Hummingbirds are unique to the New World. European explorers were astounded by the tiny glittering creatures that zipped up and down, backwards and sideways , with wings humming and blurred.Hummingbirds, America's smallest birds, are sort of miniature helicopters. They can soar, or hover for a few seconds, to fly backward or sideways, and even fly upside down. In a blur of iridescent greens, purples, or reds, a hummingbird can speed by in forward flight, then brake in midair to probe its needle-like beak into a flower for a sip of nectar. Its wings beating so fast that they resemble gossamer, the bird will back out of the flower and sidle over to the next blossom. The wings of these adroit little birds rotate rapidly at the shoulder, tilting to force air forward and down on the downstroke, but also backward and down on what should be the upstroke.

By adjusting the tilt, they can hover or move in any direction. aided by a powerful breast muscle that is proportionally four times larger than that of a chicken and a metabolism that is 10 times faster than that of a human sprinter, some hummers can beat their wings 1,000 times in the span required to read this sentence. In flight, a hummingbird beats its wings about 53 times per second when moving forward. A hummingbird's heart beats almost 10 times per second durinf activity.

About some 20 species of hummingbird have been sighted in the United States. The Black-chinned Hummingbird (Archilochus alexandri) prefer dry scrub, woodlands near streams, wooded canyons, mountain meadows and gardens. Hummmingbirds perform set figures in courtship fights. The male Black-chinned Hummingbird, for instance, swings in pendulum-like arcs above the female; at the top of each swoop, he comes to a dead stop and taps his wings together underneath his body. Favorite flwoers include ocotillo, desert honeysuckle, and tree tobacco in the arid regions this sepcies prefer. The black-chinned hummingbird is widespread as a breeding species in the Western United States. After the nesting season, most members of this species migrate south into Mexico, although some individuals spend the winter months along the Gulf Coast and in Florida.

The Rufous Hummingbird (Selasphorus rufus) flies farther north than any other hummingbird. As the birds move south toward Mexico (mainly in July and August) they may be found as high as in the mountains as 13,200 feet. Hummingbirds are generally feisty, but this species is particularly pugnacious. Yet at times Rufous Hummingbirds appear to breed in colonies, with some pairs nesting only a few feet from one another. The similar-looking Allen's Hummingbird (Selasphorus sasin), which occurs along the West Coast from Oregon south, has a green back and cap. The adult male is unmistakable with its rusty back. Both male and female rufous hummingbirds give rather a mechanical-sounding "cbp, cbp, cbp" while they're feeding or when another bird enters their territory.

The Anna's Hummingbird (Calypte anna ) has a long bill, iridescent dark red crown and throat (male); white-tipped tail (female). It prefers open woodlands and gardens. When the female Anna's Hummingbird lays her eggs, the nest may be only half finished; she completes it while incubating. Like most hummingbird nests, it consists of tiny stems and plant down, held together and lashed to a branch with spider silk and often camouflaged with bits of lichen. A female feeds her young without any help from her mate. She collects nectar, tree sap, insects, and spiders, and delivers the meal by thrusting her long bill deep down the nestlings' throats.