The migration covers thousands of kilometers. The whales come to the warm protected Tongan waters to give birth and to mate. Humpback calves are born in Tonga with very little insulation. The warm waters are very important for their months of growth. Tongan waters provide little food for the adult humpback.
Humpbacks engage in fantastic courtship and mating behavior which can last for hours.
Gestation for these enormous creatures is about 12 months. It is little wonder that they are very vocal. These whales are known for their complex songs. These songs have been recorded by scientists for a number of years. There a few mysteries of the deep like the song of the whale.