Allen's Hummingbirds look a lot like the more common Rufous Hummingbird. Their feathers are a rusty color and their bill is solid black. The males have a red throat and shiny green back and cap. The females have a white chin and chest with a varying-sized patch of red- orange or bronze feathers at the center of the throat.
Where you might see them
Allen's Hummingbird (Selasphorus sasin) are typically only seen in coastal California and Oregon. They breed from southern coastal California north to southern Oregon. They are a rare but regular sighting in southern Arizona during fall migration (July - August) and rare but regular in southern Louisiana from August - February.