Meeting Abstract
The spatial distribution of conspecifics can provide important insights into aggression and competition in social species, particularly those in which both sexes possess weaponry. The maritime earwig (Anisolabis maritima) lives in high densities under beach debris in coastal ecosystems, and both sexes are aggressive yet differ drastically in both forceps morphology and temperament. Previous research showed that the differential behavior of the sexes affect the spatial distribution of small confined groups—females exhibit more hostile, territorial behavior than males, who tend to interact with one another more frequently—but interactions in more natural arrangements of free-moving individuals had not yet been examined. Given its natural history, the maritime earwig is well-suited for social network analyses, where the movement and proximity of individuals can be tracked to determine how complex interactions within and between the sexes influence social and reproductive behavior. In this study, we ran 30 trials of eighteen marked male and female earwigs collected from San Juan Island, WA, where half the groups had a 2:1 ratio of females to males and half the groups had a 1:1 sex ratio. Each arena contained four possible wood shelters, and we photographed the dispersion of individuals beneath them twice daily for 7 days. By tracking their positions and cohabitation patterns, we mapped social networks to analyze degrees of centrality and cliquishness within each group. We here report that the size and sex of individuals affected their social position and the nature of their connections within the group. Additionally, alteration of the sex ratio, and therefore the social environment, affected the social networks and overall group dynamics.
