Tetrachromatic Vision

Tetrachromatic vision means that an animal uses four distinct types of photoreceptor in colour vision. Birds are a good example of tetrachromats: they not only see parts of the spectrum that humans see as red (longwave), green (mediumwave), and blue (shortwave), but they can also see ultraviolet (UV) light. This may provide them with more complex perception of the world than our own, able to see hidden detail and colours that trichromats cannot.

Currently we have evidence of two tetrachromats as being a predator of our nightjars: a grey-headed bush shrike that ate one of our nightjar cluches in Zambia, and pied crow that ate one of the plover clutches in South Africa.