Colour vision in fallow deer: a behavioural study

To examine whether fallow deer, Dama dama, have colour vision, we trained f our adult females on a two-choice discrimination task, where a positive chr omatic stimulus (green) and a negative achromatic stimulus (grey) had simil ar brightness. The criterion for learning was set at 80% correct responses. To exclude the possibility that the hinds used small differences in bright ness to distinguish between the green and the grey stimulus, we conducted a test that differed from the training situation. A light green positive sti mulus combined with a dark grey negative stimulus was alternated with a dar k green positive stimulus combined with a light grey negative stimulus on e very second trial. The positive green stimuli had different reflectance spe ctra. After training, each of the four hinds showed over 80% correct respon ses in the test. These results suggest that fallow deer can use colour visi on in a discrimination situation by generalizing over slightly different co lours, at least in the range of the green spectrum. (C) 2001 The Associatio n for the Study of Animal Behaviour.