Begin listening for the Cardinal's song late in January. It is loud, clear, and whistled. One song begins with a long downward slurred note followed by three or four short notes: cheeeer, whip, whip, whip, whip. Cardinals also have other whistled songs. One resembles "ru-by, ru-by, ru-by" (Birding by Ear: Disk 2, Track 1; Common Birds CD: Track 3) Listen