Figure 2

Sensitisation of flight responses and interruption of foraging behaviour in response to the startle pulse and pre-sound. Likelihood of sound presentations being followed by (a) an immediate fast flight response and (b) an instant interruption of foraging behaviour. Curves represent predicted values and their 5/95% confidence intervals derived from the logistic regression model fitted to the binomial raw data. Symbols represent the observed ratio of events averaged for each playback session. In animals that startled, exposure to the startle pulse caused marked sensitisation meaning that flight responses and the prevention of fish retrieval increased dramatically. In later playback sessions, the pre-sound alone caused a similar effect with respect to flight and interruption of foraging behaviour. Animals that did not startle habituated (inverted triangles).