Meeting Abstract
Signals that mediate repeated social interactions have the potential to drive dynamic feedback between signaling phenotype, physiology, and the social environment. In gregarious species, social interactions are ubiquitous, but the consequence of each individual interaction is probably quite small. Thus, for signals that mediate the frequency or nature of repeated interactions, costs and benefits likely arise through the accumulation of many minor interactions. Tree swallows are semi-colonial breeders and are gregarious throughout the year. We previously found that the brightness of the white breast feathers in female tree swallows is correlated with nest visitation patterns, corticosterone levels, and stress resilience. Based on these results, we hypothesized that integration of this suite of traits might be maintained by the experience of repeated social interactions that are mediated by signaling. In this study, we experimentally dulled female breast feathers during the breeding season. Using a network of RFID readers installed at each nest box, we identified ~40,000 instances of an individual visiting a box at which they were not part of the breeding pair. Relative to controls, dulled females had significantly more repeated female visitors at their box but significantly fewer male visitors and these effects persisted throughout the breeding season. As a result of color manipulation, dulled females fledged significantly more offspring at their own nest despite having similar clutch sizes and initiation dates as control females. At this time, the mechanism resulting in increased fitness is unclear, but is consistent with reduced harassment by males and increased investment in breeding effort as a response to the altered social environment that females experienced.
