The effect of sociality on competitive interactions among birds During the 2016–17 season, FeederWatch began inviting project participants to report behavioral interactions between birds that they observed during their counts. One of the interactions participants report is displacement: when one bird tries to take over a resource (food or perch) that is occupied by another bird. Researchers Ilias Berberi and Roslyn Dakin of Carleton University and Eliot Miller, who launched the behavior interactions component of FeederWatch, used the displacement data to examine how a bird’s sociability impacts their competitive ability. The researchers found that more social species—birds that tend to visit bird feeders in groups in winter, based on flock sizes reported by FeederWatch participants—are less likely to succeed in displacement interactions with other similarly sized birds. So being social might come with the tradeoff of being more mild-mannered for your size, compared to other species. However, the researchers also found that birds from more social species are more likely to succeed in displacing other birds when members of their own species are nearby—what the researchers called “the conspecific effect.” In other words, individuals from more social species have less displacement success when alone but more success when in a group. The researchers theorize that birds that have evolved to be more social have also evolved to be less aggressive. Additionally, the researchers theorize that competitors from other species respond to competition from individuals in a group differently than they respond to competition from individuals at a feeder alone. Perhaps having lots of allies wearing their team colors helps bolster an individual’s clout when fighting over a sunflower seed. Ilias Berberi, Eliot T. Miller, Roslyn and Dakin. “The effect of sociality on competitive interactions among birds.” bioRxiv, doi.org/10.1101/2022.05.09.491173.