|Mating takes place on communal breeding grounds in warmer waters usually in shallow bays within the 100 meter contour.
Courtship can be exuberant and seemingly aggressive; involving energetic displays of high speed chasing, pectoral and tail fluke slapping, head-lunges and breaching. Sometimes the confusion ends in a single pair rising with their pectoral fins interlaced, belly-to-belly above the water, clasping each other and holding that position for 30 seconds or more and then subsiding into the deep.
Mating may also occur in a less dramatic fashion with the whales swimming along the water in horizontal position. In either case mating seems to take place in a belly to belly position.
The age of sexual maturity is 4-5 years, when the male is approximately 11.5m and the female 12.0m.
LEFT: Pair of Humpbacks in mating posture.
(Image source:Lyall Watson, Sea Guide to Whales of the World, Hutchinson, 1981.)