Two ecotypes of the common bottlenose dolphin (Tursiops truncatus) occur in New Zealand waters: a widely studied Nationally Endangered coastal ecotype and a little‐known oceanic ecotype. Site fidelity and association patterns of the oceanic ecotype, and home range overlap with the coastal ecotype, are examined from photo‐identification records collected off northeastern New Zealand between 2005 and 2016. The oceanic ecotype occurs widely in the study area: distance from shore ranged from <1 to ~150 km and home ranges of the two ecotypes overlap in some areas. Forty‐nine percent of the 478 identified distinctive or very distinctive individuals were sighted during more than 1 year and resightings spanned over 10 years and 650 km. All individuals were linked by association in a single, albeit clustered, social network. Unlike the coastal ecotype, interspecific associations with false killer (Pseudorca crassidens) and southern long‐finned pilot whales (Globicephala melas edwardii) were frequent, occurring during 84% of encounters. Only one oceanic individual matched any of the individuals from the coastal ecotype photo‐identification catalogues throughout the study area, suggesting that the two ecotypes co‐occur parapatrically. We recommend that the two ecotypes be considered independent management units for conservation purposes due to their divergent ecologies.

中文翻译：

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新西兰东北部海域常见宽吻海豚（Tursiops truncatus）的发生，位置保真度和关联

常见的宽吻海豚有两种生态型（Tursiops truncatus）发生在新西兰水域：一种广泛研究的全国濒危沿海生态型和一种鲜为人知的海洋生态型。根据2005年至2016年间在新西兰东北部收集的照片识别记录，研究了海洋生态型的站点保真度和关联模式，以及家庭范围与沿海生态型的重叠。海洋生态型广泛出现在研究区域：距海岸的距离从<1到〜150 km，这两种生态型的居住范围在某些地区重叠。在478个中，有49％表示与众不同或非常与众不同在超过1年的时间里看到了个人，并且跨越了10年和650公里的范围。所有个人都通过关联链接到一个单一的，尽管是群集的社交网络中。与沿海生态型不同，与假杀手（Pseudorca crassidens）和南部长鳍pilot鲸（Globicephala melas edwardii）的种间关联频繁发生，发生在84％的遭遇中。在整个研究区域中，只有一个海洋个体与沿海生态型照片识别目录中的任何一个个体相匹配，这表明这两种生态型是同伴生的。我们建议出于生态保护的目的将这两种生态类型视为不同的独立管理单位，因为它们的生态学不同。