Data for: modelling a predator-prey interaction

MSc students from the Ecological Modelling course from the Faculty of Sciences of the University of Lisbon took part in an experiment that intended to model a typical predator-prey situation. These students played the role of predators, while prey was represented by animal shaped pasta (each measuring approximately 1 cm2) displayed on separate tables of the same size. In total there were 34 predators (each assigned a number), divided into
groups of 3 to 5. Two main methods were used: (1) Capture Attempts and (2) Capture time, as a function of different abundances of prey (N=15,30,50,60,70,80,100,140,160).
The first method assessed how many attempts (C1, C2, C3) were needed for predators to capture a total of three preys, while blindfolded and using only their fingertips. In the second method, predators moved a single finger along each table until they touched 3 preys, timing each capture cumulatively (T1, T2, T3). Each predator performed both methods on all prey groups, i.e. on all tables.
Explanatory variables were defined as follows: prey abundance, the order in which the different tables of prey were preyed upon, predator number, predator size (represented by student's height and hand size) and predator's eye colour. Response variables (capture attempts and capture time) were modeled as a function of the previous explanatory variables. Modelling predation phenomena that occur in nature implies simplifying complex relationships. As such, in this study we focus on three key aspects: (1) ascertaining variables that influence predation success; (2) searching for a possible predator learning process throughout the experiment; (3) assessing if individual heterogeneity affects predation success, and if so how.
Firstly, we expect that out of all tested variables only predator eye colour does not have a significant effect on the response variables. Secondly, we predict a decline in capture attempts and capture time according to the order in which the different tables of prey were preyed upon, which may suggest a learning curve during the procedure. Finally, and often ignored in modelling exercises, here we anticipate that individual heterogeneity between predators is an underlying factor.

里斯本大学理学院生态建模课程的理学硕士（Master of Science）学生参与了一项旨在模拟典型捕食者-猎物（predator-prey）情境的实验。这些学生扮演捕食者角色，猎物则由外形模仿动物的意面替代，每块面积约1 cm²，放置在多张尺寸一致的独立试验台面上。本次实验共有34名带有编号的捕食者学生，被划分为3至5人不等的小组。实验采用两种核心测试方法：(1) 捕获尝试次数法，(2) 捕获时长法，实验自变量为不同梯度的猎物丰度（N=15、30、50、60、70、80、100、140、160）。第一种方法用于评估：捕食者在蒙眼且仅使用指尖的条件下，捕获共计3只猎物所需的尝试次数（记为C1、C2、C3）。第二种方法要求捕食者用单根手指在每张试验台面上移动，直至触碰3只猎物，并累计记录每次捕获的时长（记为T1、T2、T3）。每名捕食者需针对所有猎物丰度组（即所有试验台面）完成两种方法的测试。本次实验的解释变量（explanatory variables）定义如下：猎物丰度、各猎物试验台面被捕食的先后顺序、捕食者编号、捕食者体型（以学生身高与手长表征）以及捕食者虹膜颜色。响应变量（response variables，即捕获尝试次数与捕获时长）将以上述解释变量为自变量开展建模分析。模拟自然界中的捕食现象需要简化复杂的相互关系，因此本研究聚焦于三个核心方向：(1) 明确影响捕食成功率的关键变量；(2) 探索实验过程中捕食者可能存在的学习进程；(3) 评估个体异质性（individual heterogeneity）是否会对捕食成功率产生影响，若存在影响则分析其作用机制。研究提出以下假设：其一，在所有测试变量中，仅捕食者虹膜颜色对响应变量无显著影响；其二，随着各猎物试验台面被捕食的先后顺序递增，捕获尝试次数与捕获时长均会呈现下降趋势，这或可暗示实验过程中存在学习曲线；其三，尽管捕食建模研究中常忽略个体异质性，但本研究预期捕食者间的个体差异是一项潜在的关键影响因素。