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Author Dubois, F.; Giraldeau, L.-A. openurl 
  Title The forager's dilemma: food sharing and food defense as risk-sensitive foraging options Type Journal Article
  Year 2003 Publication The American Naturalist Abbreviated Journal Am Nat  
  Volume 162 Issue 6 Pages 768-779  
  Keywords Animals; Competitive Behavior/*physiology; *Environment; Feeding Behavior/*physiology; *Game Theory; *Models, Biological; Population Density; Population Dynamics  
  Abstract Although many variants of the hawk-dove game predict the frequency at which group foraging animals should compete aggressively, none of them can explain why a large number of group foraging animals share food clumps without any overt aggression. One reason for this shortcoming is that hawk-dove games typically consider only a single contest, while most group foraging situations involve opponents that interact repeatedly over discovered food clumps. The present iterated hawk-dove game predicts that in situations that are analogous to a prisoner's dilemma, animals should share the resources without aggression, provided that the number of simultaneously available food clumps is sufficiently large and the number of competitors is relatively small. However, given that the expected gain of an aggressive animal is more variable than the gain expected by nonaggressive individuals, the predicted effect of the number of food items in a clump-clump richness-depends on whether only the mean or both the mean and variability associated with payoffs are considered. More precisely, the deterministic game predicts that aggression should increase with clump richness, whereas the stochastic risk-sensitive game predicts that the frequency of encounters resulting in aggression should peak at intermediate clump richnesses or decrease with increasing clump richness if animals show sensitivity to the variance or coefficient of variation, respectively.  
  Address Departement des Sciences Biologiques, Universite du Quebec a Montreal, Case postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada. fdubois@u-bourgogne.fr  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-0147 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:14737714 Approved no  
  Call Number Serial 2132  
Permanent link to this record
 

 
Author Klein, E.D.; Zentall, T.R. doi  openurl
  Title Imitation and affordance learning by pigeons (Columba livia) Type Journal Article
  Year 2003 Publication Journal of comparative psychology (Washington, D.C. : 1983) Abbreviated Journal J Comp Psychol  
  Volume 117 Issue 4 Pages 414-419  
  Keywords Animals; *Behavior, Animal; Columbidae; Cues; *Imitative Behavior; *Learning; Odors; Sound  
  Abstract The bidirectional control procedure was used to determine whether pigeons (Columba livia) would imitate a demonstrator that pushed a sliding screen for food. One group of observers saw a trained demonstrator push a sliding screen door with its beak (imitation group), whereas 2 other groups watched the screen move independently (possibly learning how the environment works) with a conspecific either present (affordance learning with social facilitation) or absent (affordance learning alone). A 4th group could not see the screen being pushed (sound and odor control). Imitation was evidenced by the finding that pigeons that saw a demonstrator push the screen made a higher proportion of matching screen pushes than observers in 2 appropriate control conditions. Further, observers that watched a screen move without a demonstrator present made a significantly higher proportion of matching screen pushes than would be expected by chance. Thus, these pigeons were capable of affordance learning.  
  Address Department of Psychology, University of Kentucky, Lexington, KY 40506-004, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0735-7036 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:14717643 Approved no  
  Call Number refbase @ user @ Serial 234  
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Author Shapiro, A.D.; Janik, V.M.; Slater, P.J.B. url  doi
openurl 
  Title A gray seal's (Halichoerus grypus) responses to experimenter-given pointing and directional cues Type Journal Article
  Year 2003 Publication Journal of Comparative Psychology Abbreviated Journal J Comp Psychol  
  Volume 117 Issue 4 Pages 355-362  
  Keywords Animals; Behavior, Animal/*physiology; Cognition/physiology; Conditioning, Operant/physiology; *Cues; Eye Movements/physiology; Female; Seals, Earless  
  Abstract A gray seal (Halichoerus grypus) was trained to touch a target on its left or right by responding to pointing signals. The authors then tested whether the seal would be able to generalize spontaneously to altered signals. It responded correctly to center pointing and head turning, center upper body turning, and off-center pointing but not to head turning and eye movements alone. The seal also responded correctly to brief ipsilateral and contralateral points from center and lateral positions. Pointing gestures did not cause the seal to select an object placed centrally behind it. Like many animals in similar studies, this gray seal probably did not understand the referential character of these gestures but rather used signal generalization and experience from initial operant conditioning to solve these tasks.  
  Address School of Biology, University of St Andrews, St Andrews, Fife, United Kingdom  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. : 1983 Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0735-7036 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:14717636 Approved yes  
  Call Number Equine Behaviour @ team @ Serial 4977  
Permanent link to this record
 

 
Author Komar, N. openurl 
  Title West Nile virus: epidemiology and ecology in North America Type Journal Article
  Year 2003 Publication Advances in Virus Research Abbreviated Journal Adv Virus Res  
  Volume 61 Issue Pages 185-234  
  Keywords Animals; Bird Diseases/virology; Birds/virology; Culex/virology; Disease Reservoirs; Ecosystem; Epidemiology, Molecular; Horse Diseases/virology; Horses/virology; Humans; Insect Vectors; North America/epidemiology; Risk Factors; West Nile Fever/*epidemiology/transmission/veterinary; West Nile virus/genetics  
  Abstract  
  Address Centers for Disease Control and Prevention, Division of Vector-Borne Infectious Diseases, Fort Collins, Colorado 80522, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0065-3527 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:14714433 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2638  
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Author Wallner, B.; Brem, G.; Muller, M.; Achmann, R. doi  openurl
  Title Fixed nucleotide differences on the Y chromosome indicate clear divergence between Equus przewalskii and Equus caballus Type Journal Article
  Year 2003 Publication Animal Genetics Abbreviated Journal Anim Genet  
  Volume 34 Issue 6 Pages 453-456  
  Keywords Animals; Base Sequence; DNA, Mitochondrial/genetics; Genetic Variation/*genetics; Horses/classification/*genetics; Male; Molecular Sequence Data; Phylogeny; Probability; Species Specificity; Y Chromosome/*genetics  
  Abstract The phylogenetic relationship between Equus przewalskii and E. caballus is often a matter of debate. Although these taxa have different chromosome numbers, they do not form monophyletic clades in a phylogenetic tree based on mtDNA sequences. Here we report sequence variation from five newly identified Y chromosome regions of the horse. Two fixed nucleotide differences on the Y chromosome clearly display Przewalski's horse and domestic horse as sister taxa. At both positions the Przewalski's horse haplotype shows the ancestral state, in common with the members of the zebra/ass lineage. We discuss the factors that may have led to the differences in mtDNA and Y-chromosomal observations.  
  Address Institut fur Tierzucht und Genetik, Veterinarmedizinische Universitat Wien, Veterinarplatz, Wien, Austria. wallner@i122server.vu-wien.ac.at  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0268-9146 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:14687077 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5038  
Permanent link to this record
 

 
Author Passler, S.; Pfeffer, M. openurl 
  Title Detection of antibodies to alphaviruses and discrimination between antibodies to eastern and western equine encephalitis viruses in rabbit sera using a recombinant antigen and virus-specific monoclonal antibodies Type Journal Article
  Year 2003 Publication Journal of Veterinary Medicine. B, Infectious Diseases and Veterinary Public Health Abbreviated Journal J Vet Med B Infect Dis Vet Public Health  
  Volume 50 Issue 6 Pages 265-269  
  Keywords Animals; Antibodies, Monoclonal/*immunology; Antibodies, Viral/*analysis/blood; DNA Primers; Encephalitis Virus, Eastern Equine/genetics/*immunology; Encephalitis Virus, Western Equine/genetics/*immunology; Encephalomyelitis, Equine/*diagnosis/*virology; Epitopes; Fluorescent Antibody Technique/*veterinary; Horses; Rabbits; Recombination, Genetic; Reverse Transcriptase Polymerase Chain Reaction/veterinary  
  Abstract Three arthropod-borne alphaviruses, western equine encephalitis viruses (WEEV), eastern equine encephalitis viruses (EEEV) and Venezuelan equine encephalitis viruses are the aetiological agents of a sometimes severe encephalomyelitis in equines and humans in the New World. With regard to the different ecology and epidemiology of these viruses, a method applied in serological screening should be able to distinguish between them as well as other related members of the genus Alphavirus in the American continent. However, this has been hampered in the past by (a) the close antigenic relationship between alphaviruses in traditional serological assays, especially in the routinely used haemagglutination-inhibition, and (b) the need of biosafety level 3 facilities to grow the viral antigens. An epitope blocking assay using an EEEV glycoprotein E1-expressing recombinant Sindbis virus and virus-specific monoclonal antibodies (mAbs) binding to the E1 of EEEV (strain NJ/60) and the E1 of Sindbis virus was established using automated flow cytometry. The test was evaluated using sera of infected and vaccinated rabbits. A cut-off value of 30% inhibition for antigenic complex-specific seroconversion was found to be sufficient for the detection of the respective infection. By using three different mAbs in parallel, we were able to detect alphavirus genus-, EEEV- and WEEV-complex-specific serum antibodies. As this test is based on the inhibition of binding of virus-specific mAbs, sera of every origin other than mouse can be tested. Thus, this assay may prove useful in the serological screening of a variety of animal species during an outbreak investigation.  
  Address Institute for Medical Microbiology, Infectious and Epidemic Diseases, Veterinary Faculty, Ludwig-Maximilians-University, Munich, Germany  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0931-1793 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:14628996 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2639  
Permanent link to this record
 

 
Author Sole, L.M.; Shettleworth, S.J.; Bennett, P.J. openurl 
  Title Uncertainty in pigeons Type Journal Article
  Year 2003 Publication Psychonomic bulletin & review Abbreviated Journal Psychon Bull Rev  
  Volume 10 Issue 3 Pages 738-745  
  Keywords Animals; Behavior, Animal; Columbidae; *Decision Making; Reinforcement (Psychology); Reward; Transfer (Psychology); Visual Perception  
  Abstract Pigeons classified a display of illuminated pixels on a touchscreen as sparse or dense. Correct responses were reinforced with six food pellets; incorrect responses were unreinforced. On some trials an uncertain response option was available. Pecking it was always reinforced with an intermediate number of pellets. Like monkeys and people in related experiments, the birds chose the uncertain response most often when the stimulus presented was difficult to classify correctly, but in other respects their behavior was not functionally similar to human behavior based on conscious uncertainty or to the behavior of monkeys in comparable experiments. Our data were well described by a signal detection model that assumed that the birds were maximizing perceived reward in a consistent way across all the experimental conditions.  
  Address University of Toronto, Toronto, Ontario, Canada  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1069-9384 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:14620372 Approved no  
  Call Number refbase @ user @ Serial 366  
Permanent link to this record
 

 
Author Bergman, T.J.; Beehner, J.C.; Cheney, D.L.; Seyfarth, R.M. doi  openurl
  Title Hierarchical classification by rank and kinship in baboons Type Journal Article
  Year 2003 Publication Science (New York, N.Y.) Abbreviated Journal Science  
  Volume 302 Issue 5648 Pages 1234-1236  
  Keywords Animals; Animals, Wild; Botswana; *Cognition; Family; Female; *Hierarchy, Social; Language; *Papio/psychology; Social Dominance; Vocalization, Animal  
  Abstract Humans routinely classify others according to both their individual attributes, such as social status or wealth, and membership in higher order groups, such as families or castes. They also recognize that people's individual attributes may be influenced and regulated by their group affiliations. It is not known whether such rule-governed, hierarchical classifications are specific to humans or might also occur in nonlinguistic species. Here we show that baboons recognize that a dominance hierarchy can be subdivided into family groups. In playback experiments, baboons respond more strongly to call sequences mimicking dominance rank reversals between families than within families, indicating that they classify others simultaneously according to both individual rank and kinship. The selective pressures imposed by complex societies may therefore have favored cognitive skills that constitute an evolutionary precursor to some components of human cognition.  
  Address Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA. thore@sas.upenn.edu  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1095-9203 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:14615544 Approved no  
  Call Number refbase @ user @ Serial 689  
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Author Dunbar, R. doi  openurl
  Title Evolution of the social brain Type Journal Article
  Year 2003 Publication Science Abbreviated Journal Science  
  Volume 302 Issue 5648 Pages 1160-1161  
  Keywords Animals; Animals, Wild; *Cognition; Endorphins/physiology; *Evolution; Female; Grooming; Hierarchy, Social; Language; Neocortex/anatomy & histology/physiology; Papio/physiology/*psychology; *Reproduction; *Social Behavior; Social Dominance; Social Support; Vocalization, Animal  
  Abstract  
  Address School of Biological Sciences, University of Liverpool, Liverpool L69 7ZB, UK. rimd@liv.ac.uk  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1095-9203 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:14615522 Approved no  
  Call Number refbase @ user @ Serial 548  
Permanent link to this record
 

 
Author Imura, T.; Tomonaga, M. doi  openurl
  Title Perception of depth from shading in infant chimpanzees ( Pan troglodytes) Type Journal Article
  Year 2003 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 6 Issue 4 Pages 253-258  
  Keywords Age Factors; Animals; Contrast Sensitivity/*physiology; Depth Perception/*physiology; Discrimination Learning/*physiology; Female; Male; Pan troglodytes/growth & development/*physiology/*psychology; Pattern Recognition, Visual/physiology  
  Abstract We investigated the ability to perceive depth from shading, one of the pictorial depth cues, in three chimpanzee infants aged 4-10 months old, using a preferential reaching task commonly used to study pictorial depth perception in human infants. The chimpanzee infants reached significantly more to three-dimensional toys than to pictures thereof and more to the three-dimensional convex than to the concave. Furthermore, two of the three infants reached significantly more to the photographic convex than to the photographic concave. These infants also looked longer at the photographic convex than the concave. Our results suggest that chimpanzees perceive, at least as early as the latter half of the first year of life, pictorial depth defined by shading information. Photographic convexes contain richer information about pictorial depth (e.g., attached shadow, cast shadow, highlighted area, and global difference in brightness) than simple computer-graphic graded patterns. These cues together might facilitate the infants' perception of depth from shading.  
  Address Graduate School of Humanities, Kwansei Gakuin University, Uegahara, Nishinomiya, Hyogo 662-8501, Japan  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:14610661 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2550  
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