| Records |
Author  |
Fairhurst, S.; Gallistel, C.R.; Gibbon, J. |
| Title |
Temporal landmarks: proximity prevails |
Type |
Journal Article |
| Year |
2003 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
| Volume |
6 |
Issue |
2 |
Pages |
113-120 |
| Keywords |
Animals; Columbidae; Conditioning, Operant; Reaction Time; *Time Perception |
| Abstract |
Subjects in conditioning experiments time their conditioned responses relative to the onsets of the conditioned stimuli (CSs). These onsets are temporal landmarks, by reference to which subjects may estimate the location of the unconditioned stimulus (US) in time. In a serial compound conditioning paradigm, a long duration CS comes on first, followed later by a second shorter CS, creating both a long-range and a short-range predictor of the US. We ask whether displacing the short-range predictor relative to the long-range predictor causes subjects to strike a compromise between the different temporal locations predicted by the two CSs. In three experiments with pigeons, we varied the training conditions so as to favor or militate against this outcome. However, in all conditions, there was no compromise; after the onset of the displaced short-range CS, the timing of conditioned responding was governed by it alone. This result contrasts with the compromises that are seen when the feeding time predicted by a CS is put in conflict with the time predicted by the circadian clock, and with the similar compromises sometimes seen when a nearby spatial landmark is displaced relative to a larger spatial context. |
| Address |
New York State Psychiatric Institute, 1051 Riverside Dr., Unit 50, New York, NY 10032, USA |
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English |
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| ISSN |
1435-9448 |
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| Notes |
PMID:12720110 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
2573 |
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| Author |
Faber, M.J.; van Weeren, P.R.; Schepers, M.; Barneveld, A. |
| Title |
Long-term follow-up of manipulative treatment in a horse with back problems |
Type |
Journal Article |
| Year |
2003 |
Publication |
Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine |
Abbreviated Journal |
J Vet Med A Physiol Pathol Clin Med |
| Volume |
50 |
Issue |
5 |
Pages |
241-245 |
| Keywords |
Animals; Female; Horse Diseases/*physiopathology/*therapy; Horses; Manipulation, Spinal/*veterinary; Range of Motion, Articular; Scoliosis/physiopathology/therapy/*veterinary; Severity of Illness Index; Thoracic Vertebrae |
| Abstract |
In order to objectively quantify the effect of manipulation on back-related locomotion anomalies in the horse, a recently developed kinematic measuring technique for the objective quantification of thoracolumbar motion in the horse was applied in a dressage horse that was suffering from a back problem. In this horse, clinically, a right-convex bending (scoliosis) from the 10th thoracic vertebra to the second lumbar vertebra was diagnosed. As a result, there was a marked asymmetric movement of the thoracolumbar spine. Functionally, there was severe loss of performance. Thoracolumbar motion was measured in terms of ventrodorsal flexion, lateral flexion, and axial rotation using an automated gait analysis system. Measurements were repeated before and 2 days after treatment, before the second treatment 3 weeks later, and at 4 weeks and 8 months after the second treatment to assess long-term effect. At the same time, performance of the horse was assessed subjectively by the trainer as well. Symmetry of movement improved dramatically after the first treatment. After this, there was a slight decrease in symmetry, but 8 months after the last treatment the symmetry indexes for the various joints were still considerably better than during the first (pre-treatment) measuring session. Subjectively, the trainer did not notice improvement until after measurement session 4. Between sessions 4 and 5 (at 4 weeks and 8 months after the second treatment) there was a change of trainer. The new trainer did not report any back problem, and succeeded in bringing the horse back to its former level in competition. It is concluded that manipulation had a measurable influence on the kinematics of the thoracolumbar spine. However, it is recognized that an improvement in symmetry of motion is not equivalent to clinical improvement and that other measures, such as changes in management, may be more decisive. |
| Address |
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands |
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English |
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0931-184X |
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| Notes |
PMID:14567510 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3720 |
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| Author |
Earley, R.L.; Tinsley, M.; Dugatkin, L.A. |
| Title |
To see or not to see: does previewing a future opponent affect the contest behavior of green swordtail males (Xiphophorus helleri)? |
Type |
Journal Article |
| Year |
2003 |
Publication |
Naturwissenschaften |
Abbreviated Journal |
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| Volume |
90 |
Issue |
5 |
Pages |
226-230 |
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| Abstract |
Animals assess the fighting ability of conspecifics either by engaging in aggressive interactions or observing contests between others. However, whether individuals assess physical prowess outside the context of aggressive interactions remains unknown. We examined whether male green swordtails (Xiphophorus helleri) extract information about the fighting ability of solitary individuals via observation and whether acquiring such information elicits behavioral modifications. Contests preceded by mutual visual assessment were significantly shorter than fights where only one or neither of the two individuals was informed in advance. Focal animals initiated aggressive behavior more often against larger opponents only after previewing their adversary, indicating that swordtails can extract information about relative body size from watching solitary conspecifics. When a fighting disadvantage is perceived, observers adopt tactics that increase their probability of winning the contest. |
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no |
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Equine Behaviour @ team @ |
Serial |
2180 |
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| Author |
Dyson, S.; Murray, R. |
| Title |
Pain associated with the sacroiliac joint region: a clinical study of 74 horses |
Type |
Journal Article |
| Year |
2003 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
| Volume |
35 |
Issue |
3 |
Pages |
240-245 |
| Keywords |
Age Factors; Analgesia/veterinary; Anesthetics, Local/pharmacology; Animals; Body Height; Body Weight; Breeding; Female; Forelimb; Gait; Hindlimb; Horse Diseases/*diagnosis/radionuclide imaging; Horses; Lameness, Animal/*physiopathology; Lumbar Vertebrae/physiopathology; Male; Pain/diagnosis/drug therapy/radionuclide imaging/*veterinary; Sacroiliac Joint/*physiopathology; Sacrum/physiopathology |
| Abstract |
REASONS FOR PERFORMING STUDY: There has been no large study of horses with suspected sacroiliac (SI) joint region pain in which the clinical diagnosis has been supported by either abnormal radiopharmaceutical activity in the SI joint region or by periarticular infiltration of local anaesthetic solution. OBJECTIVES: To describe the clinical features of horses with SI joint region pain, to document the age, breed, sex, discipline, size and conformation of affected horses and to compare these with the author's (SD) normal case population and to document the results of infiltration of local anaesthetic solution around the SI joint region. METHODS: Horses were selected for inclusion in the study based upon the exclusion of other causes of lameness or poor performance, together with clinical signs suggestive of SI joint pain and abnormal radiopharmaceutical activity in the SI joint region and/or a positive response to periarticular infiltration of local anaesthetic solution. RESULTS: Sacroiliac joint region disease was identified in 74 horses between November 1997 and March 2002. Dressage and showjumping horses appeared to be at particular risk (P < 0.001). Affected horses were generally slightly older than the normal clinic population (P < 0.0001), taller at the withers (P < 0.0001) and of greater bodyweight (P < 0.01). There was a significant effect of breed (P < 0.001), with a substantially higher proportion of Warmblood horses (51%) in the SI pain group compared to the normal clinic population (29%). There was no correlation between conformation and the presence of SI joint region pain. The tubera sacrale appeared grossly symmetrical in most (95%) horses. Poor development of the epaxial muscles in the thoracolumbar region and asymmetry of the hindquarter musculature were common. Twenty-six horses (35%) showed restricted flexibility of the thoracolumbar region and 10 (16%) had an exaggerated response to pressure applied over the tubera sacrale. Fourteen horses (19%) were reluctant to stand on one hindlimb for prolonged periods. The majority of horses (75%) had a straight hindlimb flight and only 18% moved closely behind or plaited. In all horses restricted hindlimb impulsion was the predominant feature; invariably this was most obvious when the horse was ridden. Stiffness, unwillingness to work on the bit and poor quality canter were common. Sacroiliac joint region pain was seen alone (47%), or in conjunction with thoracolumbar pain (16%), hindlimb lameness (20%), forelimb lameness (7%) or a combination of problems (10%). Seventy-three horses (99%) had abnormalities of the SI joint region identified using nuclear scintigraphy. Infiltration of local anaesthetic solution around the SI joint region produced profound improvement in gait in all 34 horses in which it was performed. CONCLUSIONS AND POTENTIAL RELEVANCE: Careful clinical examination combined with scintigraphic evaluation of the SI joint region and local analgesia can enable a more definitive diagnosis of SI joint region pain than has previously been possible. |
| Address |
Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK |
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English |
Summary Language |
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Edition |
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| ISSN |
0425-1644 |
ISBN |
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| Notes |
PMID:12755425 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3723 |
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| Author |
Dunbar, R. |
| 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 |
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| Address |
School of Biological Sciences, University of Liverpool, Liverpool L69 7ZB, UK. rimd@liv.ac.uk |
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English |
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Series Issue |
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Edition |
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| ISSN |
1095-9203 |
ISBN |
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Medium |
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Conference |
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| Notes |
PMID:14615522 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
548 |
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| Author |
Dugatkin, L.A.; Perlin, M.; Atlas, R. |
| Title |
The Evolution of Group-beneficial Traits in the Absence of Between-group Selection |
Type |
Journal Article |
| Year |
2003 |
Publication |
Journal of Theoretical Biology |
Abbreviated Journal |
J. Theor. Biol. |
| Volume |
220 |
Issue |
1 |
Pages |
67-74 |
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| Abstract |
One specific prediction emerging from trait-group models of natural selection is that when individuals possess traits that benefit other group members, natural selection will favor “cheating” (i.e. not possessing the group-beneficial trait) within groups. Cheating is selected within groups because it allows individuals to avoid bearing the relative costs typically associated with group-beneficial traits, but to still reap the benefits associated with the acts of other group members. Selection between groups favors traits that benefit other group members. The relative strength of within- and between-group selection then determines the equilibrium frequency of those who produce group-beneficial traits and those that do not. Here we demonstrate that individual-level selection, that is selection within groups can also produce an intermediate frequency of such group-beneficial traits by frequency-dependent selection. The models we develop are general in nature, but were inspired by the evolution of antibiotic resistance in bacteria. The theory developed here is distinct from prior work that relies on reciprocity or kinship per'se to achieve cooperation and altruism among group members. |
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no |
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refbase @ user @ |
Serial |
491 |
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| Author |
Dugatkin, L.A.; Earley, R.L. |
| Title |
Group fusion: the impact of winner, loser, and bystander effects on hierarchy formation in large groups |
Type |
Journal Article |
| Year |
2003 |
Publication |
Behavioral Ecology |
Abbreviated Journal |
Behav. Ecol. |
| Volume |
14 |
Issue |
3 |
Pages |
367-373 |
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| Abstract |
We present the results of a series of computer simulations that examined the impact of winner, loser, and bystander effects on hierarchy formation in fused groups. These effects and their implications for hierarchy structure and aggressive interactions were first examined in small four-member groups. Subsequent to this, the two small groups were fused into a single larger group. Further interactions took place in this fused group, generating a new hierarchy. Our models demonstrate clearly that winner, loser, and bystander effects strongly influence both the structure and types of interactions that emerge from the fusion of smaller groups. Four conditions produced results in which the same general patterns were uncovered in pre- and postfusion groups: (1) winner effects alone, (2) bystander loser effects alone, (3) winner and bystander winner effects operating simultaneously, and (4) all four effects in play simultaneously. Outside this parameter space, hierarchy structure and the nature of aggressive interactions differed in pre- and postfusion groups. When only loser effects were in play, one of the two clear alphas from the prefused groups dropped in rank in the eight-member fused group. When bystander winner effects were in play, it was difficult to rank any of the eight individuals in the fused group, and players interacted almost exclusively with those that were not in their original four-member group. When loser and bystander loser effects operated simultaneously, two top-ranking individuals emerged in the fused groups, but the relative rank of the other players was difficult to assign. |
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| Notes |
10.1093/beheco/14.3.367 |
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no |
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refbase @ user @ |
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519 |
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| Author |
Dugatkin, L.A.; Bekoff, M. |
| Title |
Play and the evolution of fairness: a game theory model |
Type |
Journal Article |
| Year |
2003 |
Publication |
Behavioural Processes |
Abbreviated Journal |
Behav. Process. |
| Volume |
60 |
Issue |
3 |
Pages |
209-214 |
| Keywords |
Play; Fairness; Game theory |
| Abstract |
Bekoff [J. Consci. Stud. 8 (2001) 81] argued that mammalian social play is a useful behavioral phenotype on which to concentrate in order to learn more about the evolution of fairness. Here, we build a game theoretical model designed to formalize some of the ideas laid out by Bekoff, and to examine whether `fair' strategies can in fact be evolutionarily stable. The models we present examine fairness at two different developmental stages during an individual's ontogeny, and hence we create four strategies--fair at time 1/fair at time 2, not fair at time 1/not fair at time 2, fair at time 1/not fair at time 2, not fair at time 1/fair at time 2. Our results suggest that when considering species where fairness can be expressed during two different developmental stages, acting fairly should be more common than never acting fairly. In addition, when no one strategy was evolutionarily stable, we found that all four strategies we model can coexist at evolutionary equilibrium. Even in the absence of an overwhelming database from which to test our model, the general predictions we make have significant implications for the evolution of fairness. |
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refbase @ user @ |
Serial |
488 |
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| Author |
Dubois, F.; Giraldeau, L.-A. |
| 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 |
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English |
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0003-0147 |
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| Notes |
PMID:14737714 |
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no |
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Serial |
2132 |
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| Author |
Drent, P.J.; van Oers, K.; van Noordwijk, A.J. |
| Title |
Realized heritability of personalities in the great tit (Parus major) |
Type |
Journal Article |
| Year |
2003 |
Publication |
Proceedings. Biological sciences / The Royal Society |
Abbreviated Journal |
Proc Biol Sci |
| Volume |
270 |
Issue |
1510 |
Pages |
45-51 |
| Keywords |
Aggression; Animals; Animals, Domestic; Animals, Wild; *Behavior, Animal; Breeding; Exploratory Behavior; Female; *Heredity; Male; Selection (Genetics); Songbirds/*genetics/*physiology; Variation (Genetics) |
| Abstract |
Behaviour under conditions of mild stress shows consistent patterns in all vertebrates: exploratory behaviour, boldness, aggressiveness covary in the same way. The existence of highly consistent individual variation in these behavioural strategies, also referred to as personalities or coping styles, allows us to measure the behaviour under standardized conditions on birds bred in captivity, link the standardized measurements to the behaviour under natural conditions and measure natural selection in the field. We have bred the great tit (Parus major), a classical model species for the study of behaviour under natural conditions, in captivity. Here, we report a realized heritability of 54 +/- 5% for early exploratory behaviour, based on four generations of bi-directional artificial selection. In addition to this, we measured hand-reared juveniles and their wild-caught parents in the laboratory. The heritability found in the mid-offspring-mid-parent regression was significantly different from zero. We have thus established the presence of considerable amounts of genetic variation for personality types in a wild bird. |
| Address |
Netherlands Institute of Ecology, PO Box 40, 6666 ZG Heteren, The Netherlands. drent@cto.nioo.knaw.nl |
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0962-8452 |
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| Notes |
PMID:12590770 |
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no |
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refbase @ user @ |
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591 |
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