Although yet to be proven, songs are thought to be broadcast by sexually mature, lone males and may have some purpose in mating rituals. Humpback whales eat krill, mackerel, sand lance, capelin, herring, pollock, smelt, cod, sardines, salmon, and anchovies. These whales are lunge-feeders but use several different techniques to concentrate their food before lunging. In bubble netting, one or more humpbacks exhale while circling below a food source. The resulting bubble column effectively forms a net to concentrate food items through which the whales lunge with open mouths.
Females give birth to a single calf in tropical or subtropical waters in winter.
The gestation period is approximately 11 months. Newborn humpbacks are 4.6 m in length and weigh about 1.3 metric tons. The period of lactation lasts approximately 5 months. Sexual maturity is reached at 2-5 years, at which time the young whales measure about 12 m in length. Physical maturity occurs at 12-15 years of age.