Results for Generalized Additive Mixed Models fit to data from MARU 1 and MARU 2.

“Dataset”: results are shown for a GAMM analysis using data from the entire period of singing activity, 9 June to 1 December 2008 (“Full”), and the reduced dataset during only the first period of seismic activity, 5–31 July 2008 (“Reduced”) for each of the two hydrophones (“MARU” 1 and 2). For each of the potential covariates (“Survey Day”, “Hour”, “Peak Power” and “Moon Phase”, see text for detailed descriptions) a blank cell indicates the variable was not included in the model, otherwise the significance level for the variable is shown (‘***’1Six rather than the top five models are shown for MARU 1, as these all have a Delta AIC value of less than 2.