In animal societies with fission‐fusion dynamics, demographic disturbances can influence the social and spatial structure of the population. Within the Indian River Lagoon (IRL), Florida, common bottlenose dolphins (Tursiops truncatus) have experienced recurrent unusual mortality events (UMEs) providing an opportunity to examine postdisturbance population and social cluster restructuring. This study investigates the impact of the potentially nonepizootic 2008 UME on the IRL dolphin population. Photo‐identification surveys conducted from August 2006 to May 2010 were stratified into pre‐ (August 2006–April 2008) and post‐UME (September 2008–May 2010) time periods. Social network and spatial (univariate kernel density) analyses were limited to individuals sighted 5+ times per period (pre‐UME = 183, post‐UME = 134), and indicated a change from 11 to ten social clusters, although individuals did not always reassociate with pre‐UME cluster associates. Despite the social and spatial disconnect between IRL proper and Mosquito Lagoon clusters, both network density and core area spatial overlap increased post‐UME allowing for increased intercluster interactions. However, intracluster associations increased as well, allowing the population to maintain multiple social clusters within a loosely connected network. This study shows the important role sociality may play in the adaptability of cetaceans to environmental and demographic changes.

中文翻译：

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2008年佛罗里达州印第安河泻湖发生异常死亡事件后，普通宽吻海豚（Tursiops truncatus）的社会结构和分布发生了变化

在具有裂变融合动力学的动物社会中，人口统计干扰会影响种群的社会和空间结构。在佛罗里达州印第安河泻湖（IRL）内，常见的宽吻海豚（Tursiops truncatus）经历了反复发生的异常死亡事件（UME），这为检查骚乱后人口和社会群体结构调整提供了机会。这项研究调查了潜在的非动物2008 UME对IRL海豚种群的影响。2006年8月至2010年5月进行的照片识别调查分为UME之前（2006年8月至2008年4月）和UME之后（2008年9月至2010年5月）时间段。社交网络和空间（单变量内核密度）分析仅限于每个时期被发现5次以上的个体（UME之前= 183，UME之后= 134），并指出从11个社交群变为10个社交群，尽管个人并不总是如此与UME之前的集群关联重新关联。尽管IRL固有群和蚊子泻湖群之间在社会和空间上存在脱节，在UME之后，网络密度和核心区域空间重叠都增加了，从而增加了集群间的交互。但是，集群内部的关联也增加了，从而使人群可以在松散连接的网络中维护多个社会集群。这项研究表明，社交性可能在鲸类对环境和人口变化的适应性中发挥重要作用。