Ontogeny of food-associated calls in cotton-top tamarins

Abstract

Abstract. Adult cotton-top tamarins, Saguinus oedipus oedipus, use two chirps (C and D) almost exclusively in food contexts. The rate of calling in food contexts correlates positively with the food preference ranking of tested foods. The ontogeny of the production and usage of these food-associated calls was investigated in captive tamarins. Food preferences of 14 tamarins (4-29 months old) were determined, and their vocalizations were recorded in the presence of six foods, two non-food manipulable objects, an empty food bowl and a control condition. Across all ages, juvenile and subadult tamarins produced adult-like C- and D-chirps; however, 50% of food-associated calls, on average, were not structured like those of adults. Juveniles and subadults produced significantly more adult-like food-associated calls to non-food manipulable objects than in the control condition and used many other types of vocalizations in food contexts. Juvenile and subadult calling rate did not correlate with food preference in any age-related pattern. All juvenile and subadult tamarins showed different patterns of usage than reproductive adults. The feeding behaviour of juveniles and subadults is more highly competitive than that of adults, a difference which may partially explain the results found. Acting immaturely, regardless of age, may be beneficial for juveniles and subadults, enabling them to stay in the group and not be perceived as a threat by the breeding pair.