Exploring positive feedback in the waggle dance and its effect on collective behavior

Social insects recruit nestmates to exploit food sources collectively, creating positive feedback that steers foraging effort to the best locations. The nature of this feedback varies among species, with implications for collective foraging. The recruitment trails of many ants are nonlinear, meaning that small increases in effort yield disproportionately large increases in recruitment success. The waggle dance of honeybees, in contrast, is believed to be linear, meaning that success increases proportionately to effort. At the collective level, linear and nonlinear recruitment make distinct predictions about how a colony will exploit two resources of identical quality—nonlinear systems break symmetry, directing nearly all foragers to only one resource, while linear systems exploit the two equally. We earlier found evidence consistent with linear recruitment in honey bees. However, we could not rule out the alternative explanation that our finding was an artifact of confining the bees to a small flight cage – possibly allowing other explanations. To test whether recruitment plays a significant role within flight cages, we presented enclosed colonies with an unequal choice of feeders (1.0 M versus 2.25 M sucrose) and tipped the hives on their side to disrupt their ability to use the waggle dance. After one hour, we returned the hives to an upright position. If dance recruitment plays a significant role in directing foragers, we predict impaired ability by the colonies to collectively choose the stronger feeder when the hives were tipped compared to when they were upright. Ongoing analysis of the results will test this prediction.