Our vision is thus “trichromatic.” In contrast, many birds have “tetrachromatic” vision. They have red, green, and blue cones similar to our own, but they also have a cone enabling them to ...

Many birds, such as pigeons and hummingbirds, have tetrachromatic vision. In addition to red, green and blue, they can also see UV light. This helps them identify mates, find food and navigate.