Navigating by following the contours of the sea floor, migrating gray whales travel 60 to 80 km each day-often close enough to shore that they can be sighted from land. B.C. summer resident whales do not visit Arctic waters. Warm winters Gray whales spend winters, from December to February, in the warm waters of Baja California, Mexico, where pregnant females give birth. By mid-February, they start swimming northward. Adult males, newly-pregnant females and juveniles leave first, followed by females and their calves.
Some gray whales start feeding when they reach the waters along Vancouver Island.
Summer gorging During summer months, gray whales feed in the Bering Sea, the Chukchi Sea, the western Beaufort Sea and the Arctic Ocean. Gray whales rely almost entirely on their fat reserves as an energy source during their winters and migrations. They build up their blubber and other fat reserves by feasting through the summer months, gaining 16-30 percent of their body weight. In October, as the northern winter begins, pregnant females lead the procession of migrating gray whales returning to the warmer waters of Baja California. Each spring, thousands of people flock to Pacific Rim National Park on Vancouver Island hoping to catch a glimpse of migrating gray whales heading up to their summer feeding grounds.