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Author Johnstone, R.A. doi  openurl
  Title Eavesdropping and animal conflict Type Journal Article
  Year 2001 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 98 Issue 16 Pages 9177-9180  
  Keywords *Aggression; Animals; *Behavior, Animal; *Conflict (Psychology); Models, Theoretical  
  Abstract Fights between pairs of animals frequently take place within a wider social context. The displays exchanged during conflict, and the outcome of an encounter, are often detectable by individuals who are not immediately involved. In at least some species, such bystanders are known to eavesdrop on contests between others, and to modify their behavior toward the contestants in response to the observed interaction. Here, I extend Maynard Smith's well known model of animal aggression, the Hawk-Dove game, to incorporate the possibility of eavesdroppers. I show that some eavesdropping is favored whenever the cost of losing an escalated fight exceeds the value of the contested resource, and that its equilibrium frequency is greatest when costs are relatively high. Eavesdropping reduces the risk of escalated conflict relative to that expected by chance, given the level of aggression in the population. However, it also promotes increased aggression, because it enhances the value of victory. The net result is that escalated conflicts are predicted to occur more frequently when eavesdropping is possible.  
  Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, United Kingdom. raj1003@hermes.cam.ac.uk  
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  Series Volume Series Issue Edition  
  ISSN 0027-8424 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:11459936 Approved no  
  Call Number refbase @ user @ Serial 497  
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Author Seferta, A.; Guay, P.-J.; Marzinotto, E.; Lefebvre, L. doi  openurl
  Title Learning Differences between Feral Pigeons and Zenaida Doves: The Role of Neophobia and Human Proximity Type Journal Article
  Year 2001 Publication Ethology Abbreviated Journal Ethology  
  Volume 107 Issue Pages 281-293  
  Keywords  
  Abstract Learning differences predicted from ecological variables can be confounded with differences in wariness of novel stimuli (neophobia). Previous work on feral pigeons (Columba livia), as well as on group-feeding and territorial zenaida doves (Zenaida aurita), reported individual and social learning differences predicted from social foraging mode. In the present study, we show that speed of learning a foraging task covaries with neophobia and latency to feed from a familiar dish in the three types of columbids. Pigeons were much faster than either territorial or group-feeding zenaida doves on all tests conducted in captivity, but showed unexpectedly strong neophobia in some urban flocks during field tests. Human proximity strongly affected performance in group-feeding doves both in the field and in captivity. They were slightly faster at learning than their territorial conspecifics in cage tests. In multiple regressions, species identity, but not social foraging mode, significantly predicted individual variation in learning, as did individual variation in neophobia. Wariness of novel stimuli and species differences associated with artificial selection appear to be more important than foraging mode and wariness of humans in accounting for learning differences between these columbids.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 2184  
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Author Wilson, A.M.; McGuigan, M.P.; Su, A.; van Den Bogert, A.J. doi  openurl
  Title Horses damp the spring in their step Type Journal Article
  Year 2001 Publication Nature Abbreviated Journal Nature  
  Volume 414 Issue 6866 Pages 895-899  
  Keywords Animals; Biomechanics; Elasticity; Forelimb; Gait; Horses/anatomy & histology/*physiology; Leg Bones/*physiology; Locomotion; Models, Biological; Muscle Fibers/physiology; Muscle, Skeletal/anatomy & histology/*physiology; Tendons/anatomy & histology/*physiology; Vibration  
  Abstract The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle-tendon units.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes in the muscle. Despite being apparently redundant for such a mechanism, the muscle fibres in the digital flexors are well developed. Here we show that the mechanical arrangement of the elastic leg permits it to vibrate at a higher frequency of 30-40 Hz that could cause fatigue damage to tendon and bone. Furthermore, we show that the digital flexor muscles have minimal ability to contribute to or regulate significantly the 2.5-Hz cycle of movement, but are ideally arranged to damp these high-frequency oscillations in the limb.  
  Address Department of Veterinary Basic Sciences, The Royal Veterinary College, Hatfield, Herts AL9 7TA, UK. awilson@rvc.ac.uk  
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  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
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  Notes PMID:11780059 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2300  
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Author Spengler M.I.; Rasia M. doi  openurl
  Title Influence of Plasma Proteins on Erythrocyte Aggregation in Three Mammalian Species Type Journal Article
  Year 2001 Publication Veterinary Research Communications Abbreviated Journal Vet.Res.Comm  
  Volume 25 Issue 7 Pages 591-599  
  Keywords albumin – bovine – equine – erythrocyte aggregation – dextran – haemorheology – human – plasma protein – polyvinylpyrrolidone  
  Abstract The aggregation capacity of human erythrocytes lies between that of the non-aggregating bovine erythrocytes and the remarkably aggregating equine ones. As the ability to aggregate is attributed to cell factors and the composition of the plasma proteins, the role that plasma proteins play in the aggregation process in these three species was studied. Washed erythrocytes were suspended in phosphate-buffered saline (PBS; pH 7.4, 300 mOsm/L) plus polyvinylpyrrolidone (PVP) in a suitable concentration to obtain an average intensity of aggregation (control media). The superimposed effect of replacing 80% of the medium by either autologous plasma, serum or albumin solution was studied. The plasma proteins appeared to enhance aggregation by human and equine erythrocytes, but impaired this process in bovine erythrocytes. Some evidence was obtained supporting the existence of serum factors capable of reducing aggregation of erythrocytes in cattle and it was concluded that the non-aggregating behaviour of bovine erythrocytes may be due to the cells interacting particularly with the macromolecules in the serum.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 2013  
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Author Reader, S.; Laland, K. doi  openurl
  Title Primate Innovation: Sex, Age and Social Rank Differences Type Journal Article
  Year 2001 Publication International Journal of Primatology Abbreviated Journal Int. J. Primatol.  
  Volume 22 Issue 5 Pages 787-805  
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  Abstract Analysis of an exhaustive survey of primate behavior collated from the published literature revealed significant variation in rates of innovation among individuals of different sex, age and social rank. We searched approximately 1,000 articles in four primatology journals, together with other relevant databases, for examples of innovation. The reported incidence of innovation is higher in males and adults, and lower in females and nonadults, than would be expected by chance given the estimated relative proportions of these groups. Amongst chimpanzees, the only species for which there are sufficient data to consider alone, there is a similar sex difference in the propensity to innovate, but no effect of age. Chimpanzees of low social rank are reported as innovators more frequently than high-ranking chimpanzees are. Male chimpanzees innovate more often than females in sexual, courtship, mating and display contexts; that is, in contexts likely to increase access to mates. The largest number of recorded observations are in the foraging context, wherein contrary to expectations, there is no evidence for female chimpanzees exhibiting more innovation than males. The study is the first extensive investigation of behavioral innovation in primates and provides evidence that much individual variation in the propensity to innovate can be explained in terms of sex, age, and social rank.  
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  Notes Approved no  
  Call Number Serial 2152  
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Author Macphail, E.M.; Boldhuis, J.J doi  openurl
  Title The evolution of intelligence: adaptive specializations versusgeneral process Type Journal Article
  Year 2001 Publication Biological Reviews Abbreviated Journal  
  Volume 76 Issue 3 Pages 341-364  
  Keywords biological constraints, corvids, ecology, food-storing birds, hippocampal size, parids, spatial learning, spatial memory, spatial module.  
  Abstract Darwin argued that between-species differences in intelligence were differences of degree, not of kind. The contemporary ecological approach to animal cognition argues that animals have evolved species-specific and problem-specific processes to solve problems associated with their particular ecological niches: thus different species use different processes, and within a species, different processes are used to tackle problems involving different inputs. This approach contrasts both with Darwin's view and with the general process view, according to which the same central processes of learning and memory are used across an extensive range of problems involving very different inputs. We review evidence relevant to the claim that the learning and memory performance of non-human animals varies according to the nature of the stimuli involved. We first discuss the resource distribution hypothesis, olfactory learning-set formation, and the 'biological constraints' literature, but find no convincing support from these topics for the ecological account of cognition. We then discuss the claim that the performance of birds in spatial tasks of learning and memory is superior in species that depend heavily upon stored food compared to species that either show less dependence upon stored food or do not store food. If it could be shown that storing species enjoy a superiority specifically in spatial (and not non-spatial) tasks, this would argue that spatial tasks are indeed solved using different processes from those used in non-spatial tasks. Our review of this literature does not find a consistent superiority of storing over non-storing birds in spatial tasks, and, in particular, no evidence of enhanced superiority of storing species when the task demands are increased, by, for example, increasing the number of items to be recalled or the duration of the retention period. We discuss also the observation that the hippocampus of storing birds is larger than that of non-storing birds, and find evidence contrary to the view that hippocampal enlargement is associated with enhanced spatial memory; we are, however, unable to suggest a convincing alternative explanation for hippocampal enlargement. The failure to find solid support for the ecological view supports the view that there are no qualitative differences in cognition between animal species in the processes of learning and memory. We also argue that our review supports our contention that speculation about the phylogenetic development and function of behavioural processes does not provide a solid basis for gaining insight into the nature of those processes. We end by confessing to a belief in one major qualitative difference in cognition in animals: we believe that humans alone are capable of acquiring language, and that it is this capacity that divides our intelligence so sharply from non-human intelligence.  
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  Call Number Equine Behaviour @ team @ Serial 4797  
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Author Mushiake H.; Saito N.; Sakamoto K.; Sato Y.; Tanji J. doi  openurl
  Title Visually based path-planning by Japanese monkeys Type Journal Article
  Year 2001 Publication Cognitive Brain Research Abbreviated Journal  
  Volume 11 Issue Pages 165-169  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 3476  
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Author Abeyesinghe, S.M.; Nicol, C.J.; Wathes. C.M.; Randall, J.M. doi  openurl
  Title Development of a raceway method to assess aversion of domestic fowl to concurrent stressors Type Journal Article
  Year 2001 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 56 Issue 3 Pages 175-194  
  Keywords previous termConcurrent stressors; Aversion; Domestic fowlnext term; Transport; Vibration; Hyperthermia  
  Abstract The requirement for assessing the effects of stressor combinations in improving the welfare of animals has not been widely recognised. Knowledge of the effects of concurrent stressors is needed to improve environments such as transport, where animals are presented with many simultaneous challenges. However, no method for measuring the effects of different stressors with a common unit is currently available. A locomotor passive avoidance method was developed as a common currency measure of the aversion of domestic fowl to concurrent stressors, using vibrational and thermal stressors as an exemplar. Juvenile fowl, fasted overnight, were trained to run a raceway into a goal-box for small food rewards (FR1). When running consistently, the reinforcement schedule was superimposed with a FR5 treatment schedule (60 min confinement in the goal-box with either a control of no other stressors [N] or concurrent vibration and thermal stressors [VT]). Subsequent latency to return to the goal-box was recorded as a measure of aversion. The factors affecting bird response were addressed in a series of experiments to optimise the method and clarify interpretation of results. Pre-feeding (20% ration 2 h prior to testing) did not affect response, but increasing the number of treatment presentations facilitated learning and increased method sensitivity. Treatment responses were consistent across experiments; overall VT was avoided (P<0.001), but N was not. However, there was large individual variation in response to VT. A final experiment indicated that, given a visual discriminatory cue, birds were capable of learning the required association between entering the goal-box and receiving the treatment, suggesting that the delay responses were due to aversion rather than the immediate impact of treatment on ability to respond. Further work is required to test the singular stressors, but the method retains common currency potential for assessing aversion to multiple stressors.  
  Address Bio-Engineering Division, Silsoe Research Institute, Wrest Park, Silsoe, MK45 4HS, Bedford, UK  
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  Series Volume Series Issue Edition  
  ISSN 0376-6357 ISBN Medium  
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  Notes PMID:11738510 Approved no  
  Call Number refbase @ user @ Serial 85  
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Author Seralini G.-E.; Moslemi S. doi  openurl
  Title Aromatase inhibitors: past, present and future Type Journal Article
  Year 2001 Publication Molecular and Cellular Endocrinology Abbreviated Journal  
  Volume 178 Issue Pages 117-131  
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  Call Number refbase @ user @ Serial 2014  
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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 (Gr&uuml;nau, 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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  Notes Approved no  
  Call Number Serial 2081  
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