A male cheetah (Acinonyx jubatus) spraying urine on a tree to mark his territory. This chemical form of territorial marking communicates to other cheetahs that a territory is occupied. The cheetah is the fastest land mammal. Female cheetahs without litters are solitary, although young females usually occupy the same home range as their mother. Sibling males leave their mother's home range, but remain together and may be joined by an unrelated male. The species is classified as Vulnerable by the IUCN. Photographed in Mkhuze, Kwa-Zulu Natal, South Africa.