Humpbacks are fully grown by age 12 and it is estimated that they may live to age 50. Humpbacks are usually seen alone or in groups of two or three. However during feeding and mating seasons they may congregate in groups of up to twenty whales. During the winter season, female humpbacks are often temporarily accompanied by a male called an escort. If a calf is present, the male escort sometimes appears to protect the calf from intruders by placing himself between the calf and intruder.
Winter is also the season for mating.
The courtship process is not well understood for humpback whales. However, male challengers are seen trying to displace escorts in exciting surface active chases. Males use aggressive behaviors such as tail lobs and head and pec slaps against one another to attempt to maintain a position closest to a female. Humpbacks are famous for their songs. During the winter breeding season males repeat patterns of sounds for 15 minutes or more.