Learn what a Calliope hummingbird looks like, where to find these tiny birds in the U.S., and how to attract them.

their uppertail coverts and tail base have more rufous (adult female rufous can be all-green); and their chip calls are slightly lower pitched. Also see female and immature calliope hummingbird.

In his research, Halter looked at two species of migrating hummingbirds, Calliope (Selasphorus calliope) and Rufous hummingbirds (Selasphorus rufus), at a site along the Mimbres River in New Mexico.