Lucifer Hummingbird is a distinctive hummingbird due to its decurved bill and deeply forked tail. Males are most similar to Black-chinned Hummingbird, but the Black-chinned has a less extensive, clean-cut gorget and lacks a truly decurved bill. The male Lucifer's gorget color is most similar to Costa’s Hummingbird, but Costa’s is heavier-bodied, has purple feathers on top of the head, and lacks the Lucifer's long, narrow tail. Among female hummingbirds, the Lucifer has a brighter buffy breast and throat than other species. The warm buffy tones of female Rufous, Allen’s, and Broad-tailed Hummingbirds are concentrated more toward the undertail than the throat.