Meeting Abstract
Nectar foraging is a goal-directed behavior. Nevertheless, its goal – nectar – is not its causal principle. Rather, this goal-directedness is achieved by an inherited, innate program resulting from selective pressures acting on the efficiency with which foraging is performed. For this, it is fundamental that the animal can extract meaningful information from its uncertain environment. Lacking an explicit representation of what a nectar source (flower) is, pollinators control their foraging movements using multiple floral signals that increase their probabilities of nectar encounter. The use of these signals is not rigid, but user-specific (species, experience, learning) and context-dependent (spatiotemporal patterns of stimulation, signal availability, multimodal integration). In this study we evaluated the use of two important floral signals, visual display and odor, in naïve Manduca sexta hawkmoths under different illuminance conditions. We offered moths two artificial feeders (a white one and a blue one) against a dark-green background. Both feeders were either scented or unscented. Under conditions resembling starlight and crescent moonlight, a small proportion of moths (~30%) recognized unscented feeders as potential nectar sources and probed on them, but these proportions were doubled when feeders were scented. Under brighter conditions (quarter-moonlight and gibbous-moon light) moths showed equally high levels of responsiveness (60%), regardless of whether feeders were scented or unscented. Additionally, we found that moths showed a bias for white over blue feeders in dim light, which disappeared under brighter illumination. We would like to discuss the role of olfactory and visual signals, and multimodal integration, in “telling a naïve moth what a flower is”.
