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Stachurska, A., Pieta, M., & Nesteruk, E. (2002). Which obstacles are most problematic for jumping horses? Appl. Anim. Behav. Sci., 77(3), 197–207.
Abstract: The objective of this study was to examine the behaviour of horses jumping over variously designed obstacles, i.e. which obstacles are easy for them and jumped willingly or which cause difficulties. This was judged by scoring two main faults at jumping events: the number of knock-downs and run-outs with refusals. The data concerned 609 rounds made at regional competitions of various classes for 100-140 cm obstacle height. They included 5639 jumps at 343 obstacles, in total. Seventy-two horses participated in the competitions. The number of faults at a particular obstacle depended on the obstacle-type, height, colour and arrangement. Uprights and oxers were the most frequently knocked-down, while the walls were the most often run-out. When the height was increased, more obstacles were knocked-down but the number of run-outs did not change significantly. The obstacles of two contrasting colours were jumped without fault more often, whereas, those of one colour, light or dark, caused most of the faults. The least number of faults was committed at the second obstacle in a combination compared with the first, third and single ones. The third and fourth obstacles in the courses were faulty jumps most often. The results suggest that most of the factors examined, which differentiate the obstacle and course design, may influence the horse's behaviour. In consequence, the horses make more or fewer faults jumping over various obstacles.
Keywords: Horses; Jumping events; Obstacles; Behaviour
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Soproni, K., Miklósi, Á., Topál, J., & Csányi, V. (2002). Dogs' (Canis familiaris) responsiveness to human pointing gestures. J Comp Psychol, 116(1), 27–34.
Abstract: In a series of 3 experiments, dogs (Canis familiaris) were presented with variations of the human pointing gesture: gestures with reversed direction of movement, cross-pointing, and different arm extensions. Dogs performed at above chance level if they could see the hand (and index finger) protruding from the human body contour. If these minimum requirements were not accessible, dogs still could rely on the body position of the signaler. The direction of movement of the pointing arm did not influence the performance. In summary, these observations suggest that dogs are able to rely on relatively novel gestural forms of the human communicative pointing gesture and that they are able to comprehend to some extent the referential nature of human pointing.
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Simpson, B. S. (2002). Neonatal foal handling. Appl. Anim. Behav. Sci., 78(2-4), 303–317.
Abstract: Recent interest has focused on the advantage of intensively handling young foals as a means of producing more tractable horses, accustomed to humans and receptive to training. To date, the effect of this intensive handling, dubbed “imprint training” in the popular literature, has not been tested. The present study compares seven foals handled intensively as neonates with eight untreated controls. The handling protocol started from 2-8 h after birth and continued daily for a total of 5 days. The protocol consisted of a series of stimuli and experiences that were each repeated until the foal no longer resisted or reacted negatively. Subsequently, foals were tested before weaning, at 4 months of age. Results indicated that handled foals (HF) ranked higher than control foals (CF) in subjective ratings of calmness (*P<0.0117) and friendliness (*P<0.0001) and in several specific handling tasks (venipuncture *P<0.0220; placing in stock *P<0.0128). Although, in approach tests all foals but one allowed approach of a person to 4 m, significantly more HF approached the person than CF (P<0.0080). In stimulus tests, foals were presented specific stimuli to which they had been tested as neonates. Two of eight CF were too unruly and dangerous to test. Of foals that could be tested, CF required significantly more time to hook-up a heart rate monitor (**P<0.0055). Split-plot analysis indicated that HF had lower heart rates to initial left-sided stimuli, presented first, than CF (*P<0.0421). In response to right-sided stimuli, heart rate scores of CF were not significantly different from HF (P<0.2259), suggesting reduced reactivity over time due to a learning effect. Behavioral responses to specific stimuli did not differ between CF and HF, suggesting that neonatal handling has a general rather than specific effect on subsequent behavior. Cortisol concentrations were measured before and after testing and the difference calculated. All foals had higher post-testing levels than pre-testing levels. There was a significant difference between HF and CF, indicating greater reactivity among the CF (*P<0.050). In general, the results indicated that foals handled as neonates were more tractable and less reactive. Specific neonatal handling tasks, such as sticking a finger up the foal's nose or patting the bottom of the foot, seemed to have no beneficial effect on related tasks such as passing a nasogastric tube or tapping with a farrier's hammer at 4 months of age. Mechanisms for the observed effect of neonatal handling require further investigation.
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Silk, J. B. (2002). Kin Selection in Primate Groups. Int. J. Primatol., 23(4), 849–875.
Abstract: Altruism poses a problem for evolutionary biologists because natural selection is not expected to favor behaviors that are beneficial to recipients, but costly to actors. The theory of kin selection, first articulated by Hamilton (1964), provides a solution to the problem. Hamilton's well-known rule (br > c) provides a simple algorithm for the evolution of altruism via kin selection. Because kin recognition is a crucial requirement of kin selection, it is important to know whether and how primates can recognize their relatives. While conventional wisdom has been that primates can recognize maternal kin, but not paternal kin, this view is being challenged by new findings. The ability to recognize kin implies that kin selection may shape altruistic behavior in primate groups. I focus on two cases in which kin selection is tightly woven into the fabric of social life. For female baboons, macaques, and vervets maternal kinship is an important axis of social networks, coalitionary activity, and dominance relationships. Detailed studies of the patterning of altruistic interactions within these species illustrate the extent and limits of nepotism in their social lives. Carefully integrated analyses of behavior, demography, and genetics among red howlers provide an independent example of how kin selection shapes social organization and behavior. In red howlers, kin bonds shape the life histories and reproductive performance of both males and female. The two cases demonstrate that kin selection can be a powerful source of altruistic activity within primate groups. However, to fully assess the role of kin selection in primate groups, we need more information about the effects of kinship on the patterning of behavior across the Primates and accurate information about paternal kin relationships.
Keywords: Biomedical and Life Sciences
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Shettleworth, S. J., & Westwood, R. P. (2002). Divided attention, memory, and spatial discrimination in food-storing and nonstoring birds, black-capped chickadees (Poecile atricapilla) and dark-eyed juncos (Junco hyemalis). J Exp Psychol Anim Behav Process, 28(3), 227–241.
Abstract: Food-storing birds, black-capped chickadees (Poecile atricapilla), and nonstoring birds, dark-eyed juncos (Junco hyemalis), matched color or location on a touch screen. Both species showed a divided attention effect for color but not for location (Experiment 1). Chickadees performed better on location than on color with retention intervals up to 40 s, but juncos did not (Experiment 2). Increasing sample-distractor distance improved performance similarly in both species. Multidimensional scaling revealed that both use a Euclidean metric of spatial similarity (Experiment 3). When choosing between the location and color of a remembered item, food storers choose location more than do nonstorers. These results explain this effect by differences in memory for location relative to color, not division of attention or spatial discrimination ability.
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Seyfarth, R. M., & Cheney, D. L. (2002). What are big brains for? Proc. Natl. Acad. Sci. U.S.A., 99(7), 4141–4142.
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Seeley, T. D. (2002). When Is Self-Organization Used in Biological Systems? Biol Bull, 202(3), 314–318.
Abstract: Self-organization, or decentralized control, is widespread in biological systems, including cells, organisms, and groups. It is not, however, the universal means of organization. I argue that a biological system will be self-organized when it possesses a large number of subunits, and these subunits lack either the communicational abilities or the computational abilities, or both, that are needed to implement centralized control. Such control requires a well informed and highly intelligent supervisor. I stress that the subunits in a self-organized system do not necessarily have low cognitive abilities. A lack of preadaptations for evolving a system-wide communication network can prevent the evolution of centralized control. Hence, sometimes even systems whose subunits possess high cognitive abilities will be self-organized. N1 -
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Seaman, S. C., Davidson, H. P. B., & Waran, N. K. (2002). How reliable is temperament assessment in the domestic horse (Equus caballus)? Appl. Anim. Behav. Sci., 78(2-4), 175–191.
Abstract: Differences in behavioural characteristics between individuals of the same species are often described as being due to the temperament of the individuals. These differences can have enormous implications for welfare with some individuals apparently being able to adapt to environmental challenge more easily than others. Such differences have resulted in animals often being described as either `active' copers, which try to escape from or remove an aversive stimulus, or `passive' copers, which show no outward signs of a situation being aversive, thus, appearing to be unaffected. Tests previously developed to assess the temperament of animals have been criticised for several reasons. Behaviour is often recorded and categorised using methods that are not objective and tests are generally carried out once with no consideration of whether or not behavioural responses are consistent over time. This study takes these factors into account. The behaviour of 33 horses was recorded in three types of test--an arena test, response to a person and response to an object. In order to test whether or not responses were consistent over time, the tests were repeated three times with an average of 9 days between trials. Test results were validated using responses from questionnaires completed by the farm team leader. The data were analysed using an initial principal component analysis (PCA) and factor analysis. The horses were found to behave consistently over the three trials in their responses in the arena test. The responses to the person test and the object test were similar to each other; however, these responses were not consistent over trials. The behaviour in the arena test was unable to be used to make a prediction of behaviour in the person and object tests and vice versa. The responses shown by the horses did not enable them to be categorised as either active or passive copers. Behavioural responses in the tests were not predictive of the response to a startle test (water spray), nor could they be used to predict status or response to being reintroduced to the group after testing. There was no relationship between the responses in the tests and the ratings given by the farm team leader. It was concluded that horses vary widely in their responses to artificial behavioural tests, with only the responses to an open-field arena test being consistent over time, and therefore, the only type of test which can indicate some core factor of temperament.
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Schwartz, B. L., Colon, M. R., Sanchez, I. C., Rodriguez, I. A., & Evans, S. (2002). Single-trial learning of “what” and “who” information in a gorilla (Gorilla gorilla gorilla): implications for episodic memory. Anim. Cogn., 5(2), 85–90.
Abstract: Single-trial learning and long-term memory of “what” and “who” information were examined in an adult gorilla (Gorilla gorilla gorilla). We presented the gorilla with a to-be-remembered food item at the time of study. In Experiment 1, following a retention interval of either approximately 7 min or 24 h, the gorilla responded with one of five cards, each corresponding to a particular food. The gorilla was accurate on 70% of the short retention-interval trials and on 82% of the long retention-interval trials. In Experiment 2, the food stimulus was provided by one of two experimenters, each of whom was represented by a card. The gorilla identified the food (55% of the time) and the experimenter (82% of the time) on the short retention-interval trials. On the long retention-interval trials, the gorilla was accurate for the food (73%) and for the person (87%). The results are interpreted in light of theories of episodic memory.
Keywords: Animals; Cognition; Gorilla gorilla/*psychology; *Learning; Male; *Memory; Perception; Reinforcement Schedule
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Schuck-Paim, C., & Kacelnik, A. (2002). Rationality in risk-sensitive foraging choices by starlings. Anim. Behav., 64(6), 869–879.
Abstract: Normative models of choice usually predict preferences between alternatives by computing their value according to some criterion, then identifying the alternative with greatest value. An important consequence of this procedure is captured in the economic concept of rationality, defined through a number of principles that are necessary for the existence of an ordinal scale of value upon which organisms base their choices. Violations of these principles, such as some recently reported breaches of transitivity and regularity in birds and honeybees, have strong implications for the understanding of decision mechanisms in humans and nonhumans alike. We investigated rationality in risky choice using European starlings, Sturnus vulgaris. Birds had to choose between two or three food sources, each associated with a different variance in delay to reward. In three experiments, starlings were strongly risk prone, showing regular and consistent preferences in binary and trinary choices. Preferences also satisfied weak and strong stochastic transitivity. Our results extend the generality of previous research in risk-sensitive foraging to situations where more than two alternatives are present and suggest that violations of rationality in risk-sensitive choices may be expressed only under restricted sets of conditions. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.
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