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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 (up) 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 PMID:14737714 Approved no  
  Call Number Serial 2132  
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Author Chiesa, A.D.; Pecchia, T.; Tommasi, L.; Vallortigara, G. doi  openurl
  Title Multiple landmarks, the encoding of environmental geometry and the spatial logics of a dual brain Type (up) Journal Article
  Year 2006 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 9 Issue 4 Pages 281-293  
  Keywords Animals; Association Learning/*physiology; Chickens; *Cues; Dominance, Cerebral/*physiology; *Environment; Exploratory Behavior/*physiology; Logic; Space Perception/*physiology; Spatial Behavior/physiology  
  Abstract A series of place learning experiments was carried out in young chicks (Gallus gallus) in order to investigate how the geometry of a landmark array and that of a walled enclosure compete when disoriented animals could rely on both of them to re-orient towards the centre of the enclosure. A square-shaped array (four wooden sticks) was placed in the middle of a square-shaped enclosure, the two structures being concentric. Chicks were trained to ground-scratch to search for food hidden in the centre of the enclosure (and the array). To check for effects of array degradation, one, two, three or all landmarks were removed during test trials. Chicks concentrated their searching activity in the central area of the enclosure, but their accuracy was inversely contingent on the number of landmarks removed; moreover, the landmarks still present within the enclosure appeared to influence the shape of the searching patterns. The reduction in the number of landmarks affected the searching strategy of chicks, suggesting that they had focussed mainly on local cues when landmarks were present within the enclosure. When all the landmarks were removed, chicks searched over a larger area, suggesting an absolute encoding of distances from the local cues and less reliance on the relationships provided by the geometry of the enclosure. Under conditions of monocular vision, chicks tended to rely on different strategies to localize the centre on the basis of the eye (and thus the hemisphere) in use, the left hemisphere attending to details of the environment and the right hemisphere attending to the global shape.  
  Address Department of Psychology and B.R.A.I.N. Centre for Neuroscience, University of Trieste, via S. Anastasio 12, 34100, Trieste, Italy  
  Corporate Author Thesis  
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  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 PMID:16941155 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2443  
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Author Bugnyar, T.; Heinrich, B. doi  openurl
  Title Pilfering ravens, Corvus corax, adjust their behaviour to social context and identity of competitors Type (up) Journal Article
  Year 2006 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 9 Issue 4 Pages 369-376  
  Keywords Adaptation, Psychological; Animals; *Behavior, Animal; *Competitive Behavior; Crows/*physiology; *Deception; Feeding Behavior; Female; Male; Social Behavior; *Social Environment  
  Abstract Like other corvids, food-storing ravens protect their caches from being pilfered by conspecifics by means of aggression and by re-caching. In the wild and in captivity, potential pilferers rarely approach caches until the storers have left the cache vicinity. When storers are experimentally prevented from leaving, pilferers first search at places other than the cache sites. These behaviours raise the possibility that ravens are capable of withholding intentions and providing false information to avoid provoking the storers' aggression for cache protection. Alternatively, birds may refrain from pilfering to avoid conflicts with dominants. Here we examined whether ravens adjust their pilfer tactics according to social context and type of competitors. We allowed birds that had witnessed a conspecific making caches to pilfer those caches either in private, together with the storer, or together with a conspecific bystander that had not created the caches (non-storer) but had seen them being made. Compared to in-private trials, ravens delayed approaching the caches only in the presence of storers. Furthermore, they quickly engaged in searching away from the caches when together with dominant storers but directly approached the caches when together with dominant non-storers. These findings demonstrate that ravens selectively alter their pilfer behaviour with those individuals that are likely to defend the caches (storers) and support the interpretation that they are deceptively manipulating the others' behaviour.  
  Address Department of Biology, University of Vermont, Burlington, VT 05405, USA. thomas.bugnyar@univie.ac.at  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16909235 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2449  
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Author Sovrano, V.A.; Bisazza, A.; Vallortigara, G. doi  openurl
  Title How fish do geometry in large and in small spaces Type (up) Journal Article
  Year 2007 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 10 Issue 1 Pages 47-54  
  Keywords Animals; *Association Learning; Color Perception; Cues; *Discrimination Learning; *Distance Perception; *Fishes; Male; Pattern Recognition, Visual; Social Environment; *Space Perception; Visual Perception  
  Abstract It has been shown that children and non-human animals seem to integrate geometric and featural information to different extents in order to reorient themselves in environments of different spatial scales. We trained fish (redtail splitfins, Xenotoca eiseni) to reorient to find a corner in a rectangular tank with a distinctive featural cue (a blue wall). Then we tested fish after displacement of the feature on another adjacent wall. In the large enclosure, fish chose the two corners with the feature, and also tended to choose among them the one that maintained the correct arrangement of the featural cue with respect to geometric sense (i.e. left-right position). In contrast, in the small enclosure, fish chose both the two corners with the features and the corner, without any feature, that maintained the correct metric arrangement of the walls with respect to geometric sense. Possible reasons for species differences in the use of geometric and non-geometric information are discussed.  
  Address Department of General Psychology, University of Padua, Via Venezia, 8, 35131, Padova, Italy. valeriaanna.sovrano@unipd.it  
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  Language English Summary Language Original Title  
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  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16794851 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2462  
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Author Gajdon, G.K.; Fijn, N.; Huber, L. doi  openurl
  Title Limited spread of innovation in a wild parrot, the kea (Nestor notabilis) Type (up) Journal Article
  Year 2006 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 9 Issue 3 Pages 173-181  
  Keywords Animal Communication; Animals; Diffusion of Innovation; Feeding Behavior; Female; *Imitative Behavior; *Learning; Male; *Motor Skills; *Parrots; *Problem Solving; Sex Factors; Social Dominance; Social Environment; Statistics, Nonparametric  
  Abstract In the local population of kea in Mount Cook Village, New Zealand, some keas open the lids of rubbish bins with their bill to obtain food scraps within. We investigated the extent to which this innovation has spread in the local population, and what factors limit the acquisition of bin opening. Only five males of 36 individually recognised birds were observed to have performed successful bin opening. With one exception there were always other keas present, watching successful bin opening. Seventeen additional individuals were seen to have benefitted from lid opening. Their foraging success was less than that of the bin openers. Social status of bin openers did not differ from scrounging males. Among the individuals that were regularly seen at the site of the bins but were not successful in bin opening, social status and the ratio of feeding directly from open bins correlated with the amount of opening attempts. We conclude that scrounging facilitated certain behavioural aspects of bin opening rather than inhibiting them. The fact that only 9% of opening attempts were successful, and the long period of time required to increase efficiency in lid opening shows that mainly individual experience, and to a lesser extent insight and social learning, play key roles in acquisition of the opening technique. The results indicate that the spread of innovative solutions of challenging mechanical problems in animals may be restricted to only a few individuals.  
  Address Department for Behavior, Neurobiology and Cognition, University of Vienna, 1090, Vienna, Austria. gyula.gajdon@univie.ac.at  
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  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16568276 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2472  
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Author Call, J.; Carpenter, M.; Tomasello, M. doi  openurl
  Title Copying results and copying actions in the process of social learning: chimpanzees (Pan troglodytes) and human children (Homo sapiens) Type (up) Journal Article
  Year 2005 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 8 Issue 3 Pages 151-163  
  Keywords Animals; Child Behavior; Child, Preschool; *Concept Formation; Female; Humans; *Imitative Behavior; *Learning; Male; Pan troglodytes; *Problem Solving; Psychomotor Performance; Random Allocation; *Social Environment; Species Specificity  
  Abstract There is currently much debate about the nature of social learning in chimpanzees. The main question is whether they can copy others' actions, as opposed to reproducing the environmental effects of these actions using their own preexisting behavioral strategies. In the current study, chimpanzees (Pan troglodytes) and human children (Homo sapiens) were shown different demonstrations of how to open a tube-in both cases by a conspecific. In different experimental conditions, demonstrations consisted of (1) action only (the actions necessary to open the tube without actually opening it); (2) end state only (the open tube, without showing any actions); (3) both of these components (in a full demonstration); or (4) neither of these components (in a baseline condition). In the first three conditions subjects saw one of two different ways that the tube could open (break in middle; caps off ends). Subjects' behavior in each condition was assessed for how often they opened the tube, how often they opened it in the same location as the demonstrator, and how often they copied the demonstrator's actions or style of opening the tube. Whereas chimpanzees reproduced mainly the environmental results of the demonstrations (emulation), human children often reproduced the demonstrator's actions (imitation). Because the procedure used was similar in many ways to the procedure that Meltzoff (Dev Psych 31:1, 1995) used to study the understanding of others' unfulfilled intentions, the implications of these findings with regard to chimpanzees' understanding of others' intentions are also discussed.  
  Address Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103, Leipzig, Germany. call@eva.mpg.de  
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  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15490290 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2504  
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Author Gazit, I.; Goldblatt, A.; Terkel, J. doi  openurl
  Title The role of context specificity in learning: the effects of training context on explosives detection in dogs Type (up) Journal Article
  Year 2005 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 8 Issue 3 Pages 143-150  
  Keywords Animals; *Association Learning; Conditioning, Classical; *Discrimination Learning; Dogs; *Environment; *Generalization, Stimulus; *Smell  
  Abstract Various experiments revealed that if an animal learns a stimulus-response-reinforcer relationship in one context and is then tested in another context there is usually a lessening of stimulus control, and the same discriminative stimuli that reliably controlled the behavior in the first context will have less effect in the new context. This reduction in performance is known as the “context shift effect.” The effect of changing context on the probability of detecting explosives was investigated in seven highly trained explosives detection dogs (EDDs). In experiment 1 the dogs were trained alternately on path A, which always had five hidden explosives, and on a very similar path B, which never had any explosives. Within a few sessions the dogs showed a significant decrease in search behavior on path B, but not on path A. In experiment 2 the same dogs were trained only on path B with a target density of one explosive hidden every 4th day. The probability of the dogs now detecting the explosive was found to be significantly lower than in experiment 1. In experiment 3 the effect of the low target density as used in experiment 2 was investigated on a new but very similar path C. Both the detection probability for the one explosive every 4th day on the new path and the motivation to search were significantly higher than found in experiment 2. Finally, in experiment 4, an attempt was made to recondition the dogs to search on path B. Although trained for 12 daily sessions with one explosive hidden every session, the dogs failed to regain the normal levels of motivation they had shown on both new paths and on the paths that they knew usually contained explosives. The findings reveal that even a very intensively trained EDD will rapidly learn that a specific stretch of path does not contain explosives. The dog will then be less motivated to search and will miss newly placed targets. This learning is specific to the formerly always-clean path and is to some extent irreversible. However, the dog will search and detect normally on new paths even if they are very similar to the always-clean path. The data are discussed in terms of variables affecting renewal. The results suggest that following training designed to make a behavior “context independent,” any extinction training will not generalize beyond that specific context used during the extinction training. In addition, if the behavior is extinguished in a specific context, it will be very difficult to restore that behavior in that context. These conclusions should be considered by anyone attempting to extinguish well-established trans-context behaviors.  
  Address Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel. iritgazi@post.tau.ac.il  
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  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15449101 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2509  
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Author Barth, J.; Reaux, J.E.; Povinelli, D.J. doi  openurl
  Title Chimpanzees' (Pan troglodytes) use of gaze cues in object-choice tasks: different methods yield different results Type (up) Journal Article
  Year 2005 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 8 Issue 2 Pages 84-92  
  Keywords Animals; *Attention; *Choice Behavior; *Cues; *Eye Movements; Female; Male; *Nonverbal Communication; Orientation; Pan troglodytes/*psychology; Social Environment  
  Abstract To assess the influence of different procedures on chimpanzees' performance in object-choice tasks, five adult chimpanzees were tested using three experimenter-given cues to food location: gazing, glancing, and pointing. These cues were delivered to the subjects in an identical fashion but were deployed within the context of two distinct meta-procedures that have been previously employed with this species with conflicting results. In one procedure, the subjects entered the test unit and approached the experimenter (who had already established the cue) on each trial. In the other procedure, the subjects stayed in the test unit throughout a session, witnessed the hiding procedure, and waited for a delay of 10 s during which the cue was provided. The subjects scored at high levels far exceeding chance in response to the gaze cue only when they approached the experimenter for each trial. They performed at chance levels when they stayed inside the test unit throughout the session. They scored at chance levels on all other cues irrespective of the procedure. These findings imply that (a) chimpanzees can immediately exploit social gaze cues, and (b) previous conflicting findings were likely due to the different meta-procedures that were used.  
  Address Department of Neurocognition, Faculty of Psychology, Universiteit Maastricht, P.O. Box 616, 6200 MD, Maastricht, The Netherlands. j.barth@psychology.unimaas.nl  
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  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15449100 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2510  
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Author Tomasello, M.; Call, J. doi  openurl
  Title The role of humans in the cognitive development of apes revisited Type (up) Journal Article
  Year 2004 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 7 Issue 4 Pages 213-215  
  Keywords Animals; *Behavior, Animal; *Cognition; Culture; Hominidae/*psychology; Humans; *Imitative Behavior; Imprinting (Psychology); *Intention; Social Behavior; *Social Environment; Species Specificity  
  Abstract  
  Address Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany. tomas@eva.mpg.de  
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  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15278733 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2517  
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Author Fripp, D.; Owen, C.; Quintana-Rizzo, E.; Shapiro, A.; Buckstaff, K.; Jankowski, K.; Wells, R.; Tyack, P. doi  openurl
  Title Bottlenose dolphin (Tursiops truncatus) calves appear to model their signature whistles on the signature whistles of community members Type (up) Journal Article
  Year 2005 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 8 Issue 1 Pages 17-26  
  Keywords Acoustic Stimulation; Animals; Dolphins/*psychology; Female; *Imitative Behavior; Individuality; *Learning; *Social Environment; *Vocalization, Animal  
  Abstract Bottlenose dolphins are unusual among non-human mammals in their ability to learn new sounds. This study investigates the importance of vocal learning in the development of dolphin signature whistles and the influence of social interactions on that process. We used focal animal behavioral follows to observe six calves in Sarasota Bay, Fla., recording their social associations during their first summer, and their signature whistles during their second. The signature whistles of five calves were determined. Using dynamic time warping (DTW) of frequency contours, the calves' signature whistles were compared to the signature whistles of several sets of dolphins: their own associates, the other calves' associates, Tampa Bay dolphins, and captive dolphins. Whistles were considered similar if their DTW similarity score was greater than those of 95% of the whistle comparisons. Association was defined primarily in terms of time within 50 m of the mother/calf pair. On average, there were six dolphins with signature whistles similar to the signature whistles of each of the calves. These were significantly more likely to be Sarasota Bay resident dolphins than non-Sarasota dolphins, and (though not significantly) more likely to be dolphins that were within 50 m of the mother and calf less than 5% of the time. These results suggest that calves may model their signature whistles on the signature whistles of members of their community, possibly community members with whom they associate only rarely.  
  Address Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA. deborah.fripp@verizon.net  
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  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:15221637 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2520  
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