
It's difficult sometimes to determine the gender of Allen's Hummingbirds that are not adult males. Adult males have the bright red gorget and head that is unmistakable, even in flight. But one has to look closely at the gorget of the young to determine their gender. According to the Peterson's Field Guide of Hummingbirds of North America, by Sherri L. Williamson, the young male is similar to the female but the "gorget is usually more heavily marked, often with large mirrorlike metallic feathers in patches throughout the gorget area or concentrated in lower center". Hence, the red patch, just in view at the bottom of his throat, marks this as a young man.