title: Bees, birds and yellow flowers: pollinator-dependent convergent evolution of UV patterns.
abstract: Colour is one of the most obvious advertisements of flowers, and occurs in a huge diversity among the angiosperms. Flower colour is responsible for attraction from a distance, whereas contrasting colour patterns within flowers aid orientation of flower visitors after approaching the flowers. Due to the striking differences in colour vision systems and neural processing across animal taxa, flower colours evoke specific behavioural responses by different flower visitors. We tested whether and how yellow flowers differ in their spectral reflectance depending on the main pollinator. We focused on bees and birds and examined whether the presence or absence of the widespread UV reflectance pattern of yellow flowers predicts the main pollinator. Most bee-pollinated flowers displayed a pattern with UV-absorbing centres and UV-reflecting peripheries, whereas the majority of bird-pollinated flowers are entirely UV- absorbing. In choice experiments we found that bees did not show consistent preferences for any colour or pattern types. However, all tested bee species made their first antennal contact preferably at the UV-absorbing area of the artificial flower, irrespective of its spatial position within the flower. The appearance of UV patterns within flowers is the main difference in spectral reflectance between yellow bee- and bird-pollinated flowers, and affects the foraging behaviour of flower visitors. The results support the hypothesis that flower colours and the visual capabilities of their efficient pollinators are adapted to each other.
authors.affiliation: Department Biology, Institute of Sensory Ecology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Papiorek
authors.affiliation: Department of Ecology and Evolution, University Salzburg, Salzburg, Austria.
authors.forename: R R
authors.initials: RR
authors.lastname: Junker
authors.affiliation: Instituto de Biociências da USP, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: I
authors.initials: I
authors.lastname: Alves-Dos-Santos
authors.affiliation: Laboratório de Biologia Comparada de Hymenoptera, Departamento de Zoologia, Universidade Federal do Paraná, Curitiba, Brazil.
authors.forename: G A R
authors.initials: GA
authors.lastname: Melo
authors.affiliation: Laboratório de Biologia Comparada de Hymenoptera, Departamento de Zoologia, Universidade Federal do Paraná, Curitiba, Brazil.
authors.forename: L P
authors.initials: LP
authors.lastname: Amaral-Neto
authors.affiliation: Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Sazima
authors.affiliation: Programa de Pós-Graduação em Botânica, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Wolowski
authors.affiliation: Jardim Botânico do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Freitas
authors.affiliation: Department Biology, Institute of Sensory Ecology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Lunau
mesh_terms: D000818:Animals; D001516:Bees / Q000502:physiology*; D005075:Biological Evolution; D001717:Birds; D003116:Color; D035264:Flowers / Q000737:chemistry* / Q000502:physiology*; D010858:Pigmentation; D057048:Plant Nectar; D054817:Pollination / Q000502:physiology*; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays
chemical_list: D057048:Plant Nectar
keywords: Bee pollination; UV pattern; bird pollination; colour vision; flower colour; nectar guides; stingless bees