Social functions of cetacean acoustic communication

Acoustic communication in animals serves many functions. Acoustic signals contain information about sender identity, sender location, and particular contexts. Until recently, studies of cetacean acoustic communication have been hindered by the difficulty of localizing sounds underwater and thus identifying vocalizing individuals. New techniques integrate studies of the cetacean communication with social interaction. Cetaceans produce a large repertoire of complex vocalizations. For cetaceans, conflict resolution calls, sexual calls, social integration calls, parent-offspring calls, and environmental calls have been reported. Many cetaceans show patterns of intra-specific variation in vocalizations by individual, by group, and by geographical area. These variations are considered to have a strong correlation with social systems of the species. The individual variations are observed in those species forming fission-fusion societies. The inter-group variations are seen in the species forming stable groups. The inter-population variations are thought to have importance in maintaining group cohesion and for reproductive purpose.