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Author Bugnyar, T.; Kotrschal, K. url  openurl
  Title Observational learning and the raiding of food caches in ravens, Corvus corax: is it `tactical' deception? Type Journal Article
  Year 2002 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 64 Issue 2 Pages 185-195  
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  Abstract Group-foraging ravens scatter-hoard when they are competing for food and, to some extent, also raid the caches made by others. We investigated the effects of observational spatial memory on individual caching and raiding tactics. With captive ravens, we found visual observation was essential for locating and raiding the caches of conspecifics. Both captive and free-ranging ravens, food cachers as well as potential cache raiders, responded to each other's presence. Cachers withdrew from conspecifics and most often placed their caches behind structures, obstructing the view of potential observers. Raiders watched inconspicuously and kept at a distance to cachers close to their cache sites. In response to the presence of potential raiders or because of their initial movements towards caches, the cachers frequently interrupted caching, changed cache sites, or recovered their food items. These results suggest that ravens, regardless of whether they act as cachers or raiders, are capable of withholding information about their intentions and, hence, manipulate the other bird's attention either to prevent or to achieve social-learning opportunities. Such interactions may qualify as `tactical' deception and may have created a considerable pressure selecting for social cognition in ravens. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.  
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  Call Number Equine Behaviour @ team @ Serial 2904  
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Author Range, F.; Bugnyar, T.; Schlogl, C.; Kotrschal, K. doi  openurl
  Title Individual and sex differences in learning abilities of ravens Type Journal Article
  Year 2006 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 73 Issue 1 Pages 100-106  
  Keywords Animals; Behavior, Animal/*physiology; *Crows; Discrimination Learning/*physiology; Exploratory Behavior/physiology; Female; *Individuality; Male; Sex Factors; Spatial Behavior  
  Abstract Behavioral and physiological characteristics of individuals within the same species have been found to be stable across time and contexts. In this study, we investigated individual differences in learning abilities and object and social manipulation to test for consistency within individuals across different tasks. Individual ravens (Corvus corax) were tested in simple color and position discrimination tasks to establish their learning abilities. We found that males were significantly better in the acquisition of the first discrimination task and the object manipulation task, but not in any of the other tasks. Furthermore, faster learners engaged less often in manipulations of conspecifics and exploration of objects to get access to food. No relationship between object and social manipulation and reversal training were found. Our results suggest that individual differences in regard to the acquisition of new tasks may be related to personalities or at least object manipulation in ravens.  
  Address Konrad Lorenz Research Station, A-4645 Gruenau 11, Austria. friederike.range@univie.ac.at  
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  ISSN 0376-6357 ISBN (up) Medium  
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  Notes PMID:16675158 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4146  
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Author Kralj-Fiser, S.; Scheiber, I.B.R.; Blejec, A.; Moestl, E.; Kotrschal, K. doi  openurl
  Title Individualities in a flock of free-roaming greylag geese: behavioral and physiological consistency over time and across situations Type Journal Article
  Year 2007 Publication Hormones and Behavior Abbreviated Journal Horm Behav  
  Volume 51 Issue 2 Pages 239-248  
  Keywords Animals; Behavior, Animal/*physiology; Corticosterone/metabolism; Feces; Female; Geese/*physiology; Individuality; Male; Personality/*physiology; Population Density; Reproducibility of Results; Seasons; *Social Behavior; Social Environment; Testosterone/*metabolism  
  Abstract The concept of personality implies individual differences in behavior and physiology that show some degree of repeatability/consistency over time and across contexts. Most studies of animal personality, particularly studies of individuals' variation in physiological mechanisms, have been conducted on selected individuals in controlled conditions. We attempted to detect consistent behaviors as well as physiological patterns in greylag ganders (Anser anser) from a free-roaming flock living in semi-natural conditions. We tested 10 individuals repeatedly, in a handling trial, resembling tests for characterization of “temperaments” in captive animals. We recorded the behavior of the same 10 individuals during four situations in the socially intact flock: (1) a “low density feeding condition”, (2) a “high density feeding condition”, (3) a “low density post-feeding situation” and (4) while the geese rested. We collected fecal samples for determination of excreted immuno-reactive corticosterone (BM) and testosterone metabolites (TM) after handling trials, as well as the “low density feeding” and the “high density feeding” conditions. BM levels were very highly consistent over the repeats of handling trials, and the “low density feeding condition” and tended to be consistent over the first two repeats of the “high density feeding condition”. Also, BM responses tended to be consistent across contexts. Despite seasonal variation, there tended to be inter-test consistency of TM, which pointed to some individual differences in TM as well. Aggressiveness turned out to be a highly repeatable trait, which was consistent across social situations, and tended to correlate with an individual's resistance during handling trials. Also, “proximity to the female partner” and “sociability” – the average number of neighboring geese in a close distance while resting – were consistent. We conclude that aggressiveness, “affiliative tendencies” and levels of excreted corticosterone and testosterone metabolites may be crucial factors of personality in geese.  
  Address University of Ljubljana, Biotechnical faculty, Slovenia. simona.kralj@guest.arnes.si  
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  ISSN 0018-506X ISBN (up) Medium  
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  Notes PMID:17196200 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4189  
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Author Bugnyar, T.; Kotrschal, K. doi  openurl
  Title Leading a conspecific away from food in ravens ( Corvus corax)? Type Journal Article
  Year 2004 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 7 Issue 2 Pages 69-76  
  Keywords Misleading – Deception – Raven – Social foraging  
  Abstract Active misleading of conspecifics has been described as a social strategy mainly for primates. Here we report a raven leading a competitor away from food in a social foraging task. Four individuals had to search and compete for hidden food at color-marked clusters of artificial food caches. At the beginning of the experiment, a subordinate male found and exploited the majority of the food. As a result, the dominant male displaced him from the already opened boxes. The subordinate male then developed a pattern, when the loss of reward to the dominant got high, of moving to unrewarded clusters and opening boxes there. This diversion often led the dominant to approach those unrewarded clusters and the subordinate then had a head start for exploiting the rewarded boxes. Subsequently, however, the dominant male learned not to follow the subordinate to unrewarded clusters and eventually started searching for the reward himself. These interactions between the two males illustrate the ravens' potential for deceptively manipulating conspecifics. We discuss under which circumstances ravens might use this capacity.  
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  Call Number Serial 2080  
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Author Bugnyar, T.; Kotrschal, K. doi  openurl
  Title Movement coordination and signalling in ravens (Corvus corax): an experimental field study Type Journal Article
  Year 2001 Publication Acta ethologica Abbreviated Journal Acta. Ethol.  
  Volume 3 Issue 2 Pages 101-109  
  Keywords Ravens – Corvus corax – Foraging – Coordination – Communication  
  Abstract Vagrant non-breeding ravens frequently attract conspecifics to rich ephemeral food sources. There, grouping may allow them to overcome the defence of territorial breeders. Here, we focus on ravens making use of regular food supplies in a game park, where they divert food from the provision of park animals. We investigated if ravens foraging in the Cumberland game park (Grünau, Austria) are attentive towards one another when they experience some unpredictability in food provisioning. We confronted a group of 30-50 ravens with two different treatments. Ten minutes ahead of the feeding of either wolves or wild boars we showed buckets containing pieces of meat to the ravens flying overhead. In the reliable cue treatment (RCT), the meat was placed next to one of the two enclosures, whereas in the unreliable cue treatment (UCT), the buckets were placed simultaneously in front of both enclosures though only in one of the enclosures were the animals fed 10 min later. Thus, during RCT but not during UCT, ravens could predict where food would become available. Only during UCT, ravens moved in large groups between the two feeding sites. Many ravens moving at the same time in the same direction may indicate some co-ordination in space and time, which is most likely achieved by social attraction among individuals. Furthermore, the number of ravens approaching and leaving, respectively, a feeding site cross-correlated with a temporary increase in the rate of a food-associated call, the yell. This suggests that in addition to watching each other, calling may have contributed to group formation. Possible benefits of group formation during food inspection are discussed.  
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  Call Number Serial 2081  
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Author Schloegl, C.; Kotrschal, K.; Bugnyar, T. url  doi
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  Title Gaze following in common ravens, Corvus corax: ontogeny and habituation Type Journal Article
  Year 2007 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 74 Issue 4 Pages 769-778  
  Keywords Corvus corax; gaze following; habituation; ontogenetic development; raven  
  Abstract Co-orientation with others by using their gaze direction is considered to be adaptive for detecting food or predators or monitoring social interactions. Like the great apes, common ravens are capable of following human experimenters' gaze direction not only into distant space but also behind visual barriers. We investigated the ontogenetic development of these abilities by confronting birds with a human foster parent looking up (experiment 1) and behind visual barriers (experiment 3) and their modification by habituation (experiments 2 and 4). We tested a group of 12 hand-reared ravens during their first 10 months of life. Ravens responded to others' look-ups soon after fledging but could track their gaze behind a visual barrier only 4 months later, at the age they usually become independent from their parents. Furthermore, ravens quickly ceased responding to repeated look-ups by the model, but did not habituate to repeated gaze cues directed behind a barrier. Our findings support the idea that the two modes of gaze following reflect different cognitive levels in ravens and, possibly, have different functions.  
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  Call Number Equine Behaviour @ team @ Serial 4204  
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Author Scheiber, I. B.R.; WeiB, B. M.; Hirschenhauser, K.; Wascher, C. A.F.; Nedelcu, J.T.; Kotrschal, K. doi  openurl
  Title Does 'Relationship Intelligence' Make Big Brains in Birds? Type Journal Article
  Year 2008 Publication The Open Biology Journal Abbreviated Journal Open Biol J  
  Volume 1 Issue Pages 6-8 (3)  
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  Abstract Lately, Emery et al. developed a bird-specific modification of the *social brain hypothesis*, termed *relationship intelligence hypothesis*. Although the idea may be valuable, we doubt that it is supported by sufficient evidence and critically discuss some of the arguments raised by the authors in favour of their new idea.  
  Address AKonrad Lorenz Forschungsstelle fur Ethologie, Fischerau 11, 4645 Gruenau im Almtal, Austria.  
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  Call Number Equine Behaviour @ team @ Serial 4504  
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Author Schloegl, C.; Kotrschal, K.; Bugnyar, T. url  doi
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  Title Modifying the object-choice task: Is the way you look important for ravens? Type Journal Article
  Year 2008 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 77 Issue 1 Pages 61-65  
  Keywords Gaze; Modification; Object-choice task; Raven  
  Abstract Most animals seem to have difficulties in using gaze cues to find hidden food in object-choice tasks. For instance, chimpanzees usually fail in these tests, even though they are capable of following other's gaze geometrically behind barriers. Similar to chimpanzees, common ravens are skilled in tracking other's gaze but fail in object-choice tasks. We here explored whether procedural modifications, which had been used successfully in chimpanzees, would also yield positive results in ravens. In our modifications (a) the experimenter approached the cup while gazing at it, (b) the gaze cue was accompanied by a sound and (c) the experimenter could actually see the food while giving the gaze cue. Two out of seven birds performed above chance level in some of these conditions. However, we ascribe this improvement to the individuals' learning ability rather than to an understanding of the communicative nature of the task. This interpretation is further supported by results of a follow-up experiment suggesting that ravens may not rely on conspecifics' gaze cues for finding food caches in a natural foraging context. In sum, our results suggest that ravens may not transfer their gaze follow abilities to foraging situations involving hidden food.  
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  Call Number Equine Behaviour @ team @ Serial 4505  
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Author Stöwe, M. & Kotrschal, K. doi  openurl
  Title Behavioural phenotypes may determine whether social context facilitates or delays novel object exploration in ravens. Type Journal Article
  Year 2007 Publication International Journal of Ornithology Abbreviated Journal  
  Volume 148 Issue Suppl 2 Pages 179-184  
  Keywords Corvus corax – Novel object exploration – Personality – Social facilitation  
  Abstract Individuals consistently differ in behavioural phenotypes. Here we examine the interaction between behavioural phenotype and response to social context during novel object exploration in a neophobic corvid species, the raven (Corvus corax). The presence of conspecifics tends to encourage object exploration and learning but may also delay or even inhibit exploratory behaviour. Factors such as individual differences in response to social context may determine whether the presence of a conspecific facilitates or inhibits approach to novel objects. We confronted eleven six-month-old hand-raised ravens with novel objects, both individually and in dyadic combinations. We defined individuals as “fast” and “slow” explorers on the basis of their approach latency to novel objects when tested individually. The presence of a conspecific delayed the approach of fast birds to novel objects. Slow birds, in contrast, approached the novel objects with lower latencies and spent more time close to them when in dyads with fast siblings than when alone. The individuals" approach behaviour seemed to determine whether social context facilitated or delayed exploratory behaviour. This may contribute to explaining ambiguous results concerning the effects of social context in previous studies.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4507  
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Author Kotrschal, K.; Schöberl, I.; Bauer, B.; Thibeaut, A.-M.; Wedl, M. url  doi
openurl 
  Title Dyadic relationships and operational performance of male and female owners and their male dogs Type Journal Article
  Year 2009 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 81 Issue 3 Pages 383-391  
  Keywords Dyadic interactions; Human-animal companions; Human-animal relationships; Human-dog dyads; Personality; Social stress  
  Abstract In the paper we investigate how owner personality, attitude and gender influence dog behavior, dyadic practical functionality and the level of dog salivary cortisol. In three meetings, 12 female and 10 male owners of male dogs answered questionnaires including the Neo-FFI human personality inventory. Their dyadic behavior was video-taped in a number of test situations, and saliva samples were collected. Owners who scored highly in neuroticism (Neo-FFI dimension one) viewed their dogs as social supporters and spent much time with them. Their dogs had low baseline cortisol levels, but such dyads were less successful in the operational task. Owners who scored highly in extroversion (Neo-FFI dimension two) appreciated shared activities with their dogs which had relatively high baseline cortisol values. Dogs that had female owners were less sociable-active (dog personality axis 1) than dogs that had male owners. Therefore, it appears that owner gender and personality influences dyadic interaction style, dog behavior and dyadic practical functionality.  
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  ISSN 0376-6357 ISBN (up) Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4947  
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