Figure 4.

During experimental noise exposure, the change in the proportion of songs sung from (a) the upper bandwidth differed from (b) the lower bandwidth. The change in proportion of songs sung from the upper bandwidth (a) showed no relationship with local ambient noise. However, the change in the proportion of songs sung from the lower bandwidth (b) decreased as local ambient noise increased. Points are raw data values from individual territories. The dotted line represents a significant model relationship. The horizontal dashed lines represents point of no change from before experimental noise: points below the line reflect a downward change in the proportion of songs sung, points above the line reflect an upward change. n.s. = non-significant. n = 28 individual chickadees in each panel.