The biggest variety is found in the equatorial belt, ten degrees wide, across South America, where more than half the species are found. Moving north, the number of species declines. Fifty-one species breed regularly in Mexico, thirteen in the United States, and four in Canada. So many hummers, and every single one is found in North, Central, and South America and the Caribbean Islands. Hummingbirds virtually all have iridescent plumage, and many have other feather adornments that inspired ornithologists to give them exotic names.
Hummingbirds are famous for more than their beauty and tiny size.
They're the only birds that can fly backward as well as forward. Scientists used an instrument that flashes light at extremely short intervals, called a stroboscope, to measure it. Their hearts beat amazingly fast, too. In normal flight they can fly steadily at about 29 mph unless wind helps. Their flight muscles take up about a quarter of their body weight.