We examined the trend in residence patterns and abundance of male sperm whales in Nemuro Strait, Japan, based on long‐term photo‐identification (1,513 survey days, total 2,969 photos) between 2006 and 2017. A total of 225 unique individuals were identified during this study, with an average of 36 (SE = 2.55) new individuals identified in each season. The model chosen by maximum likelihood suggests that residence time around Nemuro Strait is 769 (SE = 372.4) days, with individuals staying in the strait about 48 days (SE = 8.36) per year. While the migration patterns of male sperm whales visiting this area are still unclear, these findings along with previous studies suggest that males move from one breeding area to another neighboring area every several weeks, shifting their home ranges gradually over a period of a few years. The abundance of sperm whales in Nemuro Strait varied greatly from year to year; from 28 (95%CI: 24–44) in 2015 and (95%CI: 22–48) in 2016 to 66 (95%CI: 57–84) in 2011. This study provides important knowledge of abundance and residency for Nemuro Strait, information which will contribute to further research on the social structure and movement pattern of male sperm whales.

中文翻译：

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日本北海道根室海峡的抹香鲸（Physeter macrocephalus）的种群数量和数量

我们根据2006年至2017年的长期照片识别（1,513个调查日，共2,969张照片），对日本根室海峡的雄性抹香鲸的栖息地格局和数量进行了研究。在此期间，共发现225个独特个体这项研究在每个季节平均识别出36个新个体（SE = 2.55）。通过最大可能性选择的模型表明，在根室海峡周围的停留时间为769（SE = 372.4）天，个体在海峡停留的时间约为48天（SE= 8.36）。虽然尚不清楚雄性抹香鲸到该地区的迁移方式，但这些发现以及先前的研究表明，雄性鲸每隔几周从一个繁殖区域移至另一个邻近区域，并在几年内逐渐转移其繁殖范围。根室海峡的抹香鲸年年变化很大。从2015年的28（95％CI：24-44）和2016年的（95％CI：22-48）到2011年的66（95％CI：57-84）。该研究提供了有关Nemuro的丰富度和居住权的重要知识海峡，这将有助于进一步研究雄性抹香鲸的社会结构和运动方式。