...) that usually occur as doublets. Some elements of courtship song are quite variable (high coefficient of variation) both within and between males, whereas others are more stereotypical. In experiments with playback of synthesized courtship songs, we studied the importance of several song parameters for mating...

... to the playback of recorded bleats of their partner or from unrelated ewes and lambs. When playback was performed 30 min after a nursing episode, both ewes and lambs responded to bleats of their partner but not to bleats from alien subjects. When playback was performed 5 min after nursing, ewes did not respond...

... are eaten and hatching prematurely increases predation by aquatic predators. Embryos use vibration duration and spacing to inform their hatching decision. This information accrues with cycles of vibration, while risk accrues over time as snakes feed. We used vibration playback experiments to test if embryos...

... conversations with S. Phelps, G. Rosenthal, I. Schlupp and M. Ryan. We thank the Smithsonian Tropical Research Institute for logistical support. K. Metcalf, A. D'Amato, K. Wright, T. Siok and M. Hughey assisted with playback experiments, and J. Touchon also provided field assistance. We thank I. Gomez-Mestre...