Learning to listen? Nestling response to heterospecific alarm calls

► Nestling scrubwrens go silent after hearing parental alarm calls signalling danger. ► We tested how nestlings respond to playback of heterospecific alarm calls. ► Nestlings went silent to heterospecific alarm calls similar to those of parents. ► Older nestlings responded to structurally different alarms, suggesting learning. ► Nestling response thus changes over time, and appears to be both innate and learned.