It has long been believed that the manatee is a solitary animal with a very simple communication system that primarily serves one purpose: to keep mom and a calf in contact. However, in recent years, these assumptions have been questioned, based on new research indicating that manatees may not be that solitary after all and that their communication system might be more complex than we previously realized.
Manatees clearly cannot compete with other marine mammals in terms of vocal complexity—such as dolphins, for example—yet we still know surprisingly little about their vocal repertoire and how extensive it is, what individual variations their calls might have, and what the actual functions of manatee calls are, aside from simply helping them to keep in contact with one another.