Female Social Feedback Reveals Non-imitative Mechanisms of Vocal Learning in Zebra Finches

Abstract

Learning of song in birds provides a powerful model for human speech development [1-3]. However, the degree to which songbirds and humans share social mechanisms of vocal learning is unknown. Although it has been demonstrated as a vocal learning mechanism in human infants [3-6], learning via active social feedback is considered rare and atypical among non-human animals [7]. We report here the first evidence that song learning in the zebra finch (Taeniopygia guttata), the most common model species of vocal learning and development, utilizes socially guided vocal learning. We demonstrate experimentally that the songs of juvenile zebra finches are guided toward mature vocal forms by real-time visual feedback from adult females that is contingent on their early, immature vocalizations. Using a video playback paradigm, we found that juvenile birds that received non-vocal female feedback contingently on their immature song learned significantly better and more accurate song than did yoked controls that received identical but non-contingent feedback. Both contingent and non-contingent groups sang at similar rates. Thus, we have provided the first evidence suggesting that non-imitative social learning is a crucial, potentially widespread mechanism of vocal development and have established a foundational parallel between humans and our most ubiquitous animal model of vocal learning: the crucial role of social feedback to immature vocalizations in the development of communication.

Keywords: development of communication; evolution of communication; social learning; songbirds; vocal development; zebra finch.