Fig. 2.

Comparisons of parameters of colour conspicuousness between human-subjective red (R) and the other six floral colours according to different colour vision models. The six other floral colours are blue (B), pink (Pi), purple (Pu), violet (V), white (W) and yellow (Y). The numbers at the bottom of the columns in (A) are sample sizes. The RNL model was used for both bees and birds, and the CH model was used in addition for bees. (A, B) Chromatic contrast and purity in bees’ vision according to the CH model. (C–F) Chromatic contrast in bees’, UVS birds’, VS birds’ and hummingbirds’ vision according to the RNL model. (G–J) Achromatic contrast in bees’, UVS birds’, VS birds’ and hummingbirds’ vision. phylANOVAs (with 1000 simulations and Holm’s method for P-value adjustment) were used. Values are shown as mean ± s.e. *P < 0.05; n.s., not significant.