Impala are gregarious, and usually form herds of 6 - 20, or, they may form herds of several hundred, especially in winter. During the mating season from January to May intense rivalry builds up between males, and, with loud snorts and grunts, they will resort to threatening displays, horn-thrusting, and, occasionally, fatal duels with each other. Those males that are not old enough to defend territories form bachelor herds. Single young are born, usually in early summer: all of the impala young are born within a period of a few weeks, the timing varying with the locality.

Calves are able to join their mothers in the herd within two days of birth, which favours their chances of eluding predators such as lions, leopards, cheetahs, wild dogs and hyaenas.
Impala are the most common antelope in the Kruger National Park, and are found in large herds, particularly south of the Sabie River.