Sometimes people also call because they are concerned that the manatees in the estrous herd are injured, stranded, or in distress. In shallower waters, the effect can be quite dramatic with churning waters and flailing flukes and flippers. These photos of a manatee mating herd were taken by SMC staff member Dana Hensarling and her husband near Bradenton, Florida. The gestation period for manatees females is about a year. Mother manatees nurse their young for a long period, and a calf may remain dependent on its mother for up to two years.
Manatees have a low reproduction rate.
It is believed that one calf is born every two to five years, and twins are rare. The cow assumes total responsibility for raising the calf. Calves nurse under water from a nipple located behind the cow's flipper and begin to eat plants a few weeks after birth.