Song is not just for males — The Female Bird Song Project
The conventional wisdom regarding bird song is that males sing to attract mates or declare territories and that females do not sing. But female birds do sing. Singing females occur throughout the tropics and temperate regions. Among the common feeder birds are female songsters such as Tufted Titmice, Black-capped Chickadees, Dark-Eyed Juncos, and Northern Cardinals. In fact, singing in both sexes may be an ancestral condition. Karen Odom (Leiden University) and Lauryn Benedict (University of Northern Colorado) have begun a the Female Bird Song Project to increase both data (documented recordings of female song) and awareness of the phenomena.