Hummingbirds can see colors we can’t even imagine
Human color vision depends on three types of cones—special cells sensitive to red, blue, or green light. However, many birds, reptiles, and fish have an additional kind of cone that can pick up ultraviolet light. (Noah Whiteman/)Hummingbirds can see an impressive array of colors that are invisible—or appear very different—to the human eye, scientists reported June 15 in the journal Proceedings of the National Academy of Sciences. In a series of experiments involving sugar water and LED tubes, the researchers found that wild broad-tailed hummingbirds can discern colors created from various combinations of ultraviolet and visible light. This ability likely helps the birds home in on nectar-bearing flowers covered in patterns that are imperceptible to people.“Our findings…suggest that these birds really are experiencing a whole range of colors we humans can only imagine,” says Mary Caswell Stoddard, an ornithologist at Princeton University and coauthor of the new study. “We humans...