Black-billed Magpie (Pica pica) - Diet, habitat, and nesting of this ground-foraging bird. - http://www.npwrc.usgs.gov/resource/birds/forest/species/picapica.htm
Black-Billed Magpie (Pica pica) - Identification, range, and sounds of this bird. - http://www.enature.com/fieldguide/showSpeciesRECNUM.asp?recnum=BD0032