Innovation in groups: does the proximity of others facilitate or inhibit performance?

Foraging innovation, in which an individual eats a novel food or uses a novel foraging technique, has been observed in a wide range of species. If other individuals are nearby, they may adopt the innovation, thus spreading it through the population. Much research has focused on this social transmission of behaviour, but the effect of social context on the emergence of novel behaviour is unclear. Here, we examine the effect of social context on innovative feeding behaviour in the Carib grackle (Quiscalus lugubris), an opportunistic, gregarious bird. We test the effect of the proximity of conspecifics, while eliminating the direct effects of interference, scrounging, or aggression. Using a repeated-measures design, we found that birds took significantly longer to contact novel foraging tasks when in the presence of others vs. alone, and during playbacks of alarm calls vs. a control sound. Further, performance of a food-processing behaviour decreased when birds were with others, and individuals adjusted their behaviour depending on their distance from conspecifics. Our results suggest that feeding in groups may slow down or inhibit innovative foraging behaviour in this species. We discuss the implications of a trade-off between feeding in groups and taking advantage of new feeding opportunities.