Aepyceros melampus melampus
The impala is a familiar sight in many of South Africa’s reserves and national parks, and often so numerous that most visitors do not give them more than a passing glance, which is a huge pity. They are medium sized antelope, standing around 90cm high at the shoulder and weighing between 40 and 80kg. The rams are bigger than the ewes and only they carry the beautifully shaped horns.
The Black-faced Impala, a seperate subspecies (A.m.petersi), occurs in Northern Namibia.
Impalas occur in fairly dense woodland and bushveld, especially where acacias and mopane trees are dominant, and reach their highest population densities in riverine vegetation. They are mixed feeders, including large amounts of grass and browse in their diet, with considerable variation in the plants they feed on during the different seasons. They prefer to drink daily and access to a reliable water source is an important habitat factor for impala – they’re seldom further than 2 or 3km from water.
Outside the mating season, impalas occur in large, mixed herds of up to 300 animals. In the mating season, adult rams (between 4 and 8 years old) establish territories in which they herd harem groups of about 20 ewes and lambs that they defend vigorously from the attentions of any other males. During this time, males that cannot successfully demarcate a territory or hold on to their harems will band together in bachelor groups.
Impalas are most active in the early morning and afternoons, and sometimes into the night. During the heat of the day they rest up in thickets or shade near water, at night they sleep in open areas. Impala herds do not have large home ranges and they often associate with other herbivores, most notably zebras, giraffes, kudus, blue wildebeest and monkeys and baboons. They’re extremely athletic, capable of speeds in excess of 60km/h and leaps 3m high and 12m far.
In South Africa, the impala mating season falls in autumn, with most of the lambs arriving en masse in early summer. Ewes give birth to single lambs in thickets or long grass, to rejoin the herd with their lamb after two days. Almost all the lambs in a herd are born within a few days of each other, ensuring that there are more lambs than predators can handle. In the herd, the lambs group together in nurseries watched over by one or two ewes.
Impalas are a staple of many of Africa’s large predators, especially cheetah, leopard, wild dog and crocodiles. Lambs are also taken by eagles, pythons, jackals and baboons. Owing to their dependence on drinking water and reluctance to move over longer distances, impala suffer greatly during prolonged droughts. They have a life expectancy of between 8 and 15 years in the wild.
In South Africa, the common impala’s natural distribution stretches across the Kwazulu-Natal, Mpumalanga, Limpopo and North West Provinces, and they are frequently encountered in the Hluhluwe-Imfolozi Park, uMkhuze Game Reserve, Ithala Game Reserve, Tembe Elephant Park, Kruger National Park, Mapungubwe, Marakele and Pilanesberg National Parks. The IUCN considers the common impala’s conservation status to be secure, with a stable population estimated at about 2 million, half of which occurs on private land, often outside their natural distribution range, being a popular game ranching animal.