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.

里斯本大学科学学院生态建模课程的研究生参与了旨在模拟典型捕食-猎物情况的实验。这些学生在实验中扮演捕食者的角色，而猎物则由形状为动物的意面（每个约1平方厘米）代表，分别放置在大小相同的单独桌子上。总共有34只捕食者（每只捕食者被分配一个编号），分为每组3至5只。实验中采用了两种主要方法：（1）捕获尝试和（2）捕获时间，作为猎物丰度的函数（N=15,30,50,60,70,80,100,140,160）。第一种方法评估了捕食者需要多少次尝试（C1、C2、C3）才能捕获总共三只猎物，条件是捕食者被蒙上眼睛，仅使用指尖进行操作。第二种方法中，捕食者沿着每张桌子移动一根手指，直到触及3只猎物，并累计记录每次捕获的时间（T1、T2、T3）。每只捕食者对所有猎物组（即所有桌子）都进行了这两种方法的测试。解释变量定义为：猎物丰度、不同猎物桌子被猎捕的顺序、捕食者编号、捕食者体型（由学生的身高和手部大小表示）以及捕食者的眼睛颜色。响应变量（捕获尝试和捕获时间）被建模为先前解释变量的函数。模拟自然界中发生的捕食现象意味着简化复杂的关系。因此，在本研究中，我们关注三个关键方面：（1）确定影响捕食成功率的变量；（2）在整个实验过程中寻找可能的捕食者学习过程；（3）评估个体异质性是否影响捕食成功率，以及如果影响，影响的方式。首先，我们预期在所有测试变量中，只有捕食者的眼睛颜色对响应变量没有显著影响。其次，我们预测随着不同猎物桌子被猎捕的顺序，捕获尝试和捕获时间将呈下降趋势，这可能表明在实验过程中存在学习曲线。最后，在建模练习中通常被忽视的是，我们预计捕食者之间的个体异质性是一个潜在因素。