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Author Conradt, L.; Krause, J.; Couzin, I. D.; Roper, T. J. url  doi
openurl 
  Title (down) “Leading According to Need” in Self-Organizing Groups Type Journal Article
  Year 2009 Publication The American Naturalist Abbreviated Journal Am Nat  
  Volume 173 Issue 3 Pages 304-312  
  Keywords behavioral synchrony, collective group decisions, democracy and egalitarianism in animals, public goods experiments, sexual segregation, social choice theory  
  Abstract Self‐organizing‐system approaches have shed significant light on the mechanisms underlying synchronized movements by large groups of animals, such as shoals of fish, flocks of birds, or herds of ungulates. However, these approaches rarely consider conflicts of interest between group members, although there is reason to suppose that such conflicts are commonplace. Here, we demonstrate that, where conflicts exist, individual members of self‐organizing groups can, in principle, increase their influence on group movement destination by strategically changing simple behavioral parameters (namely, movement speed, assertiveness, and social attraction range). However, they do so at the expense of an increased risk of group fragmentation and a decrease in movement efficiency. We argue that the resulting trade‐offs faced by each group member render it likely that group movements are led by those members for which reaching a particular destination is most crucial or group cohesion is least important. We term this phenomenon leading according to “need” or “social indifference,” respectively. Both kinds of leading can occur in the absence of knowledge of or communication about the needs of other group members and without the assumption of altruistic cooperation. We discuss our findings in the light of observations on fish and other vertebrates.  
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  Call Number Equine Behaviour @ team @ Serial 5121  
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Author Hagen, S.J.; Eaton, W.A. doi  openurl
  Title (down) Two-state expansion and collapse of a polypeptide Type Journal Article
  Year 2000 Publication Journal of Molecular Biology Abbreviated Journal J Mol Biol  
  Volume 301 Issue 4 Pages 1019-1027  
  Keywords Animals; Computer Simulation; Cytochrome c Group/*chemistry/*metabolism; Horses; Kinetics; Lasers; Models, Chemical; Peptides/*chemistry/*metabolism; Protein Conformation; Protein Denaturation; *Protein Folding; Spectrometry, Fluorescence; Temperature; Thermodynamics  
  Abstract The initial phase of folding for many proteins is presumed to be the collapse of the polypeptide chain from expanded to compact, but still denatured, conformations. Theory and simulations suggest that this collapse may be a two-state transition, characterized by barrier-crossing kinetics, while the collapse of homopolymers is continuous and multi-phasic. We have used a laser temperature-jump with fluorescence spectroscopy to measure the complete time-course of the collapse of denatured cytochrome c with nanosecond time resolution. We find the process to be exponential in time and thermally activated, with an apparent activation energy approximately 9 k(B)T (after correction for solvent viscosity). These results indicate that polypeptide collapse is kinetically a two-state transition. Because of the observed free energy barrier, the time scale of polypeptide collapse is dramatically slower than is predicted by Langevin models for homopolymer collapse.  
  Address Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Building 5, Bethesda, MD, 20892-0520, USA  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0022-2836 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:10966803 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3790  
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Author Peltzer, K.; Mabilu, M.G.; Mathoho, S.F.; Nekhwevha, A.P.; Sikhwivhilu, T.; Sinthumule, T.S. openurl 
  Title (down) Trauma history and severity of gambling involvement among horse-race gamblers in a South African gambling setting Type Journal Article
  Year 2006 Publication Psychological Reports Abbreviated Journal Psychol Rep  
  Volume 99 Issue 2 Pages 472-476  
  Keywords Adult; African Continental Ancestry Group/*psychology/statistics & numerical data; Aged; Aged, 80 and over; Cross-Sectional Studies; Female; Gambling/*psychology; Humans; *Life Change Events; Male; Middle Aged; Personality Inventory; Risk Factors; *Social Environment; Socioeconomic Factors; South Africa; Statistics; Stress Disorders, Post-Traumatic/epidemiology/*psychology  
  Abstract The purpose of this study was to ascertain the frequency of gambling involvement and the prevalence of problem gambling among horse race gamblers and to discover whether problem gambling in this sample is associated with a history of trauma. Among a sample of 266 South African horse-race gamblers (94% men and 6% women, Mage 46.8 yr., SD = 13.9, range 18-85 years), 31.2% were classified as probable pathological gamblers and 19.9% with problem gambling. Major weekly gambling activities included racetrack betting (82%), purchase of lottery tickets or scratch tickets (35%), purchase of sports lottery tickets (23%), and using casino type games (18%). Trauma history was significantly associated with gambling severity.  
  Address Human Sciences Research Council, University of Limpopo, Pretoria, South Africa. KPeltzer@hsrc.ac.za  
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  ISSN 0033-2941 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17153816 Approved no  
  Call Number Serial 1850  
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Author Brosnan, S.F.; Schiff, H.C.; de Waal, F.B.M. doi  openurl
  Title (down) Tolerance for inequity may increase with social closeness in chimpanzees Type Journal Article
  Year 2005 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci  
  Volume 272 Issue 1560 Pages 253-258  
  Keywords Analysis of Variance; Animals; *Attitude; Group Processes; Pan troglodytes/*psychology; Reward; *Social Behavior; Socioeconomic Factors  
  Abstract Economic decision-making depends on our social environment. Humans tend to respond differently to inequity in close relationships, yet we know little about the potential for such variation in other species. We examine responses to inequity in several groups of chimpanzees (Pan troglodytes) in a paradigm similar to that used previously in capuchin monkeys (Cebus apella). We demonstrate that, like capuchin monkeys, chimpanzees show a response to inequity of rewards that is based upon the partner receiving the reward rather than the presence of the reward alone. However, we also found a great amount of variation between groups tested, indicating that chimpanzees, like people, respond to inequity in a variable manner, which we speculate could be caused by such variables as group size, the social closeness of the group (as reflected in length of time that the group has been together) and group-specific traditions.  
  Address Yerkes National Primate Research Center, Emory University, 954 North Gatewood Drive, Atlanta, GA 30329, USA. sbrosna@emory.edu  
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  Series Volume Series Issue Edition  
  ISSN 0962-8452 ISBN Medium  
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  Notes PMID:15705549 Approved no  
  Call Number refbase @ user @ Serial 169  
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Author de Waal, F.B.; Luttrell, L.M. openurl 
  Title (down) The similarity principle underlying social bonding among female rhesus monkeys Type Journal Article
  Year 1986 Publication Folia primatologica; international journal of primatology Abbreviated Journal Folia Primatol (Basel)  
  Volume 46 Issue 4 Pages 215-234  
  Keywords Aggression; Animals; Dominance-Subordination; Female; Grooming; *Group Processes; Macaca/*physiology; Macaca mulatta/*physiology; Male; *Object Attachment  
  Abstract Twenty adult female rhesus monkeys (Macaca mulatta) were observed over a three-year period. They lived in a mixed captive group with kinship relations known for three generations. The study's aim was to test Seyfarth's [J. theor. Biol. 65: 671-698, 1977] model of rank-related grooming and to investigate two other possible determinants of social bonding, i.e. relative age and the group's stratification into two social classes. Data on affiliation, coalitions, and social competition were collected by means of both focal observation and instantaneous time sampling. Whereas certain elements of the existing model were confirmed, its explanatory principles were not. Social competition did not result in more contact among close-ranking females (the opposite effect was found), and the relation between affiliative behavior and coalitions was more complex than predicted. Based on multivariate analyses and a comparison of theoretical models, we propose a simpler, more encompassing principle underlying interfemale attraction. According to this 'similarity principle', rhesus females establish bonds with females whom they most resemble. The similarity may concern genetical and social background, age, hierarchical position and social class. Effects of these four factors were independently demonstrated. The most successful model assumed that similarity factors influence female bonding in a cumulative fashion.  
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  ISSN 0015-5713 ISBN Medium  
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  Notes PMID:3557225 Approved no  
  Call Number refbase @ user @ Serial 211  
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Author Wasserman, E.A. openurl 
  Title (down) The science of animal cognition: past, present, and future Type Journal Article
  Year 1997 Publication Journal of Experimental Psychology. Animal Behavior Processes Abbreviated Journal J Exp Psychol Anim Behav Process  
  Volume 23 Issue 2 Pages 123-135  
  Keywords Animal Communication; Animal Population Groups/*psychology; Animals; Behavior, Animal; Behavioral Sciences/*trends; *Cognition; Evolution; Forecasting; Humans; Intelligence  
  Abstract The field of animal cognition is strongly rooted in the philosophy of mind and in the theory of evolution. Despite these strong roots, work during the most famous and active period in the history of our science-the 1930s, 1940s, and 1950s-may have diverted us from the very questions that were of greatest initial interest to the comparative analysis of learning and behavior. Subsequently, the field has been in steady decline despite its increasing breadth and sophistication. Renewal of the field of animal cognition may require a return to the original questions of animal communication and intelligence using the most advanced tools of modern psychological science. Reclaiming center stage in contemporary psychology will be difficult; planning that effort with a host of strategies should enhance the chances of success.  
  Address Department of Psychology, University of Iowa, Iowa City 52242-1407, USA. ed-wasserman@uiowa.edu  
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  Series Volume Series Issue Edition  
  ISSN 0097-7403 ISBN Medium  
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  Notes PMID:9095537 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2779  
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Author Wolter, R.; Pantel, N.; Stefanski, V.; Möstl, E.; Krueger, K. doi  openurl
  Title (down) The role of an alpha animal in changing environmental conditions Type Journal Article
  Year 2014 Publication Physiology & Behavior Abbreviated Journal Physiol. Behav.  
  Volume 133 Issue Pages 236-243  
  Keywords Alpha male; Horse; Equus ferus przewalskii; Bachelor group; Group structure  
  Abstract Abstract The maintenance and development of conservation areas by grazing of large herbivores, such as Przewalski's horses, is common practice. Several nature conservation areas house male bachelor groups of this species. When males are needed for breeding they are removed from the groups, often without considering group compositions and individual social positions. However, alpha animals are needed for ensuring group stability and decision making in potentially dangerous situations in several species. To investigate the role of the alpha male in a bachelor group, we observed the behaviour of five Przewalski's horse males during the enlargement of their enclosure. We analyzed the group's social structure and movement orders, as well as the animals' connectedness, activity budgets, and whether they moved with preferred group members and how factors such as social rank influenced the horses' behaviour. We also investigated the excretion of glucocorticoid metabolites (GCM) via faeces of the horses while exploring a new area as a parameter of glucocorticoid production. Our results show that the alpha male is important for a bachelor group in changing environmental conditions. The alpha male had the highest level of connectedness within the group. When exploring the new environment, its position in the group changed from previously being the last to being the first. Furthermore the whole group behaviour changed when exploring the new area. The stallions showed reduced resting behavior, increased feeding and did not stay close to each other. We found that the excretion of glucocorticoid metabolites of most horses rose only marginally during the first days on the new area while only the alpha male showed a significant increased amount of glucocorticoid production during the first day of the enclosure enlargement.  
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  ISSN 0031-9384 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5818  
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Author Boogert, N.J.; Reader, S.M.; Hoppitt, W.; Laland, K.N. url  doi
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  Title (down) The origin and spread of innovations in starlings Type Journal Article
  Year 2008 Publication Animal Behaviour Abbreviated Journal Anim. Behav.  
  Volume 75 Issue 4 Pages 1509-1518  
  Keywords diffusion dynamics; dominance; foraging; group; innovation; neophobia; social learning; social network; starling; Sturnus vulgaris  
  Abstract There are numerous reports of novel learned behaviour patterns in animal populations, yet the factors influencing the invention and spread of these innovations remain poorly understood. Here we investigated to what extent the pattern of spread of innovations in captive groups of starlings, Sturnus vulgaris, could be predicted by knowledge of individual and social group variables, including association patterns, social rank orders, measures of neophobia and asocial learning performance. We presented small groups of starlings with a series of novel extractive foraging tasks and recorded the latency for each bird to contact and solve each task, as well as the orders of contacting and solving. We then explored which variables best predicted the observed diffusion patterns. Object neophobia and social rank measures characterized who was the first of the group to contact the novel foraging tasks, and the subsequent spread of contacting tasks was associated with latency to feed in a novel environment. Asocial learning performance, measured in isolation, predicted who was the first solver of the novel foraging tasks in each group. Association patterns did not predict the spread of solving. Contact latency and solving duration were negatively correlated, consistent with social learning underlying the spread of solving. Our findings indicate that we can improve our understanding of the diffusion dynamics of innovations in animal groups by investigating group-dependent and individual variables in combination. We introduce novel methods for exploring predictors of the origin and spread of behavioural innovations that could be widely applied.  
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  ISSN 0003-3472 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 6036  
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Author Flauger, B. url  openurl
  Title (down) The introduction of horses into new social groups with special regard to their stress level Type Manuscript
  Year 2011 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Pferd; Equiden; Eingliederungstechnik; Integrationspferd; Stress; Cortisol; Endokrine Reaktion; Gruppenhaltung; Verletzungsgefahr; Aggression; Futterplatzwahl; Kot; Geruchssinn; Mensch-Pferd Interaktion; horse; equids; introduction technique; integration horse; stress; cortisol; endocrine response; group housing; injury risk; aggression; feeding decision; faecal sample; olfaction; human-horse interaction  
  Abstract Horses are a highly social species living in complex social systems which should require them to memorise and generalise social experiences and distinguish between familiar and unfamiliar conspecifics. In the main part of my thesis I concentrated on the specific conflict situation of a horse being introduced into a new social group, and investigated its behaviour and stress level. Horses were either introduced (1) immediately, (2) after an observation period, or (3) together with an integration horse after an observation period. Additionally, in the second part of my thesis I arranged several experiments to elaborate additional aspects which could affect the behaviour of horses during introductions. In this study I could describe a simplified method for measuring stress through the analysis of faecal GCMs in horses. An enzyme immunoassay (EIA) for 11-oxoaetiocholanolone using 11-oxoaetiocholanolone-17-CMO: BSA (3?,11-oxo-A EIA) as antigen showed high amounts of immunoreactive substances. The new assay increases the accuracy of the test and lowers the expenses per sample; also storing of samples at room temperature after collection is less critical. This is a big advantage both in the field of wildlife management of equids and in the field of equestrian sports (chapter 1). Comparing the different introduction techniques, the introduction with an integration horse led to significantly less total interactions and lower levels of aggression than the introduction of single horses, both immediately and after several days of observing the new group. Additionally, by observing the behaviour of the horses during everyday sociality I could develop a formula describing the interrelationship between expected aggression level and enclosure size per horse. The curve takes an exponential shape. Starting from a space allowance of 300 m2 and more per horse, the amount of aggressions per hour approaches zero. For the reduction of aggression levels and injury risks in socially kept horses I recommend an enclosure size of at least 300 m2 per horse (chapter 2). I further investigated the stress level of the introduced animals. Horses which were immediately introduced did not show elevated faecal GCMs. In contrast, horses which were introduced after an observation period had slightly elevated values 2 and 3 days after the introduction. For horses introduced together with an integration horse faecal GCMs were significantly above the baseline value on the day of introduction and 1 day after it. These differences between introduction techniques indicate that the introduction event itself is not as stressful as previously assumed. Rather standing together with an integration horse and not being able to integrate immediately into the complete group elicits stress in horses (chapter 3). In the commentary of chapter 4 several studies are discussed which failed to demonstrate social learning in horses. It is argued that they did not consider important aspects which could have an influence, such as the dominance status or the social background of the horses (chapter 4). In chapter 5 a social feeding situation was investigated. The social rank as well as the position of conspecifics affected the feeding strategy of horses. Domestic horses used social cognition and strategic decision making in order to decide where to feed. When possible they tended to return to the same, continuously supplied feeding site and switched to an ?avoidance tendency? in the presence of dominant horses or when another horse was already feeding there (chapter 5). One possibility to recognize group members is through olfactory recognition. In chapter 6 it is shown that horses are able to distinguish their own from their conspecifics? faeces. In addition, they paid most attention to the faeces of those group members from which they received the highest amount of aggressive behaviour (chapter 6). Horses show cognitive abilities because they are able to use humans as local enhancement cues when searching for food, independently of their body posture or gaze consistency when the persons face them. Moreover, they seem to orientate on the attention of familiar persons more than of unfamiliar persons (chapter 7). Altogether, the results of this thesis provide further support for the view that horses show good conflict resolution strategies. They are perfectly able to deal with the conflict situation of being introduced to new group members, and the introduction event itself is not as stressful as previously assumed. It is rather suggested that standing together with an integration horse and not being able to integrate immediately into the complete group elicits stress in horses. All additional experimental set-ups could demonstrate that horses are well capable of social cognition.  
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  Corporate Author Thesis Ph.D. thesis  
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  Call Number Equine Behaviour @ team @ epub18463 Serial 5736  
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Author Jacobs, A.; Maumy, M.; Petit, O. url  doi
openurl 
  Title (down) The influence of social organisation on leadership in brown lemurs (Eulemur fulvus fulvus) in a controlled environment Type Journal Article
  Year 2008 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 79 Issue 2 Pages 111-113  
  Keywords Animals; *Decision Making; Dominance-Subordination; *Exploratory Behavior; Female; Group Structure; *Leadership; Lemur/*psychology; Male; Sex Factors; *Social Environment  
  Abstract Studies on leadership during group movements in several lemur species showed that females were responsible for the travelling choices concerning time and direction. Interestingly, in these species females are dominant over males. We investigated the influence of social organisation upon leadership processes by studying a lemur species in which social organisation is characterized by the absence of female dominance: the brown lemur (Eulemur fulvus fulvus). The study was conducted on a semi-free ranging group of 11 individuals and the analysis performed on 69 group movements showed that all the individuals could initiate a group movement. In 34 cases, the whole group moved. There was no significant difference in the number of start attempts or in the number of group members involved from one initiator to another. Moreover, there was no effect of sex or age of the initiator on the number of individuals following it or on the speed of the joining process. Therefore, the leadership observed is widely distributed to all group members. These results support the hypothesis of an influence of social organisation upon the decision-making processes but still remain to be studied in a more relevant ecological context.  
  Address IPHC-DEPE, Equipe d'ethologie des primates, UMR 7178, Centre National de la Recherche Scientifique-Universite Louis Pasteur and Centre de Primatologie, Strasbourg, France  
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  ISSN 0376-6357 ISBN Medium  
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  Notes PMID:18586413 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5127  
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