Calves feed with shorter or less concentration but more frequently. Nostrils open as soon as the manatee surface and close just before it submerges. Manatees take just one breath at the surface and can remain submerged for 15-20 minutes. In calves less than 2 meters long, the interval was about 4.5 minutes. These young animals have a smaller lung capacity.
Respiration also increases when traveling or when water gets colder.
Manatees can swim to about 25 knots, but rarely are observed moving over 4 knots. The tail is the major source of power, ruddering and locomotion. Newborn manatees are propelled by their flippers, but by two months old they have learned to use their tail. The configuration of the neck vertebrate prevent the manatee from turning its head, so the flippers allow the manatee to twist its whole body for a sideways view. Manatees give birth to their young in the seclusion of isolated rivers and inlets.