Dusky dolphin group dynamics and association patterns in Península Valdés, Argentina

Dusky dolphins (Lagenorhynchus obscurus) in Península Valdés, Argentina, exhibit seasonal variations in social structure and group dynamics. The study found that during the cold season, these dolphins form long-term preferred companions, while such bonds loosen or disappear in the warm season when prey availability increases. Researchers analyzed behavioral observations, photo-identification data, and association patterns from 2001 to 2012 using methods like the half-weight association index (HWI) and social differentiation (S). Group fission-fusion dynamics were also linked to feeding behaviors, with fusions primarily occurring for socializing and feeding. The findings suggest that seasonal changes in prey availability drive shifts in both foraging behavior and social structure, providing insights into the adaptability of these marine mammals.

Degrati, M., Coscarella, M. A., Crespo, E. A., & Dans, S. L. (2018). Dusky dolphin group dynamics and association patterns in Península Valdés, Argentina. Marine Mammal Science, 35(2), 416–433. Portico. https://doi.org/10.1111/mms.12536