High resolution of colour vision, but low contrast sensitivity in a diurnal raptor.

ABSTRACT: Animals are thought to use achromatic signals to detect small (or distant) objects and chromatic signals for large (or nearby) objects. While the spatial resolution of the achromatic channel has been widely studied, the spatial resolution of the chromatic channel has rarely been estimated. Using an operant conditioning method, we determined (i) the achromatic contrast sensitivity function and (ii) the spatial resolution of the chromatic channel of a diurnal raptor, the Harris's hawk Parabuteo unicinctus The maximal spatial resolution for achromatic gratings was 62.3 c deg-1, but the contrast sensitivity was relatively low (10.8-12.7). The spatial resolution for isoluminant red-green gratings was 21.6 c deg-1-lower than that of the achromatic channel, but the highest found in the animal kin

SUBMITTER: Potier S 

PROVIDER: S-EPMC6125913 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature