The cortical nucleus LMAN (lateral magnocellular nucleus of the anterior nidopallium) provides the output of a basal ganglia pathway that is necessary for vocal learning in juvenile songbirds. The shell subregion of LMAN (LMAN(shell)) gives rise to recurrent loops that may subserve specific learning-related functions. We found that lesions in the LMAN(shell) pathway caused no immediate disruption of vocal behavior, but prevented the development of stable vocal sequences and the ability to imitate vocal sounds.