Any songbird of almost 350 Old World species (family Sylviidae) or about 120 New World species (families Parulidae and Peucedramidae). Old World warblers, found in gardens, woodlands, and marshes, have a slender bill adapted for gleaning insects from foliage. They occur mainly from Europe and Asia to Africa and Australia, but a few (e.g., the gnatcatcher) live in the Americas. They are drab greenish, brownish, or black and 3.5–10 in. (9–26 cm) long. See alsoblackcap, blackpoll warbler, gnatcatcher, wood warbler.