In‐air and underwater sounds of the Ross seal, Ommatophoca rossi

Abstract

In‐air and underwater sounds were recorded from Ross seals, Ommatophoca rossi, during January 1966 in the western Ross Sea, Antarctica, from Cape Hallet to Cape Adare. In‐air sounds from seals hauled out on ice ranged from 100–1000 Hz and included short (0.05–0.1 s) tonal pulses with downward sweeping frequency, and longer (1–1.5 s) calls with downward and upward sweeping frequency, somewhat like a police siren. Underwater vocalizations included pulses and siren calls that were similar to the in‐air sounds except that they had greater and mostly higher‐frequency ranges (1–4 kHz). The underwater calls were pulse modulated at a consistent rate of about 650/s, and usually were formed of two independently varying tones, each with separate sideband harmonics. Overlapping underwater sound sequences were heard from seals scattered throughout the areas sampled. The distinctive springtime siren calls would be useful for locating groups of these elusive seals.