Colour cues for leaf food selection by long-tailed macaques (Macaca fascicularis) with a new suggestion for the evolution of trichromatic colour vision

摘要: Leaf colour, size and toughness were investigated in five plant species important the diet of Macaca fascicularis Singapore. colour examined as potential visual cues for food selection, whereas mirrored fibre content, inverse quality. As leaves matured, they changed toughened. lightness yellowness strongly negatively correlated with toughness, but variation both red-green axis CIE Lab space leaf not. Leaves selected by macaques distinguished being very light, yellow to slightly green. Some dappled red. The literature suggests that these are relatively rich protein without tough therefore would be sought after primates. We argue is an indicator nutritive value leaves. Trichromatic vision advantage finding those palatable These appear dark dichromatic primates deceptive making look older (lower quality) than actually are. This decrease perceived window feeding opportunity such who at a disadvantage trying find It possible trichromatic catarrhine may have originally evolved detection red coloration shade-tolerant tropical plants, enabling better exploitation resource.