Impala (Aepyceros melampus – Lichtenstein, 1812) although one of the more common species, are one of the most attractive. Males differ from females only in that they carry lyre shaped horns. Rams, ewes and young have identical coloration. Males are slightly heavier than females. On average, body mass is about 55 kg (121 pounds) in males and 41kg (90 pounds) in females.
Horns start appearing in males at about 6 to 8 weeks. At the age of one year the young males have straight horns and are referred to as “spike horns” (in Afrikaans “pen koppies”). At 24 months the horns have taken on a curvature, bending towards and almost touching each other. After this they bend backwards and outwards to form the typical horn configuration of adults – lyrate, S – shaped, convex for their basal half, then curving upwards as they spread.. These various stages are shown in the images. The longevity of males is about 7 – 8 years.