Observational evidences of vocal learning in southern elephant seals: A longitudinal study

Vocal learning in mammals is sparsely documented, and there are few reports of vocal learning by wild mammals. In particular, no information based on longitudinal data for identified individuals exists, even for well-studied highly social species in which vocal communication is an important aspect of social life. We present such information for the southern elephant seal (Mirounga leonina). We studied a small breeding population in the Falkland Islands over 8 yr (1995-2002). We recorded approx. 2400 agonistic vocalizations from approx. 285 different males, including many recorded over more than one breeding season (55 males were recorded for > 2 yr and 29 were recorded throughout vocal development). Vocalizations are a key element of male agonistic behaviour in this species, the world's most polygynous vertebrate. For male agonistic vocalizations, we show that: (1) a limited number of discrete vocal types exists; (2) proportions of vocal types change over time; (3) observed trends of increase or decrease of vocal types are well explained by a process of vocal learning, in which younger peripheral males imitate vocal types of older more successful breeders.