Sanvito,S. & Galimberti,F. 2000. Bioacoustics of southern elephant
seals. I. Acoustic structure of male aggressive vocalizations.
Bioacoustics. 11: 259-285.

Abstract
Southern elephant seal (Mirounga leonina) males have a complex and
stereotyped system of access to breeding females. The single most
important component of male behaviour is vocal signalling, which is used
to settle agonistic encounters in most cases. Most aspects of the
breeding biology of the species have been studied in depth, but detailed
information about structure of vocalizations is not readily available.
Here, we present data about the acoustic structure of aggressive male
vocalizations collected in the Falkland Islands, and we compare these
data to published data on the northern elephant seals. Our main goal is
to describe the structure of sounds as a preliminary and indispensable
step towards analysis of their functional significance. Male
vocalizations were low pitch sounds, made up by pulse trains, with
scarce frequency modulation: low frequency of emission and high sound
pressure level are typical of male vocalizations in Pinnipedia, but they
were particularly evident in southern elephant seals, probably due to
the unusually large body size. The comparison with published data on
northern elephant seals was not very easy, due to differences in
acoustic terminology and methodology, but it revealed many similarities
between the species. We also carried on a detailed analysis of
variability of different acoustic variables, and we discovered that
frequency and intensity measures have lower variability than temporal
ones, and should hence be the most effective way to convey information
about the individual who emits the vocalization.