The kakapo was a very successful species in pre-human New Zealand, and was well adapted to avoid the birds of prey which were their only predators. As well as the New Zealand falcon, there were two other birds of prey in pre-human New Zealand: Haast's eagle and Eyles' harrier. All these raptors soared overhead searching for prey in daylight, and to avoid them the kakapo evolved camouflaged plumage and became nocturnal. When a kakapo feels threatened, it freezes, so that it is more effectively camouflaged in the vegetation its plumage resembles. Kakapo were not entirely safe at night, when the laughing owl was active, and it is apparent from owl nest deposits on Canterbury limestone cliffs that kakapo were among their prey.