Individual-to-Resource Landscape Interaction Strength Can Explain Different Collective Feeding Behaviours

Taking in sufficient quantities of nutrients is vital for all living beings and in doing so, individuals interact with the local resource environment. Here, we focus explicitly on the interactions between feeding individuals and the resource landscape. In particular, we are interested in the emergent movement dynamics resulting from these interactions. We present an individual-based simulation model for the movement of populations in a resource landscape that allows us to vary the strength of the interactions mentioned above. The key assumption and novelty of our model is that individuals can cause the release of additional nutrients, as well as consuming them. Our model produces clear predictions. For example, we expect more tortuous individual movement paths and higher levels of aggregation in populations occupying homogeneous environments where individual movement makes more nutrients available. We also show how observed movement dynamics could change when local nutrient sources are depleted or when the population density increases. Our predictions are testable and qualitatively reproduce the different feeding behaviours observed in filter-feeding ducks, for example. We suggest that considering two-way interactions between feeding individuals and resource landscapes could help to explain fine-scale movement dynamics.

足量摄取营养物质对所有生命体而言至关重要，而个体在摄取营养的过程中，会与当地的资源环境产生交互作用。在此，我们明确聚焦于觅食个体与资源景观之间的交互作用。具体而言，我们关注的是这类交互作用所催生的涌现性运动动力学特征。本研究提出了一种适用于资源景观场景的基于个体的种群运动模拟模型，该模型可调节上述交互作用的强度。本模型的核心假设与创新之处在于，个体不仅能够摄取营养物质，还可触发额外营养物质的释放。本模型可生成明确的预测结果：例如，在个体运动能够提升可利用营养物质含量的均质环境中，种群个体的运动路径将更为蜿蜒曲折，且种群聚集程度更高。此外，我们还阐明了当地营养源枯竭或种群密度提升时，已观测到的运动动力学特征会发生何种变化。我们的预测具备可验证性，且能够定性复现例如滤食性鸭类所观测到的各类觅食行为。我们认为，纳入觅食个体与资源景观间的双向交互作用，将有助于阐释精细尺度下的运动动力学特征。