While guenons breed throughout the year, in some species, the births of the young are concentrated during specific times of the year. Pregnant for about seven months, guenon mothers, usually bear one baby, although twins sometime occur. The newborn clings to the mother's stomachs, supported by the mother's hand. According to scientists, some species of guenon newborns can walk after only a few days. At one or two months, they are active, and eat their first solid food. At four months, they can take care of themselves. Guenons mature sexually at the age of four years.