The calliope hummingbird (Selasphorus calliope) and the broad-tailed hummingbird (Selasphorus platycercus) are two small, migratory birds that breed in western North America. Both species are sexually dimorphic, with males having bright iridescent plumage and females having duller, more cryptic plumage. The calliope hummingbird is the smallest hummingbird in North America, while the broad-tailed hummingbird is slightly larger. Both species are important pollinators of wildflowers and other plants.
The calliope hummingbird breeds in the mountains of western Canada and the United States, while the broad-tailed hummingbird breeds in the mountains of the western United States and Mexico. Both species winter in Mexico and Central America. The calliope hummingbird is a long-distance migrant, traveling up to 5,000 miles each year, while the broad-tailed hummingbird is a shorter-distance migrant, traveling up to 2,000 miles each year.