Wavelet sample spectrums using a Morlet wavelet for 3 control tags.

Continuous thin lines represent the cone of influence (COI). Values outside the COI should not be interpreted due to edge effects. Thick contours represent the 95% confidence level and scale bar represents the intensity of the time-frequency space over time. The pattern without diel periodicity is indicated by the lack of thick contours on a 24 h scale (horizontal dashed line).