Trichechus senegalensis is a poorly studied species, and much of
the information about their behavior and reproduction has been
inferred based on their close similarity to the very well
studied Trichechus manatus. They are capable of reproducing
throughout the year; however, a peak in calving tends to occur
in late spring or early summer (CMC 1997). Females are sexually
mature as early as three years of age. A female in estrus is
joined by a dozen or more males. Together they form a mating
group in which copulation appears to occur at random (Save the
Manatee Club 1997). Gestation lasts about 13 months and usually
a single calf is born at a time, but twins do occur
occasionally. Calves are born tail first, and they can swim on
their own (CMC 1997). They feed from a pair of pectoral mammary
glands. Trichechus senegalensis are believed to live to about 30
years of age, and females can bear young every three to five
years (Sikes 1974 and CMC 1997).