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Walker, S. (1989). An introduction to animal cognition : By . Hillsdale, New Jersey: Lawrence Erlbaum (1988). Pp. viii + 328. Price [pound sign]8.95 paperback. Anim. Behav., 37(Part 3), 521–522.
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Visalberghi E, & Trinca L. (1989). Tool use in capuchin monkeys: distinguishing between performing and understanding. Primates, 30, 511.
Abstract: A horizontal plexiglas tube containing a food-reward was presented to four naive tufted capuchins and suitable sticks were provided to push the reward out. Three monkeys out of four spontaneously used the tools and showed very different styles of solving the task. In more complex conditions, in which the sticks needed to be combined or actively modified in order to become effective, the monkeys were always successful; however, their performance was loaded with errors which did not disappear throughout the trials. Evidence of a difference between success in solving the problem and its understanding was found. This suggests that although capuchins can discover new means through active experimentation, they do not mentally represent the characteristics necessary for a tool to be effective, nor do they modify the tool appropriately beforehand. At this level, a major difference with chimpanzees emerges.
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Valone, T. J. (1989). Group foraging, public information, and patch estimation. Oikos, 56(3), 357–363.
Abstract: Public information is information about the quality of a patch that can be obtained by observing the foraging success of other individuals in that patch. I examine the influence of the use of public information on patch departure and foraging efficiency of group members. When groups depart a patch with the first individual to leave, the use of public information can prevent the underutilization of resource patches.
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Trim, C. M., Moore, J. N., & Clark, E. S. (1989). Renal effects of dopamine infusion in conscious horses. Equine Vet J Suppl, (7), 124–128.
Abstract: An ultrasonic flow probe was implanted around a branch of the left renal artery in five horses. The effects of dopamine were studied in the unsedated horses 10 days after surgery. Three experiments, separated by at least two days, were performed in random order on each horse. In two experiments, dopamine was infused intravenously for 60 mins at either 2.5 and 5.0 micrograms/kg bodyweight (bwt)/min. Saline was infused for 60 mins before and after each infusion, and for 180 mins in the third experiment as a control. Renal blood flow increased during administration of dopamine at both dose rates (P = 0.0001). Urine volume increased (P = 0.055), and osmolality decreased (P < 0.05), with infusion of dopamine at 5.0 micrograms/kg bwt/min. Arterial blood pressure and heart rate were not significantly affected. Fractional excretions of sodium and potassium were not significantly changed with dopamine infusion. The higher dopamine dose rate was accompanied by dysrhythmias in some horses.
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Steinhoff, H. J., Lieutenant, K., & Redhardt, A. (1989). Conformational transition of aquomethemoglobin: intramolecular histidine E7 binding reaction to the heme iron in the temperature range between 220 K and 295 K as seen by EPR and temperature-jump measurements. Biochim Biophys Acta, 996(1-2), 49–56.
Abstract: Temperature-dependent EPR and temperature-jump measurements have been carried out, in order to examine the high-spin to low-spin transition of aquomethemogobin (pH 6.0). Relaxation rates and equilibrium constants could be determined as a function of temperature. As a reaction mechanism for the high-spin to low-spin transition, the binding of N epsilon of His E7 to the heme iron had been proposed; the same mechanism had been suggested for the ms-effect, found in temperature-jump experiments on aquomethemoglobin. A comparison of the thermodynamic quantities, deduced form the measurements in this paper, gives evidence that indeed the same reaction is investigated in both cases. Our results and most of the findings of earlier studies on the spin-state transitions of aquomethemoglobin, using susceptibility, optical, or EPR measurements, can be explained by the transition of methemoglobin with H2O as ligand (with high-spin state at all temperatures) and methemoglobin with ligand N epsilon of His E7 (with a low-spin ground state). Thermal fluctuations of large amplitude have to be postulated for the reaction to take place, so this reaction may be understood as a probe for the study of protein dynamics.
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Stahlbaum, C. C., & Houpt, K. A. (1989). The role of the Flehmen response in the behavioral repertoire of the stallion. Physiol. Behav., 45(6), 1207–1214.
Abstract: The role of the Flehmen response in equine behavior was investigated under field and laboratory conditions. In Experiment 1, a field study made of five stallions on pasture with between three and eighteen mares each during the season indicated the following: 1) The Flehmen response was most frequently preceded by nasal, rather than oral, investigation of substances; 2) The stallions' rate of Flehmen varied with the estrous cycles of the mares; 3) The rate of Flehmen response did not show a variation with time of day; and 4) The Flehmen response was most frequently followed by marking behaviors rather than courtship behaviors. The results suggest that the Flehmen response is not an immediate component of sexual behavior, e.g., courtship of the stallion but may be involved in the overall monitoring of the mare's estrous cycle. Therefore the Flehmen response may contribute to the chemosensory priming of the stallion for reproduction. In Experiment 2 stallions were presented with urine or feces of mares in various stages of the reproductive cycle as well as with their own or other males' urine or feces. The occurrence of sniffing and Flehmen was used to determine the discriminatory ability of the stallions. Stallions can differentiate the sex of a horse on the basis of its feces alone, but cannot differentiate on the basis of urine. This ability may explain the function of fecal marking behavior of stallions.
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Rubenstein, D. I., & Hohmann, M. E. (1989). Parasites and Social Behavior of Island Feral Horses. Oikos, 3, 312–320.
Abstract: The horses of Shackelford Banks, North Carolina, USA, are heavily parasitized by intestinal worms and harassed by dipterans, and although both types influence behavior only internal parasites affect bodily condition and the structuring of horse society. Thirteen species of internal parasites were identified, but only 4 of 13 groups contain them all and even within groups differences among individuals are large. Among individuals ova emissions vary ranging from 50 to 76,875 eggs per gram. The most important environmental factors influencing egg production are season and a group's location on the island, presumably because of salinity and soil differences and their effects on ova survival. Of the social and life history factors, age, and group size, but neither reproductive state nor dominance status are important. The fitness consequences of internal parasitism may be large since the number emitted is negatively correlated with next year's bodily condition. Biting fly burdens are also affected by a variety of environmental factors. In general, horses are covered with more flies on sunny days, when winds are moderately brisk, when occupying dunes, and around mid-day. In contrast to endoparasites, fly burden is affected by reproductive condition and dominance status and tends to decrease as groups increase in size. Since groups do not grow very large, nor do females attempt to bring groups together, the negative effects of endoparasites appear to overide those associated with ectoparasites. Consequently, endoparasites appear to exert a stronger influence on social structure, even though ectoparasites seem to play a stronger role in shaping details of behavior.
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Rubenstein, D. I. (1989). Life history and social organization in arid adapted ungulates. J. Arid. Environ., 17, 145–156.
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Rau, R. E.,. (1989). The museum's Quagga project.
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Povinelli DJ. (1989). Failure to find self-recognition in Asian elephants (Elephas maximus) in contrast to their use of mirror cues to discover hidden food. J. Comp. Psychol., 103, 122.
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