All About Manatees - Birth & Care of Young

A Florida manatee's gestation is approximately 12 months.

Manatees in Florida and West Africa breed year-round.
In Florida, most calves seem to be born during the spring and summer. Most Amazonian manatees are born between February and May.

A Florida manatee female produces a single calf about every two to five years, although females that have lost or aborted a calf have been known to give birth to another in just one year (Reynolds and Odell, 1991).
The birth of twins may occur, but is rare.

A West Indian manatee calf measures about 1.2 to 1.4 m (4-4.5 ft.) and weighs approximately 27 to 32 kg (60-70 lb.).
An Amazonian manatee calf measures about 80 cm (30 in.).
The calf can be born either head- or tail-first.
At birth, a calf has fetal folds in its skin which lasts for several weeks.

The newborn calf is capable of swimming to the surface on its own for its first breath.
Calves vocalize at or soon after birth. This auditory form of communication is an important part of the mother-calf bonding process.
The calf begins to nurse within a few hours after birth by suckling from teats under the pectoral flippers. Calves nurse under water.
Manatee milk contains mostly water with 20% solids, 7% protein, and 13% fat (lipids).
Calves begin nibbling on plants within a few weeks of birth.
Although it may be weaned by the end of its first year, the calf remains close to its mother for up to two years. It is dependent on its mother not only for nutrition, but also for learning about feeding and resting areas, travel routes, and warm water refuges.