African elephants show sexual dimorphism in weight and shoulder height by age 20, due to the rapid early growth of males; by age 25, males are double the weight of females. However, both sexes continue to grow throughout their lives. Female African elephants are able to start reproducing at around 10 to 12 years of age, and are in estrus for about 2 to 7 days. They do not mate at a specific time; however, they are less likely to reproduce in times of drought than when water is plentiful. The gestation period of an elephant is 22 months and fertile females usually give birth every 3 – 6 years, so if they live to around 50 years of age, they may produce 7 offspring. Females are a scarce and mobile resource for the males so there is intense competition to gain access to estrous females. Post sexual maturity, males begin to experience musth, a physical and behavioral condition that is characterized by elevated testosterone, aggression and more sexual activity. Musth also serves a purpose of calling attention to the females that they are of good quality, and it cannot be mimicked as certain calls or noises may be. Watch Elephant Nature playing out at a waterhole in Kruger National Park https://en.wikipedia.org/wiki/African_elephant