Whistle variation in Mediterranean common bottlenose dolphin: the role of geographical, anthropogenic, social and behavioural factors

The studies on the variation of acoustic communication in different species have provided insight that genetics, geographic isolation and adaptation to ecological and social conditions play important roles in the variability of acoustic signals. The dolphin whistles are communication signals that can vary significantly among and within populations. Although it is known that they are influenced by different environmental and social variables, the factors influencing the variation between populations have received scant attention. In the present study, we investigated the factors associated to the acoustic variability in the whistles of common bottlenose dolphin (Tursiops truncatus), inhabiting two Mediterranean areas (Sardinia and Croatia). We explored which factors, among 1) geographical isolation of populations, 2) different environments in terms of noise and boat presence and 3) social factors (including group size, behaviour and presence of calves), were associated to whistle charact...