This order includes birds commonly known as turacos which are found in sub-Saharan Africa. They are arboreal animals that often have a coloured crest and green feathers. They are the only birds known to have green colour pigment, not structural. In all birds, the feathers are green due to the breakdown of different wavelengths of light, whereas in turacos it is due to a pigment called turacoverdin. They also produce a red pigment called turacin. To produce these, they need a copper-rich diet, which they derive from the fruits they eat. Historically, they were included in the Cuculiformes (cuckoos) group, but recent classification brings them closer to the Otidiformes (bustards).