Reduction of female-directed song motifs induced by repeated singing in laboratory-bred zebra finches

Songbirds such as zebra finches show a remarkable degree of neural plasticity associated with the motor act of singing. Here we show that in adult male zebra finches repeated female-directed singing episodes are associated with a change in subsequent singing behavior involving a progressive long-lasting decline in the number of song motifs sung. This reduction in song motif production cannot be completely explained by the circadian rhythm, declining motivation or neuromuscular exhaustion. Paired song induction sessions reveal that the time course of motif reduction during repeated singing can be best explained by the cumulative effect of reduction produced by each singing episode. These results suggest that song production in zebra finches is prone to a form of rapid behavioral adaptation.