Technicolor Vision

It’s a truly brilliant world… for hummingbirds!

This is Sandra Tsing Loh with the Loh Down on Science.

Pretty blues! Vibrant reds! We humans see colors because of special cells in our eyes called cones. Hummingbirds have an extra cone that detects UV light — light from the sun WE can’t see. So, can hummingbirds see extra UV colors?

Mary Stoddard and researchers from Princeton University looked in Colorado meadows. They paired LED lights with bird feeders that had plain water or sugar water. The lights shined different colors for each feeder, either UV or regular hues. Next, they trained the hummingbirds to link a specific UV color with the sweet reward. If the lights switched, would hummingbirds follow?

Yes! Hummingbirds visited feeders with the reward color more often, even WITHOUT the sugar water. This means hummingbirds can tell colors like UV red or UV green apart.

But why have enhanced vision? The better to see…. UV lit flowers! UV light may help hummingbirds find nectar faster.

So, let’s all see the world through colorful hummingbird glasses! SPECT-acular!

Reference: Wild hummingbirds discriminate nonspectral colors. Mary Caswell Stoddard, Harold N. Eyster, Benedict G. Hogan, Dylan H. Morris, Edward R. Soucy, David W. Inouye. Proceedings of the National Academy of Sciences Jun 2020, 117 (26) 15112-15122; DOI: 10.1073/pnas.1919377117