The Rufous Hummingbird looks so much like its cousin, the Allen’s Hummingbird, that many birders refer to both by their genus, Selasphorus, which means “flame bearer” in Latin.
Rufous males have orange backs and flanks, green crowns, and white breasts. Their throat-coverings, called gorgets, are iridescent and shine like burnished gold in certain light. Generally, Rufous adult males’ backs are orange while the Allen’s Hummingbird adult males’ backs are green. Females are difficult to distinguish as both species have rufous flanks, green backs, white bellies and red-spotted throats. Both Rufous and Allen’s Hummingbirds are about 3½ inches long.
By late spring, identification of Selasphorus hummingbirds is easier because Rufous Hummingbirds leave California. They continue north to nest from Oregon to Southern Alaska. The 2,000 mile migration follows blooming red flowers such as columbines, penstemons, and flowering currants. Males arrive earlier than females, to establish breeding territories. They zealously guard territories from other hummingbirds, other songbirds, and even chipmunks. Male courtship displays include diving rapidly in a long u-shape flight, flashing females with brilliantly-colored throats, and producing distinctive whining sounds during display flights. Mating is accomplished in flight. Shortly after mating, males leave the breeding grounds for higher inland elevations.
Females build low-lying nests, sometimes right on top of a previous year’s nests. They construct the nests from plant down, lichen, and spider silk. In each nest, two white half-inch eggs are laid. Within a month of hatching, the females and their young join the males in the mountains, returning southward by following the late blooms of high meadows.