They spend the first year or so of the calf's life together. The calf learns valuable survival lessons in this short amount of time, and is then weaned and separated. A competitive pod forms when one female is pursued by a large number of males. The competition can become extremely aggressive, even resulting in blood shed. Male whales will literally head slap, and tail slap, another male, some even breach right on top of each other.
Competitive pods are usually fast moving, with the female in the front.
She can travel in a straight line or change directions as often as she pleases, as the males will follow the female wherever she decides to go. We believe this is the best spot for eventually being chosen by the female for mating. The secondary escorts are competing for the primary escort's position. The gestation period for a humpback whale is 11-12 months. During the first six months of a calf's life it goes through an amazing growth spurt.