The most common whale off the Oregon coast is the gray whale. In addition to the approximately 200 resident gray whales that live nearly year-round off Oregon, a winter and spring migration brings about 18,000 more past our coast.
Gray whales are baleen whales (mysticetes). They grow to 50 feet in length and will weigh up to 80,000 pounds; adult females are larger than males, which is common in all baleen whales. They do not have a dorsal fin on their back but instead have a series of knuckles. These whales are mottled gray and are covered with barnacles and whale lice. Newborn calves are about 15 feet long when born and are dark gray in color.
The height of the winter migration off Oregon is usually between Christmas and New Year’s Day. The Whale Watch Center in Depoe Bay reports sightings of as many as 50 whales per day moving south to their breeding grounds in the Sea of Cortez during Whale Watch Week. Those numbers decline but remain strong through January. Generally during the winter months, whales are further offshore and more difficult to see from headlands. Oregon State Parks has a program called Whale Watching Spoken Here where volunteer observers are at most outlooks during winter and spring breaks.
Tagging studies by Oregon State University scientists show that most gray whales only stay about three weeks in the warm waters off Baja, Mexico. Then they head back to the cold, but plankton-rich waters of the North Pacific. The female gray whales with calves stay on the breeding grounds an additional month or two. Their return to northern waters in April is slower and usually closer to land. This gives whale calves a break and whale watchers their best opportunity to see the whales.
To watch the migration, it is best to pick a calm morning and find a view point that is high enough to spot the spouts. Learning good binocular technique will help spot the whales. Gaze out onto the ocean, focusing on medium distances until you see a puff of white. Then raise your binoculars while continuing to look at the place you saw the blow. This technique takes some practice, but generally works best when trying to spot whales.
When warm, moist air exhaled from the animals' lungs meets the cool air at the ocean surface, it creates the bushy column called a blow or spout. Each whale species has a distinct blow. A gray whale's blow is up to 15 feet high and is visible for about five seconds on a calm day. The whale will dive for three to six minutes, then surface for three to five blows in a row, 30 to 50 seconds apart, before diving deep for three to six minutes again. Generally in winter, the animal will move to your left (south) and during spring will be heading right (north). Sometimes you can see a muddy streak in the water that surfaces as the whale churns up the ocean floor for food. The whale's tail, or fluke, moving just below the surface can create a whale "footprint," a round, smooth spot in the water.
Gray whales are the most coastal of the baleen whales and are often found within a few miles of shore as they migrate from Alaska to Baja. Gray whales have baleen instead of teeth. To feed, they fill their vast mouths with mud from the sea bottom and strain it through their baleen to capture amphipods and other small animals. This is the only type of whale to feed in this manner. Grays are amazing in their capacity to feed in a variety of ways including taking fish or mysid shrimp directly from the water column and straining food off kelp as well.
The gray whale is an Oregon Conservation Strategy Species in the Nearshore ecoregion.
Photo by ©Corbis