主催: Primate Society of Japan
開催日: 2018/07/13 - 2018/07/15
Through their senses, animals sample information from the external environment to detect and assess foods. Studying the sensory behaviors of frugivores provides insight into the interactions between plants and animals, and promotes understanding of evolutionary processes shaping sensory systems. It is well known that fruit traits—including color, size, odor, and softness—often change during the ripening process. However, there is a dearth of data on whether changes in each of these modalities are equally reliable in revealing shifts in fruit nutritional value, and which types of information animals use to guide their foraging strategies. Here, we integrate behavioral observations from a 12-month study of white-faced capuchins (Cebus imitator) with visual (size, shape, color) olfactory (volatile organic compounds—VOCs), haptic (elastic modulus), and nutritional data from 14 species of fruits sampled across ripeness stages. We find: 1) variation among plant species in how well changes in fruit softness, color, size, and odor correlate with nutritional changes; 2) that primate behavior maps predictably onto this variation; 3) that color and size are typically the least reliable cues of ripeness. These results help explain why primates also sniff and squeeze fruits that change color as they ripen, the smaller than expected difference in foraging efficiency between “colorblind” and “color-normal” monkeys, and highlight a role for color in long-distance signaling by plants to attract foraging animals. This study contributes to knowledge about the foraging cues available to primates and other frugivores, and how multiple sensory modalities are integrated to inform food selection.