In pop pursuit: social bond strength predicts vocal synchrony during cooperative mate guarding in bottlenose dolphins.

Vocal communication is an emblematic feature of group-living animals, used to share information and strengthen social bonds. Vocalizations are also used to coordinate group-level behaviours in many taxa, but little is known of the factors that may influence vocal behaviour during cooperative acts. Allied male Indo-Pacific bottlenose dolphins () use the 'pop' vocalization as a coercive signal when working together to herd single oestrous females.

Allied male dolphins use vocal exchanges to "bond at a distance".

Vocal interactions are intrinsic features of social groups and can play a pivotal role in social bonding. Dunbar's social bonding hypothesis posits that vocal exchanges evolved to "groom at a distance" when social groups became too large or complex for individuals to devote time to physical bonding activities. Tests of this hypothesis in non-human primates, however, suggest that vocal exchanges occur between more strongly bonded individuals that engage in higher grooming rates and thus do not provide evidence for replacement of physical bonding.

Song structure and singing activity of two separate humpback whales populations wintering off the coast of Caño Island in Costa Rica.

Central American (CA) and Breeding Stock-G (BSG) humpback whales are known to winter off Caño Island, Costa Rica at different times of the year. To study their singing behavior, autonomous underwater recorders were used to record the whales. Song detection for BSG whales was higher than CA whales, and song structure was distinct for each population.