image: A male Broad-tailed Hummingbird (Selasphorus platycercus) at the Rocky Mountain Biological Laboratory in Gothic, Colorado, where the researchers conducted field experiments on avian color vision. view more
Credit: Image credit: Noah Whiteman (University of California, Berkeley, CA).
Wild hummingbirds can perceive a variety of nonspectral colors, accessing a rich color space that might play an underappreciated role in foraging, communication, and mate choice, a study finds. Color perception plays a critical role in foraging, mate choice, and predator avoidance. However, it has not been clear how birds and other vertebrates with more than three types of color-sensitive retinal receptors called cones perceive nonspectral colors, which are absent from the rainbow. Mary Caswell Stoddard and colleagues performed field experiments on wild broad-tailed hummingbirds, which have four cone types. Using a custom LED device, the authors displayed two different colors on circular surfaces next to hummingbird feeders containing either a reward, in the form of a sucrose solution, or water. By tracking preferential visits to the reward-associated feeder, the authors found that the hummingbirds could distinguish nonspectral colors, such as ultraviolet+red, from their pure components, such as ultraviolet and red. Additional analysis of 965 bird plumage and 2,350 plant measurements revealed that approximately 30% of plumage colors and 35% of plant colors are nonspectral colors for hummingbirds. Because four cone types evolved in early vertebrates and are present in many species, the findings might carry broad implications for understanding color vision in the animal world, according to the authors.
Article #19-19377: "Wild hummingbirds discriminate nonspectral colors," by Mary Caswell Stoddard et al.
MEDIA CONTACT: Mary Caswell Stoddard, Princeton University, NJ; e-mail: mstoddard@princeton.edu
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Journal
Proceedings of the National Academy of Sciences