Dear colleagues, I am pleased to inform you on the publication of my new paper on the association patterns of bottlenose dolphins in Argentina. Ref: Vermeulen, E. 2018. Association patterns of bottlenose dolphins (*Tursiops* *truncatus*) in Bahıa San Antonio, Argentina. Marine Mammal Science. DOI: 10.1111/mms.12481 Abstract: This study aims to investigate the association patterns of a small and resident population of bottlenose dolphins (*Tursiops truncatus*) in Bahıa San Antonio (Argentina), and assess any seasonal variation in view of the reported seasonal variation in the population’s grouping behavior. The estimation of social differentiation (S) was 0.29 (SE 5 0.08), suggesting a homogenous society. The half-weight index (HWI) averaged 0.23 (6 0.06), with evidence of long-term preferred associations. However, data showed seasonal variation in the association patterns. In winter, when large groups were reported in this population, HWI values averaged 0.30 (6 0.09) with no indication of preferred or avoided associations. However, during summer, when group size was generally small, HWI values averaged 0.14 (6 0.07), with an indication of preferred/avoided associations. This study indicates that the social structure of the bottlenose dolphins in Bahıa San Antonio seems relatively homogenous and flexible over time, with the formation of a random social network at times when large aggregations are formed, and a more disconnected network made up of strongly connected components when the cost of grouping is high. The paper is available at http://onlinelibrary.wiley.com/doi/10.1111/mms.12481/full or upon request at elsvermeulen5@gmail.com Kind regards, Els ------------------------------------- Els Vermeulen, PhD Research Manager and Post-doctoral research fellow Mammal Research Institute Whale Unit Department of Zoology and Entomology University of Pretoria, South Africa Co-founding director Whalefish -www.whalefish.org PI Sea Search - www.seasearch.co.za Cell: +27 (0)60 9714301