Abstract: Rhythmically repeated calls used during vocal communication have important implications for the extent to which pinnipeds successfully transmit information over long distances and during times of high levels of background noise. Harp seals (Pagophilus groenlandicus) have a large vocal repertoire and many of their underwater vocalizations consist of multiple elements. Between-call and within-call variability of element and interval durations for the thirteen multiple-element call types were very consistent. These elements are repeated regularly in predictable patterns. Three distinct patterns were identified with respect to the timing of call intervals: all intervals <1 s (short-short pattern), all intervals >1 s (long-long pattern) and intervals alternating between <1 s and >1 s (shortlong pattern). Harp seal multiple-element calls are rhythmically repeated and elements of the calls occur at highly predictable intervals. Rhythmical repetition would likely enhance the probability of a call being detected and could serve to identify the species of the caller.

Key Words: HARP SEAL; VOCALIZATION; MULTIPLEELEMENT; REPETITION; PATTERN; RHYTHM; ANTI-MASKING; PAGOPHILUS.

Document Type: Research article