Study on the social structure of Tappanaga off Muroran based on individual identification

我们收集了短鳍领航鲸的北方形式Tappanaga的目击记录，来自渔船和观赏鲸鱼的船只。7月至8月，塔帕纳加出现在三陆沃茨，9月至10月，它的范围扩大到北海道海岸，然后在1月至4月向南迁移，从三陆沃茨消失。每年6月至9月在三陆海岸和北海道室兰海域进行观测研究。行为学观察表明，塔帕纳加的行为没有昼夜模式，一种行为模式往往持续较长时间。对个人身份照片进行了审查，但初步分析表明，一所学校中成年男子的比例在5- 12%之间，这表明存在校际转学。有幼崽的母鲸占一群鲸鱼的15-21%，这一比例高于以前的报道。吸盘附着标签能够附着在两头鲸鱼上，并从其中一头鲸鱼身上恢复了6小时的数据。那条鲸白天潜得很浅，但晚上却潜得很深，超过100米。大部分潜水持续时间限制在200秒以下，深度与持续时间的关系在200秒左右变化。这表明在200秒的潜水时间内会有一些代谢限制。在潜水剖面中发现了两种模式，Tappanaga应该分别使用两种模式。在同一学校的同一组中听到相同的呼叫类型，而不同学校的呼叫类型并不相同。这表明个体或群体识别发声的存在。

We collected the sighting records of Tappanaga, northern form of short-finned pilot whales, from fishing and dolphin-watching boats. Tappanaga appears in Sanriku waters in July to August, expands its range up to the coast of Hokkaido in September to October, and then migrates south to disappear from Sanriku waters in January through April. Observation researches were carried out off Sanriku coast and Muroran, Hokkaido in June though September every year. Behavioral observation revealed that Tappanaga did not show diurnal pattern in the behavior, and one behavioral pattern tended to last long. Photographs for individual identification have been examining, but the preliminary analyses indicated that the proportion of adult males in a school varied 5-12%, suggesting the inter-school transfer. Females with calves accounted 15-21% of whales in a school which percentage was higher than that reported before. Suction-cup attached tag was able to be attached to two whales and recovered 6 hour data from one of them. The whale made shallow dives in the daytime but deep dives over l00m in the night. Most of dive durations were limited below 200 sec and the relationship between depth and duration changed around 200 sec. These suggest some metabolic restriction in the dive duration of 200 sec. Two patterns in dive profiles were found and Tappanaga is supposed to use two patterns separately. Same call types were heard in the same group of a school, while call types were not shared in the different schools. This suggest the existence of individual-or group-discriminating vocalizations.