The blue-gray gnatcatcher, one of 339 species of Old World warblers, is found in a variety of woodland, watercourse, and timbered marshy areas in the United States, Canada, Mexico, and Central America as far south as Guatemala. It reaches about 13 cm (5 in) in length and feeds mainly on insects. "Blue-Gray Gnatcatcher," Microsoft(R) Encarta(R) 96 Encyclopedia. (c) 1993-1995 Microsoft Corporation. All rights reserved.