Impala

Aepyceros melampus

Description

Impala are sexually dimorphic, males have thin, “S”-shaped horns that are about 45-91.7 cm long and heavily ridged. Males and females are similar in color; red-brown fur that becomes pale on the sides, white on the belly, chin, lips, inside of ears, eyebrow and tail. They have black stripes down the tail, forehead, thighs, and ear tips.

Habitat

The impala can be found from northeast South Africa to Angola, south Zaire, Rwanda, Uganda, and Kenya. This species prefers woodlands containing little undergrowth and low-medium height grasslands.

Feeding Behavior and Diet

Impala are intermediate feeders, grazing on grass and browse. They prefer grass and will consume more when grass is abundant during the wet season. Impala are ruminants, breaking down cellulose from their diet by microorganisms in their digestive tract. A water source is not necessary when there is an abundance of grass.

Reproduction

Breeding typically occurs in March through May. Males roar, snort and perform low stretches to attract a female in estrous. Once a male has the attention of a female he chases her and then shows nodding and tongue flicking behaviors before mating.  The female gives birth after 194-200 day gestation period. The female gives birth to one calf in the midday. Just before calves are born, females isolate themselves and do not return to the herd until 1-2 days after the calf is born. Young are kept in groups called crèches, to play, groom, and travel together. Calves nurse from their mother until they are weaned at 4.5 months. Impala reach sexual maturity after 1.5 years of age, males usually do not mate until age 4 because they have not yet established territories.

Months and Times of Activity

This species is diurnal, spending the nights laying down and ruminating/ digesting. Impala reach the peak of their activity after dawn and just before dusk when the herd moves. Social structures within the herd change based on the season. During the wet season there are three main social organizations present; territorial males with and without breeding females, bachelor herds of non-territorial adult and juvenile males, and breeding herds of females and juveniles. Female herds of 15-100 impala live in clans, during the wet season the home range of these clans are heavily defended. During the dry season, males can be found together or mixed with female herds. Even individuals and/or multiple clans of females will overlap ranges in the dry season. This is not true for eastern populations of impala; they remain territorial during the dry season. During the breeding season the male impala have smaller territories which they defend, males return to the same territory every breeding season to declare dominance. To defend its territory and declare dominance, a male impala will display tail-raising, forehead marking, forehead rubbing, herd chasing, erect posture, fighting and roaring.

Special Features, Stories, Relationships

•    This species can leap 3 meters in the air in any direction to confuse a predator and escape.

•    Impalas have scent glands on their rear feet and also sebaceous glands located on the forehead

•    Aepyceros melampus pertersi a subspecies of impala are declared as endangered by the U.S. ESA and IUCN. The decrease in population has been a result of habitat loss

•    Children’s book featuring this animal: Izzy Impala’s Imaginary Illness by Barbara deRubertis

References

Lundrigan, B. and K. Sproull 2000. "Aepyceros melampus" (On-line), Animal Diversity Web. Accessed November 04, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Aepyceros_melampus/ 28 Feb. 2013.