The variability of song variability in zebra finch (Taeniopygia guttata) populations

Birdsong is a classic example of a learned social behaviour. Song behaviour is also influenced by genetic factors, and understanding the relative contributions of genetic and environmental influences remains a major goal. In this study, we take advantage of captive zebra finch populations to examine variation in a population-level song trait: song variability. Song variability is of particular interest in the context of individual recognition and in terms of the neuro-developmental mechanisms that generate song novelty. We find that the Australian zebra finch Taeniopygia guttata castanotis (TGC) maintains higher song diversity than the Timor zebra finch T. g. guttata (TGG) even after experimentally controlling for early life song exposure, suggesting a genetic basis to this trait. Although wild-derived TGC were intermediate in song variability between domesticated TGC populations and TGG, the difference between domesticated and wild TGC was not statistically significant. The observed variation in song behaviour among zebra finch populations represents a largely untapped opportunity for exploring the mechanisms of social behaviour.