# reader_01_social_learning **Abstract:** Sociality may not be a defining feature of social learning. Complex social systems have been predicted to favour the evolution of social learning, but the evidence for this relationship is weak. In birds, only one study supports the hypothesis that social learning is an adaptive specialisation to social living. In nonhuman primates, social group size and social learning frequency are not correlated. Though cetaceans may prove an exception, they provide a useful group with which to test these ideas. Rendell & Whitehead (R&W) provide a timely review of cetacean culture, with compelling evidence for group-specific suites of socially learned behaviour patterns in sympatric populations. In particular, the association of vocal mimicry and motor imitation in cetaceans fits with a wide-ranging trend that includes parrots (Dawson & Foss 1965; Moore 1992), songbirds (Campbell et al. 1999; Lefebvre et al. 1997), and possibly humans (Iacoboni et al. 1999). In many ways, the evidence for cetacean cultures could be considered more compelling than that for apes (Whiten et al. 1999) because of the sympatric element, voiding geographical variation as an explanation for behavioural variation between groups. We agree that the ethnographic approach will often be the only feasible method of collecting social learning data in cetaceans. Determination of the precise social learning mechanism will be difficult, if not impossible, to ascertain in the field, but, as R&W argue, the exact mechanism of t