Tonkean Macaques Orient Their Food Search From Olfactory Cues Conveyed by Conspecifics

Abstract

We investigated the ability of monkeys to use referential information about environmental resources from cues passively transmitted by conspecifics. The subjects and their companions were four young males belonging to a group of semifree-ranging Tonkean macaques (Macaca tonkeana) raised in a 2-acre wooded park. In a first experiment, a subject had to orient its search strategy from the information obtained from a conspecific. It first had to smell the mouth of a companion having just eaten a food item, and then search for same quality food in the field. The results showed that subjects adjusted their foraging speed according to the value of the reward to be found. They were able to recognize the food resource on the basis of the item previously eaten by their companion. In a second experiment, we asked whether the subjects could anticipate a given food quantity from smelling a companion associated with that given food quantity. When testing whether subjects oriented their search strategy on the basis of companion's identity, they did not appear to use it as a referential cue to food quantity. They nonetheless adapted their foraging speed according to food value. Both experiments indicated that macaques are liable to assess and select food from information extracted from conspecifics, and hence avoid some costs associated with individual food searching.

Neophobia and Learning Mechanisms: How Captive Orangutans Discover Medicinal Plants

“…Indeed the majority of fresh plants sniffed at were not ingested by orangutans. Olfaction is the first response to novel food in infant chimpanzees [Ueno and Matsuzawa, 2005], and it has been proved to be essential to obtain foodrelated information in Tonkean macaques [Chauvin and Thierry, 2005]. Among the plants not sniffed at by the orangutans were garlic mustard and bear's garlic, which have a strong garlic odour.…”

Foraging Cognition in Nonhuman Primates

“…Moreover, although food competition is likely to increase with group size, larger groups also benefit from increased search swath and accumulated knowledge of individuals to locate food sources, avoid predators, and deal with neighboring groups (Garber & Boinski, 2000;Janson & Di Bitetti, 1997). Individuals are especially likely to benefit from older and more knowledgeable group members during periods of food scarcity when long-term experience is more crucial (Byrne, 1995;Chauvin & Thierry, 2005;van Roosmalen, 1988). The social intelligence hypothesis also struggles to explain how exactly primates were able to grow expensive large brains in the first place.…”

“…In free-ranging tamarins (Saguinus imperator and S. fuscicollis), high-ranking individuals tended to monitor the activities of other group members, rather than to initiate their own food searches, providing evidence that these primates were able to associate social cues with the presence of foods (Bicca-Marques & Garber, 2005). Similarly, Tonkean macaques, Macaca tonkeana, kept in a large outdoor enclosure used food odor cues, acquired by smelling the mouths of other group members, to guide their own search for food (Chauvin & Thierry, 2005).…”

The neglected sense–olfaction in primate behavior, ecology, and evolution

“…Since Laska and coworkers have shown that several primate species are highly sensitive to ecologically relevant olfactory stimuli, and many primates are known to sniff at potential food, studying the role of olfaction in primate ecology will bring new insights into the mechanisms of food choice and optimal foraging. Olfaction, in combination with touch, may provide more relevant cues for food quality (e.g., ripeness of fruits) than color [Dominy, 2004], and may play an important role in food learning [Chauvin & Thierry, 2005]. As with the accessory olfactory system, a better understanding of the morphological and genetic basis and physiological mechanisms of the main olfactory system will be needed before we can fully appreciate its role in primate ecology.…”