Animal behavior research is increasingly concentrated on the collective behaviors that emerge from social living. Significant work is underway to understand how such apparent organization is achieved without any conscious oversight or direction from a leader; however, researchers understanding of these behaviors are incomplete without an understanding of how natural selection operates on both the group and its individual constituents. The goal of this project is to investigate the influence of within-group conflict on collective decision-making in the North American slave-making ant Protomognathus americanus. Through coupled analysis of cooperation and conflict, this project contributes to our understanding of how social insects achieve superorganism status, which can more generally be applied to the other major transitions in biological organization (e.g. genes to chromosomes, unicellular to multicellular organisms). This project will also establish slave-making ants as models of collective decision-making and contribute a novel mechanism distinct from the relatively well studied collective decision-making behaviors by rock ants and honeybees searching for new nests. Over the course of this project, 4-5 undergraduates will be mentored and the investigators will continue their outreach and science education activities using portable, acorn-nesting ant colonies. Ultimately understanding what principles make collective behavior effective may also help guide the structure of human groups in our increasingly networked world.
This project will investigate the relationship between within-group conflict and the efficiency of group-level behaviors by studying P. americanus' collective decision over where to launch slave-raids. The researchers will combine observational experiments in the lab and naturalistic field experiments to achieve three main goals: (1) test how resilient collective decision-making is to within-group conflict; (2) describe how individual behaviors differ between high and low conflict groups; and (3) test if the emergent benefits from collective behaviors influence the evolution of cooperation. In this experiment, the researchers will manipulate the degree of selfishness in slave-maker colonies by inducing ovarian development in half of the lowest ranking slave-maker workers. A slavemaker colony will then be introduced to a glass arena containing three host colonies of low, medium and high quality. The maximum number of scouts actively searching, total time spent searching before first nest discovery and before raid initiation, number of nests located and recruited to, duration of recruitment, quality of the nest raided, size of the raiding party and number of brood items stolen will be analyzed using video tracking software. Lastly, P. americanus colonies will be moved into artificial nests and placed in a study plot. After a year, the number of slaves and the number of male and sexual female pupae will be counted and ovarian development will be measured in the workers. Both eCommons (http://ecommons.library.cornell.edu/), and the Knowledge Network for Biocomplexity (http://knb.ecoinformatics.org) will be used to make data accessible to a wide audience.
