Pollen Foraging Bees Don't Learn Unsaturated Floral Color

Abstract

We investigated whether bees have an innate preference for flowers with saturated pigments and whether experience altered any preference. Preference could be a result of reward quality varying by color morph and/or responses to the petals, anthers, or their combination. Consequently, we gave bees experience on one of four floral configurations created from two color morphs of Solanum tridynanum. We subsequently tested learned preference using an array of all four configurations. Changes in preference as a result of experience were not mediated by anthers, only by petals. Bees that first experienced configurations with purple petals subsequently preferred configurations with purple petals, relative to naïve bees. However, bees that first experienced white petals showed no subsequent change in preference relative to naïve bees. Surprisingly, naïve bees showed no preference for any particular floral configuration. Rather than an innate preference for flowers with more saturated colors, bees are less able to develop a preference for unsaturated types. Because individuals are more able to develop a preference for saturated flowers, these flowers experience greater visitation, and thus greater pollination success, over unsaturated types.