摘要
波罗的海灰海豹的种群增长导致其与渔业的冲突增加。尽管有关灰海豹的生态学数据甚少,最近也采取了一些诸如剔除法之类的管理措施。本研究采用基于个体照片辨识(photo-id)的标志-重捕法研究了波罗的海灰海豹的迁移和恋地性。对夏季主要聚群地点的灰海豹进行拍照,将灰海豹头颈部侧面图片通过特别编写的软件进行拟合,建立一个1995～2000年灰海豹捕获历史数据库。聚群地点分为7个区域。采用Darroch的双样本捕获-再捕获法评估灰海豹在各聚群地点之间的迁移。结果表明,灰海豹大多停留在同一个聚群区域之内,说明波罗的海灰海豹在夏季具有高水平的恋地性,并且这种忠诚性维持一个季节以上。
The growing gray seal population in the Baltic Sea has led to increased conflicts with fisheries. Despite limited data on gray seal ecology,management measures,such as culling,have been implemented recently.We studied movements and site fidelity of Baltic gray seals using mark-recapture analysis based on photographic identification of individuals (photoid). Seals were photographed at the major summer haul-out sites.Profile photographs of the head and neck were matched using purpose-written software to generate a database of capture histories from 1995-2000.The haul-outs were grouped into seven areas.Darroch's method (20) for a two-sample capture-recapture census was adapted to estimate rates of movement between the areas.The majority of seals were estimated to remain within the same area, suggesting that Baltic gray seals exhibit a high degree of site fidelity during the summer, and that fidelity to a site lasts for more than one season.
