Have you ever seen a baby blue whale? First a female whale gives birth every two or three years. That means they have about 40 babies. Thats crazy! Also did you know that baby blue whales when born there already 5000 pounds! Additionally a calf leaves its mother after a year. Bet you never know that.Their gestation period lasts approximately ten to twelve months. Thats long for a whale! Finally did you know blue whales when born can already swim. Therefore baby blue whales are also massive animals even from when they are born!