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Author | Kerr, R.A. | ||||
Title | PALEOCLIMATOLOGY. Atlantic mud shows how melting ice triggered an ancient chill | Type | Journal Article | ||
Year | 2006 | Publication | Science (New York, N.Y.) | Abbreviated Journal | Science |
Volume | 312 | Issue | 5782 | Pages | 1860 |
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Language | English | Summary Language | Original Title | ||
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ISSN | 1095-9203 | ISBN | Medium | ||
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Notes | PMID:16809498 | Approved | no | ||
Call Number | refbase @ user @ | Serial | 283 | ||
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Author | Melis, A.P.; Hare, B.; Tomasello, M. | ||||
Title | Engineering cooperation in chimpanzees: tolerance constraints on cooperation | Type | Journal Article | ||
Year | 2006 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
Volume | 72 | Issue | 2 | Pages | 275-286 |
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Abstract | The cooperative abilities of captive chimpanzees, Pan troglodytes, in experiments do not match the sophistication that might be predicted based on their naturally occurring cooperative behaviours. This discrepancy might partly be because in previous experiments potential chimpanzee cooperators were partnered without regard to their social relationship. We investigated the ability of chimpanzee dyads to solve a physical task cooperatively in relation to their interindividual tolerance levels. Pairs that were most capable of sharing food outside the test were also able to cooperate spontaneously (by simultaneously pulling two ropes) to obtain food. In contrast, pairs that were less inclined to share food outside of the test were unlikely to cooperate. Furthermore, previously successful subjects stopped cooperating when paired with a less tolerant partner, even when the food rewards were presented in a dispersed and divisible form to reduce competition between subjects. These results show that although chimpanzees are capable of spontaneous cooperation in a novel instrumental task, tolerance acts as a constraint on their ability to solve such cooperative problems. This finding highlights the importance of controlling such social constraints in future experiments on chimpanzee cooperation, and suggests that the evolution of human-like cooperative skills might have been preceded by the evolution of a more egalitarian social system and a more human-like temperament. | ||||
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Call Number | refbase @ user @ | Serial | 287 | ||
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Author | McGregor, A.; Saggerson, A.; Pearce, J.; Heyes, C. | ||||
Title | Blind imitation in pigeons, Columba livia | Type | Journal Article | ||
Year | 2006 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
Volume | 72 | Issue | 2 | Pages | 287-296 |
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Abstract | Pigeons that had been trained with a food reward both to peck at and to step on a horizontal plate were allowed to observe a conspecific demonstrator pecking at or stepping on the plate before a test in which the observers were not rewarded for either pecking or stepping. In experiment 1, the demonstrators were not rewarded while being observed. In spite of this, the observers provided evidence of imitation: those that had observed pecking made a greater proportion of pecking responses on test than observers of stepping. In experiment 2, each observer was exposed to a pecking or a stepping conspecific on two occasions. On one occasion, the demonstrator received a food reward for each demonstrated response (continuous reinforcement condition), and on the other the demonstrator's responses were rewarded only rarely (variable interval condition). The observers provided equally strong evidence of imitation in each of these conditions; on test, they made proportionally more of the observed response both when the demonstrators had been richly rewarded and when they had been rarely rewarded. These results show that pigeons engage in `blind' imitation, that is, their imitative behaviour is not always guided by observational learning about response outcomes. | ||||
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Call Number | refbase @ user @ | Serial | 294 | ||
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Author | Kelly, C.D. | ||||
Title | Fighting for harems: assessment strategies during male-male contests in the sexually dimorphic Wellington tree weta | Type | Journal Article | ||
Year | 2006 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
Volume | 72 | Issue | 3 | Pages | 727-736 |
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Abstract | Females often aggregate at particular sites for feeding or shelter, thus giving adult males the opportunity to defend harems and increase male reproductive success. Rival males compete for control of harems via ritualized displays or direct combat using weaponry. Contests for harems or the resources required by females can be settled based on asymmetries in fighting ability or resource ownership. Males that accurately assess a rival's fighting ability prior to engaging in potentially costly combat should be favoured by selection. Game theory and optimality models provide three models to explain how individuals decide to persist in or flee from a fight. These models are the energetic war of attrition, the sequential assessment model and the cumulative assessment model. Using staged contests in the laboratory, I tested predictions of these models using the Wellington tree weta, Hemideina crassidens, a sexually dimorphic insect native to New Zealand. Male H. crassidens use their enlarged mandibles as weapons in fights for access to adult females that reside in cavities in trees. My results supported a prediction common to each assessment model: contest duration was negatively correlated with the asymmetry in opponent's weapon size. The sequential assessment model of contest settlement was partially supported but the strongest support was for the cumulative assessment model. Predictions of the latter model were supported because: (1) fights are apparently settled based on own-size assessment; (2) fights occur in a single phase and escalate; and (3) contests involve physical combat and injury. I suggest that, in nocturnal species, cumulative assessment will generally be most applicable. | ||||
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Call Number | refbase @ user @ | Serial | 297 | ||
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Author | de Vries, H.; Stevens, J.M.G.; Vervaecke, H. | ||||
Title | Measuring and testing the steepness of dominance hierarchies | Type | Journal Article | ||
Year | 2006 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
Volume | 71 | Issue | 3 | Pages | 585-592 |
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Abstract | In the analysis of social dominance in groups of animals, linearity has been used by many researchers as the main structural characteristic of a dominance hierarchy. In this paper we propose, alongside linearity, a quantitative measure for another property of a dominance hierarchy, namely its steepness. Steepness of a hierarchy is defined here as the absolute slope of the straight line fitted to the normalized David's scores (calculated on the basis of a dyadic dominance index corrected for chance) plotted against the subjects' ranks. This correction for chance is an improvement of an earlier proposal by de Vries (appendix 2 in de Vries, Animal Behaviour, 1998, 55, 827-843). In addition, we present a randomization procedure for determining the statistical significance of a hierarchy's steepness, which can be used to test the observed steepness against the steepness expected under the null hypothesis of random win chances for all pairs of individuals. Whereas linearity depends on the number of established binary dominance relationships and the degree of transitivity in these relationships, steepness measures the degree to which individuals differ from each other in winning dominance encounters. Linearity and steepness are complementary measures to characterize a dominance hierarchy. | ||||
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Call Number | refbase @ user @ | Serial | 454 | ||
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Author | Poisbleau, M.; Fritz, H.; Valeix, M.; Perroi, P.-Y.; Dalloyau, S.; Lambrechts, M.M. | ||||
Title | Social dominance correlates and family status in wintering dark-bellied brent geese, Branta bernicla bernicla | Type | Journal Article | ||
Year | 2006 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
Volume | 71 | Issue | 6 | Pages | 1351-1358 |
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Abstract | In many gregarious species, including ducks and geese, being dominant provides more benefits than costs, because dominants have better access to resources essential for survival or reproduction. In geese, being in better body condition during migration towards the breeding grounds positively influences reproductive success. However, underlying proximate mechanisms linking prebreeding body condition on the wintering grounds to breeding success remain poorly understood. We investigated social dominance correlates and family status, in three consecutive winters, in a free-ranging, migrating, dark-bellied brent goose population. Families with juveniles dominated pairs, and pairs dominated singletons. Dominance rank did not increase with the number of juveniles per family. Males were dominant over females. Social dominance and reproductive status for a given winter were significantly correlated with body mass, body size and body condition during the previous winter, suggesting that body condition in winter also affects subsequent breeding success and hence also dominance. Levels of testosterone and triiodothyronine were not correlated with immediate or later dominance or reproductive status. We discuss the role of family status as a signal of social status in determining reproductive strategies. | ||||
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ISSN | 0003-3472 | ISBN | Medium | ||
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Notes | Approved | no | |||
Call Number | Equine Behaviour @ team @ | Serial | 4690 | ||
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Author | Poisbleau, M.; Jenouvrier, S.; Fritz, H. | ||||
Title | Assessing the reliability of dominance scores for assigning individual ranks in a hierarchy | Type | Journal Article | ||
Year | 2006 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
Volume | 72 | Issue | 4 | Pages | 835-842 |
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Abstract | The dominance score (number of wins divided by the total number of interactions) is the most widely used procedure in field studies to rank individuals. Its reliability depends on the number of interactions on which it is calculated. However, most authors use it without any estimate of the associated error. We describe the precision associated with a dominance score estimate as a function of the number of interactions on which it is based, and hence provide a tool to plan field protocols and effort. The precision error decreases according to a power function with increasing number of interactions, but with more precision for extreme scores for any given number of interactions. We discuss the fact that the minimum number of interactions should be based on the precision associated with the 50% score, the least precise of all scores. We also emphasize the trade-off between recording effort and precision of the estimator, and give an example of our choice of 26 interactions for fieldwork on ducks and geese. When comparing individual ranks based on dominance scores with ranks given by the dominance matrix, we found a good correlation, with more mismatches around the middle of the hierarchy. This was consistent with the precision calculated with our model. We conclude that dominance score is a reliable tool, but conclusions must take into account the number of interactions on which the calculations are done. We also discuss the importance of initial assumptions and sources of bias in field studies. | ||||
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Call Number | refbase @ user @ | Serial | 456 | ||
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Author | Nudds, M.; Hurley, S. | ||||
Title | Rational Animals? | Type | Book Whole | ||
Year | 2006 | Publication | Oxford University Press | Abbreviated Journal | Oxf. Univ. Pr. |
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Abstract | To what extent can animal behaviour be described as rational? What does it even mean to describe behaviour as rational? This book focuses on one of the major debates in science today – how closely does mental processing in animals resemble mental processing in humans. It addresses the question of whether and to what extent non-human animals are rational, that is, whether any animal behaviour can be regarded as the result of a rational thought processes. It does this with attention to three key questions, which recur throughout the book and which have both empirical and philosophical aspects: What kinds of behavioural tasks can animals successfully perform? What if any mental processes must be postulated to explain their performance at these tasks? What properties must processes have to count as rational? The book is distinctive in pursuing these questions not only in relation to our closest relatives, the primates, whose intelligence usually gets the most attention, but also in relation to birds and dolphins, where striking results are also being obtained. Some chapters focus on a particular species. They describe some of the extraordinary and complex behaviour of these species – using tools in novel ways to solve foraging problems, for example, or behaving in novel ways to solve complex social problems – and ask whether such behaviour should be explained in rational or merely mechanistic terms. Other chapters address more theoretical issues and ask, for example, what it means for behaviour to be rational, and whether rationality can be understood in the absence of language. The book includes many of the world's leading figures doing empirical work on rationality in primates, dolphins, and birds, as well as distinguished philosophers of mind and science. The book includes an editors' introduction which summarises the philosophical and empirical work presented, and draws together the issues discussed by the contributors. | ||||
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ISSN | ISBN | 0198528272 | Medium | ||
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Call Number | refbase @ user @ | Serial | 608 | ||
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Author | Allen, C. | ||||
Title | Transitive inference in animals: Reasoning or conditioned associations? | Type | Book Chapter | ||
Year | 2006 | Publication | Rational Animals? | Abbreviated Journal | |
Volume | Issue | Pages | 175-186 | ||
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Abstract | It is widely accepted that many species of nonhuman animals appear to engage in transitive inference, producing appropriate responses to novel pairings of non-adjacent members of an ordered series without previous experience of these pairings. Some researchers have taken this capability as providing direct evidence that these animals reason. Others resist such declarations, favouring instead explanations in terms of associative conditioning. Associative accounts of transitive inference have been refined in application to a simple 5-element learning task that is the main paradigm for laboratory investigations of the phenomenon, but it remains unclear how well those accounts generalise to more information-rich environments such as social hierarchies which may contain scores of individuals, and where rapid learning is important. The case of transitive inference is an example of a more general dispute between proponents of associative accounts and advocates of more cognitive accounts of animal behaviour. Examination of the specific details of transitive inference suggests some lessons for the wider debate. |
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Address | Texas A&M University | ||||
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Publisher | Oxford University Press | Place of Publication | Oxford | Editor | Hurley, S.; Nudds, M. |
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ISSN | ISBN | 978-0-19-852827-2 | Medium | ||
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Notes | Approved | no | |||
Call Number | refbase @ user @ | Serial | 611 | ||
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Author | Chase, I.D. | ||||
Title | Music notation: a new method for visualizing social interaction in animals and humans | Type | Journal Article | ||
Year | 2006 | Publication | Frontiers in zoology | Abbreviated Journal | Front Zool |
Volume | 3 | Issue | Pages | 18 | |
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Abstract | ABSTRACT: BACKGROUND: Researchers have developed a variety of techniques for the visual presentation of quantitative data. These techniques can help to reveal trends and regularities that would be difficult to see if the data were left in raw form. Such techniques can be of great help in exploratory data analysis, making apparent the organization of data sets, developing new hypotheses, and in selecting effects to be tested by statistical analysis. Researchers studying social interaction in groups of animals and humans, however, have few tools to present their raw data visually, and it can be especially difficult to perceive patterns in these data. In this paper I introduce a new graphical method for the visual display of interaction records in human and animal groups, and I illustrate this method using data taken on chickens forming dominance hierarchies. RESULTS: This new method presents data in a way that can help researchers immediately to see patterns and connections in long, detailed records of interaction. I show a variety of ways in which this new technique can be used: (1) to explore trends in the formation of both group social structures and individual relationships; (2) to compare interaction records across groups of real animals and between real animals and computer-simulated animal interactions; (3) to search for and discover new types of small-scale interaction sequences; and (4) to examine how interaction patterns in larger groups might emerge from those in component subgroups. In addition, I discuss how this method can be modified and extended for visualizing a variety of different kinds of social interaction in both humans and animals. CONCLUSION: This method can help researchers develop new insights into the structure and organization of social interaction. Such insights can make it easier for researchers to explain behavioural processes, to select aspects of data for statistical analysis, to design further studies, and to formulate appropriate mathematical models and computer simulations. | ||||
Address | Department of Sociology, Stony Brook University, Stony Brook, NY 11794-4345, USA. ichase@notes.cc.sunysb.edu | ||||
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Language | English | Summary Language | Original Title | ||
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ISSN | 1742-9994 | ISBN | Medium | ||
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Notes | PMID:17112384 | Approved | no | ||
Call Number | refbase @ user @ | Serial | 751 | ||
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