 A map of the hummingbird family treereconstructed from analysis of 284 of the world's 338 known speciesshows rapid diversification from 22 million years ago.Hummingbirds fall into nine main clades, the topazes, hermits, mangoes, brilliants, coquettes, "Patagona," mountain gems, bees, and emeralds, defining their relationship to nectar-bearing flowering plants and the birds' continued spread into new geographic areas.While all hummingbirds depend on flower nectar to fuel their high metabolisms and hovering flight, coordinated changes in flower and bill shape stimulated the formation of new species of hummingbirds and plants.