Skip to main content
Dryad

Data from: Visual modelling suggests a weak relationship between the evolution of ultraviolet vision and plumage colouration in birds

Data files

Feb 02, 2015 version files 2.37 MB

Abstract

Birds have sophisticated colour vision mediated by four cones types that cover a wide visual spectrum including ultraviolet (UV) wavelengths. Many birds have modest UV-sensitivity provided by violet-sensitive (VS) cones with sensitivity maxima between 400-425 nm. However, some birds have evolved higher UV-sensitivity and a larger visual spectrum given by UV-sensitive (UVS) cones maximally sensitive at 360-370 nm. The reasons for VS-UVS transitions and their relationship to visual ecology remain unclear. It has been hypothesized that the evolution of UVS-cone vision is linked to plumage colours so that visual sensitivity and feather colouration are “matched”. This leads to the specific prediction that UVS-cone vision enhance the discrimination of plumage colours of UVS-birds while such an advantage is absent or less pronounced for VS-bird colouration. We test this hypothesis using knowledge of the complex distribution of UVS-cones among birds combined with mathematical modelling of colour discrimination during different viewing conditions. We find no support for the hypothesis, which, combined with previous studies suggests only a weak relationship between UVS-cone vision and plumage colour evolution. Instead we suggest that UVS-cone vision generally favours colour discrimination, which creates a non-specific selection pressure for the evolution of UVS-cones.