Many antelope are sexually dimorphic. In most species, both sexes have horns, but those of males tend to be larger. Males tend to be larger than the females, but exceptions in which the females tend to be heavier than the males include the bush duiker, dwarf antelope, Cape grysbok, and oribi, all rather small species. A number of species have hornless females (e.g. sitatunga, red lechwe, and suni). In some species, the males and females have differently coloured pelages (e.g. blackbuck and nyala).