title: Floral iridescence, produced by diffractive optics, acts as a cue for animal pollinators.
abstract: Iridescence, the change in hue of a surface with varying observation angles, is used by insects, birds, fish, and reptiles for species recognition and mate selection. We identified iridescence in flowers of Hibiscus trionum and Tulipa species and demonstrated that iridescence is generated through diffraction gratings that might be widespread among flowering plants. Although iridescence might be expected to increase attractiveness, it might also compromise target identification because the object's appearance will vary depending on the viewer's perspective. We found that bumblebees (Bombus terrestris) learn to disentangle flower iridescence from color and correctly identify iridescent flowers despite their continuously changing appearance. This ability is retained in the absence of cues from polarized light or ultraviolet reflectance associated with diffraction gratings.
authors.affiliation: Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Whitney
authors.forename: Mathias
authors.initials: M
authors.lastname: Kolle
authors.forename: Piers
authors.initials: P
authors.lastname: Andrew
authors.forename: Lars
authors.initials: L
authors.lastname: Chittka
authors.forename: Ullrich
authors.initials: U
authors.lastname: Steiner
authors.forename: Beverley J
authors.initials: BJ
authors.lastname: Glover
mesh_terms: D000818:Animals; D001516:Bees / Q000502:physiology*; D003116:Color; D003118:Color Perception; D003463:Cues; D035264:Flowers / Q000166:cytology; D031584:Hibiscus / Q000166:cytology; D055620:Optical Phenomena; D010858:Pigmentation; D010860:Pigments, Biological; D019441:Plant Epidermis / Q000166:cytology; D054817:Pollination; D013057:Spectrum Analysis; D031447:Tulipa / Q000166:cytology
chemical_list: D010860:Pigments, Biological