<p>Frugivory is frequently related to morphological and chemical attributes of fruits, which vary among individuals and species. American primates vary in fruit finding ability owing to sexual dimorphism in visual systems; females are either di- or trichromatic, whereas males are dichromatic. Foraging experience also influences fruit finding across developmental stages. We monitored a <i>Sapajus xanthosternos</i> group for 9 months, collecting data on fruit foraging behavior to assess how sex and age-class influenced their discovery of fruit plants. We hypothesized that sex differences in vision system and nutritional requirements lead to females finding a greater proportion of fruits with warm colors and a more diverse set of plants and fruit traits than males, while males find more fruits with achromatic cues (larger and/or clustered) than do females. We further hypothesized that their greater foraging experience allows adults and subadults to find fruits with higher nutrient content than do juveniles and infants. We found no sex differences in the visual attributes of fruit found, nor in the set of species found, but females encountered a more heterogeneous combination of fruit traits than males. All age-classes visited lipid-rich species frequently. Subgroups composed only of infants and juveniles encountered more protein- and carbohydrate-rich species than subgroups that included adults. Although limited, the sex differences suggest that different vision systems and nutrient demands affect fruit discovery. The higher protein- and carbohydrate content in fruits found by groups of infants and juveniles may compensate for their limited access to animal protein and meet the high energy demands of inexperienced individuals.</p>