Tufted capuchin monkeys (Cebus apella) spontaneously use visual but not acoustic information to find hidden food items.

Foraging choices in tufted capuchins monkeys are guided by perceptual, cognitive, and motivational factors, but little is known about how these factors might interact. The present study investigates how different types of sensory information affect capuchins' ability to locate hidden food. In two experiments, capuchins were presented with two cups, one baited and one empty. Monkeys were given visual, acoustic, or acoustic-visual information related to the baited cup, the empty cup, or both baited and empty cup. Results show that capuchins spontaneously used visual information to locate food, and that information indicating presence and absence of food led to higher success rates than information indicating only absence of food. In contrast, acoustic information did not lead to success rates above chance levels and failed to enhance performance in combination with visual information. Capuchins spontaneously avoided a visually empty cup, but they did not appear to associate sounds with either the presence or absence of food. Being able to locate food items with the aid of acoustic cues might be a learned process that requires interactive experiences with the task's contingencies.