Pinnipeds
Gray seal
Scientific name: Halichoerus grypus
Code: GRSE
Gray seals produce various vocalizations and acoustic signaling. Nonvocal behaviors range from surface interactions, such as breaching/porpoising, to underwater ‘claps’ or knocks (Hocking et al., 2019).
Vocalizations
Nowak, 2021 describes the following variability in gray seal calls:
S1: Frequency modulated above and sub-surface vocalizations (tonal, 400 - 420 Hz) - example was recorded on the surface.
S2: A series of short bursts with no tonal components (only occurring underwater and by male seals, 45 - 50 Hz) - example was recorded underwater.
S3: A series of short, pulses with harmonic components (explicitly water-born vocalizations, frequencies between 50 - 160 Hz) - example was recorded underwater.
Nonvocal acoustics
Seal claps are unique in the aspect that they have a greater frequency range than seal vocalizations. Claps are thought to be part of social and/or antagonistic interactions (below).
Gray seal vocalizations as observed by PAB:
Sources
Hocking DP, Burville B, Parker WMG, Evans AR, Park T, Marx FG. Percussive underwater signaling in wild gray seals. Mar Mam Sci. 2020; 36: 728–732. https://doi.org/10.1111/mms.12666
Lukasz J. Nowak (2021) Observations on mechanisms and phenomena underlying underwater and surface vocalisations of grey seals, Bioacoustics, 30:6, 696-715, DOI: 10.1080/09524622.2020.1851298