When Shimmer? When Not?
When you look at an animal, it's usually easy to tell what color it is, but hummingbirds can fool us! Sometimes the hummer's throat feathers, called the gorget, shimmers with color. But other times it looks dark.

For a long time, scientists didn't know what made the gorgets of many male hummingbirds seem to change. But now they have an idea, thanks to special microscopes that allowed them to take a closer look at the feather structures.

Think Mirrors
Feathers are not exactly like mirrors, but they do have similar tiny plate-like structures. Light that hits them bounces back in just one direction. What you see depends on the angle of light hitting the feathers and where you are in relation to the bird. If no light is bounced back to you, the gorget will look black. If the conditions are just right, you will see brilliant red, orange, or purple, depending on what kind of hummingbird you've spotted!

Always a Reason
In nature, there's always a "why" behind what you see. Brilliant gorget colors probably attract female hummingbirds and, when puffed out, help warn competitors to stay away. Hummingbirds' iridescent feathers are an amazing natural adaptation!