The Influence of Nest Architecture on the Ant Temnothorax Rugatulus

Spatial constraints from the environment shape the evolution, ecology, and behavior of many forms of life. To this end, organisms may produce an architectural extended phenotype, or built extension of their phenotype into the environment, which can increase their fitness, but at the cost of both investing energy and taking on temporary risk. To what extent do an organism’s architectural extended phenotype and behavior interact, and how does this relate to fitness? The common rock ant Temnothorax rugatulus provides an excellent system to test how behavior is affected by an architectural extended phenotype (here, nest architecture). In my thesis, I probe how environmental constraints influence the relationship between the extended phenotype and behavior by examining how different imposed nest shapes affect their inhabitants and how the inhabitants can in turn alter the shape itself. This body of work suggests that nest shape significantly impacts the spatial organization and behavior of the inhabiting ant colony, but that these differences may not directly translate to increased fitness. I also do not find support for the hypothesis that environmental humidity influences the nest architecture of rock-dwelling ants but emphasize that this hypothesis is difficult to test empirically. Based on these results, I hypothesize that ant colonies employ adaptive behavioral strategies that mediate consequences from occupying presumably sub-optimal nest sites, which may also lower the nest site competition and promote colony success