Conspicuousness, not colour as foraging cue in plant–animal signalling

摘要: The global prevalence of red and black fruits has still not been explained. Hypotheses based on innate consumer preferences have tested rejected. Though colour itself plays an important role in animal foraging, it is only one component signals. Another major are contrasts against background achieving the conspicuousness In order to evaluate which signal determines consumers behaviour, we measured fruit 43 species their natural under ambient light conditions. Red exhibit stronger therefore more conspicuous than other colours. Subsequently, trials were carried out determine whether or influences avian food choice. Four bird strongly preferred contrasting red–green black–green over uni-coloured red, green, displays, while no preference for particular hues was found. We hypothesize that selection define contrast hypothesis: Diurnal dispersers select colours itself. Because vision ancient trait, entire heterogeneous group frugivorous birds most likely perceives uniformly evolutionary time spans. Conspicuousness thus potential explain fruits.