Ball Laura, Shreves Kypher, Pilot Małgorzata, Moura André E
School of Life Sciences, University of Lincoln, Lincoln, UK.
Behav Ecol Sociobiol. 2017;71(8):123. doi: 10.1007/s00265-017-2351-z. Epub 2017 Jul 21.
Social structure plays a crucial role in determining a species' dispersal patterns and genetic structure. Cetaceans show a diversity of social and mating systems, but their effects on dispersal and genetic structure are not well known, in part because of technical difficulties in obtaining robust observational data. Here, we combine genetic profiling and GIS analysis to identify patterns of kin distribution over time and space, to infer mating structure and dispersal patterns in short-beaked common dolphins (). This species is highly social, and exhibits weak spatial genetic structure in the Northeast Atlantic and Mediterranean Sea, thought to result from fluid social structure and low levels of site fidelity. We found that although sampled groups were not composed of closely related individuals, close kin were frequently found in the same geographic location over several years. Our results suggest that common dolphin exhibits some level of site fidelity, which could be explained by foraging for temporally varying prey resource in areas familiar to individuals. Dispersal from natal area likely involves long-distance movements of females, as males are found more frequently than females in the same locations as their close kin. Long-distance dispersal may explain the near panmixia observed in this species. By analysing individuals sampled in the same geographic location over multiple years, we avoid caveats associated with divergence-based methods of inferring sex-biased dispersal. We thus provide a unique perspective on this species' social structure and dispersal behaviour, and how it relates to the observed low levels of population genetic structure in European waters.
Movement patterns and social interactions are aspects of wild animal's behaviour important for understanding their ecology. However, tracking these behaviours directly can be very challenging in wide-ranging species such as whales and dolphins. In this study, we used genetic information to detect how patterns of kin associations change in space and time, to infer aspects of movement and social structure. We identified previously unknown site fidelity, and suggested that dispersal usually involves females, travelling long distances from the natal area. Our data analysis strategy overcomes known limitations of previously used genetic inference methods, and provides a new approach to identify differences in dispersal between the sexes, which contribute to better understanding of the species' behaviour and ecology. In this case, we suggest that females are more likely to disperse than males, a pattern unusual amongst mammals.
社会结构在决定物种的扩散模式和遗传结构方面起着至关重要的作用。鲸类动物表现出多样的社会和交配系统，但其对扩散和遗传结构的影响尚不清楚，部分原因是获取可靠观测数据存在技术困难。在此，我们结合基因分型和地理信息系统分析，以识别短吻真海豚（）亲缘分布在时间和空间上的模式，从而推断其交配结构和扩散模式。该物种具有高度社会性，在东北大西洋和地中海表现出较弱的空间遗传结构，这被认为是由灵活的社会结构和低水平的地点忠诚度导致的。我们发现，尽管采样群体并非由亲缘关系密切的个体组成，但在数年时间里，亲缘关系较近的个体经常出现在同一地理位置。我们的研究结果表明，真海豚表现出一定程度的地点忠诚度，这可以通过在个体熟悉的区域觅食随时间变化的猎物资源来解释。从出生区域的扩散可能涉及雌性的长距离移动，因为在与其亲缘关系较近的个体所处的相同位置，雄性比雌性更常见。长距离扩散可能解释了该物种中观察到的近乎随机交配现象。通过分析多年来在同一地理位置采样的个体，我们避免了与基于分化的推断性别偏向扩散方法相关的限制。因此，我们为该物种的社会结构和扩散行为，以及其与欧洲水域中观察到的低水平种群遗传结构之间的关系提供了独特的视角。
运动模式和社会互动是野生动物行为的重要方面，对于理解它们的生态学至关重要。然而，对于鲸鱼和海豚等广泛分布的物种来说，直接追踪这些行为可能极具挑战性。在本研究中，我们利用遗传信息来检测亲缘关系关联模式如何在空间和时间上变化，以推断运动和社会结构的各个方面。我们识别出了此前未知的地点忠诚度，并表明扩散通常涉及雌性，它们从出生区域长途迁徙。我们的数据分析策略克服了先前使用的遗传推断方法的已知局限性，并提供了一种识别性别间扩散差异的新方法，这有助于更好地理解该物种的行为和生态学。在这种情况下，我们认为雌性比雄性更有可能扩散，这在哺乳动物中是一种不寻常的模式。
