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Author Cameron, E.Z.; du Toit, J.T. doi  openurl
  Title Winning by a neck: tall giraffes avoid competing with shorter browsers Type Journal Article
  Year 2007 Publication The American naturalist Abbreviated Journal Am Nat  
  Volume 169 Issue 1 Pages 130-135  
  Keywords Acacia/growth & development; Animals; Feeding Behavior/*physiology; Neck/*anatomy & histology; Plant Leaves/growth & development; Ruminants/*anatomy & histology/*physiology; South Africa  
  Abstract With their vertically elongated body form, giraffes generally feed above the level of other browsers within the savanna browsing guild, despite having access to foliage at lower levels. They ingest more leaf mass per bite when foraging high in the tree, perhaps because smaller, more selective browsers deplete shoots at lower levels or because trees differentially allocate resources to promote shoot growth in the upper canopy. We erected exclosures around individual Acacia nigrescens trees in the greater Kruger ecosystem, South Africa. After a complete growing season, we found no differences in leaf biomass per shoot across height zones in excluded trees but significant differences in control trees. We conclude that giraffes preferentially browse at high levels in the canopy to avoid competition with smaller browsers. Our findings are analogous with those from studies of grazing guilds and demonstrate that resource partitioning can be driven by competition when smaller foragers displace larger foragers from shared resources. This provides the first experimental support for the classic evolutionary hypothesis that vertical elongation of the giraffe body is an outcome of competition within the browsing ungulate guild.  
  Address Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1537-5323 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17206591 Approved no  
  Call Number refbase @ user @ Serial 410  
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Author Broom, M. openurl 
  Title A unified model of dominance hierarchy formation and maintenance Type Journal Article
  Year 2002 Publication Journal of theoretical biology Abbreviated Journal J. Theor. Biol.  
  Volume 219 Issue 1 Pages 63-72  
  Keywords Animals; *Behavior, Animal; Feeding Behavior; *Models, Psychological; *Social Dominance; Social Environment  
  Abstract In many different species it is common for animals to spend large portions of their lives in groups. Such groups need to divide available resources amongst the individuals they contain and this is often achieved by means of a dominance hierarchy. Sometimes hierarchies are stable over a long period of time and new individuals slot into pre-determined positions, but there are many situations where this is not so and a hierarchy is formed out of a group of individuals meeting for the first time. There are several different models both of the formation of such dominance hierarchies and of already existing hierarchies. These models often treat the two phases as entirely separate, whereas in reality, if there is a genuine formation phase to the hierarchy, behaviour in this phase will be governed by the rewards available, which in turn depends upon how the hierarchy operates once it has been formed. This paper describes a method of unifying models of these two distinct phases, assuming that the hierarchy formed is stable. In particular a framework is introduced which allows a variety of different models of each of the two parts to be used in conjunction with each other, thus enabling a wide range of situations to be modelled. Some examples are given to show how this works in practice.  
  Address Centre for Statistics and Stochastic Modelling, School of Mathematical Sciences, University of Sussex, Falmer, Brighton, BN1 9QH, U.K. m.broom@sussex.ac.uk  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-5193 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12392975 Approved no  
  Call Number refbase @ user @ Serial 439  
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Author Amdam, G.V.; Csondes, A.; Fondrk, M.K.; Page, R.E.J. doi  openurl
  Title Complex social behaviour derived from maternal reproductive traits Type Journal Article
  Year 2006 Publication Nature Abbreviated Journal Nature  
  Volume 439 Issue 7072 Pages 76-78  
  Keywords Aging/physiology; Animals; Bees/*physiology; *Evolution; Feeding Behavior/*physiology; Female; Infertility, Female; Maternal Behavior/*physiology; Ovary/physiology; Pollen/metabolism; Reproduction/*physiology; *Social Behavior  
  Abstract A fundamental goal of sociobiology is to explain how complex social behaviour evolves, especially in social insects, the exemplars of social living. Although still the subject of much controversy, recent theoretical explanations have focused on the evolutionary origins of worker behaviour (assistance from daughters that remain in the nest and help their mother to reproduce) through expression of maternal care behaviour towards siblings. A key prediction of this evolutionary model is that traits involved in maternal care have been co-opted through heterochronous expression of maternal genes to result in sib-care, the hallmark of highly evolved social life in insects. A coupling of maternal behaviour to reproductive status evolved in solitary insects, and was a ready substrate for the evolution of worker-containing societies. Here we show that division of foraging labour among worker honey bees (Apis mellifera) is linked to the reproductive status of facultatively sterile females. We thereby identify the evolutionary origin of a widely expressed social-insect behavioural syndrome, and provide a direct demonstration of how variation in maternal reproductive traits gives rise to complex social behaviour in non-reproductive helpers.  
  Address Arizona State University, School of Life Sciences, Tempe, Arizona 85287, USA. Gro.Amdam@asu.edu  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1476-4687 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16397498 Approved no  
  Call Number refbase @ user @ Serial 531  
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Author Brauer, J.; Kaminski, J.; Riedel, J.; Call, J.; Tomasello, M. doi  openurl
  Title Making inferences about the location of hidden food: social dog, causal ape Type Journal Article
  Year 2006 Publication Journal of comparative psychology Abbreviated Journal J Comp Psychol  
  Volume 120 Issue 1 Pages 38-47  
  Keywords Animals; Communication; Cues; Dogs; Exploratory Behavior; *Feeding Behavior; Female; *Food; Male; Pan paniscus; Pan troglodytes; *Visual Perception  
  Abstract Domestic dogs (Canis familiaris) and great apes from the genus Pan were tested on a series of object choice tasks. In each task, the location of hidden food was indicated for subjects by some kind of communicative, behavioral, or physical cue. On the basis of differences in the ecologies of these 2 genera, as well as on previous research, the authors hypothesized that dogs should be especially skillful in using human communicative cues such as the pointing gesture, whereas apes should be especially skillful in using physical, causal cues such as food in a cup making noise when it is shaken. The overall pattern of performance by the 2 genera strongly supported this social-dog, causal-ape hypothesis. This result is discussed in terms of apes' adaptations for complex, extractive foraging and dogs' adaptations, during the domestication process, for cooperative communication with humans.  
  Address Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany. jbraeuer@eva.mpg.de  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. : 1983 Editor  
  Language English Summary Language Original Title  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0735-7036 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16551163 Approved yes  
  Call Number refbase @ user @ Serial 597  
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Author Caldwell, C.A.; Whiten, A. doi  openurl
  Title Testing for social learning and imitation in common marmosets, Callithrix jacchus, using an artificial fruit Type Journal Article
  Year 2004 Publication Animal cognition Abbreviated Journal Anim. Cogn.  
  Volume 7 Issue 2 Pages 77-85  
  Keywords Animals; *Association Learning; Callithrix/*psychology; Discrimination Learning; *Feeding Behavior; Female; Food Preferences; Fruit; *Imitative Behavior; Male; *Social Behavior; Social Environment  
  Abstract We tested for social learning and imitation in common marmosets using an artificial foraging task and trained conspecific demonstrators. We trained a demonstrator marmoset to open an artificial fruit, providing a full demonstration of the task to be learned. Another marmoset provided a partial demonstration, controlling for stimulus enhancement effects, by eating food from the outside of the apparatus. We thus compared three observer groups, each consisting of four animals: those that received the full demonstration, those that received the partial demonstration, and a control group that saw no demonstration prior to testing. Although none of the observer marmosets succeeded in opening the artificial fruit during the test periods, there were clear effects of demonstration type. Those that saw the full demonstration manipulated the apparatus more overall, whereas those from the control group manipulated it the least of the three groups. Those from the full-demonstration group also contacted the particular parts of the artificial fruit that they had seen touched (localised stimulus enhancement) to a greater extent than the other two groups. There was also an interaction between the number of hand and mouth touches made to the artificial fruit for the full- and partial-demonstration groups. Whether or not these data represent evidence for imitation is discussed. We also propose that the clear differences between the groups suggest that social learning mechanisms provide real benefits to these animals in terms of developing novel food-processing skills analogous to the one presented here.  
  Address Centre for Social Learning and Cognitive Evolution and Scottish Primate Research Group, University of St Andrews, KY16 9JU, St Andrews, Fife, Scotland. C.A.Caldwell@exeter.ac.uk  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15069606 Approved no  
  Call Number refbase @ user @ Serial 735  
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Author Devenport, J.A.; Patterson, M.R.; Devenport, L.D. doi  openurl
  Title Dynamic averaging and foraging decisions in horses (Equus callabus) Type Journal Article
  Year 2005 Publication Journal of Comparative psychology Abbreviated Journal J. Comp. Psychol.  
  Volume 119 Issue 3 Pages 352-358  
  Keywords Animals; *Decision Making; *Feeding Behavior; Female; Horses/*psychology; Male; *Memory, Short-Term; Motivation; Orientation; *Social Environment  
  Abstract The variability of most environments taxes foraging decisions by increasing the uncertainty of the information available. One solution to the problem is to use dynamic averaging, as do some granivores and carnivores. Arguably, the same strategy could be useful for grazing herbivores, even though their food renews and is more homogeneously distributed. Horses (Equus callabus) were given choices between variable patches after short or long delays. When patch information was current, horses returned to the patch that was recently best, whereas those without current information matched choices to the long-term average values of the patches. These results demonstrate that a grazing species uses dynamic averaging and indicate that, like granivores and carnivores, they can use temporal weighting to optimize foraging decisions.  
  Address Department of Psychology, University of Central Oklahoma, 73034, USA. jdevenport@ucok.edu  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0735-7036 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16131264 Approved no  
  Call Number refbase @ user @ Serial 752  
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Author Hirsch, B.T. doi  openurl
  Title Costs and benefits of within-group spatial position: a feeding competition model Type Journal Article
  Year 2007 Publication The Quarterly review of biology Abbreviated Journal Q Rev Biol  
  Volume 82 Issue 1 Pages 9-27  
  Keywords Animals; Competitive Behavior/*physiology; Dominance-Subordination; Feeding Behavior/*physiology/*psychology; Population Dynamics; Predatory Behavior/*physiology  
  Abstract An animal's within-group spatial position has several important fitness consequences. Risk of predation, time spent engaging in antipredatory behavior and feeding competition can all vary with respect to spatial position. Previous research has found evidence that feeding rates are higher at the group edge in many species, but these studies have not represented the entire breadth of dietary diversity and ecological situations faced by many animals. In particular the presence of concentrated, defendable food patches can lead to increased feeding rates by dominants in the center of the group that are able to monopolize or defend these areas. To fully understand the tradeoffs of within-group spatial position in relation to a variety of factors, it is important to be able to predict where individuals should preferably position themselves in relation to feeding rates and food competition. A qualitative model is presented here to predict how food depletion time, abundance of food patches within a group, and the presence of prior knowledge of feeding sites affect the payoffs of different within-group spatial positions for dominant and subordinate animals. In general, when feeding on small abundant food items, individuals at the front edge of the group should have higher foraging success. When feeding on slowly depleted, rare food items, dominants will often have the highest feeding rates in the center of the group. Between these two extreme points of a continuum, an individual's optimal spatial position is predicted to be influenced by an additional combination of factors, such as group size, group spread, satiation rates, and the presence of producer-scrounger tactics.  
  Address Department of Anthropology, Stony Brook University Stony Brook, New York 11794, USA. BTHIRSCH@IC.SUNYSB.EDU  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0033-5770 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17354992 Approved no  
  Call Number refbase @ user @ Serial 803  
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Author Li, F.-H.; Zhong, W.-Q.; Wang, Z.; Wang, D.-H. doi  openurl
  Title Rank in a food competition test and humoral immune functions in male Brandt's voles (Lasiopodomys brandtii) Type Journal Article
  Year 2007 Publication Physiology & behavior Abbreviated Journal Physiol. Behav.  
  Volume 90 Issue 2-3 Pages 490-495  
  Keywords Animals; Antibody Formation/*physiology; Arvicolinae/immunology/*physiology; Competitive Behavior/*physiology; *Dominance-Subordination; Feeding Behavior/physiology; Hydrocortisone/blood; Male; *Social Dominance; Spleen/immunology/physiology  
  Abstract Social status can influence an animal's immune and reproductive functions, eventually leading to alterations in immunocompetence and reproductive success. Here, we report that rank assessed in a food competition test, considered as an index of social status, has significant influences on humoral immune functions in male Brandt's voles (Lasiopodomys brandtii) living in a group. Our data reveal a negative correlation of the spleen mass and serum antibody levels with social status, as well as a positive correlation of serum cortisol levels with social status. Males winning in food competition had a smaller spleen, a lower level of serum antibodies, and a higher level of serum cortisol than did their conspecific counterparts. These data indicate interactions between social status and humoral immune functions and might illustrate a trade-off between infection risks and reproductive success in male Brandt's voles.  
  Address State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, The Chinese Academy of Sciences, No. 25 Beisihuan Xilu, Zhongguancun, Haidian, Beijing 100080, China  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9384 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17141282 Approved no  
  Call Number refbase @ user @ Serial 804  
Permanent link to this record
 

 
Author Fragaszy, D.; Visalberghi, E. openurl 
  Title Socially biased learning in monkeys Type Journal Article
  Year 2004 Publication Learning & behavior : a Psychonomic Society publication Abbreviated Journal Learn Behav  
  Volume 32 Issue 1 Pages 24-35  
  Keywords Adaptation, Psychological; Animal Communication; Animals; Behavior, Animal; *Feeding Behavior/psychology; Food Preferences/psychology; Haplorhini/*psychology; *Imitative Behavior; Imprinting (Psychology); *Learning; *Social Environment; *Social Facilitation  
  Abstract We review socially biased learning about food and problem solving in monkeys, relying especially on studies with tufted capuchin monkeys (Cebus apella) and callitrichid monkeys. Capuchin monkeys most effectively learn to solve a new problem when they can act jointly with an experienced partner in a socially tolerant setting and when the problem can be solved by direct action on an object or substrate, but they do not learn by imitation. Capuchin monkeys are motivated to eat foods, whether familiar or novel, when they are with others that are eating, regardless of what the others are eating. Thus, social bias in learning about foods is indirect and mediated by facilitation of feeding. In most respects, social biases in learning are similar in capuchins and callitrichids, except that callitrichids provide more specific behavioral cues to others about the availability and palatability of foods. Callitrichids generally are more tolerant toward group members and coordinate their activity in space and time more closely than capuchins do. These characteristics support stronger social biases in learning in callitrichids than in capuchins in some situations. On the other hand, callitrichids' more limited range of manipulative behaviors, greater neophobia, and greater sensitivity to the risk of predation restricts what these monkeys learn in comparison with capuchins. We suggest that socially biased learning is always the collective outcome of interacting physical, social, and individual factors, and that differences across populations and species in social bias in learning reflect variations in all these dimensions. Progress in understanding socially biased learning in nonhuman species will be aided by the development of appropriately detailed models of the richly interconnected processes affecting learning.  
  Address Psychology Department, University of Georgia, Athens, Georgia 30602, USA. doree@uga.edu  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1543-4494 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15161138 Approved no  
  Call Number refbase @ user @ Serial 828  
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Author van Heel, M.C.V.; Kroekenstoel, A.M.; van Dierendonck, M.C.; van Weeren, P.R.; Back, W. openurl 
  Title Uneven feet in a foal may develop as a consequence of lateral grazing behaviour induced by conformational traits Type Journal Article
  Year 2006 Publication Equine veterinary journal Abbreviated Journal Equine. Vet. J.  
  Volume 38 Issue 7 Pages 646-651  
  Keywords Aging/*physiology; Animals; Animals, Newborn/anatomy & histology/growth & development/physiology; Feeding Behavior/*physiology; Female; Forelimb/*anatomy & histology/*physiology; *Horses/anatomy & histology/growth & development/physiology; Male  
  Abstract REASONS FOR PERFORMING STUDY: Conformational traits are important in breeding, since they may be indicative for performance ability and susceptibility to injuries. OBJECTIVES: To study whether certain desired conformational traits of foals are related to lateralised behaviour while foraging and to the development of uneven feet. METHODS: Twenty-four Warmblood foals, born and raised at the same location, were studied for a year. Foraging behaviour was observed by means of weekly 10 min scan-sampling for 8 h. A preference test (PT) was developed to serve as a standardised tool to determine laterality. The foals were evaluated at age 3, 15, 27 and 55 weeks. The PT and distal limb conformation were used to study the relation between overall body conformation, laterality and the development of uneven feet. Pressure measurements were used to determine the loading patterns under the feet. RESULTS: About 50% of the foals developed a significant preference to protract the same limb systematically while grazing, which resulted in uneven feet and subsequently uneven loading patterns. Foals with relatively long limbs and small heads were predisposed to develop laterality and, consequently unevenness. CONCLUSIONS: Conformational traits may stimulate the development of laterality and therefore indirectly cause uneven feet.  
  Address Derona Equine Performance Laboratory, Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 12, NL-3584 CM Utrecht, The Netherlands  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:17228580 Approved no  
  Call Number Serial 1774  
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