Hummingbirds' big eyes can see more colors than humans. Human retinas have three cones for blue, green, and red tones, but hummingbirds have four.
The fourth cone in hummingbird eyes detects UV light, which humans cannot see. When ultraviolet hues mix with visible ones, new colors appear.
Hummingbirds adore red for a good reason: Their retinas have a higher cone density, which mutes blue and boosts red and yellow. How a little creature can have such sophisticated anatomy is fascinating.
Hummers use their wide vision to find food and mates. This applies especially to finding flowers with life-sustaining nectar.
Plant phlox, hollyhock, foxglove, and lantana to attract hummingbirds. Red attracts hummingbirds, so the more red you have flowering, the faster they may come.
Next time you see a jeweled marvel fly by, welcome it with a variety of nectar sources and envision the amazing colors it sees in nature.
Researchers proved UV theory this way. Wild hummingbirds were tested for ultraviolet color vision outside by the scientists. They created LED tubes that radiated visible and UV hues.
They placed LED tubes near two feeders. One with sugar water emitted UV light, whereas another with ordinary water did not.
Hummingbirds learned to link UV light with sugar water and conventional light with plain water.
When scientists rearranged the feeders, similar to the Pavlovian dog experiment, the hummingbirds were still more drawn to the ultraviolet light feeder, proving that they could distinguish it from the normal feeder.