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Author Reid, P.J.; Shettleworth, S.J. openurl 
  Title Detection of cryptic prey: search image or search rate? Type Journal Article
  Year 1992 Publication Journal of experimental psychology. Animal behavior processes Abbreviated Journal J Exp Psychol Anim Behav Process  
  Volume 18 Issue (up) 3 Pages 273-286  
  Keywords Animals; Appetitive Behavior; *Attention; Color Perception; Columbidae; *Discrimination Learning; Food Preferences/psychology; *Imagination; *Mental Recall; *Predatory Behavior  
  Abstract Animals' improvement in capturing cryptic prey with experience has long been attributed to a perceptual mechanism, the specific search image. Detection could also be improved by adjusting rate of search. In a series of studies using both naturalistic and operant search tasks, pigeons searched for wheat, dyed to produce 1 conspicuous and 2 equally cryptic prey types. Contrary to the predictions of the search-rate hypothesis, pigeons given a choice between the 2 cryptic types took the type experienced most recently. However, experience with 1 cryptic type improved accuracy on the other cryptic type, a result inconsistent with a search image specific to 1 prey type. Search image may better be thought of as priming of attention to those features of the prey type that best distinguish the prey from the background.  
  Address 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:1619395 Approved no  
  Call Number refbase @ user @ Serial 381  
Permanent link to this record
 

 
Author Shettleworth, S.J.; Plowright, C.M. openurl 
  Title 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 (up) 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 Horse signals: The sounds and scents of fury Type Journal Article
  Year 1992 Publication Evolutionary Ecology Abbreviated Journal Evol. Ecol.  
  Volume 6 Issue (up) 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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  Language Summary Language Original Title  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 506  
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Author Harkins, J.D.; Kamerling, S.G.; Church, G. openurl 
  Title 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 (up) 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  
  Publisher Place of Publication Editor  
  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  
Permanent link to this record
 

 
Author Dugatkin, L.A.; Godin, G.J. doi  openurl
  Title Predator inspection, shoaling and foraging under predation hazard in the Trinidadian guppy,Poecilia reticulata Type Journal Article
  Year 1992 Publication Environmental Biology of Fishes Abbreviated Journal  
  Volume 34 Issue (up) 3 Pages 265-276  
  Keywords Antipredation – Social group – Feeding – Predation risk – Trade-off – Fish  
  Abstract Guppies,Poecilia reticulata, living in stream pools in Trinidad, West Indies, approached a potential fish predator (a cichlid fish model) in a tentative, saltatory manner, mainly as singletons or in pairs. Such behavior is referred to as predator inspection behavior. Inspectors approached the trunk and tail of the predator model more frequently, more closely and in larger groups than they approached the predator's head, which is presumably the most dangerous area around the predator. However, guppies were not observed in significantly larger shoals in the stream when the predator model was present. In a stream enclosure, guppies inspected the predator model more frequently when it was stationary compared to when it was moving, and made closer inspections to the posterior regions of the predator than to its head. Therefore, the guppies apparently regarded the predator model as a potential threat and modified their behavior accordingly when inspecting it. Guppies exhibited a lower feeding rate in the presence of the predator, suggesting a trade-off between foraging gains and safety against predation. Our results further suggest that predator inspection behavior may account for some of this reduction in foraging. These findings are discussed in the context of the benefits and costs of predator inspection behavior.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 2176  
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Author Dvoinos, G.M.; Kharchenko, V.A.; Zviagnitsova, N.S. url  openurl
  Title The characteristics of the helminth community in the Turkmen kulan (Equus hemionus) Type Journal Article
  Year 1992 Publication Parazitologiia Abbreviated Journal Parazitologiia  
  Volume 26 Issue (up) 3 Pages 246-251  
  Keywords Animals; Female; Helminthiasis/parasitology; Helminthiasis, Animal; Helminths/classification/*isolation & purification; Male; Perissodactyla/*parasitology; Turkmenistan; Ukraine  
  Abstract The helminth fauna of 24 kulans from Askaniya-Nova and Badkhyz was studied. 42 species of helminths were found, 34 of which belong to strongylids. The helminth species composition of kulan is similar to that of other species of horses. This is a result of an intensive parasite exchange in the historical past when numerous populations of different Equidae species made long seasonal migrations over steppe inter-river lands of Asia and grazed for some time on common pastures.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Russian Summary Language Original Title K kharakteristike soobshchestva gel'mintov turkmenskogo kulana (Equus hemionus)  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-1847 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1408368 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2285  
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Author Mills, M.G.L.; Shenk, M.G.L. doi  openurl
  Title Predator--Prey Relationships: The Impact of Lion Predation on Wildebeest and Zebra Populations Type Journal Article
  Year 1992 Publication The Journal of Animal Ecology Abbreviated Journal T. J. Anim. Ecol.  
  Volume 61 Issue (up) 3 Pages 693-702  
  Keywords  
  Abstract 1. The role of lion Panthera leo predation in the dynamics of blue wildebeest Connochaetes taurinus and zebra Equus burchelli populations was investigated through simulation models. The data used in the models were from intensive observations over 4 years in the south-east of the Kruger National Park. 2. Population estimates of wildebeest and zebra were made from aerial surveys, sex and age ratios from ground counts. Lion numbers were determined from observations of marked and radio-collared animals. Predation was studied by following lions for continuous periods of up to 336 h. 3. Two models were constructed. Model 1 ascertained the number of killing lions (adult females) that could be supported by each prey population while remaining stable. A single model was constructed for the sedentary wildebeest population. A summer and winter model was constructed for the semi-migratory zebra population. The sensitivity of the parameters in the model was tested by changing their value by 10%. In model 2, the kill age structure for each species was changed to determine the number of killing lions the altered prey selection parameters could support. 4. There was no difference in the vulnerability of either species to predation. Zebra foals (<1 year) were killed more frequently than expected. No selection for sex or by season could be found for either species. 5. Model 1 predicted that the wildebeest population stabilizes with 7.7 killing lions, close to the number in the study area. The winter zebra population stabilizes with 6.8 killing lions and the summer zebra population with 19.4. Manipulation of kill rate followed by adult fecundity rate had the greatest effect on population size of both species. In model 2, wildebeest predation was made selective towards calves and zebra predation was made non-selective for sex and age. With these parameters the wildebeest population stabilizes with 10.7 killing lions and the zebra population with 5.4 in winter and 15.1 in summer. 6. The models suggest that lion predation affected wildebeest more severely than zebra during the study. This was through the way in which lions selected their prey, and because of the sedentary behaviour of the wildebeest, as opposed to the semi-migratory behaviour of the zebra.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 2376  
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Author Steinhoff, H.J.; Schrader, J.; Schlitter, J. openurl 
  Title Temperature-jump studies and polarized absorption spectroscopy of methemoglobin-thiocyanate single crystals Type Journal Article
  Year 1992 Publication Biochimica et Biophysica Acta Abbreviated Journal Biochim Biophys Acta  
  Volume 1121 Issue (up) 3 Pages 269-278  
  Keywords Animals; Crystallization; Horses; Kinetics; Methemoglobin/*chemistry; Solutions; Spectrum Analysis; Temperature; Thiocyanates/*chemistry  
  Abstract Association equilibria and association kinetics of the thiocyanate binding reaction to methemoglobin in single crystals and solution are studied using temperature-jump technique and polarized absorption spectroscopy. Different kinetic constants are found for the reaction in solution and crystal phase for the alpha- and beta-subunits of the methemoglobin tetramer. The reduction of the reactivity of the alpha- and beta-subunits in crystalline phase is 6-fold and 2.4-fold, respectively, compared to the values found in solution. The intramolecular binding reaction of the N epsilon of the distal histidine E7 which is observed in methemoglobin in solution cannot be detected in single crystals. Our results suggest that crystallization of hemoglobin has little influence on small-scale structural fluctuations which are necessary for ligands to get to the binding sites and large-scale structural motions are suppressed.  
  Address Institut fur Biophysik, Ruhr-Universitat Bochum, Germany  
  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 0006-3002 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:1627604 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3800  
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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 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 (up) 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.  
  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 4833  
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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 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 (up) 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.  
  Address  
  Corporate Author Thesis  
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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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