Monogamy in a moment: how do brief social interactions change over time in pair-bonded zebra finches (Taeniopygia guttata)?

Abstract

AbstractResearch on monogamy has largely focused on marked behaviors that are unique to pair bonded partners. However, these marked behaviors represent only a subset of the pair-directed behaviors that partners engage in; the influence of pair bonding on mundane or subtle social interactions among partners remains largely unknown. In the current study, we describe the changes that occur during brief social reunions (or greets) over the course of pair bonding in zebra finches. We quantified pair-directed behavior during five-minute reunions from three stages of pair bonding: initial pairing (between 4-72 hrs), early pairing (1-2 weeks) and late pairing (>1 month). These social interactions were operationalized in multiples ways. First, we quantified the overall activity levels (call and movement rates) for both the male and female. Overall, females were more active than males, but for both males and females calling activity was highest during the initial timepoint (between 4-72 hrs post-pairing). We quantified behavioral coordination between partners in two ways, 1) similarity in call and movement rates between partners, and 2) temporal synchrony between calls and movements (via sliding correlation coefficients of time-stamped calls and movements). Overall there were no effects of pairing on behavioral coordination. Finally, we used principal component analyses to disentangle behavioral coordination from the activity levels of the male and female. These results contribute to a growing line of evidence that male and female zebra finches differentially contribute to social dynamics and highlight the influence of pair bonding on the development of social dynamics. Behavioral coordination is clearly important for marked interactions (e.g. duetting, courtship displays and biparental care). Our results raise the question of what the roles of such mundane social interactions are in monogamous partnerships.