Gray whales have the longest migration of any mammal. Each year they cover more than 9,000km traveling between their summer feeding areas and their winter breeding lagoons. Navigating by following the contours of the sea floor, migrating gray whales travel 60 to 80km kilometres each day - often close enough to shore that they can be sighted from land. By mid-February, they start swimming northwards. 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, British Columbia.
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. 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. West coast whale watching companies use small boats to bring people closer.