What colors can you see in these feathers? The way humans and other animals perceive color depends on how many types of visual receptors they have, and how these are "tuned" to various wavelengths of light (colors). Humans have fewer types of color receptors (three) than birds (four), and thus much more limited color vision. Anders Ödeen and Olle Håsted at Uppsala University in Sweden have discovered that some birds (e.g., gulls) have color receptor proteins (opsins) that allow them to see ultraviolet (UV) light particularly well, whereas others (e.g., hawks) have opsins that are not as sensitive to UV light. Their studies have contributed to a body of research indicating that UV sensitivity has evolved only a few times in birds, and is found mainly in parrots, most perching birds, and some shorebirds. Can you imagine how a bird's UV light perception might affect its social interactions with potential mates or predators? Its ability to find food?
or this project, the Burke GRC loaned tissues from 21 bird species from around the world. Ödeen and Håsted sequenced opsin DNA to help determine whether these species were UV sensitive.
Ödeen, A., N. Hart, and O. Håstad. 2009. Assessing the use of genomic DNA as a predictor of the maximum absorbance wavelength of avian SWS1 opsin visual pigments. Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology, 195:167-173.