“Intraspecific variation in learning: worker wasps are less able to learn and remember individual conspecific faces than queen wasps”
Elizabeth A. Tibbetts, Allison Injaian, Michael J. Sheehan, and Nicole Desjardins (May 2018)
Worker paper wasps have lower individual recognition ability than queens, even though castes are flexible
Research on individual recognition often focuses on species-typical recognition abilities rather than assessing intraspecific variation in recognition. As individual recognition is cognitively costly, the capacity for recognition may vary within species. We test how individual face recognition differs between nest-founding queens (foundresses) and workers in Polistes fuscatus paper wasps. Individual recognition mediates dominance interactions among foundresses. Three previously published experiments have shown that foundresses (1) benefit by advertising their identity with distinctive facial patterns that facilitate recognition, (2) have robust memories of individuals, and 3)rapidly learn to distinguish between face images. Like foundresses, workers have variable facial patterns and are capable of individual recognition. However, worker dominance interactions are muted. Therefore, individual recognition may be less important for workers than foundresses. We find: (1) workers with unique faces receive similar amounts of aggression as workers with common faces, indicating that wasps do not benefit from advertising their individual identity with a unique appearance, (2) workers lack robust memories for individuals, as they cannot remember unique conspecifics after a six-day separation and (3) workers learn to distinguish between facial images more slowly than foundresses during training. The recognition differences between foundresses and workers are notable because Polistes lack discrete castes; foundresses and workers are morphologically similar and workers can take over as queens. Overall, social benefits and receiver capacity for individual recognition are surprisingly plastic.