Hirsch Philipp Emanuel, Thorlacius Magnus, Brodin Tomas, Burkhardt-Holm Patricia
Research Centre for Sustainable Energy and Water Supply; Program Man-Society-Environment Department of Environmental Sciences University of Basel Basel Switzerland.
Department of Ecology and Environmental Science Umeå University Umeå Sweden.
Ecol Evol. 2016 Dec 23;7(2):720-732. doi: 10.1002/ece3.2629. eCollection 2017 Jan.
Animal personalities are an important factor that affects the dispersal of animals. In the context of aquatic species, dispersal modeling needs to consider that most freshwater ecosystems are highly fragmented by barriers reducing longitudinal connectivity. Previous research has incorporated such barriers into dispersal models under the neutral assumption that all migrating animals attempt to ascend at all times. Modeling dispersal of animals that do not perform trophic or reproductive migrations will be more realistic if it includes assumptions of which individuals attempt to overcome a barrier. We aimed to introduce personality into predictive modeling of whether a nonmigratory invasive freshwater fish (the round goby, ) will disperse across an in-stream barrier. To that end, we experimentally assayed the personalities of 259 individuals from invasion fronts and established round goby populations. Based on the population differences in boldness, asociability, and activity, we defined a priori thresholds with bolder, more asocial, and more active individuals having a higher likelihood of ascent. We then combined the personality thresholds with swimming speed data from the literature and in situ measurements of flow velocities in the barrier. The resulting binary logistic regression model revealed probabilities of crossing a barrier which depended not only on water flow and fish swimming speed but also on animal personalities. We conclude that risk assessment through predictive dispersal modeling across fragmented landscapes can be advanced by including personality traits as parameters. The inclusion of behavior into modeling the spread of invasive species can help to improve the accuracy of risk assessments.
动物个性是影响动物扩散的一个重要因素。在水生物种的背景下，扩散模型需要考虑到大多数淡水生态系统因阻碍纵向连通性的屏障而高度碎片化。先前的研究已在中性假设下将此类屏障纳入扩散模型，即所有迁徙动物在任何时候都试图向上游游动。如果在动物扩散模型中纳入关于哪些个体试图克服屏障的假设，那么对不进行营养或繁殖迁徙的动物进行扩散建模将更符合实际情况。我们旨在将个性因素引入对一种非洄游性入侵淡水鱼（圆口铜鱼）是否会跨越溪流中的屏障进行扩散的预测模型中。为此，我们对来自入侵前沿和已建立的圆口铜鱼种群的259个个体的个性进行了实验测定。基于大胆程度、社交性和活动水平方面的种群差异，我们预先设定了阈值，即更大胆、更不合群且更活跃的个体向上游游动的可能性更高。然后，我们将个性阈值与文献中的游泳速度数据以及屏障处的现场流速测量值相结合。由此得到的二元逻辑回归模型揭示了跨越屏障的概率，该概率不仅取决于水流和鱼类游泳速度，还取决于动物个性。我们得出结论，通过在碎片化景观中进行预测性扩散建模来进行风险评估，可以通过将个性特征作为参数来加以推进。将行为因素纳入入侵物种扩散建模有助于提高风险评估的准确性。
