Contingent parental responses are naturally associated with zebra finch song learning

Abstract

Active guidance of vocal learning by conspecifics has recently been found in several species, including some cetaceans and primates. However, in the zebra finch, Taeniopygia guttata, a commonly studied songbird, vocal learning was traditionally considered the product of memorization and imitation of a song model. Only recently have specific social feedback cues been shown to enhance song learning. What mechanisms drive the superior learning associated with social interactions? We recently found that ‘fluff-ups’, a nonvocal female arousal cue, facilitated song learning when played over video contingently on juvenile song production throughout development. However, it is unknown whether adults naturally respond in a contingent fashion to immature song, and whether young finches incorporate naturally occurring feedback into song learning. To investigate whether social influences affect song learning, the present study addressed the nature and significance of maternal and paternal cues associated with song development. We recorded unmanipulated zebra finch families throughout juvenile development and analysed their social interactions. We found that behaviours of both parents were associated with offspring song outcomes. Juvenile song learning could be predicted by the amount of contingent ‘fluff-up’ behaviours they received from their mothers throughout development. Fathers often sang immediately after a juvenile had sung, and paternal singing after juvenile singing was positively correlated with more accurate song learning in their sons. Conversely, when fathers sang before the juvenile sang, juveniles learned song less accurately. Our data suggest that parental vocal and gestural feedback plays a reinforcing role for song learning in zebra finches. There are many nonavian species, including chiropterans, pachyderms and pinnipeds, that modify their vocalizations in different developmental or social contexts but whose mechanisms of vocal learning are not known. Our findings suggest that these species should be closely examined for adult sensitivity to immature vocalizations and developmental capacity to learn from social feedback.