Angle dependent colors, such as iridescenee, are produced by structures present on flower petals changing their visual appearanee. These colors have been proposed to act as signals for plantinsect communication. Howev...Angle dependent colors, such as iridescenee, are produced by structures present on flower petals changing their visual appearanee. These colors have been proposed to act as signals for plantinsect communication. However, there is a paucity of behavioral data to allow for interpretations of how to classify these colors either as a signal or a cue when con sidering the n atural con ditions under which pollination occurs. We sampled flowers from 6 plant species across various viewpoints looking for changes in the visual appearanee of the petals. Spectral characteristics were measured with different instruments to simulate both the spectral and spatial characteristics of honeybee's vision. We show the presenee of color patches produced by angle dependent effects on the petals and the calyx of various species;however, the appearance of the angle dependent color patches significantly varies with viewpoint and would only be resolved by the insect eye at close distances. Behavior experiments with honeybees revealed that pollinators did not use angle dependent colors to drive behavior when presented with novel flower presentations. Results show that angle dependent colors do not comply with the requirements of a signal for plant-pollinator communication since the information transmitted by these colors would be unreliable for potential, free-flying pollination vectors. We thus classify angle dependent colors produced by micro- and ultra-structures as being a cue (a feature which has not evolved for communication), and observe no evidence supporting claims of these angle dependent colors having evolved as visual signal.展开更多
文摘Angle dependent colors, such as iridescenee, are produced by structures present on flower petals changing their visual appearanee. These colors have been proposed to act as signals for plantinsect communication. However, there is a paucity of behavioral data to allow for interpretations of how to classify these colors either as a signal or a cue when con sidering the n atural con ditions under which pollination occurs. We sampled flowers from 6 plant species across various viewpoints looking for changes in the visual appearanee of the petals. Spectral characteristics were measured with different instruments to simulate both the spectral and spatial characteristics of honeybee's vision. We show the presenee of color patches produced by angle dependent effects on the petals and the calyx of various species;however, the appearance of the angle dependent color patches significantly varies with viewpoint and would only be resolved by the insect eye at close distances. Behavior experiments with honeybees revealed that pollinators did not use angle dependent colors to drive behavior when presented with novel flower presentations. Results show that angle dependent colors do not comply with the requirements of a signal for plant-pollinator communication since the information transmitted by these colors would be unreliable for potential, free-flying pollination vectors. We thus classify angle dependent colors produced by micro- and ultra-structures as being a cue (a feature which has not evolved for communication), and observe no evidence supporting claims of these angle dependent colors having evolved as visual signal.
