| The fourteen species of finch that inhabit the Galápagos Islands are believed to have evolved from a single species resembling the blue-black grassquit, Volatinia jacarina, abundant in Latin America and the Pacific coast of South America. The ancestral finch, with its short, stout, conical bill specialized for crushing seeds, probably migrated from the mainland to the Galápagos Islands. Its descendants, free to exploit the resources they would otherwise share with warblers, woodpeckers, and other birds, adapted to the available range of habitats (tree, cactus, or ground) and food (seeds, cactus, fruit, or insects). The size and shape of their bills reflect these specializations, an example of adaptive radiation. |