Harp Seals Do Not Increase Their Call Frequencies When It Gets Noisier

Some species avoid low-frequency masking by shifting their calls to higher frequencies. We addressed the hypothesis that Pagophilus groenlandicus (harp seals) will make more high-frequency underwater calls to avoid low-frequency conspecific masking as calling rates increase. The spectral shapes at high and low calling rates were compared (after equalizing the broadband amplitudes). There were no significant differences between the spectral shapes. Pagophilus groenlandicus do not alter the proportions of low- and high-frequency calls as it gets noisier. This suggests that they may not shift their calling frequencies when encountering low-frequency, broadband anthropogenic noise.