Color discrimination in Caspian pony

Although an early and influential review led to the often-cited conclusion that color visionis rare among mammals, more recent findings suggest that it is actually widespread. Accordingto Jacobs, all non-nocturnal mammalian species that have been adequately examined showsome color vision capacity, although the degree varies enormously. Data on the presence andcharacteristics of color vision in the horse, however, remain sparse and none in the case of ponies.Eight Caspian ponies were presented with a series of two-choice color vs. grey discriminationproblems. One mare pony was eliminated due to traumatic injury to the eye. Experiments wereperformed in a box of 3 × 3 meter containing a wall with two translucent panels that wereilluminated from behind by light projected through color or grey filters to provide thediscriminative stimuli. Ponies were first adopted to the stall (box) with two panels in it and thenlearned to push one of the panels in order to receive the food rewards behind the positive stimuliin an achromatic light-dark discrimination task. The ponies were then tested on their ability todiscriminate between grey and four individual colors: red; 617 nm., yellow; 581 nm., green; 538nm. and blue; 470 nm. The criterion for learning was set at 85% correct response, and finaltesting for all color vs. grey discrimination involved grey of varying intensities, makingbrightness an irrelevant cue. The ponies were tested with all four colors vs. grey discriminations.Except two ponies, the rest were successfully reached the criterion for learning blue color vs.grey discrimination. Only two ponies reached the criterion for learning green color vs. greydiscrimination. Only tow ponies reached the criterion for discriminating red and yellow vs. grey.So the answer to the question "do the ponies see color" is yes, they can discriminate between thefour selected color vs. grey.

Keywords:

color , discrimination , Caspian , pony