The Ruby-throated Hummingbird Archilochus colubris is the most common and widely distributed of the hummingbirds in Canada. From the tip of its bill to the tip of its tail it measures from 7.5 cm to slightly more than 9 cm. No larger than a good-sized insect, it is often confused with hawk moths, especially at dusk, as these moths are similar in size, form, and flight.

The male Ruby-throated Hummingbird is shiny metallic green above, greyish white below, and has a forked tail. He wears a splendid gorget, or throat patch, of silky, ruby red feathers, which sometimes appear orange, or even jet black, depending on the light. The female is similar but has a greyish-white throat patch. Her tail is rounded, and some of the outer tail feathers are marked with white spots. These she often displays when posturing and in flight. The Ruby-throated Hummingbird’s bill is long, straight, and almost as slender as a darning needle.