Cognitive Ecology of Foraging: Multimodal Signals and the Speed-Accuracy Trade-off

Abstract

Many signals in nature are complex and composed of several components. However, the advantages and disadvantages of complex signaling are not completely understood. Although complex signals are advantageous for vertebrate decision-making processes, our understanding of whether similar advantages exist for invertebrates is limited. To investigate how signal complexity influences learning and decision-making in foraging bumblebees (Bombus impatiens), I trained them on unimodal (shape or olfactory) or multimodal (shape and olfactory) flowers. Addition of olfactory cues to visual cues improved the learning of bees. A speed-accuracy trade-off in decision-making reflects the difficulty of decisions. The bees trained on multimodal flowers made more accurate decisions without reducing their speed, and had higher target finding rates (correct visits/total decision time). These results suggest that bees forage more efficiently when flowers signal in more than one modality, and support arguments pointing out problems with studying signal components separately.