Gorilla babies are introduced to solid food at an earlier age than human babies, at about two months, because they start to teethe at about this time. Young gorillas will be eating an adult diet by age four and, like human infants, are introduced to vegetables, before fruits. Females reach sexual maturity at 6 years, males at 11 years. The gestation period for a baby gorilla is about 250-285 days. The huge silverback is a patient father who takes care of the baby while the mother forages for food.
Gorillas form small, non-territorial harems usually dominated by a single, mature male.
There is no defense of the home range and the ranges of neighboring groups overlap. The groups tend to avoid each other. Mutual evasion is accomplished by frequent calls from dominant males. On rare occasions of encounters, the dominant males display chest beating, charging, and plant beating. Sometimes these incidences culminate in fighting.