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Wild bearded capuchins (Cebus libidinosus, quadrupedal, medium-sized monkeys) crack nuts using large stones. We examined the kinematics and energetics of the nut-cracking action of two adult males and two adult females. From a bipedal stance, the monkeys raised a heavy hammer stone (1.46 and 1.32 kg, from 33 to 77% of their body weight) to an average height of 0.33 m, 60% of body length. Then, they rapidly lowered the stone by flexing the lower extremities and the trunk until the stone contacted the nut. A hit consisting of an upward phase and a downward phase averaged 0.74 s in duration. The upward phase lasted 69% of hit duration. All subjects added discernable energy to the stone in the downward phase. The monkeys exhibited individualized kinematic strategies, similar to those of human weight lifters. Capuchins illustrate that human-like bipedal stance and large body size are unnecessary to break tough objects from a bipedal position. The phenomenon of bipedal nut-cracking by capuchins provides a new comparative reference point for discussions of percussive tool use and bipedality in primates. KEY WORDS tool use; percussion; upright stance; nonhuman primate

Data from the first systematic study of stone handling (SH) behavior in a captive troop of Japanese Macaques that were known to exhibit the behavior is presented. Age-related differences in SH performance and behavioral patterns were seen showing possible differences in the immediate cause and ultimate functions between young and adults.

The surveys of long tailed macaques at Piak Nam Yai Island, Laem Son National Park, Ranong Province, situated in Southern Thailand have observed that they use axe-shaped stones to crack rock oysters, detached gastropods, bivalves, and swimming crabs. The tool usage by Thai long-tailed macaques that crack rock oysters with stones could be characterized as level 1, and that cracking drifting mollusks and crabs with stones by placing them on rock could be characterized as level 2.

Chimpanzees and capuchins demonstrate greater varieties and higher rates of tool-use when compared to other non-human primates. Although capuchins have been studied extensively in captivity, data on their tool-using behavior under free-ranging conditions are limited. This is the first long-term field research to systematically study complex object manipulation in capuchins. The aims of this research are 1) to examine the types, rates, and contexts of tool- and object-use in free-ranging capuchins and 2) to determine if free-ranging capuchins' object manipulation behavior is comparable to the behavior exhibited by captive individuals. Data on 3 troops of white-faced capuchins (Cebus capucinus) were collected from February 1995 to January 1996 at Palo Verde, Costa Rica. Data were collected using focal animal and ad libitum sampling techniques. Any observed incident of tool-use and object-use was recorded. No tool-use was observed during the 11-month study. Object-use (pound, rub, and fulcrum-use) occurred at a rate of 0.19/hr and made up less than 1% of the monkeys' time (there were no differences among the age/sex classes). The results indicate that free-ranging capuchins do not exhibit the range of tool-using behavior demonstrated by their captive counterparts. This may be the result of differential motivational responses to objects, arboreal lifestyle, absence of adequate tool material, and/or absence of food resources that require extraction involving tool-use. KEY WORDS primates; tool-use; object manipulation; extractive foraging

Several studies are conducted to determine size, weight, structure and other physical properties of the palm fruits that are processed with tools by wild bearded capuchins (Cebus libidinosus) living in Boa Vista. The peak-force-at-failure of these trees is shown to be positively related to greater weight and structural complexity.

The article explains the invention and modification of the 'ant-fishing' behavior, which is used as a tool use behavior by the wild chimpanzees at Bossou, Guinea. The accumulation of the behavior at the site is also studied.

The observation from 3-year ecological study on Cross River gorillas at the Kagwene Mountain in Cameroon about three cases of tool use is reported. The observations were identified as a unique behavior in the gorillas learned through interactions with humans and as a response to particular local conditions.

An experiment is conducted to examine the effect of substrate on the nut-cracking behavior of a group of semicaptive capuchin monkeys (Cebus apella). The results have shown that adult capuchins chose the hardest substrates, and that these substrates have supported efficient cracking.

The first observation of tool use by the chimpanzees of the Ngogo, community of Kibale National Park, Ugana, in insect foraging is reported. The importance of this observation, and the behavioral similarities with chimpanzees from other sites is discussed.

A detailed description of the different types of chimpanzee tools is provided found during a 7-month survey of the Ngotto Forest to the south of the village of Grima and the tools with types found at other sites were compared. It was expected that the chimpanzees would construct stick tools of different lengths depending on whether they were using them for honey-probing or ant-dipping.

Brown capuchins (Cebus apella) at Raleighvallen Nature Preserve in Suriname have recently been discovered to exhibit object manipulation abilities in foraging, specifically frequent substrate use and a remarkable episode of tool use. The food items being processed with these exceptional skills are numerous species of morphologically diverse, thickly husked fruits, with fruit walls impenetrable even to the powerful jaws of C. apella. These fruit taxa, many in the Lecythidaceae, the Brazil nut family, are rare in Western Amazonia and Central America, regions in which capuchins have been most often studied. Based on extensive qualitative observations, we provide a preliminary description of this phenomenon within a natural history perspective. The manipulative skills of brown capuchins in Suriname are poised to upheave current understandings of tool use and object manipulation in capuchins. Moreover, the implications of these findings for the cognitive evolution of human and nonhuman primates are significant. The capacity to use tools is considered one of the major achievements of our species and figures deeply in explanations for the origin of human intelligence and behavior. Many hold that tool and object manipulation, language, social skills, and morphology are linked in primate evolution. Given that unusually complex social and communication skills are not evident in capuchins, the proposed connection between the evolution of tool use, language, and social skills in human evolution is thereby weakened. Instead, our observations in Suriname support a paradigm premised on the concept of functionally and evolutionarily distinct brain modules. [tool use, evolution of intelligence, cognitive domain, chimpanzees, seed predation]

For comparative purposes, culture can be defined as socially transmitted behavioral innovations. Orangutan tool use has earlier been shown to exhibit critical features of culture: all-or-nothing distribution across sites, stability, and loss across a dispersal barrier. Using the Whiten et al. (1999, Nature 399: 682) heuristic criteria for recognizing culture from geographic distributions of behavioral variants, the orangutan research community has so far recognized 24 putative cultural elements. Hence, orangutans have similar cultural variation to that found in chimpanzees, implying that the capacity for great-ape cultures, including material culture, is at least 14 My old. In addition, we could use these data to test for the existence of properties of cultural systems, as in humans, and these tests were successful. However, because culture, as defined above, may be more common among animals, we need to distinguish between different kinds of culture, and develop a comparative study of culture that identifies the major evolutionary differences and their underlying mechanistic bases.