Manatees are very sensitive to sound. But they themselves are mostly silent. When they are afraid or aggravated they will give a high-pitched squeal or scream. Scientist believe that some of their calls help the group gather together after fleeing a dangerous situation. The most common vocal dialogue is a mother screaming an alarm to warn her baby of danger and the responding squeals of the baby.
Manatees give birth to one young each year.
Mother manatees are called cows and the babies are called calves. The babies are born at any time during the year because they live in warm, tropical areas. The mother is pregnant for about thirteen months, that's four months longer than people. The calf can swim and surface on its own the same day it is born. It begins eating plants when it is about two months old.