Abstract or Keywords
Social structures and grouping behaviors of odontocetes are under strong evolutionary pressures, as they influence mating opportunities, calf survival, predation, and foraging efficiency. The fission-fusion nature of most odontocete groups facilitates fine-scale spatial and temporal variability and establishes relationship complexity at the core of odontocete social structure. Different communities of the same species vary in social structure, as do different individuals within the same community. The same individuals can also display different social structures in different conditions. Advances in field techniques and data analyses have improved our ability to tease out nuances of social structure. Future work is essential for understanding evolutionary bases of odontocete social grouping, to focus more on interactions as well as associations, incorporate long-range acoustic communication and multivariate analyses of social and ecological variables, and move to agent-based analysis, where each individual (or collection of individuals) can act autonomously and independently. Social structural plasticity is key to the success of odontocetes and may also play an important role in speciation.