Scale Invariance of Spontaneous Exploratory Behaviors of Marmoset Monkeys

Abstract

Exploration is an essential part of human and animal life. Using animal behavior as their primary focus, numerous studies have centered their investigations on what drives behavior. In this study, we explicitly test whether marmoset monkey exploratory behavior is influenced by external factors or by internal constraints. Using a Microsoft Kinect, a three-dimensional tracking device, we observe marmoset exploration in a custom-built enclosure that is adjustable in length and that accommodates three different experimental conditions—big, medium, small. In this setting, we can observe differences of exploratory behaviors across marmosets and determine whether changing the size of the enclosure influences the behavior. We find that marmoset monkeys exhibit individualized exploratory behaviors. Additionally, we find that changing the size of the enclosure does not have a statistically significant effect on marmoset behavior and that differences in marmoset exploration are not correlated with weight or age. In all, we provide experimental evidence that marmoset exploratory behaviors are individualized and invariant of cage size. These findings suggest that understanding behavior, as an interaction between different factors, is important to advance our understanding of explorative movement.