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Stoehr S. (1998). Evolution of mate-choice copying: a dynamic model. Anim. Behav., 55(4), 893–903.
Abstract: Mate-choice copying has recently been demonstrated in several species. Two, not mutually exclusive, explanations for copying have been proposed: it reduces sampling costs and/or error of mate choice. In guppies, Poecilia reticulata, and black grouse, Tetrao tetrix, young females seem most likely to copy. Therefore, copying may teach inexperienced females what attractive males look like. I developed a 2-year dynamic model, to investigate under which conditions a mate-copying strategy might first evolve. An original population of pure choosers was assumed, which was invaded by a mutant female, able to copy during her first mating season, thereby instantly improving her ability to assess male quality. Alternatively, she could either wait and learn by observing males, just as non-copiers may do, but incurring some time costs, or choose, relying on her own abilities. The degree to which copying occurred among these mutant, young, inexperienced females increased with an increasing proportion of old, experienced females in the population, and with decreasing time left until the end of the season. The model demonstrates that mate-choice copying may evolve, when young females are poor at discrimination and need to learn what high-quality males look like. Male quality proved to be unimportant for copying to evolve, as long as there are sufficient differences in quality for mate choice to be meaningful. As with previous models, time constraints are an important assumption for copying to be advantageous over non-copying. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.
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Spinka, M., Duncan, I. J. H., & Widowski, T. M. (1998). Do domestic pigs prefer short-term to medium-term confinement? Appl. Anim. Behav. Sci., 58(3-4), 221–232.
Abstract: A preference test was used to demonstrate that gilts have the ability to associate two sets of neutral cues with two different periods of confinement and water deprivation and to anticipate the long-term consequences of their choice in the test. Twelve gilts housed in two large, straw-bedded pens were trained to go to two sets of 12 crates, positioned on each side of a choice point, for feeding twice a day. Following initial training, the two sets of crates were marked with contrasting visual patterns and the patterns were associated with either 30 min (`short' confinement) or 240 min (`long' confinement) of confinement in the crates after entry. During 16 days of preference testing, the gilts were sent alternately to one side or the other in the mornings and allowed to choose in the afternoons. Eight gilts chose the short confinement side more often, two, the long confinement side more often and two, each side an equal number of times, indicating that most gilts learned the association and preferred to be released shortly after feeding. However, gilts still chose the long confinement side on occasion, suggesting that they did not find 240 min of confinement very aversive. When the gilts were sent to the crates in the morning, their behaviour indicated that they expected to be released or confined depending on which crate they were in. The cognitive abilities of animals with respect to perception of time and anticipation of future events have important implications for their welfare. This study demonstrates that methods can be developed to ask animals about such things.
Keywords: Cognition; Pig-housing; Preference tests
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Smith, W. J. (1998). Cognitive Implications of an Information-sharing Model of Animal Communication. In Russell P. Balda, Irene M. Pepperberg, & Alan C. Kamil (Eds.), Animal Cognition in Nature (pp. 227–243). London: Academic Press.
Abstract: Summary In social communication, one animal signals and another responds. Several cognitive steps are involved as the second animal selects its responses; these steps can be described as follows in terms of an informational model. First, the responding individual must evaluate the information made available by the signaling on the basis of other information, available from sources contextual to the signal. Second, the respondent must fit all of the relevant information into patterns generated from recall of past events (conscious recall is not generally required; pattern fitting is a fundamental skill). Third, conditional predictions must be made; and fourth, the individual must test and modify any of these predictions for which significant consequences exist. Many vertebrate animals appear to respond to signaling with considerable flexibility. Communicative events are thus complex but are by no means intractable. Indeed, communication provides us with excellent opportunities to investigate animal cognition.
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Sinha, A. (1998). Knowledge acquired and decisions made: triadic interactions during allogrooming in wild bonnet macaques, Macaca radiata. Philos Trans R Soc Lond B Biol Sci, 353(1368), 619–631.
Abstract: The pressures of developing and maintaining intricate social relationships may have led to the evolution of enhanced cognitive abilities in many nonhuman primates. Knowledge of the dominance ranks and social relationships of other individuals, in particular, is important in evaluating one's position in the rank hierarchy and affiliative networks. Triadic interactions offer an excellent opportunity to examine whether decisions are taken by individuals on the basis of such knowledge. Allogrooming supplants among wild female bonnet macaques (macaca radiata) usually involved the subordinate female of a grooming dyad retreating at the approach of a female dominant to both members of the dyad. In a few exceptional cases, however, the dominant member of the dyad retreated; simple non-cognitive hypotheses involving dyadic rank differences and agonistic relationships failed to explain this phenomenon. Instead, retreat by the dominant individual was positively correlated with the social attractiveness of her subordinate companion (as measured by the duration of grooming received by the latter from other females in the troop). This suggests that not only does an individual evaluate relationships among other females, but does so on the basis of the amount of grooming received by them. Similarly, the frequency of approaches received by any female was correlated with her social attractiveness when she was the dominant member of the dyad, but not when she was the subordinate. This indicated that approaching females might be aware of the relative dominance ranks of the two allogrooming individuals. In logistic regression analyses, the probability of any individual retreating was found to be influenced more by her knowledge of her rank difference with both the other interactants, rather than by their absolute ranks. Moreover, information about social attractiveness appeared to be used in terms of correlated dominance ranks. The nature of knowledge acquired by bonnet macaque females may thus be egotistical in that other individuals are evaluated relative to oneself, integrative in that information about all other interactants is used simultaneously, and hierarchical in the ability to preferentially use certain categories of knowledge for the storage of related information from other domains.
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Shuster, G., & Sherman, P. W. (1998). Tool use by naked mole-rats. Anim. Cogn., 1(1), 71–74.
Abstract: Naked mole-rats (Heterocephalus glaber, Rodentia: Bathyergidae) excavate extensive subterranean burrows with their procumbent incisors. Captive individuals often place a wood shaving or tuber husk behind their incisor teeth and in front of their lips and molar teeth while gnawing on substrates that yield fine particulate debris. This oral barrier may prevent choking or aspiration of foreign material. Consistent use of tools has rarely been reported in rodents.
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Shettleworth, S. J. (1998). Cognition, Evolution and Behaviour. Oxford: Oxford University Press.
Abstract: Description
How do animals perceive the world, learn, remember, search for food or mates, and find their way around? Do any non-human animals count, imitate one another, use a language, or think as we do? What use is cognition in nature and how might it have evolved? Historically, research on such questions has been fragmented between psychology, where the emphasis has been on theoretical models and lab experiments, and biology, where studies focus on evolution and the adaptive use of perception, learning, and decision-making in the field. Cognition, Evolution and the Study of Behavior integrates research from psychology, behavioral ecology, and ethology in a wide-ranging synthesis of theory and research about animal cognition in the broadest sense, from species-specific adaptations in fish to cognitive mapping in rats and honeybees to theories of mind for chimpanzees. As a major contribution to the emerging discipline of comparative cognition, the book is an invaluable resource for all students and researchers in psychology, zoology, behavioral neuroscience. It will also interest general readers curious about the details of how and why animals--including humans--process, retain, and use information as they do. Reviews “This book is a very comprehensive review of animal cognition. It differs from other texts on this topic in a number of ways, as outlined by Shettleworth in her preface and in the opening chapter. Essentially, Shettleworth wants to advocate an 'adaptationist or ecological approach to cognition'. In doing so, she brings together a wealth of data on animal cognition, studied from quite different theoretical viewpoints, such as cognitive ethology, animal learning theory, neuroscience, behavioural ecology and cognitive psychology. . . . Each chapter ends with a clear and useful summary, and helpful suggestions for further reading. The book's numerous illustrations, which are mostly tables or figures redrawn by Margaret Nelson, greatly add to its appeal. . . . [T]his is a marvellously rich, well-written and stimulating book. . . . I greatly enjoyed reading [and] recommend it highly to anyone interested in animal cognition, evolution and behaviour.”--Animal Behaviour “Sara Shettleworth has probably written the most comprehensive study of the animal mind ever and therefore a fundamental textbook on 'comparative cognition'. She first gets consciousness out of the way: whether an animal is conscious or not is impossible to determine, since consciousness is a private, subjective phenomenon. We can study cognition, and certainly cognition lends credibility to the idea that at least some animals must be at least to some degree conscious, but experiments can only prove facts about cognition. She reviews the field of cognitive ethology from the beginning and then analyzes the main cognitive tasks from an information-processing perspective By the end of her review of cognitive faculties, it become apparent that, at least among vertebrates, there are no significant differences in learning, except for language. All vertebrates are capable of 'associative' learning What no other vertebrate seems to be capable of is 'syntax'.” -- Piero Scaruffi, Thymos.com |
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Schwartz, E. B., Granger, D. A., Susman, E. J., Gunnar, M. R., & Laird, B. (1998). Assessing Salivary Cortisol in Studies of Child Development. Child Development, 69(6), 1503–1513.
Abstract: In a series of studies, we evaluated the susceptibility of radioimmunoassays (RIA) for saliva cortisol to interference effects caused by oral stimulants used to facilitate saliva collection in studies with children. When added directly to saliva samples, oral stimulants (drink mix crystals) artificially inflated estimated cortisol concentrations. The magnitude of the interference effect was concentration-dependent and more pronounced for some stimulants and RIA procedures than for others. Analysis of samples collected using oral stimulants from child and adult participants confirmed stimulant interference as an extraneous source of variability in measured saliva cortisol. Associations between serum and saliva cortisol and between saliva cortisol and “behavioral” variables were attenuated by stimulant interference. A survey of six large child studies estimated interference effects, indexed by low sample pH, to be present in 14.7% of the 1,148 total saliva samples, or 2%-54% (M= 22%) of samples within each study. Recommendations to minimize the impact of stimluant interference in studies involving salivary cortisol in the context of child health and development are outlined.
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Schooening, B. (1998). Ethology of the horse. Prakt. Tierarzt, 79(6 Suppl.), 25–28.
Abstract: The paper starts with a short introduction/definition about ethology and the used methods in this scientific field, giving special examples for horses and about how their “normal behaviour” is measured. The behaviour repertoire of horses is described in a brief outline with special emphasis on their social systems and hierarchies and the problem of dominance, especially in interaction with humans. Schlütersche GmbH & Co. KG, Verlag und Druckerei.
Keywords: Dominance; Ethology; Horse; Propedeutics
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Schnitzer, U. (1998). Grundsätze der Gymnastizierung des Reitpferdes.
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Schnall, S., & Gattis, M. (1998). Transitive Inference by Visual Reasoning.
Abstract: Two experiments are reported that investigated the influence
of linear spatial organization on transitive inference performance. Reward/no-reward relations between overlapping pairs of elements were presented in a context of linear spatial order or random spatial order. Participants in the linear arrangement condition showed evidence for visual reasoning: They systematically mapped spatial relations to conceptual relation and used the spatial relations to make inferences on a reasoning task in a new spatial context. We suggest that linear ordering may be a “good figure”, by constituting a parsimonious representation for the integration of premises, as well as for the inferencing process. The late emergence of transitive inference in children may be the result of limited cognitive capacity, which --unless an external spatial array is available --constrains the construction of an internal spatial array. |