Data from: Shades of red: bird-pollinated flowers target the specific colour discrimination abilities of avian vision

Colour signals are a major cue in putative pollination syndromes. There is
evidence that the reflectance spectra of many flowers target the
distinctive visual discrimination abilities of hymenopteran insects, but
far less is known about bird-pollinated flowers. Birds are hypothesized to
exert different selective pressures on floral colour compared with
hymenopterans because of differences in their visual systems. We measured
the floral reflectance spectra of 206 Australian angiosperm species whose
floral visitors are known from direct observation rather than inferred
from floral characteristics. We quantified the match between these spectra
and the hue discrimination abilities of hymenopteran and avian vision, and
analysed these metrics in a phylogenetically informed comparison of
flowers in different pollination groups. We show that bird-visited flowers
and insect-visited flowers differ significantly from each other in the
chromatic cues they provide, and that the differences are concentrated
near wavelengths of optimal colour discrimination by whichever class of
pollinator visits the flowers. Our results indicate that angiosperms have
evolved the spectral signals most likely to reinforce their pollinators’
floral constancy (the tendency of individual pollinators to visit flowers
of the same species) in communities of similarly coloured floral
competitors.