Sea otters are expert divers.
Reproduction Sexual maturity of female otters is reached at 3 or 4 years of age. It is unclear as to the maturity ages for males. Reproduction occurs throughout the year, but there is a peak mating season occuring in October and November, a five or six month gestation period, and then a peak birthing season in late May and June. Studies show a slightly higher number of females than males in most populations. Probably the most fascinating of these behaviors is maternal care of pups.