Non-whistle sounds used in bottlenose dolphin aggressive interactions recorded on digital acoustic tags

Bottlenose dolphins (Tursiops truncatus) produce a wide array of sounds, including clicks for echolocation and whistles for communication, both of which have been studied intensively. However, sounds other than whistles and echolocation clicks have received less attention, probably due to their high variability. These include the class of sounds loosely described as “burst pulses,” which in several studies of dolphins under human care have been linked to aggressive interactions. Few studies have been carried out in the wild, beyond those describing basic acoustic parameters of sounds. Here we use acoustic and movement recording tags (DTAGs) placed simultaneously on both members of pairs of free-ranging bottlenose dolphins in Sarasota Bay, Florida, USA, to investigate acoustic behavior during aggressive interactions between male alliances and female-calf pairs. Using unsupervised clustering and discriminant function analysis on parameters such as frequency content, duration and rise time, we separate three...