A baby blue whale weighs as much as three tons at birth and is 25 feet long. The mother blue whale nurses her calf for at least a year, and the calf gains 200 pounds a day during that time.
Female blue whales breed once every three years, and the gestation period lasts 11 to 12 months. Only one calf is normally produced at a time. Once the calf is born, the mother and other females guide the calf to the surface of the water so that she can breathe. The calf forms a strong bond with the mother and often swims close to her.