Hummingbirds can see an array of colors invisible to humans

CNN — When hummingbirds make decisions regarding food, evading predators or choosing a mate, they’re influenced by the diverse colors they can see that are invisible to human eyes, according to a new study. “Even though biologists have long assumed that birds can discriminate a variety of diverse nonspectral colors, our results confirm that this is indeed the case for hummingbirds,” said Mary Caswell Stoddard, study author and assistant professor in the Princeton University department of ecology and evolutionary biology, in an email. The LED devices displayed a range of colors, including nonspectral colors like ultraviolet+green, which is how the researchers refer to this combination of light components that the hummingbirds can see. “Personally, it was thrilling to watch hummingbirds learn to discriminate two different colors that appeared identical to us,” Stoddard said. This makes sense because they evolved to respond to flower colors that advertise sweet nectar rewards.” The researchers also analyzed 3,315 feather and plant colors and found that 30% of feather colors and 35% of plant colors likely appear nonspectral to hummingbirds — even though humans can’t make that distinction.