Sometimes they gather in small but temporary bull herds. There is a great amount of toleration between them, except possibly when cows are in estrus. Young males appear to leave the herds and become solitary at about the time of puberty, whereas young females tend to remain in their natal herd. Newborn baby elephants have a coat of widely spaced brown hairs that produces a halo effect as it stands out from the body. After several months it begins to eat grass and foliage but may nurse occasionally for about 18 months.
Parental supervision lasts for several years.
Young males are capable of some independent movement at 4 years, and by 7-8 years they may form subgroups of their own or temporarily associate with older bulls. Growth slows in females at 10-12 years, in males at 15 years, and full size is attained at about 17 years. Both sexes may become sexually fertile at as early as 9 years, but males usually do not reach maturity until 14-15 years, and even then they are not capable of the social dominance that usually is necessary for successful reproductive activity. Females generally first give birth at 15-16 years. Although there have been some reports of elephants living over 100 years, the record documented age is of a captive that was estimated to be either 69 or 77 years old.