Most humpback whales make mammoth journeys every year between their feeding and breeding sites. Because seasons are reversed either side of the equator, Northern and Southern Hemisphere populations of humpbacks probably never meet; those in the north travel towards their breeding grounds in tropical waters as those in the south are travelling towards the pole to feed, and vice versa.
Humpbacks are capable of travelling at 5 mph but, during such a long journey, they average only 1 mph, resting and socialising along the way. Not all members of a particular population will travel together. For example, the humpbacks that pass the eastern shores of Australia, on their way to summer feeding grounds in Antarctica each year, stop off in the warm waters of Hervey Bay. The first to arrive there are groups of older juveniles, followed by mature males and then by mothers and calves.