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Author Pruett-Jones, S. url  openurl
  Title (down) Independent Versus Nonindependent Mate Choice: Do Females Copy Each Other? Type Journal Article
  Year 1992 Publication The American Naturalist Abbreviated Journal Am Nat  
  Volume 140 Issue 6 Pages 1000-1009  
  Keywords  
  Abstract There is increasing evidence from both observational and experimental studies that females may copy each other's mating decisions. Female copying can be defined as a type of nonindependent choice in which the probability that a female chooses a given male increases if other females have chosen that male and decreases if they have not. The important characteristic of copying behavior that separates it from other similar processes is that the change in the probability of choice is strictly because of the actions of other females and not the consequences of those actions (e.g., a male's behavior changing as a result of successful matings). A gametheory model suggests that the adaptive significance of female copying may depend primarily on the ratio of the costs to the benefits of active mate choice. Copying behavior, and more generally conspecific cueing, may be important in many behavioral processes beyond mate choice.  
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  Language Summary Language Original Title  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 2182  
Permanent link to this record
 

 
Author Shettleworth, S.J.; Plowright, C.M. openurl 
  Title (down) How pigeons estimate rates of prey encounter Type Journal Article
  Year 1992 Publication Journal of experimental psychology. Animal behavior processes Abbreviated Journal J Exp Psychol Anim Behav Process  
  Volume 18 Issue 3 Pages 219-235  
  Keywords Analysis of Variance; Animals; *Appetitive Behavior; Columbidae; Conditioning, Operant; Food Preferences/*psychology; Motivation; *Predatory Behavior; *Probability Learning; *Reinforcement Schedule; Social Environment  
  Abstract Pigeons were trained on operant schedules simulating successive encounters with prey items. When items were encountered on variable-interval schedules, birds were more likely to accept a poor item (long delay to food) the longer they had just searched, as if they were averaging prey density over a short memory window (Experiment 1). Responding as if the immediate future would be like the immediate past was reversed when a short search predicted a long search next time (Experiment 2). Experience with different degrees of environmental predictability appeared to change the length of the memory window (Experiment 3). The results may reflect linear waiting (Higa, Wynne, & Staddon, 1991), but they differ in some respects. The findings have implications for possible mechanisms of adjusting behavior to current reinforcement conditions.  
  Address Department of Psychology, University of Toronto, Ontario, Canada  
  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 0097-7403 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1619391 Approved no  
  Call Number refbase @ user @ Serial 382  
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Author Rubenstein, D. I.; Hack, M. A. doi  openurl
  Title (down) Horse signals: The sounds and scents of fury Type Journal Article
  Year 1992 Publication Evolutionary Ecology Abbreviated Journal Evol. Ecol.  
  Volume 6 Issue 3 Pages 254-260  
  Keywords ommunication – combat – fighting ability – individual identity – signals – information – assessment – displays  
  Abstract During contests animals typically exchange information about fighting ability. Among feral horses these signals involve olfactory or acoustical elements and each type can effectively terminate contests before physical contact becomes necessary. Dung transplant experiments show that for stallions, irrespective of rank, olfactory signals such as dung sniffing encode information about familiarity suggesting that such signals can be used as signatures. As such they can provide indirect information about fighting ability as long as opponents associate identity with past performance. Play-back experiments, however, show that vocalizations, such as squeals, directly provide information about status regardless of stallion familiarity. Sonographs reveal that squeals of dominants are longer than those of subordinates and that only those of dominants have at their onset high-frequency components.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 506  
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Author Poysa, Hannu doi  openurl
  Title (down) Group Foraging in Patchy Environments: The Importance of Coarse-Level Local Enhancement Type Journal Article
  Year 1992 Publication Ornis Scandinavica Abbreviated Journal Ornis[ Scand[  
  Volume 23 Issue 2 Pages 159-166  
  Keywords  
  Abstract Local enhancement is one way individuals may realize foraging advantages from grouping. A distinction between fine-level and coarse-level local enhancement is made, the latter often being neglected in theoretical research on group foraging. In the former case, an individual has a higher feeding rate as a member of a group because individuals copy other group members' foraging, whereas in the latter, groups simply attract other individuals to patches where food is particularly abundant and copying does not occur within the group. Coarse-level local enhancement may decrease the time needed to find profitable feeding patches in spatially and temporally variable environments. A review of the empirical literature indicated that coarse-level local enhancement is typical in bird species foraging in open habitats and in large groups with relatively little competition between group members whereas the opposite attributes fit the species for which fine-level local enhancement had been documented. Furthermore, species in which coarse-level local enhancement prevails usually forage in temporary groups. However, coarse-level and fine-level local enhancement are not necessarily mutually exclusive, but which one is more important in a particular case may be habitat-dependent.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4272  
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Author Clark, M.L.; Ayers, M. url  doi
openurl 
  Title (down) Friendship similarity during early adolescence: gender and racial patterns Type Journal Article
  Year 1992 Publication The Journal of Psychology Abbreviated Journal J Psychol  
  Volume 126 Issue 4 Pages 393-405  
  Keywords Achievement; Adolescent; African Americans/*psychology; *Cross-Cultural Comparison; Female; *Gender Identity; Humans; Individuality; *Interpersonal Relations; Male; *Personality Development; Personality Inventory; Sociometric Techniques  
  Abstract We studied the relationship of reciprocity, gender, and racial composition (Caucasian, African American, cross-race) of adolescent friendship dyads to similarity and proximity in 136 young adolescents. We found that adolescents selected friends who were of the same gender and race and that female dyads were more similar than male dyads on verbal achievement and several personality dimensions. Caucasian dyads were more similar than African American dyads on verbal achievement, mental alertness, and dominance. African American adolescents had more contact with their best friends outside school, whereas Caucasian adolescent friends had more in-school contact. African American students had fewer reciprocal relationships than the Caucasian students. Cross-race friendships were less reciprocal than same-race friendships. Race and gender were important in determining friendship patterns. Similarity and proximity were more important than reciprocity in understanding early adolescent friendships.  
  Address Department of Psychology, Virginia Commonwealth University  
  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 0022-3980 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1403972 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5628  
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Author Schneider, K. isbn  openurl
  Title (down) Emotionen Type Book Chapter
  Year 1992 Publication Allgemeine Psychologie Abbreviated Journal  
  Volume Issue Pages  
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  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Verlag Hans Huber Place of Publication Bern Editor Spada Hans  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN 3456823029 Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5070  
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Author Covalesky, M.E.; Russoniello, C.R.; Malinowski, K. url  doi
openurl 
  Title (down) Effects of show-jumping performance stress on plasma cortisol and lactate concentrations and heart rate and behavior in horses Type Journal Article
  Year 1992 Publication Journal of Equine Veterinary Science Abbreviated Journal  
  Volume 12 Issue 4 Pages 244-251  
  Keywords  
  Abstract Summary Effects of show jumping competition on stress levels in horses was examined. Twenty-six homes were sampled in both show and farm environments from three levels of show experience schooling, (least experience, n=11); intermediate, (moderate experience, n=6); open, (most experience, n=9). Blood samples were taken at 6 time points; 3 at the horse show and 3 at the home farm (baseline at rest, pre-schooling and post-performance over a jump course). Stress responses were assessed through comparison of the behavioral response of the horses (determined by a subjective scoring system) to plasma cortisol (F) concentrations. Physical exertion was evaluated by heart rate (HR) and plasma lactate (L) concentrations. Schooling jumpers displayed higher baseline F concentrations than open jumpers (83g±9.2 vs 46.4±10.2 ng/ml, respectively; p<.05); but not when compared to intermediate jumpers (66.2 ± 13.7 ng/ml; p>.05) at the horse show. At the farm, there were no differences in F concentrations between experience levels at a time point (p<.05). Least experienced horses displayed higher F values at rest at the show compared to the home farm. At the show, open jumpers had higher L concentrations post-exercise compared to intermediate horses (40.3±3.4 vs 25.5±4.0 mg/dL, respectively; p<.05); but were not different compared to schooling jumpers (34.8±2.0 mg/dL; p>.05). There were no differences in heart rates or behavior score between experience levels at specific time points at either the show or farm (p>.05). Low positive correlations were found between HR and F (r=.24, p<.05); HR and L (r-.48, p<.05); and HR and behavior (r=.22, p<.05). Results suggest that conditioned jumpers that have previously been exposed to horse show environments do not appear stressed during acute show-jumping competition.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0737-0806 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5622  
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Author Stutz, W.A.; Topliff, D.R.; Freeman, D.W.; Tucker, W.B.; Breazile, J.W.; Wall, D.L. url  doi
openurl 
  Title (down) Effects of dietary cation-anion balance on blood parameters in exercising horses Type Journal Article
  Year 1992 Publication Journal of Equine Veterinary Science Abbreviated Journal  
  Volume 12 Issue 3 Pages 164-167  
  Keywords  
  Abstract Summary Four geldings and four mares of primarily Thoroughbred and Quarter Horse breeding were used in simultaneous 4x4 Latin square experiments to test the effects of dietary cation-anion balance (DCAB), defined as meq ((Na+K)-C1)/kg diet dry matter, on blood pH, blood gases, acid-base status and plasma glucose in horses at rest and following anaerobic exercise. Four diets, consisting of a base concentrate of corn, soybean meal and cottonseed hulls fed in a 60:40 ratio with Bermudagrass hay, were formulated to provide a DCAB of 5 (L=Low), 107 (ML=Medium Low), 201 (MH=Medium High) and 327 (H=High) meq ((Na+K)-C1)/kg diet dry matter. Calcium chloride and ammonium chloride were added to treatment L and ML and sodium bicarbonate and potassium citrate were added to treatment H to achieve the desired cation-anion balance. Treatment MH was not supplemented and served as the control treatment. Prior to the experiment, horses performed six weeks of long, slow, distance (LSD) work. During the experimental periods, horses were subjected to an exercise regimen alternating LSD with an interval training protocol 6 days/week. Venous blood pH, pCO2 and bicarbonate levels were significantly lower in horses at rest consuming diet L versus diets MH and H. Blood pH and acid-base parameters decreased with decreasing DCAB. There were no significant differences in blood pH or acid-base parameters between treatments, after anaerobic exercise. Plasma glucose concentrations for treatment L were significantly lower than treatment H at 10, 20, and 30 minutes post-exercise. These data suggest that DCAB has significant effect on acid-base status and indicate that horses consuming diets with low DCAB may experience a metabolic acidosis.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0737-0806 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4834  
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Author Wall, D.L.; Topliff, D.R.; Freeman, D.W.; Wagner, D.G.; Breazile, J.W.; Stutz, W.A. url  doi
openurl 
  Title (down) Effect of dietary cation-anion balance on urinary mineral excretion in exercised horses Type Journal Article
  Year 1992 Publication Journal of Equine Veterinary Science Abbreviated Journal  
  Volume 12 Issue 3 Pages 168-171  
  Keywords  
  Abstract Summary Four mares and four geldings of Quarter Horse and Thoroughbred breeding were used in two simultaneous 4x4 Latin square experiments to study the effects of dietary cation-anion balance (DCAB), defined as meq ((Na+K)-C1)/kg dry matter, on urinary pH and mineral excretion in exercised horses. Diets consisted of a pelleted concentrate of corn, soybean meal and cottonseed hulls fed with bermudagrass hay. Treatments with DCAB of +5 (Low, L), +107 (Medium Low, ML), +201 (Medium High, MH) and +327 (High, H), meq ((Na+K)-Cl)/kg dry matter were formed by supplementing diet L with calcium chloride and ammonium chloride, diet ML with calcium chloride and diet H with sodium bicarbonate and potassium citrate (Table 1). Diet MH was not supplemented and served as the control treatment. Horses were conditioned aerobically for 6 weeks using long, slow, distance (LSD) workouts. During the experimental periods, horses were subjected to a combined exercise regimen alternating LSD with an interval-training protocol 6 days/week. There was a significant (P<.01) treatment effect on urine pH; least squares means for L, ML, MH and H were 6.73, 7.17, 7.38, and 7.92. Horses consuming diet L excreted more calcium in the urine (P<.05) than those consuming MH or H. Least squares means for daily urine calcium excretion tended to be linear across treatments and ranged from 19.66 g/day for diet L to 9.12 g/day for diet H. Urinary chloride excretion was higher (P<.05) for L than for MH or H. Horses fed diet H excreted more sodium (P<.05) in urine than horses fed the other diets. Lowering DCAB, increases urinary calcium loss; depending on the level of calcium intake, this could lead to negative calcium balance in exercising horses.  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0737-0806 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4833  
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Author Harkins, J.D.; Kamerling, S.G.; Church, G. openurl 
  Title (down) Effect of competition on performance of thoroughbred racehorses Type Journal Article
  Year 1992 Publication Journal of Applied Physiology (Bethesda, Md. : 1985) Abbreviated Journal J Appl Physiol  
  Volume 72 Issue 3 Pages 836-841  
  Keywords Age Factors; Animals; Anxiety/physiopathology; Competitive Behavior/*physiology; Exertion/*physiology; Fatigue/physiopathology; Female; Heart Rate; Horses/*physiology; Lactates/blood; Lactic Acid; Male; Sex Characteristics  
  Abstract The effect of competition and the influence of age and sex on performance were examined in a study of 18 Thoroughbred racehorses. The horses performed two solo and two competitive runs at 1,200 and 1,600 m for a total of eight runs. No group ran faster during competition, which may have been a reflection of the quality of horses used for this study and their susceptibility to stress-induced impairment of performance. Males showed no significant difference between competitive and solo run times, whereas females were consistently slower during competition. Males ran significantly faster than females in all runs. There was no difference in run times due to age, which may have been due to the high mean age (5.9 yr) of the group. The slower competitive run times may have occurred because of an earlier onset of fatigue when compared with solo runs. Plasma lactate was significantly greater for the 1,200-m competitive than for the solo runs.  
  Address Department of Veterinary Physiology, Pharmacology, and Toxicology, School of Veterinary Medicine, Louisiana State University, Baton Rouge 70803  
  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 8750-7587 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1568979 Approved no  
  Call Number refbase @ user @ Serial 1947  
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