The broad-tailed hummingbird (_Selasphorus platycercus_) and the ruby-throated hummingbird (_Archilochus colubris_) are two common species of hummingbirds found in North America. Both species are small, iridescent birds with long, slender bills and wings that beat rapidly to keep them hovering in the air. However, there are some key differences between the two species.
Size and appearance: The broad-tailed hummingbird is slightly larger than the ruby-throated hummingbird, with a body length of 3.5-4 inches compared to 2.8-3.2 inches. The broad-tailed hummingbird also has a longer, more decurved bill than the ruby-throated hummingbird. In terms of coloration, the male broad-tailed hummingbird has a bright green back and iridescent gorget (throat feathers), while the female has a duller green back and a white throat. The male ruby-throated hummingbird has a metallic red throat, while the female has a white throat with green speckles.