Do porpoises choose their associates? A new method for analyzing social relationships among cetaceans.
Do porpoises choose their associates? A new method for analyzing social relationships among cetaceans.
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海豚会选择它们的伙伴吗？
DOI：
10.1371/journal.pone.0028836
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Akamatsu T
中科院分区：
文献类型：
--
作者：
Sakai M;Wang D;Wang K;Li S;Akamatsu T
观察和监测鲸目动物的水下社会互动具有挑战性。因此，以前的鲸目动物研究通过表面观测监测了这些相互作用。然而，由于鲸目动物大部分时间都在水下，因此必须持续监测它们的水下行为，以更好地了解它们的社会关系和社会结构。江豚很小，没有背鳍。在野外很难观察到这个物种，对它的社会性也知之甚少。利用时间同步生物记录系统对6头自由放养的江豚的游泳深度进行了同步记录。同步潜水被用作关联指数。两对海豚，#27（一只未成熟的雌性，估计年龄为3.5岁）和#32（一只成年雄性），#28（一只幼年雄性，估计年龄为2岁）和#29（一只成年雄性），比其他13对可能的海豚更频繁地参与长时间的同步潜水，这表明4只海豚选择了他们的社会伙伴。成年雄性（#32，#29）倾向于分别跟随未成熟雌性（#27）和幼年雄性（#28）。然而，在双人跳水中，发起者的角色经常在双人中发生变化，他们的身体动作似乎是非对抗性的，例如，身体相互摩擦，而不是像在追逐和逃跑行为中观察到的那样在一侧摩擦。本研究采用时间同步生物记录法，观察基于游泳深度的自由放养水生动物的社会关系。研究结果表明，某些个体即使不是母子配对，也会形成关联。长时间的同步潜水发生在特定的成员团聚时，这表明同步潜水不是机会主义聚集的副产品。
Observing and monitoring the underwater social interactions of cetaceans is challenging. Therefore, previous cetacean studies have monitored these interactions by surface observations. However, because cetaceans spend most of their time underwater, it is important that their underwater behavior is also continuously monitored to better understand their social relationships and social structure. The finless porpoise is small and has no dorsal fin. It is difficult to observe this species in the wild, and little is known of its sociality. The swim depths of 6 free-ranging finless porpoises were simultaneously recorded using a time-synchronized bio-logging system. Synchronous diving was used as an index of association. Two pairs, #27 (an immature female estimated to be 3.5 years old) and #32 (an adult male), #28 (a juvenile male estimated to be 2 years old) and #29 (an adult male), tended to participate in long periods of synchronized diving more frequently than 13 other possible pairs, indicating that the 4 porpoises chose their social partners. The adult males (#32, #29) tended to follow the immature female (#27) and juvenile male (#28), respectively. However, during synchronized diving, the role of an initiator often changed within the pair, and their body movements appeared to be non-agonistic, e.g., rubbing of bodies against one another instead of that on one-side, as observed with chasing and escaping behaviors. The present study employed a time-synchronized bio-logging method to observe the social relationships of free-ranging aquatic animals based on swimming depth. The results suggest that certain individuals form associations even if they are not a mother and calf pair. Long synchronized dives occurred when particular members were reunited, and this suggests that the synchronized dives were not a by-product of opportunistic aggregation.