Abstract: The effect of observational learning on the acquisition of an operant response was examined in eighteen riding horses and ponies. The test horses were randomly divided into three groups of six and individually exposed to one of three treatments. An additional horse was trained as a demonstrator, to perform the operant response. The observer horses watched either the demonstrator performing the bin-opening response (Group D+B); the demonstrator standing passively (Group D); or the operant bin in the absence of the demonstrator (Group B). Observers had access to and were free to interact with an identical bin during testing. Observers in Groups D+B and D were socially familiar with the demonstrator. Each test horse was tested once a day for 10 days. An ANOVA revealed no significant differences between treatment groups in the number of responses or the time taken to reach the learning criterion. However, there were highly significant differences between breed types, with non-warmbloods performing more bouts of opening the bin and feeding (p=0.02), feeding from the bin sooner (p=0.01) and reaching the criterion for learning sooner than warmbloods (p=0.05). There was also a significant negative linear relationship between horses' ages and time spent investigating the bin, with younger horses performing more investigative behaviour (y=-3.08x+106.86; p=0.02).

Abstract: The definition of tool proposed by Beck (1980) is still the one referred to in ethology when discussing the question of tool-use in animals, and its pertinence is rarely questioned. However, observations on technical behaviours in animals have multiplied over the last 20 years, and these have profoundly altered our earlier representations. In the present article, we show that Beck's definition is insufficient and that it does not, in fact, work. More generally, we replace a theory of tools with a theory of mediations of actions to account for technical behaviours in animals. We show that a culturally overcharged notion such as that of tool hinders our perception of the diversity and the complexity of tool uses. By speaking of mediations of actions and not of tools, we eliminate the problem of first defining the pertinent object (is it a tool or not?) and are free to concentrate on the means by which the animal externalizes its actions and thus procures greater means of acting on these within a group. In so doing, we prepare the ground for a genuine evolutionary understanding of the dynamics of actions within a given animal population. Whereas, with a few exceptions, ethologists have always separated the question of techniques from that of social behaviour, we emphasize the importance of an ecology of mediations of actions for understanding the structure and dynamics of animal societies, in particular by attempting to rethink such notions as “culture” in the perspective of a general analysis of mediations of actions.

Abstract: Western scrub-jays (Aphelocoma californica) often visually assess and handle several whole (unshelled) peanuts before selecting one to transport and cache; this behavior is a search for a preferred heavy nut. I repeatedly video-taped individually identifiable jays as they landed on a feeding platform and chose from presentations of peanuts that varied in the number of items or in the distribution of sizes. I examined how differences among these presentations and a bird's social status affected the amount of assessment and the economic consequences of choice. I also examined the specific patterns of handling peanuts, called sampling, to quantify the degree to which sampling sequences were typified by repeated comparisons among sampled peanuts (retrospective sampling), or sequential assessment and rejection of peanuts (prospective sampling). Peanut assessment was more extensive and prospective when there were many options from which to choose than when there were few. Peanut assessment was more extensive and retrospective when options were similar in size than when they varied. Scrub-jays were more likely to make repeated comparisons immediately before selecting a peanut than elsewhere in a sampling sequence. Subordinate scrub-jays, who were at the greatest risk of pre-emption by competitors, assessed peanuts less extensively and were more prospective in their sampling than dominants. Unless peanuts were very similar in size, jays were more accurate at selecting a high-quality peanut and achieved a higher rate of food storage than if they had not assessed. These results show that scrub-jays can adaptively modify how they search to improve their rate of food storage, and also suggest some of the specific search tactics used by jays when assessing peanuts.

Abstract: When novel behaviour patterns spread through animal populations, typically one animal will initiate the diffusion. It is not known whether such 'innovators' are particularly creative individuals, individuals exposed to the appropriate environmental contingencies, or individuals in a particular motivational state. We describe three experiments that investigated the factors influencing foraging innovation in the guppy Poecilia reticulata. We exposed small laboratory populations of fish to novel foraging tasks, which involved exploration and problem solving to locate a novel food source. Experiments 1 and 2 found that (1) females were more likely to innovate than males, (2) food-deprived fish were more likely to innovate than nonfood-deprived subjects, and (3) smaller fish were more likely to innovate than larger fish. We suggest that the sex difference may reflect parental investment asymmetries in males and females. Experiment 3 found that past innovators were more likely to innovate than past noninnovators. Collectively, the results suggest that differences in foraging innovation in guppies are best accounted for by differences in motivational state, but, in addition, guppies may vary in their predisposition to innovate. Copyright 1999 The Association for the Study of Animal Behaviour.

Abstract: This paper summarizes the current views on coping styles as a useful concept in understanding individual adaptive capacity and vulnerability to stress-related disease. Studies in feral populations indicate the existence of a proactive and a reactive coping style. These coping styles seem to play a role in the population ecology of the species. Despite domestication, genetic selection and inbreeding, the same coping styles can, to some extent, also be observed in laboratory and farm animals. Coping styles are characterized by consistent behavioral and neuroendocrine characteristics, some of which seem to be causally linked to each other. Evidence is accumulating that the two coping styles might explain a differential vulnerability to stress mediated disease due to the differential adaptive value of the two coping styles and the accompanying neuroendocrine differentiation.