Adult Male
This is an adult male, but a male's red throat patch, called the gorget, may not be apparent when viewed from the side or in low light. That's because the colors of these birds' feathers are structural and not pigmented. The colors vary with the intensity and angle of the light. In poor light, a Ruby-throated Hummingbird can look almost black rather than green or red. In brighter light, the colors look iridescent or metallic.

Image: Laura Erickson

Male Ruby-throated Hummingbird