Food Neophobia and Social Learning Opportunities in Great Apes

Animal Behaviour, 2000

Animal Cognition, 2001

Learning about food palatability from watching what conspecifics eat might be one of the advantages of group living. A previous study investigated whether group members' presence or eating activity account for social facilitation of eating of foods never previously tasted. Capuchins encountered novel colored foods when (1) alone (Alone condition) or (2) with group members visible in the nearby cage (Group-present condition) or (3) with group members present and eating a familiar food that had not been colored (Group+food condition). Social facilitation of eating occurred when group members were eating, despite the difference in color between the familiar food eaten by them and the novel food presented to the experimental subject. To clarify what subjects learnt from group members when social facilitation occurred, we further analyze here the data from the previous study. The number of visual exposures to the colored novel food (as a group member) correlated with increased consumption of that novel food when encountered later (as experimental subject). In contrast, the number of times that an individual fed on the familiar food (as a group member) did not decrease its consumption of novel food (as experimental subject). Therefore, capuchins (1) habituated to the colors of the novel foods, and (2) did not take into account that seeing group members eating a food does not provide information about the palatability of a differently colored food. Since social facilitation of eating occurs when foods do not match in color, at least in capuchins, social facilitation of eating should not be considered as a way of learning about a safe diet, but rather as a way of overcoming neophobia.

American Journal of Primatology, 1998

Animal Behaviour, 1995

Social influences affect individual responsiveness to key features of the environment, such as food. Galef (1993, Anim. Behav., 46, 257-265) has predicted that social facilitation should affect food choice more powerfully when the food is novel than when it is familiar. This prediction was tested in monkeys. Eleven capuchin monkeys were tested individually (Individual condition) and in a group (Social condition) with eight familiar foods presented simultaneously (experiment 1). In experiment 2, the same subjects received 20 novel and four familiar foods presented singly in Individual or in Social testing conditions. More food was expected to be eaten in the Social condition than in the Individual condition, particularly when food was novel. In experiment 1, testing condition (Individual or Social) did not affect consumption of familiar foods. In experiment 2, capuchins ate more familiar foods than novel foods in both conditions. However, they were more interested in another individual's food when foods were novel than when they were familiar. Consumption of, and responses to, the novel foods were more frequent in social testing than in individual testing; testing conditions did not affect consumption of, or response to, the familiar foods. Nine of 10 individuals ate more types of novel foods in the Social condition than in the Individual condition. In short, social facilitation of eating was evident, but only with novel foods. These findings support Galef's prediction and suggest that social facilitation can have a role in enlarging dietary selection in capuchins.

Zoo Biology, 2002

Hesitancy to eat novel foods hampers the immediate enlargement of the diet but serves to limit the risk of ingesting toxic foods. Neophobia has been systematically investigated in only a few primate species, in which it appears to be affected by social influences. Surprisingly, little is known about neophobia in chimpanzees. We studied the response of eight adult captive chimpanzees to 16 foods (foods commonly eaten by humans and never tasted before by chimpanzees). Each novel food was presented twice to the chimpanzee by a familiar or an unfamiliar human. Between the two trials the human ate the food face to face with the chimpanzee (demonstration). Results showed that some foods were almost unanimously accepted, whereas others were not. Moreover, there were marked interindividual differences in food acceptance and consumption; chimpanzees ranged from being almost completely neophobic to accepting almost all foods. Familiarity with the human and the human's demonstration did not affect responses to the foods. The humans' predictions concerning the chimpanzees' acceptance of the different foods were rather good; furthermore, in seven cases out of eight the humans' preferences did not correlate with their predictions on the chimpanzees' preferences. The finding that most captive chimpanzees are initially cautious toward novel foods supports the little information there is regarding this subject in wild chimpanzees. However, the lack of influence of the humans' familiarity and demonstration on the response to food by the chimpanzees calls for more naturalistic studies, in which social influences are provided by group members. Since novel stimuli provide sensory stimulation and elicit exploration and social interest, occasional presentation of novel foods could be a promising and cheap device for feeding enrichment. Zoo

Animal Behaviour, 2017

Ethology, 2015

/full. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Food acceptance and social learning opportunities in semi-free eastern chimpanzees (Pan troglodytes schweinfurthii)

American Journal of Primatology, 2007

Neophobia, defined as showing caution toward novel features of the environment, is widespread in birds and mammals; it can be affected by ecology, early experience, and social context. In this study, we aimed to (i) investigate the response to novel food in adult common marmosets and Goeldi's monkeys and (ii) assess the role of social influences. We used an experimental paradigm employed previously with capuchin monkeys and children, in which a subject (observer) was presented with a novel food under three conditions: (i) Presence: group members did not have food; (ii) Different color: group members received familiar food whose color differed from that of the observer's novel food; (iii) Same color: group members received familiar food of the same color as the observer's novel food. Although most common marmosets tasted and/or ate the novel food, none of the Goeldi's monkeys ate it and only two sampled it. Differences in home range size and early social experience might explain the divergent behavior of the two species. Observers of both species similarly attended to group members and their visual attention increased with the number of group members eating, especially when the observer's and group members' foods were perceptually similar. However, we observed social influences on explorative behavior in Goeldi's monkeys but not on explorative or eating behavior in common marmosets. This result might be explained by the different pattern of response to novel food observed in the two species. Moreover, social influences on Goeldi's monkeys' behavior were nonspecific, i.e. they were not based on an appreciation that the food is safe because eaten by group members. Am. J. Primatol. 69:1210–1222, 2007. © 2007 Wiley-Liss, Inc.

Primates, 2014

Hundreds of rehabilitant great apes have been released into the wild, and thousands await release. However, survival rates after release can be as low as 20 %. Several factors influence individuals' survival rates, one of which is the capacity to obtain an adequate diet once released. Released individuals are faced with a mixture of familiar and novel foods in an unfamiliar forest; therefore, it is important to understand how they increase acceptance and consumption of novel foods. This is especially vital for omnivorous species, such as wild great apes, which consume several hundred species of different foods. We assessed the effects of repeated exposures and sociality (i.e. co-feeding in the presence of one or more other individuals) on the acceptance and consumption of novel foods by captive orangutans (Pongo sp). Repeated exposures of food (novel, at first) did not cause an increase of acceptance of food; in other words, the orangutans did not start to eat a food item after being exposed to that food more often, but repeated exposures of food increased consumption (i.e. quantity). After repeated exposures, the orangutans also became gradually more familiar with the food, decreasing their explorative behaviour. The presence of co-feeding conspecifics resulted in an increased acceptance of the novel food by orangutans, and they ate a larger amount of said foods than when alone. Repeated exposure and sociality may benefit rehabilitant great apes in augmenting and diversifying diet and, once practiced before release, may accelerate an individuals' adaptation to their new habitat, improving survival chances. Great ape rescue, rehabilitation and reintroduction require large financial and logistic investments; however, their effectiveness may be improved at low cost and low effort through the suggested measures.

Ethology, 2015

/full. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Food acceptance and social learning opportunities in semi-free eastern chimpanzees (Pan troglodytes schweinfurthii)