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. The songs sound like moans and squeaking doors. Each singer sings the same song, even as the song changes as the season progresses. Little singing occurs outside of the breeding season. However, when the whales return for the next breeding season they resume singing the version of the song sung at the end of the previous breeding season.