fuscicaudata is smaller than the nominate and has a shorter and stouter bill. handleyi has the same color pattern as the nominate but is significantly larger and darker. The outer half of the bill's maxilla is black and the inner half red the mandible is red with a black tip. Juveniles have a cinnamon wash to the lower breast and sides and the feathers of the lower back and rump have narrow cinnamon tips. The adult female's lower breast is a paler gray than the male's and the scalloping on the throat is more pronounced. The lower breast is gray, the belly white, and the undertail coverts chestnut-brown. The throat, upper breast, and sides are green the throat feathers sometimes have thin white edges giving a scalloped effect. The tail is also mostly chestnut-brown, giving the species its English name the feathers' outer webs and tips are bronze green. The adult male of the nominate subspecies has a green head and upperparts except for chestnut-brown lores and uppertail coverts. The rufous-tailed hummingbird is 9 to 11 cm (3.5 to 4.3 in) long and weighs approximately 5 g (0.18 oz). fuscicaudata should be a separate subspecies. At least one author treated the rufous-tailed hummingbird and the chestnut-bellied hummingbird ( Saucerottia castaneiventris) as a superspecies the latter was included in genus Amazilia at that time, but the two are now known to not be closely related. handleyi was originally described as a separate species, the Escudo hummingbird. Immature birds look similar to the adult female, although the immature males typically show more rufous on the rump and lower back as well as heavier markings on the throat.The rufous-tailed hummingbird has these five recognized subspecies: The outer three pairs of tail feathers have white tips. The rounded tail extends past the wingtips it is rufous at the base and banded with black. The throat is marked with red-orange, from just a few spangles to a large patch. The gorget is off-white, spangled with green to bronze (concentrated on the sides).

The face and sides of the gorget are also washed rufous. The adult female is bright green above and white below, strongly washed with rufous color on the sides, flanks, and undertail coverts. The tail feathers are black-tipped and pointed. The underparts are creamy white with a rufous “vest.” The crown is bright green, and the gorget is iridescent scarlet to orange, appearing golden or yellow-green from some angles. The back of the adult male Rufous Hummingbird is cinnamon-colored (rufous), sometimes spangled with green, and rarely more than half green. Spring migration is mostly along the Pacific Flyway. They prefer to breed and nest in the Northwest and Alaska in second-growth forest communities and openings, but they will also use mature forests, parks, and residential areas.

These birds do not breed in Arizona or New Mexico. The hummingbirds get protein and fat from eating insects, particularly gnats, midges, and flies taken from the air and aphids taken from plants. Rufous Hummingbirds feed primarily on nectar from colorful, tubular flowers, including columbine, scarlet gilia, penstemon, Indian paintbrush, mints, lilies, fireweeds, larkspurs, currants, and heaths. At least one climate change model predicts this species will lose its entire nonbreeding habitat in the United States by the end of this century because of climate change. Unfortunately, the population of this species has declined by about 60 percent over the last 50 years. Rufous Hummingbirds are found in a wide variety of habitats. Rufous Hummingbirds are one of the most common and widespread hummingbird species in Arizona and New Mexico and occur in all five BCRs in both States. These birds visit Arizona and New Mexico primarily during fall migration, which takes place from July through October. Although they are relatively small hummingbirds, they have an aggressive nature and frequently chase larger hummingbirds from nectar sources. Rufous Hummingbirds travel farther north than any other hummingbird, wintering in Mexico and migrating to breeding sites as distant as Alaska. Rufous Hummingbird (Selasphorus rufus) Range

Rufous hummingbird