Wild hummingbirds discriminate nonspectral colors
Abstract
Birds have four color cone types in their eyes, compared to three in humans. In theory, this enables birds to discriminate a broad range of colors, including many nonspectral colors. Nonspectral colors are perceived when nonadjacent cone types (sensitive to widely separated parts of the light spectrum) are predominantly stimulated. For humans, purple (stimulation of blue- and red-sensitive cones) is a nonspectral color; birds' fourth color cone type creates many more possibilities. We trained wild hummingbirds to participate in color vision tests, which revealed that they can discriminate a variety of nonspectral colors, including UV+red, UV+green, purple, and UV+yellow. Additionally, based on an analysis of ∼3,300 plumage and plant colors, we estimate that birds perceive many natural colors as nonspectral.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- June 2020
- DOI:
- 10.1073/pnas.1919377117
- Bibcode:
- 2020PNAS..11715112S