A BRAIN OF HER OWN - A NEURAL CORRELATE OF SONG ASSESSMENT IN A FEMALE SONGBIRD

The song control region in the avian forebrain is a series of discrete , interconnected nuclei mediating song learning and production. It has been studied in males or in species where both sexes sing. Little is known about the neural correlates of song perception in nonsinging fem ales, often the intended recipients of song. We studied cowbirds (Molo thrus ater), a species in which only males sing but in which females d iscriminate between males on the basis of song. We focused on nucleus lMAN because it has been implicated in early song acquisition, a stage relevant to both sexes to choose among competing acoustic models. We found that volume of lMAN was monomorphic in cowbirds. Moreover, the v olume and neuronal number of female lMAN were positively correlated wi th selectivity of copulatory responding. The results provide strong ev idence of nonsinging female's use of ''song'' control nuclei for song perception without the possibility of song production. (C) 1997 Academ ic Press.