Behavioural evidence for marsupial trichromacy

Abstract

The ability to discriminate red–green colours was thought to be unique among mammals to trichromatic primates [1,2], until recent microspectrophotometric studies revealed that marsupials also have the potential for trichromatic colour vision [3,4]. Functional colour vision cannot be inferred from physiological studies alone [5–8], however, a point of particular importance in this case as molecular analyses have failed to identify the third marsupial cone photoreceptor type [9]. Here we report that an Australian marsupial, the fat-tailed dunnart (Sminthopsis crassicaudata), has trichromatic colour vision that encompasses ultraviolet sensitivity.