Fig. 3

Noise effects on startle duration during contests and interactions with nest presence and opponent size. a Startle durations were not affected by acoustic conditions or opponent size when territory included bubble-nests. Conversely, b startle duration was shorter under noise when no nest was present, resulting in an effect from the interaction between acoustic condition and nest presence. c Interaction effects were also identified between acoustic condition and opponent size, where decreases in motivation (revealed by a longer startle duration) are only noted when facing bigger opponents under noise. Interval bars indicate standard error and effect sizes are indicated by Cohen’s d where appropriate. [*P ≤ 0.05, ***P ≤ 0.001]