Effect of colour vision status on insect prey capture efficiency of captive and wild tamarins (Saguinus spp.)

The colour vision polymorphism of most New World primates is a model system to study the function of colour vision. Theories for the evolution of primate trichromacy focus on the efficient detection and selection of ripe fruits and young leaves amongst mature leaves, when trichromats are likely to be better than dichromats. We provide data on whether colour vision status affects insect capture in primates. Trichromatic tamarins (Saguinus spp.) catch more prey than dichromats, but dichromats catch a greater proportion of camouflaged prey than trichromats. The prey caught does not differ in size between the two visual phenotypes. Thus two factors may contribute to the maintenance of genetic polymorphism of middle- to long-wavelength photopigments in Platyrrhines: the advantage in finding fruit and leaves, which supports the maintenance of the polymorphism through a heterozygote advantage, and the dichromats’ exploitation of different (e.g., camouflaged) food, which results in frequency-dependent selection on the different colour vision phenotypes.