Fig. 1. Hatching response of Agalychnis callidryas embryos to 300 s vibration playbacks eliciting similar overall levels of hatching and matched for duty cycle but differing in cycle length. (A) Hatching as a function of time; hatching was slower with longer cycles. Inset: stimuli used in playbacks, constructed from bursts of 0–100 Hz synthetic white noise. Waveforms of 12 s of the pattern of (top to bottom) 0.1:1 s, 0.25:2.5 s, 0.5:5 s, 1:10 s duration: interval times. (B) Hatching as a function of cycles of vibration. As cycle length increased, embryos sampled progressively fewer cycles before hatching. Data are means ± s.e.m. of 10 clutches per stimulus. Different letters indicate significantly different cumulative hatching curves.