Coloração de flores na visão de polinizadores

Abstract

Flower coloration is as intriguing as the ecological and environmental factors behind it. Since the beginning of studies in floral biology, the question of the reasons behind floral coloration has been asked. Many authors have attributed flower colors to sexual selection and pollinator pressure. This is well exemplified by the idea of pollination syndromes: flowers with certain similar characteristics, such as color, are visited by similar groups of pollinators. Such a diverse array of coloration, however, is hardly ever explained by one factor alone. In this study, we aimed at understanding which environmental, ecological and physiological pressures are behind flower coloration, emphasizing, in testing, if flowers predicted by pollination syndromes are in fact conspicuous to their pollinators. We used Apis mellifera (honeybee), Drosophila melanogaster (housefly), Heliconius erato (butterfly) and Sephanoides sephanoides (hummingbird) as models to study how different pollinators see flowers. Flowers were more conspicuous to tetrachromat (housefly, female butterfly and hummingbird) than to trichromat (honeybee and male butterfly) pollinators. Therefore, flowers were not more conspicuous for their respective pollinators, and colors attributed by pollination syndromes do are not supported by empirical data. Probably different factors have shaped the coloration of flowers across time, and pollination syndromes are a piece of the whole picture.