Behaviour 2019
Producer-scrounger dynamics in foraging bumble bees
Aimee S. Dunlap1, Matthew W. Austin1, Isabel Rojas-Ferrer2. 1University of Missouri--St. Louis, Saint Louis, Missouri, United States; 2University of Ottawa, Ottawa, Ontario, Canada

Social information use is often modeled using producer/scrounger game theory, where the benefit to producing information versus using social information depends heavily on frequency-dependence of strategies. Producing, finding a new patch, is favored when scroungers are many. Scrounging, joining others at a patch, is favored when many are producing. Well-tested in birds, bumble bees are also predicted to flexibly match their behavior to the economics of the producer-scrounger ratio in foraging. Using predictions from theory, we set up two foraging worlds in flight arenas, one in which producing is favored and one in which scrounging is favored. Each is determined by the placement of conspecifics and the rewards associated with each patch. Bees experience the reward contingencies in a within subject design and we assess their tendencies towards producing or scrounging. We find, among other results, that individual bees dramatically shift whether they join conspecifics at individual flowers when the proportion of scroungers to producers becomes high, as predicted. We discuss implications of these results for the plasticity of social information use in competitive nectar foraging.