Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Christchurch, 8041, New Zealand.
Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA.
Ecol Lett. 2021 Mar;24(3):520-532. doi: 10.1111/ele.13670. Epub 2021 Jan 6.
Functional responses relate a consumer's feeding rates to variation in its abiotic and biotic environment, providing insight into consumer behaviour and fitness, and underpinning population and food-web dynamics. Despite their broad relevance and long-standing history, we show here that the types of density dependence found in classic resource- and consumer-dependent functional-response models equate to strong and often untenable assumptions about the independence of processes underlying feeding rates. We first demonstrate mathematically how to quantify non-independence between feeding and consumer interference and between feeding on multiple resources. We then analyse two large collections of functional-response data sets to show that non-independence is pervasive and borne out in previously hidden forms of density dependence. Our results provide a new lens through which to view variation in consumer feeding rates and disentangle the biological underpinnings of species interactions in multi-species contexts.
功能反应将消费者的摄食率与其生物和非生物环境的变化联系起来，为消费者行为和适应性提供了深入的了解，并为种群和食物网动态提供了基础。尽管它们具有广泛的相关性和悠久的历史，但我们在这里表明，经典的资源依赖型和消费者依赖型功能反应模型中发现的密度依赖性类型等同于对摄食率背后过程独立性的强烈且往往难以维持的假设。我们首先从数学上演示了如何量化摄食与消费者干扰之间以及摄食多种资源之间的非独立性。然后，我们分析了两个大型功能反应数据集，以表明非独立性是普遍存在的，并以以前隐藏的密度依赖性形式表现出来。我们的研究结果为观察消费者摄食率的变化提供了一个新的视角，并在多物种背景下理清了物种相互作用的生物学基础。
