Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.
University of Chinese Academy of Sciences, Beijing, China.
Integr Zool. 2021 Jul;16(4):527-537. doi: 10.1111/1749-4877.12542. Epub 2021 Apr 8.
Humpback dolphins (Sousa spp.) are obligate shallow-water and resident species, and they typically live in fission-fusion societies composed of small-sized groups with changeable membership. However, we have scant knowledge of their behavioral ecology, starting with potential factors influencing inter-population variability of their group sizes. Here, we compiled a new global dataset of humpback dolphin group sizes based on 150 published records. Our data indicated an inter-specific consistency of group-living strategy among the 4 species in the Sousa genus, as these species preferred living in small-sized groups with a mean size of mostly no more than 10, a minimum size of single individual or small pairs, and a maximum size of several tens or ≈100. In addition, we clearly showed the geographic variations in group sizes of humpback dolphins at a global scale. We found that the geographic variations in humpback dolphin group sizes were primarily associated with the latitude, sea surface temperature, and abundance. To conclude, our findings provide insights into social dynamics and socioecological trade-offs of humpback dolphins, and help better understand how these resident animals adapted to their shallow-water habitats from the perspectives of biogeography and socioecology.
弓头鲸（Sousa spp.）是专性浅海和定居物种，它们通常生活在由小群体组成、成员不断变化的融合-分裂社会中。然而，我们对它们的行为生态学知之甚少，首先是影响其群体大小的种群间变异性的潜在因素。在这里，我们根据 150 份已发表的记录，编制了一个弓头鲸群体大小的新的全球数据集。我们的数据表明， Sousa 属的 4 个物种之间存在特定的群居策略一致性，因为这些物种更喜欢生活在小群体中，平均大小大多不超过 10，最小大小为单个个体或小对，最大大小为数个或≈100。此外，我们还在全球范围内清楚地显示了弓头鲸群体大小的地理变化。我们发现，弓头鲸群体大小的地理变化主要与纬度、海面温度和丰度有关。总之，我们的研究结果为弓头鲸的社会动态和社会生态权衡提供了新的见解，并从生物地理学和社会生态学的角度帮助更好地了解这些定居动物是如何适应其浅海栖息地的。
