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Author Reebs, S.G. url  doi
openurl 
  Title Can a minority of informed leaders determine the foraging movements of a fish shoal? Type Journal Article
  Year 2000 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 59 Issue 2 Pages 403-409  
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  Abstract (up) There is no information on whether the daily foraging movements of fish shoals are the result of chance, the collective will of all shoalmates, or the leadership of a few individuals. This study tested the latter possibility. Shoals of 12 golden shiners, Notemigonus crysoleucas, were trained to expect food around midday in one of the brightly lit corners of their tank. They displayed daily food-anticipatory activity by leaving the shady area of their tank and spending more and more time in the food corner up to the normal time of feeding. Past this normal time they remained in the shade, even on test days when no food was delivered. Most of these experienced individuals were then replaced by naïve ones. The resulting ratio of experienced:naïve fish could be 5:7, 3:9 or 1:11. On their own, naïve individuals would normally spend the whole day in the shade, but in all tests the experienced individual(s) were able to entrain these more numerous naïve fish out of the shade and into the brightly lit food corner at the right time of day. Entrainment was stronger in the 5:7 than in the 1:11 experiment. The test shoals never split up and were always led by the same fish, presumably the experienced individuals. These results indicate that in a strongly gregarious species, such as the golden shiner, a minority of informed individuals can lead a shoal to food, either through social facilitation of foraging movements or by eliciting following behaviour.  
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  ISSN 0003-3472 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5255  
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Author Peirce, J.W.; Leigh, A.E.; Kendrick, K.M. url  doi
openurl 
  Title Configurational coding, familiarity and the right hemisphere advantage for face recognition in sheep Type Journal Article
  Year 2000 Publication Neuropsychologia Abbreviated Journal  
  Volume 38 Issue 4 Pages 475-483  
  Keywords Asymmetry; Hemispheric lateralisation; Chimeric; Face processing; Expertise; Internal features  
  Abstract (up) This study examined characteristics of visual recognition of familiar and unfamiliar faces in sheep using a 2-way discrimination task. Of particular interest were effects of lateralisation and the differential use of internal (configurational) vs external features of the stimuli. Animals were trained in a Y-maze to identify target faces from pairs, both of which were familiar (same flock as the subjects) or both of which were unfamiliar (different flock). Having been trained to identify the rewarded face a series of stimuli were presented to the sheep, designed to test for the use of each visual hemifield in the discriminations and the use of internal and external facial cues. The first experiment showed that there was a left visual hemifield (LVF) advantage in the identification of [`]hemifaces', and [`]mirrored hemifaces' and [`]chimeric' faces and that this effect was strongest with familiar faces. This represents the first evidence for visual field bias outside the primate literature. Results from the second experiment showed that, whilst both familiar and unfamiliar faces could be identified by the external features alone, only the familiar faces could be recognised by the internal features alone. Overall the results suggest separate recognition methods for socially familiar and unfamiliar faces, with the former being coded more by internal, configurational cues and showing a lateral bias to the left visual field.  
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  Series Volume Series Issue Edition  
  ISSN 0028-3932 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5343  
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Author Beauchamp, G. url  doi
openurl 
  Title Individual Differences In Activity And Exploration Influence Leadership In Pairs Of Foraging Zebra Finches Type Journal Article
  Year 2000 Publication Behaviour Abbreviated Journal Behaviour  
  Volume 137 Issue Pages 301-314  
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  Abstract (up) This study investigated the role of dominance and level of activity and exploration on leadership in zebra finches (Taenopygia guttata) searching for food. In pairs of zebra finches fairly matched in size and that experienced the same level of food deprivation, the same bird consistently reached first one foraging patch over several trials. The same pattern of arrival to food occurred when resources were provided in two distant patches available concurrently, a situation that would potentially allow subordinates a greater access to resources. In further testing, the formation of new pairs with the same birds led to several changes in leadership, indicating that leadership is not an absolute feature. The member of a pair that proved to be the most active and exploratory during independent, solitary trials became the leader in nearly all pairs tested. The same pattern held true in newly rearranged pairs where individuals often experienced changes in dominance status. Dominance failed to be associated with leadership in all tests. The results suggest that in a relatively egalitarian species, level of activity and exploration may be a stronger predictor of leadership than dominance.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4698  
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Author von Fersen, L.; Delius, J.D. doi  openurl
  Title Acquired equivalences between auditory stimuli in dolphins (Tursiops truncatus) Type Journal Article
  Year 2000 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 3 Issue 2 Pages 79-83  
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  Abstract (up) This study investigated whether dolphins would show evidence of equivalence class formation between auditory stimuli. Bottlenose dolphins were trained to press one or other of two response levers depending on which one of four auditory stimuli had been previously presented. Once they had learned the initial discriminations, the stimulus-lever contingencies was repeatedly reversed. Within any given session, however, pressing of one lever always led to reward with one set of two tones and pressing the other lever led to non-reward with an alternative set of two tones. After sufficient experience with this response reversal procedure, the dolphins spontaneously chose the same levers they had first learned to be correct with one of the across-set stimulus pairs when later in the session they were presented with the other of the across-set stimulus pairs. They thus demonstrated that they had associated the tones belonging to the two sets within two separate functional classes. It is discussed why the dolphins succeeded with auditory stimuli when they had previously failed in a similar task with visual stimuli.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 3342  
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Author Brannon, E.M.; Terrace, H.S. openurl 
  Title Representation of the numerosities 1-9 by rhesus macaques (Macaca mulatta) Type Journal Article
  Year 2000 Publication Journal of Experimental Psychology. Animal Behavior Processes Abbreviated Journal J Exp Psychol Anim Behav Process  
  Volume 26 Issue 1 Pages 31-49  
  Keywords Animals; *Cognition; Macaca mulatta/*psychology; *Mathematics; Perception; Reaction Time  
  Abstract (up) Three rhesus monkeys (Macaca mulatta) were trained to respond to exemplars of 1, 2, 3, and 4 in an ascending, descending, or a nonmonotonic numerical order (1-->2-->3-->4, 4-->3-->2--1, 3-->1-->4-->2). The monkeys were then tested on their ability to order pairs of the novel numerosities 5-9. In Experiment 1, all 3 monkeys ordered novel exemplars of the numerosities 1-4 in ascending or descending order. The attempt to train a nonmonotonic order (3-->1-->4-->2) failed. In Experiment 2A, the 2 monkeys who learned the ascending numerical rule ordered pairs of the novel numerosities 5-9 on unreinforced trials. The monkey who learned the descending numerical rule failed to extrapolate the descending rule to new numerosities. In Experiment 2B all 3 monkeys ordered novel exemplars of pairs of the numerosities 5-9. Accuracy and latency of responding revealed distance and magnitude effects analogous to previous findings with human participants (R. S. Moyer & T. K. Landaeur, 1967). Collectively these studies show that monkeys represent the numerosities 1-9 on at least an ordinal scale.  
  Address Department of Psychology, Columbia University, New York, New York 10027, USA. liz@psych.columbia.edu  
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  Series Volume Series Issue Edition  
  ISSN 0097-7403 ISBN Medium  
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  Notes PMID:10650542 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2775  
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Author Abbruzzetti, S.; Crema, E.; Masino, L.; Vecli, A.; Viappiani, C.; Small, J.R.; Libertini, L.J.; Small, E.W. openurl 
  Title Fast events in protein folding: structural volume changes accompanying the early events in the N-->I transition of apomyoglobin induced by ultrafast pH jump Type Journal Article
  Year 2000 Publication Biophysical Journal Abbreviated Journal Biophys J  
  Volume 78 Issue 1 Pages 405-415  
  Keywords Animals; Apoproteins/*chemistry; Horses; *Hydrogen-Ion Concentration; Kinetics; Models, Molecular; Myoglobin/*chemistry; Protein Conformation; *Protein Folding; Protein Structure, Secondary; Spectrometry, Fluorescence  
  Abstract (up) Ultrafast, laser-induced pH jump with time-resolved photoacoustic detection has been used to investigate the early protonation steps leading to the formation of the compact acid intermediate (I) of apomyoglobin (ApoMb). When ApoMb is in its native state (N) at pH 7.0, rapid acidification induced by a laser pulse leads to two parallel protonation processes. One reaction can be attributed to the binding of protons to the imidazole rings of His24 and His119. Reaction with imidazole leads to an unusually large contraction of -82 +/- 3 ml/mol, an enthalpy change of 8 +/- 1 kcal/mol, and an apparent bimolecular rate constant of (0.77 +/- 0.03) x 10(10) M(-1) s(-1). Our experiments evidence a rate-limiting step for this process at high ApoMb concentrations, characterized by a value of (0. 60 +/- 0.07) x 10(6) s(-1). The second protonation reaction at pH 7. 0 can be attributed to neutralization of carboxylate groups and is accompanied by an apparent expansion of 3.4 +/- 0.2 ml/mol, occurring with an apparent bimolecular rate constant of (1.25 +/- 0.02) x 10(11) M(-1) s(-1), and a reaction enthalpy of about 2 kcal/mol. The activation energy for the processes associated with the protonation of His24 and His119 is 16.2 +/- 0.9 kcal/mol, whereas that for the neutralization of carboxylates is 9.2 +/- 0.9 kcal/mol. At pH 4.5 ApoMb is in a partially unfolded state (I) and rapid acidification experiments evidence only the process assigned to carboxylate protonation. The unusually large contraction and the high energetic barrier observed at pH 7.0 for the protonation of the His residues suggests that the formation of the compact acid intermediate involves a rate-limiting step after protonation.  
  Address Dipartimento di Fisica, Universita di Parma, 43100 Parma, Italia  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0006-3495 ISBN Medium  
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  Notes PMID:10620304 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3792  
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Author Waite, T.A.; Field, K.L. doi  openurl
  Title Erroneous choice and foregone gains in hoarding gray jays (Perisoreus canadensis) Type Journal Article
  Year 2000 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 3 Issue 3 Pages 127-134  
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  Abstract (up) Under the conventional assumption that natural selection favors choice behavior that maximizes some fitness-related currency, a forager making repeated binary choices should consistently choose the more valuable option. Under the alternative assumption that natural selection favors choice behavior that minimizes costly errors, erroneous choice is not only expected but is expected to be common when the cost of errors is low. This cost depends on the potential rate of return: the higher this rate, the smaller the cost of choosing the less valuable option. When this rate is very high, a forager may err frequently and yet forego no appreciable fitness gain. Errors should thus be more common when interruptions to foraging are shorter. Our experimental results supported this prediction: gray jays chose the less valuable option more frequently when subjected to shorter interruptions (experimentally imposed delays to access to food rewards). This tendency is consistent with the idea that an adaptive decision-making process may routinely produce errors, not because errors are in some way adaptive but because their fitness cost is minimal, particularly when delays are short. From a proximate perspective, this tendency to commit errors more frequently following shorter delays may be due to constraints on the jays' information-processing capacity. In general, choice behavior should be viewed as the joint byproduct of adaptive decision making and cognitive constraints.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 3339  
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Author Goncalves, D.M.; Oliveira, R.F.; Korner, K.; Poschadel, J.R.; Schlupp, I. url  doi
openurl 
  Title Using video playbacks to study visual communication in a marine fish, Salaria pavo Type Journal Article
  Year 2000 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 60 Issue 3 Pages 351-357  
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  Abstract (up) Video playbacks have been successfully applied to the study of visual communication in several groups of animals. However, this technique is controversial as video monitors are designed with the human visual system in mind. Differences between the visual capabilities of humans and other animals will lead to perceptually different interpretations of video images. We simultaneously presented males and females of the peacock blenny, Salaria pavo, with a live conspecific male and an online video image of the same individual. Video images failed to elicit appropriate responses. Males were aggressive towards the live male but not towards video images of the same male. Similarly, females courted only the live male and spent more time near this stimulus. In contrast, females of the gynogenetic poecilid Poecilia formosa showed an equal preference for a live and video image of a P. mexicana male, suggesting a response to live animals as strong as to video images. We discuss differences between the species that may explain their opposite reaction to video images.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 541  
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Author Durier, V.; Rivault, C. doi  openurl
  Title Learning and foraging efficiency in German cockroaches, Blattella germanica (L.) (Insecta: Dictyoptera) Type Journal Article
  Year 2000 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 3 Issue 3 Pages 139-145  
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  Abstract (up) We analysed, under laboratory test conditions, how German cockroach larvae oriented their outgoing foraging trip from their shelter. Our results stressed the importance of external factors, like availability and spatial distribution of food sources, in the choice of a foraging strategy within their home range. When food sources were randomly distributed, larvae adopted a random food search strategy. When food distribution was spatially predictable and reliable, cockroaches were able to relate the presence of food with a landmark during a 3-day training period and to develop an oriented search strategy. Cockroaches were able to associate learned spatial information about their home range to the presence of food resources and then to improve their foraging efficiency. However, conflict experiments revealed that detection of food odour overrode learned landmark cues.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 3203  
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Author Vervaecke, H.; de Vries, H.; van Elsacker, L. doi  openurl
  Title The Pivotal Role Of Rank In Grooming And Support Behavior In A Captive Group Of Bonobos (Pan Paniscus) Type Journal Article
  Year 2000 Publication Behaviour Abbreviated Journal Behaviour  
  Volume 137 Issue 11 Pages 1463-1485  
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  Abstract (up) We investigated dyadic grooming relationships in a captive group of bonobos (Pan paniscus) and questioned what social function grooming fulfils in the 'market of services and favors'. Hereto we examined which of two theoretical models – grooming for support (Seyfarth, 1977, 1980) or grooming according to the similarity principle (de Waal & Luttrell, 1986) – best accounted for the observed grooming distribution. Similarity in traits did not correlate with increased grooming or close proximity among the individuals. Therefore, the similarity hypothesis was rejected. Seyfarth's model of rank-related grooming was largely confirmed. The animals distributed their grooming according to the rank of the receivers. We found an exchange between grooming and receipt of support. There was more grooming up than down the hierarchy. However, not all predictions about rank-related competition over grooming were confirmed. We found that dyadic grooming reciprocity indeed increased with decreasing rank distance. Yet, there was no increase of grooming within the dyad with decreasing rank distance and high ranking individuals were not competed over at the highest rates. The observed correlation between grooming and support received represents an important fit with Seyfarth's prediction, but does not allow for conclusions about underlying causal processes. Other causal explanations, besides the 'groom to receive support' hypothesis, that could explain a similar correlation are discussed.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 2196  
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