In winter, it travels north, but it avoids the tropical regions. The mating season is around July. There is usually only 1 offspring. Born in the ocean, the calf knows how to swim and dive as soon as it is born. For the first 6 months, it eats 150 pounds each day of a very thick milk that is produced by its mother's body.
Blue whales are part of a family of whales called rorquals.
After the blue whale, the most familiar rorqual is the humpback whale, frequently seen on whale-watching expeditions off America's east coast or off Hawaii. It is also famous for its songs, which have been recorded and featured on record albums.