Warblers are a family of small birds that have a pleasant song. Any songbird of almost 350 Old World species (family Sylviidae) or about 120 New World species (family Parulidae, see wood warbler). 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 also blackcap, blackpoll warbler, gnatcatcher, wood warbler