Nyala are a type of antelope with spiral horns. They are interesting because of the high levels of sexual dimorphism they show. Males are much larger and darker with large horns, while females are a reddish colour with more distinctive white stripes. They are social animals, but prefer to group in small numbers of 2-3 males or 3-15 females. There are also mixed gender groups of less than 15. Herds are not stable, and individuals tend to move between different groups. They will breed throughout the year, though there are birth peaks in spring and autumn with most young born in the spring. They are prolific breeders, and are seemingly resistant to inbreeding.