Neural activation in response to conspecific songs in zebra finch (Taeniopygia guttata) embryos and nestlings.

Classic studies on the effects of auditory stimulation in embryonic birds have largely been limited to precocial taxa. In altricial taxa, physiological responses of embryos and, subsequently, the behavioral responses of nestlings have begun to receive increasing attention, yet it remains unclear whether and to what specificity neural responses are generated in ovo. Using in-situ hybridization for an immediate early gene, ZENK, we detected significant neural activation in both the embryos and nestlings of an altricial songbird, the zebra finch (Taeniopygia guttata) when exposed to conspecific song playbacks relative to silence. In turn, embryonic ZENK responses to heterospecific songs were intermediate in strength. These results are consistent with physiological evidence for conspecific song selectivity in embryos of other altricial songbird taxa.