Figures 3. In repeated playback experiments, Plain-tailed Wren Thryothorus euophrys groups showed weaker responses over time measured by (a) closeness of approach to the speaker, (b) latency of vocal response, and (c) latency of visual response.

In each figure the red line shows the population trend line (all wren groups combined) and the other lines show fitted trend lines for each group from Gaussian mixed-effect models with random intercepts. Data points with maximum values on the y-axis indicate no response (i.e. latency of response of 3,600 seconds or closeness of approach of 50 m).