title: Butterfly pollination and high-contrast visual signals in a low-density distylous plant.
abstract: In low-density butterfly-pollinated Mussaenda frondosa (Rubiaceae), flowers attract pollinators at short distances while conspicuous, non-rewarding accessory bracts are detectable at long distances by long-ranging pollinators such as the birdwing butterfly Troides minos that did not detect flower-bearing plants in the absence of these bracts. However, even in the absence of flowers, the white, ultraviolet-absorbing bracts attracted butterflies that visited flowerless plants. Although flower visits by short-ranging territorial butterflies declined significantly on removal of bracts, they did not cease completely. Nectar-robbing carpenter bees and birds did not change their behaviour following bract removal. Bract removal caused a significant decline in fruit set, indicating their importance as visual signals to pollinators.
authors.affiliation: Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, India. renee@ces.iisc.ernet.in
authors.forename: Renee M
authors.initials: RM
authors.lastname: Borges
authors.forename: Vinita
authors.initials: V
authors.lastname: Gowda
authors.forename: Merry
authors.initials: M
authors.lastname: Zacharias
mesh_terms: D000818:Animals; D001516:Bees; D001717:Birds; D002080:Butterflies; D035264:Flowers; D009068:Movement; D012098:Reproduction; D019666:Rubiaceae / Q000502:physiology*; D014466:Ultraviolet Rays; D014796:Visual Perception