Contribution of Learning in the Origin of New Niches. How Learning Can Compensate for Climbing Skills in a Non-Specialized Amphibian.

Abstract

During the origin of new niches, animals face novel situations and must adapt to access new resources. Innovative individuals may develop strategies and behaviors to take advantage of these resources, although these individuals often lack striking adaptations for the new niche. In these individuals, adequate performance must be achieved, even in cases where behaviors are not typical or usual, which does not necessarily imply optimal performance in terms of energy or speed, but rather the flexibility to choose a different scenario to pursue a biological purpose. Through experience, animals can improve their ability to perform complex movements and adapt to new conditions. We evaluated the existence of additional locomotor skills in a widespread anuran amphibian, Rhinella arenarum. This toad has a terrestrial niche, probably the ancestral condition within the genus. Therefore, it allows us to know the limits of these capacities to execute novel behaviors. Specifically, we analyzed whether the climbing abilities demonstrated by this terrestrial toad can be improved through learning. Adult male and female toads were tested in a climbing device during eight daily sessions. After training, animals improved climbing performance, measured by climbing latency, climbing speed, and stride frequency. The improvement by learning the ability to climb could thus represent an adaptation that allows the exploitation of arboreal niches. Our results indicate that it is possible that innovative individuals who manage to acquire and perfect the ability to climb could expand their range of available niches and, potentially, give rise to new evolutionary lines.