Fig. 2.

Changes in call amplitude in response to BFN presentation. (A) Shifts in call amplitude in response to different BFN conditions (BFN amplitude: 100 dB SPL; playback attenuation: 30 dB) compared with the control (no BFN); data averaged for all three bats. Medians: horizontal lines inside boxes; first and third quartiles: upper and lower margins of boxes, respectively; 5% and 95% quantile: small horizontal bars above and below boxes, respectively. Dotted lines indicate the thresholds of the population effect size (±1.2 dB). (B) Effects of different BFN intensities (B₁) and playback attenuations (B₂) on call amplitude in condition 2. (B₁) Shift in call amplitude is slightly lower for weaker noise amplitudes (playback attenuation constant at 30 dB). (B₂) Shift in call amplitude is slightly higher for the lowest playback attenuation (30 dB). (C) Changes of call amplitude of the last 10 calls prior and the first 10 calls just after BFN presentation relative to the call amplitude of the 10th call before noise onset. Data averaged for all three bats and noise conditions 1–6 (36 trials; medians with first and third quartile). First calls uttered after noise onset show a significant increase in call amplitude (Kruskal–Wallis with post hoc signed-rank test).