And then there's the smallest bird in the U.S., the calliope hummingbird with its fringed collar under its chin, which I have seen on a hummingbird migration cam I tune in to sometimes. Check out these adorable and very unique birds I'm fairly certain none of you have ever seen before either. 
Meet the World’s Largest and Smallest Hummingbirds
John SheweyUpdated: Apr. 22, 2021
"You may think all hummingbirds are the same size, but the giant hummingbird and bee hummingbird stand out as the largest and smallest hummingbirds on earth.
Not all hummingbirds are created equal. Discover the species that are the largest and smallest hummingbirds in the world, as well as the smallest birds you can see in the United States.
Courtesy Timber Press
Giant hummingbirds live in the Andes in South America
Largest Hummingbird in the World
Giant Hummingbird
The largest of the 340-odd worldwide species is—you guessed it—the giant hummingbird, which is widely distributed in the Andes. This enigmatic bird is 9 inches long with a wingspan of more than 8 inches. It’s bigger than a barn swallow and as long as an American robin or northern cardinal, though more slender. And like all hummers, even this behemoth is extremely light in weight, at about 0.85 ounces, and capable of amazingly acrobatic flight. But compared to smaller hummers it appears somewhat cumbersome and hovers at a rate of only about 15 wingbeats per second—on the slow side.
Courtesy Timber Press
Bee hummingbirds live in Cuba
Smallest Hummingbird in the World
Bee Hummingbird
At the other end of the size spectrum, the tiny bee hummingbird, endemic to Cuba, is the world’s smallest bird. It weighs less than a tenth of an ounce—less than a U.S. penny—and is just barely over 2 inches long from bill tip to tail tip. This species buzzes along at 80 wingbeats per second; some say it sounds like a bumblebee. Males are turquoise with vibrant red heads.
Courtesy Albert Russell
Male calliope hummingbird
Smallest Bird in the United States
Calliope Hummingbird
The dainty calliope hummingbird, at about 3 1/4 inches long, is the smallest bird breeding north of Mexico in North America. Males have a red-and-white-streaked throat or gorget (sometimes the red verges on magenta). A mountain specialist, this species breeds as high as timberline from the Sierra Nevada and Cascade crest to the Rockies. When subalpine meadows burst into colorful bloom, look for these unobtrusive little birds hover-feeding at wildflowers that may not grow more than a few inches high.
Their annual path takes them as far north as ... "
https://www.birdsandblooms.com/birding/ ... 62901B6418
