Iridescent color among birds is one of nature's wonders, and hummingbirds display a full spectrum. Hummingbirds are found only in the New World, arising in the tropics and diversifying in abundance in the Andes and along the backbone of the Central America.
Many endemics exist on Caribbean islands or isolated mountain chains.
Further, their interdependence on and co-evolution with flowers provide a fascinating correlation and field for study. Because the sources of nectar is constantly changing as flowers bloom and fade, most hummingbirds live solitary lives, aggressively defending nectar sources from rivals. When natural nectar is harder to locate, hummingbirds readily adapt to human-made hummingbird feeders. Hummingbirds range in size from the smallest birds on earth to several quite large species in the Andes. Between them, these hummers range in size from 2 to 8.5 inches, and in weight from 1.6 to 19 grams.