Calliope Hummingbird: Smallest Bird in the US, and ID

Weigh out a penny and a half. That is a Calliope Hummingbird: two and a half grams of bird, the smallest that breeds anywhere in the United States or Canada.
Hummingbirds in the Southwest: Species, Seasons, and Gardening

The desert Southwest is the hummingbird capital of the United States. Two states dominate the all-time lists, with Texas holding the longest at nineteen recorded species and Arizona just behind. But Arizona is where you actually see them
Hummingbirds in the Rocky Mountains: Species, Altitude, and Gardening

In the Rockies, hummingbird season is short, intense, and governed almost entirely by altitude. Birds arrive late, breed fast, and leave early, squeezing an entire nesting cycle into the brief window when high-country meadows are in flower. They do it in a place where the temperature can drop below freezing on a July night.
Hummingbirds in the Pacific Northwest: Species, Timing, and Gardening

The Pacific Northwest is one of the best places in North America to be a hummingbird gardener, and one of the few places on the continent where you can watch a hummingbird in the snow.
Types of Hummingbirds: A Field Guide to North American Species

Somewhere between 300 and 360 species of hummingbird live in the Americas, but you do not need to know all of them to identify the one hovering at your feeder. North of Mexico the list is far shorter and very learnable.
Hummingbird Migration: Where They Go and How Far They Travel

If there were an Olympic event for most improbable migration, hummingbirds would take gold, silver, and bronze. These tiny adventurers, weighing less than

