Evidence for color vision in procyonides: Comparison between diurnal coatis (Nasua) and nocturnal kinkajous (Potos flavus)

The color-vision capacity of two species of procyonides was analyzed using a binary simultaneous discrimination paradigm. To make hue the only salient cue, the color sets of red, yellow, green, and blue were each presented in five different saturation intervals and were tested against a variety of brightness steps. Unlike the nocturnal kinkajous, the diurnal coatis showed highly significant discriminative performance on the color problems, especially in tests on blue and yellow, yet failed to differentiate unsaturated green from achromatic stimuli. The results are discussed with respect to procedural variables and the utility of color discrimination in the coati’s natural environment.