COGNITIVE ASPECTS OF FORAGING IN JAPANESE MONKEYS

The reaction of free-ranging Japanese macaques, Macaca fuscata, after finding a piece of experimentally introduced, native akebi fruit is very different from that after finding other, equally preferred foods such as chocolate or non-native banana. Their behaviour suggests extrapolation of a search beyond an initial food item, matching of search routines to particular kinds of food, long-term memory and one-trial learning of new food sites. These abilities might help to explain why Japanese macaques can maintain an exceptionally broad diet and why they can use new food sources, find last year's acorns under leaf piles, and adjust to seasonal changes in the availability of food. Learning and memory capabilities have frequently been postulated by other primate field researchers, and this report provides an experimental demonstration of the operation of learning and memory capabilities in monkeys under natural conditions. © 1991.