Experiment 9: Determining Light Preference in Behavioral Ecology of Armadillidium

Abstract

In this experiment, we tested the Armadillidium’s ability to recognize differences in light and dark environments using concepts of behavioral ecology. We hypothesized that the Armadillidium would indeed recognize this difference and would also prefer darker regions. After running ten experimental trials, we found that there was no statistical significance to our findings. However, the gross data does show that the crustaceans spent 67% of their time in the dark regions. Published data concurs with this finding. We suggest a greater sample size for more accurate statistical results in future experiments.

Introduction

Behavioral Ecology is defined as "the research approach based on the expectation that animals increase their Darwinian fitness by optimal behavior" (Campbell et al., 1999). We will use this concept to test the ecology preference of Armadillidium crustaceans, also referred to as pill bugs or roly-polys. Pill bugs are land-dwelling crustacea within the order Isopoda. Since they can inhabit a variety of habitats including temperate, tropical, and desert, they are considered to be the largest group of truly terrestrial crustaceans (Ammerlaan et al. 2001).

Pill bugs tend to spend daytime in moist, cool environments, since they lack a waxy cuticle. If a pill bug was to sustain several hours of constant sunshine, it is very possible that the pill bug would become dehydrated and die. However, they absorb water through their food, drinking water, and capillary action via uropods. These bugs must also be weary of predators such as frogs, toads, and small mammals. The basic defense mechanism of the pill bug is to ball up and protect itself with its outer covering.

In this experiment we are researching on habitation selection for pill bugs. Habitat selection is important for recognizing ecological niches and focuses on identifying environmental conditions relevant to survival of an animal species, and environmental cues that the...