The functions of signal complexity
Many organisms produce signals that span multiple sensory modalities, despite the costs and risks of producing a complex and conspicuous display.
Many mating displays combine visual and acoustic signals, and prey often warn predators using both chemical and visual signals. Likewise, plants attract pollinators with visual, olfactory, tactile, gustatory and even thermal stimuli. What benefit does a more complex signal provide senders and/or receivers? How do receivers compare alternatives that differ in several attributes? The lab group addresses these basic questions from a variety of perspectives. Key findings and products include:
Floral Signal complexity
We recently produced an integrative review of multisensory processing in bees. From the plant perspective, we also have developed a framework of hypotheses for floral signal complexity, and a more focused review of hypotheses involving pollinator learning and memory. These complement recent empirical findings that the presence of floral scent facilitates learning about color, and enhances foraging in the face of environmental variability.
Visual complexity is another topic of interest: for example, we found that classic "nectar guide" floral patterns promote pollen transfer for plants, by attracting bees from a distance and increasing the chances that they "legitimately" access nectar (rather than nectar robbing). From the bee perspective, patterns' effect on foraging performance is context-dependent, even reducing it in some circumstances.
Multimodal signals in mate choice
During dissertation research at UC Davis, PI Leonard studied multimodal communication in field crickets, exploring how females use multiple male mating signals to make a decision; how males and females differ in their use of multisensory cues; and how competitor signals influence male behavior.