Thresholds and noise limitations of colour vision in dim light

Bird colour vision: behavioural thresholds reveal receptor noise.

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 reflecting object colours that they encounter in nature. With behavioural experiments, we determined colour discrimination thresholds of chickens in bright and dim light. We performed the experiments with two colour...

Vision in dim light: highlights and challenges.

On amoonless night or in the depths of the sea, where light levels aremany orders of magnitude dimmer than sunlight, animals rely on their visual systems to orient andnavigate, to find foodandmates and toavoidpredators. To seewell at such low light levels is far from trivial. The paucity of light means that visual signals generated in the light-sensitive photoreceptors of the retina can easily ...

Colour Vision in Birds Comparing behavioural thresholds and model predictions

Evolution of dim-light and color vision pigments.

A striking level of diversity of visual systems in different species reflects their adaptive responses to various light environments. To study the adaptive evolution of visual systems, we need to understand how visual pigments, the light-sensitive molecules, have tuned their wavelengths of light absorption. The molecular basis of spectral tuning in visual pigments, a central unsolved problem in...

Neural adaptations for dim light vision in hawkmoths