: 1-800-747-7329
This is a wonderful, complete everything-you-ever-wanted-to-know-about-Gray-Whales site!

BC Cetacean Sightings Network - (go to How to ID whales, then Commonly Seen Cetaceans & click on the Gray whale for info. & a great recording of Gray whale sounds)

Whale Spoken Here - Why do they migrate? How long does the migration last? The Whale Watching Spoken Here program places volunteers at great whale watching sites during Watch Weeks so they can teach others while watching the whales too.

Good Gray Reading:

Gray Whales: Wandering Giants by Robert H. Busch

Eye of the Whale, Epic Passage From Baja to Siberia by Dick Russell

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