Illumination varies greatly both across parts of a natural scene and as a function of time,
whereas the spectral reflectance function of surfaces remains more stable and is of much …

Birds are assumed to use half of their cones (double cones) to detect fine spatial detail while
their other half (single cones) is used for color vision. However, the spatial resolution of the …

Today, there is good knowledge of the physiological basis of bird colour vision and how
mathematical models can be used to predict visual thresholds. However, we still know only …

Of all the vertebrate classes, birds are the most visual dependent. Many aspects of their
adaptation to their environment and their survival depend on precise and sometimes quite …

Bird colour vision is mediated by single cones, while double cones and rods mediate
luminance vision in bright and dim light, respectively. In daylight conditions, birds use colour …

Birds have impressive physiological adaptations for colour vision, including tetrachromacy
and coloured oil droplets, yet it is not clear exactly how well birds can discriminate the …

The color vision of Old World primates and humans uses two cone-opponent systems; one
differences the outputs of L and M cones forming a red–green (RG) system, and the other …

The evolutionary relationship between signals and animal senses has broad significance,
with potential consequences for speciation, and for the efficacy and honesty of biological …

Researchers must assess similarities and differences in colour from an animal's eye view
when investigating hypotheses in ecology, evolution and behaviour. Nervous systems …

It is well known that development of vision is affected by experience, but there are few
studies of environmental effects on colour vision. Natural scenes contain predominantly a …