Parallel tool industries in New Caledonian crows.
(1/131)
Individual specialization in the use of foraging tools occurs in hunter-gatherer societies but is absent in non-human primate tool use. 'Parallel tool industries' in hunter-gatherers are mainly based on strict sexual division of labour that is highly reliant on social conformity. Here, we show that 12 individuals in a population of New Caledonian crows on Mare Island had strong preferences for either stick tools or pandanus tools. Eight of the 12 crows had exclusive preferences. The individual specialization that we found is probably associated with different foraging niches. However, in spite of sexual size dimorphism there was no significant association between the sex of crows and their tool preferences. Our findings demonstrate that highly organized, strict sexual division of labour is not a necessary prerequisite for the evolution of parallel tool industries. (+info)
Savanna chimpanzees, Pan troglodytes verus, hunt with tools.
(2/131)
Although tool use is known to occur in species ranging from naked mole rats [1] to owls [2], chimpanzees are the most accomplished tool users [3-5]. The modification and use of tools during hunting, however, is still considered to be a uniquely human trait among primates. Here, we report the first account of habitual tool use during vertebrate hunting by nonhumans. At the Fongoli site in Senegal, we observed ten different chimpanzees use tools to hunt prosimian prey in 22 bouts. This includes immature chimpanzees and females, members of age-sex classes not normally characterized by extensive hunting behavior. Chimpanzees made 26 different tools, and we were able to recover and analyze 12 of these. Tool construction entailed up to five steps, including trimming the tool tip to a point. Tools were used in the manner of a spear, rather than a probe or rousing tool. This new information on chimpanzee tool use has important implications for the evolution of tool use and construction for hunting in the earliest hominids, especially given our observations that females and immature chimpanzees exhibited this behavior more frequently than adult males. (+info)
Animal cognition: bring me my spear.
(3/131)
Chimpanzees regularly hunt mammals, but use only their hands and teeth: for the first time, chimpanzees have now been found to make tools in order to spear mammalian prey. (+info)
The active and skilful use of tools has been claimed to lead to the "extension" of the visual receptive fields of single neurons representing peripersonal space--the visual space immediately surrounding one's body parts. While this hypothesis provides an attractive and potentially powerful explanation for one neural basis of tool-use behaviours in human and nonhuman primates, a number of competing hypotheses for the reported behavioural effects of tool-use have not yet been subjected to empirical test. Here, we report five behavioural experiments in healthy human participants (n=120) involving the effects of tool-use on visual-tactile interactions in peripersonal space. Specifically, we address the possibility that the use of only a single tool, which is typical of many neuropsychological studies of tool-use, induces a spatial allocation of attention towards the side where the tool is held. Participants' tactile discrimination responses were more strongly affected by visual stimuli presented on the right side when they held a single tool on the right, compared to visual stimuli presented on the left. When [corrected] two tools were held, one in each hand, this spatial effect disappeared. Our results are incompatible with the hypothesis that tool-use extends peripersonal space, and suggest instead that the use and/or manipulation of [corrected] tools results in an automatic multisensory shift of spatial attention to the side of space where the tip of the tool is actively held. These results have implications for many of the cognitive neuroscientific studies of tool-use published to date. (+info)
Raising the level: orangutans use water as a tool.
(5/131)
We investigated the use of water as a tool by presenting five orangutans (Pongo abelii) with an out-of-reach peanut floating inside a vertical transparent tube. All orangutans collected water from a drinker and spat it inside the tube to get access to the peanut. Subjects required an average of three mouthfuls of water to get the peanut. This solution occurred in the first trial and all subjects continued using this successful strategy in subsequent trials. The latency to retrieve the reward drastically decreased after the first trial. Moreover, the latency between mouthfuls also decreased dramatically from the first mouthful in the first trial to any subsequent ones in the same trial or subsequent trials. Additional control conditions suggested that this response was not due to the mere presence of the tube, to the existence of water inside, or frustration at not getting the reward. The sudden acquisition of the behaviour, the timing of the actions and the differences with the control conditions make this behaviour a likely candidate for insightful problem solving. (+info)
Action-related properties shape object representations in the ventral stream.
(6/131)
The principles driving the organization of the ventral object-processing stream remain unknown. Here, we show that stimulus-specific repetition suppression (RS) in one region of the ventral stream is biased according to motor-relevant properties of objects. Quantitative analysis confirmed that this result was not confounded with similarity in visual shape. A similar pattern of biases in RS according to motor-relevant properties of objects was observed in dorsal stream regions in the left hemisphere. These findings suggest that neural specificity for "tools" in the ventral stream is driven by similarity metrics computed over motor-relevant information represented in dorsal structures. Support for this view is provided by converging results from functional connectivity analyses of the fMRI data and a separate neuropsychological study. More generally, these data suggest that a basic organizing principle giving rise to "category specificity" in the ventral stream may involve similarity metrics computed over information represented elsewhere in the brain. (+info)
Spontaneous metatool use by New Caledonian crows.
(7/131)
A crucial stage in hominin evolution was the development of metatool use -- the ability to use one tool on another [1, 2]. Although the great apes can solve metatool tasks [3, 4], monkeys have been less successful [5-7]. Here we provide experimental evidence that New Caledonian crows can spontaneously solve a demanding metatool task in which a short tool is used to extract a longer tool that can then be used to obtain meat. Six out of the seven crows initially attempted to extract the long tool with the short tool. Four successfully obtained meat on the first trial. The experiments revealed that the crows did not solve the metatool task by trial-and-error learning during the task or through a previously learned rule. The sophisticated physical cognition shown appears to have been based on analogical reasoning. The ability to reason analogically may explain the exceptional tool-manufacturing skills of New Caledonian crows. (+info)
Video cameras on wild birds.
(8/131)
New Caledonian crows (Corvus moneduloides) are renowned for using tools for extractive foraging, but the ecological context of this unusual behavior is largely unknown. We developed miniaturized, animal-borne video cameras to record the undisturbed behavior and foraging ecology of wild, free-ranging crows. Our video recordings enabled an estimate of the species' natural foraging efficiency and revealed that tool use, and choice of tool materials, are more diverse than previously thought. Video tracking has potential for studying the behavior and ecology of many other bird species that are shy or live in inaccessible habitats. (+info)