The male Costa's Hummingbirds iridescent violet gorget extends down on both sides of the throat like a mustache. The crown and patch behind the eye are the same color as the throat. Back is green and undersides are a pale gray. He has a white eyebrow. Female has a bright green back and pale underparts. Her chin is unmarked or may have a small patch of purple in the center.
Where you might see them
Costa's Hummingbirds can be found in the Sonoran and Mojave Deserts of California and Arizona.