Age composition is an important population parameter for understanding and managing endangered species. There are very few studies involving cetaceans in estimating the age of individuals in the wild. In this study, we rigorously quantified the body color pattern of 37 stranded Indo-Pacific humpback dolphins (Sousa chinensis) of the Pearl River Estuary (PRE), which showed a significant, albeit with variability between individuals, correlation with age for both the males (between age 1 and 35, r2 = 0.84) and females (between age 1 and 25, r2 = 0.85). The population-averaged correlation (r2 = 0.85) was then applied to a large volume of photo-identification data (2011–2015) to estimate the age composition of the population occurring in the greater deltaic region, which further suggested a spatial difference in age composition and, therefore, a complex demographic process of the humpback dolphin across the region. In particular, the age composition of humpback dolphins in the east PRE (Lingding Bay) is severely aged. Finally, a population viability analysis with the consideration of observed age structure and the simulated age-specific fecundity suggested that 95.75% of the Lingding Bay humpback dolphins are projected to be lost after three generations. Given the sophisticated anthropogenic landscape in the PRE, we suggest that management units of the humpback dolphins should be clearly defined and the regional-specific conservation measures are much needed.

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更正：根据色素沉着模式调查珠江口印度洋-太平洋座头海豚的年龄组成

年龄构成是了解和管理濒危物种的重要种群参数。很少有研究涉及鲸类动物来估计野外个体的年龄。在这项研究中，我们严格量化了珠江口 (PRE) 37 只搁浅的印度-太平洋座头海豚 (Sousa chinensis) 的体色模式，尽管个体之间存在显着差异，但它们与雄性的年龄相关（1 岁至 35 岁之间，r2 = 0.84）和女性（1 岁至 25 岁之间，r2 = 0.85）。然后将人口平均相关性（r2 = 0.85）应用于大量照片识别数据（2011-2015）以估计大三角洲地区人口的年龄构成，这进一步表明年龄的空间差异组成，因此，整个地区座头海豚的复杂人口统计过程。特别是东部PRE（岭顶湾）的座头海豚年龄构成严重老化。最后，考虑到观察到的年龄结构和模拟的特定年龄繁殖力的种群生存力分析表明，预计 95.75% 的零丁湾座头海豚在三代后将消失。鉴于 PRE 复杂的人为景观，我们建议应明确界定座头海豚的管理单位，并且非常需要针对特定​​区域的保护措施。考虑到观察到的年龄结构和模拟的特定年龄繁殖力的种群生存力分析表明，预计 95.75% 的零丁湾座头海豚会在 3 代后消失。鉴于 PRE 复杂的人为景观，我们建议应明确界定座头海豚的管理单位，并且非常需要针对特定​​区域的保护措施。考虑到观察到的年龄结构和模拟的特定年龄繁殖力的种群生存力分析表明，预计 95.75% 的零丁湾座头海豚会在 3 代后消失。鉴于 PRE 复杂的人为景观，我们建议应明确界定座头海豚的管理单位，并且非常需要针对特定​​区域的保护措施。