Spontaneous metatool use by New Caledonian crows

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.     

Animal cognition: rooks team up to solve a problem

A recent study has found that rooks team up to get food in a cooperative instrumental task, but they may have difficulties in understanding when cooperation is necessary and how it works.     

Individual and social factors affecting the ability of American crows to solve and master a string pulling task

Crows and other birds in the family Corvidae regularly share information to learn the identity and whereabouts of dangerous predators, but can they use social learning to solve a novel task for a food reward? Here, we examined the factors affecting the ability of 27 wild-caught American crows to solve a common string pulling task in a laboratory setting. We split crows into two groups; one group was given the task after repeatedly observing a conspecific model the solution and the other solved in the absence of conspecific models. We recorded the crows’ estimated age, sex, size, body condition, level of nervousness, and brain volume using DICOM images from a CT scan. Although none of these variables were statistically significant, crows without a conspecific model and large brain volumes consistently mastered the task in the minimum number of days, whereas those with conspecific models and smaller brain volumes required varying and sometimes a substantial number of days to master the task. We found indirect evidence that body condition might also be important for motivating crows to solve the task. Crows with conspecific models were no more likely to initially solve the task than those working the puzzle without social information, but those that mastered the task usually copied the method most frequently demonstrated by their knowledgeable neighbors. These findings suggest that brain volume and possibly body condition may be factors in learning new tasks and that crows can use social learning to refine their ability to obtain a novel food source, although they must initially learn to access it themselves.     

Animal cognition: monkey meteorology

Mangabey monkeys have been shown to rely on memory of recent trends in temperature and solar radiation to decide whether to feed on a particular patch of fruit. These observations reveal a rich mental representation of the physical environment in monkeys and suggest foraging may have been an important selective pressure in primate cognitive evolution.     

Complex cognition and behavioural innovation in New Caledonian crows

Apes, corvids and parrots all show high rates of behavioural innovation in the wild. However, it is unclear whether this innovative behaviour is underpinned by cognition more complex than simple learning mechanisms. To investigate this question we presented New Caledonian crows with a novel three-stage metatool problem. The task involved three distinct stages: (i) obtaining a short stick by pulling up a string, (ii) using the short stick as a metatool to extract a long stick from a toolbox, and finally (iii) using the long stick to extract food from a hole. Crows with previous experience of the behaviours in stages 1–3 linked them into a novel sequence to solve the problem on the first trial. Crows with experience of only using string and tools to access food also successfully solved the problem. This innovative use of established behaviours in novel contexts was not based on resurgence, chaining and conditional reinforcement. Instead, the performance was consistent with the transfer of an abstract, causal rule: ‘out-of-reach objects can be accessed using a tool’. This suggests that high innovation rates in the wild may reflect complex cognitive abilities that supplement basic learning mechanisms.     

Animal cognition: 1900-2000

During the 20th century there has been considerable progress in the study of animal cognition, based on essential ideas that were developed earlier. These essential ideas include the metaphors of the animal, the questions, the sources of hypotheses, and the types of explanations. The progress cannot be generally characterized as continuous improvement, cyclic changes, or discrete steps, but the quality of the empirical results has increased substantially since the first experiments in the field. Improvements in research methods have been primarily responsible for this progress. These have included improvements in animal husbandry, stimulus control, apparatus design, the measurement of behavior, experimental procedures, and data analysis. In the last third of the century the computer has led to major improvements in all stages of the research process in animal cognition. Although they have greatly improved the quality of the empirical results, they have not led to a general theory of animal cognition. In the near future the available research methods are likely to lead to further progress in the developments of quantitative theories of animal cognition.     

Animal cognition: know your enemy

Food-storing corvids are able to remember which individual saw them store food, and take preventive action that is tailored to that particular competitor's knowledge. This raises the question of whether abilities like 'theory of mind' have arisen independently more than once in evolution.     

Animal cognition: bring me my spear

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.     

Animal cognition: monkey looks contradict Hume

Wild rhesus monkeys have been found to attend to causal anomalies, suggesting that they make inferences about possible and impossible physical transformations in the absence of direct relevant experience.     

Animal cognition: concepts from apes to bees

New research shows that honeybees can classify arrangements of two visual patterns according to their spatial configuration. Can bees learn relational concepts of 'above' and 'below'? And are the underlying psychological processes comparable in humans and other primates facing similar tasks?     

Animal cognition: great apes wait for grapes

Humans may be patient when it comes to money, but chimpanzees are willing to wait longer than humans for food, suggesting patience is neither innate nor uniquely human.     

Animal cognition: monkeys recall previously seen images

A recent study has found that rhesus macaques can recall newly presented shapes: this demonstration of recall in non-human primates suggests that some animals have recollection processes similar to those of humans.     

Animal cognition: multimodal tactics of orangutan communication

Orangutans select different tactics for repairing failed communication, depending upon how well they are understood: they repeat signals if they are partially understood and switch tactics entirely if completely misunderstood.     

Female zebra finches prefer the songs of males who quickly solve a novel foraging task to the songs of males unable to solve the task

Correlative evidence suggests that high problem‐solving and foraging abilities in a mate are associated with direct fitness advantages, so it would benefit females to prefer problem‐solving males. Recent work has also shown that females of several bird species who directly observe males prefer those that can solve a novel foraging task over those that cannot. In addition to or instead of direct observation of cognitive skills, many species utilize assessment signals when choosing a mate. Here, we test whether females can select a problem‐solving male over a non‐solving male when presented only with a signal known to be used in mate assessment: song. Using an operant conditioning assay, we compared female zebra finch (Taeniopygia guttata) preference for the songs of males that could quickly solve a novel foraging task to the songs of males that could not solve the task. Females were never housed with the test subject males whose song they heard, and the only information provided about the males was their song. We found that females elicited more songs of problem‐solving males than of non‐solvers, indicating that song may contain information about a male’s ability to solve a novel foraging task and that naïve females prefer the songs of problem‐solving males.     

Animal cognition: time flies when chimps are having fun

Chimpanzees, like children, actively distract themselves to cope with waiting for a desired but delayed reward. Self-control may thus be a capacity we share with our nonhuman primate relatives.     

Learning to solve a spatial task in a water maze in aggressive and submissive mice

Learning and retention of the spatial memory were studied in mice with alternative under conditions of various experimental protocols. Visible and hidden platform acquisition in a simple model of the water maze was similarly fast both in aggressive and submissive mice, but extinction differed. Retention of the platform location preference persisted in aggressive mice in four testing trials. In submissive mice, extiction of the spatial memory was accompanied with a prolongation of search with parallel production of episodes of "passive drift". Differences in spatial learning between aggressive and submissive mice were revealed in a water maze complicated with partitions. In this case, aggressors were able to learn the position of a hidden platform (in contrast to submissive mice with the dominant response of "passive drift"). During testing the response, aggressive mice longer retained the spatial preference without extinction.     

Raising the level: orangutans solve the floating peanut task without visual feedback

Primates - Chimpanzees and orangutans are able to generate innovative behaviors to solve complicated physical problems. For example, when presented with an out-of-reach peanut at the bottom of a...     

Animal cognition: chimpanzee alarm calls depend on what others know

After a wild chimpanzee encounters a model of a dangerous snake, whether or not he gives an alarm call depends on his perception of another individual's knowledge.